Article

Cartis, C., Kaouri, M. H., Lawless, A. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2024) Convergent least-squares optimisation methods for variational data assimilation. Optimization. ISSN 1029-4945 (In Press)

Wright, A., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Lea, D. J. and Martin, M. J. (2024) Assessment of short-range forecast error atmosphere-ocean cross-correlations from the Met Office coupled NWP system. Quarterly Journal of the Royal Meteorological Society. ISSN 1477-870X doi: https://doi.org/10.1002/qj.4735 (In Press)

Shataer, S., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2023) Conditioning of hybrid variational data assimilation. Numerical Linear Algebra with Applications. e2534. ISSN 1099-1506 doi: https://doi.org/10.1002/nla.2534

Wells, C. A., Kalise, D., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Poll, I. and Williams, P. D. ORCID: https://orcid.org/0000-0002-9713-9820 (2023) The role of airspeed variability in fixed-time, fuel-optimal aircraft trajectory planning. Optimization and Engineering, 24. pp. 1057-1087. ISSN 1389-4420 doi: https://doi.org/10.1007/s11081-022-09720-9

Wells, C. A. ORCID: https://orcid.org/0000-0001-9438-4954, Williams, P. D. ORCID: https://orcid.org/0000-0002-9713-9820, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Kalise, D. and Poll, I. (2023) Minimising emissions from flights through realistic wind fields with varying aircraft weights. Transportation Research Part D: Transport and Environment, 117. 103660. ISSN 1361-9209 doi: https://doi.org/10.1016/j.trd.2023.103660

Di Mauro, C. D., Hostache, R., Matgen, P., Pelich, R., Chini, M., Van Leeuwen, P. J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Blöschl, G. (2022) A tempered particle filter to enhance the assimilation of SAR-derived flood extent maps into flood forecasting models. Water Resources Research, 58 (8). e2022WR031940. ISSN 1944-7973 doi: https://doi.org/10.1029/2022WR031940

Tabeart, J. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Waller, J. A. (2022) New bounds on the condition number of the Hessian of the preconditioned variational data assimilation problem. Numerical Linear Algebra with Applications, 29 (1). e2405. ISSN 1099-1506 doi: https://doi.org/10.1002/nla.2405

Leung, T. Y. ORCID: https://orcid.org/0000-0003-0056-284X, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Lea, D. J. and Martin, M. J. (2022) The impact of hybrid oceanic data assimilation in a coupled model: a case study of a tropical cyclone. Quarterly Journal of the Royal Meteorological Society, 148 (746). pp. 2410-2430. ISSN 0035-9009 doi: https://doi.org/10.1002/qj.4309

Di Mauro​​​​​​​, C. ORCID: https://orcid.org/0000-0003-4026-6850, Hostache, R. ORCID: https://orcid.org/0000-0002-8109-6010, Matgen, P., Pelich, R., Chini, M., Van Leeuwen, P. J. ORCID: https://orcid.org/0000-0003-2325-5340, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Blöschl, G. ORCID: https://orcid.org/0000-0003-2227-8225 (2021) Assimilation of probabilistic flood maps from SAR data into a coupled hydrologic–hydraulic forecasting model: a proof of concept. Hydrology and Earth System Sciences, 25 (7). pp. 4081-4097. ISSN 1027-5606 doi: https://doi.org/10.5194/hess-25-4081-2021

Wells, C. A. ORCID: https://orcid.org/0000-0001-9438-4954, Williams, P. D. ORCID: https://orcid.org/0000-0002-9713-9820, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Kalise, D. ORCID: https://orcid.org/0000-0003-2327-1957 and Poll, I. ORCID: https://orcid.org/0000-0001-8057-8467 (2021) Reducing transatlantic flight emissions by fuel-optimised routing. Environmental Research Letters, 16 (2). 025002. ISSN 1748-9326 doi: https://doi.org/10.1088/1748-9326/abce82

Smith, P. J., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2020) The role of cross-domain error correlations in strongly coupled 4D-Var atmosphere-ocean data assimilation. Quarterly Journal of the Royal Meteorological Society, 146 (730). pp. 2450-2465. ISSN 1477-870X doi: https://doi.org/10.1002/qj.3802

Cleator, S. F.,, Harrison, S. P. ORCID: https://orcid.org/0000-0001-5687-1903, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Prentice, I. C. and Roulstone, I. (2020) A new multivariable benchmark for Last Glacial Maximum climate simulations. Climate of the Past, 16. pp. 699-712. ISSN 1814-9324 doi: https://doi.org/10.5194/cp-16-699-2020

Tabeart, J. M., Dance, S.L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Migliorini, S., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Smith, F. and Waller, J. A. (2020) The impact of using reconditioned correlated observation error covariance matrices in the Met office 1D-Var system. Quarterly Journal of the Royal Meteorological Society, 146 (728). pp. 1372-1390. ISSN 1477-870X doi: https://doi.org/10.1002/qj.3741

Cleator, S. F., Harrison, S. P. ORCID: https://orcid.org/0000-0001-5687-1903, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Prentice, I. C. and Roulstone, I. (2020) A method for generating coherent spatially explicit maps of seasonal palaeoclimates from site-based reconstructions. Journal of Advances in Modeling Earth Systems, 12 (1). e2019MS001630. ISSN 1942-2466 doi: https://doi.org/10.1029/2019MS001630

Zobitz, J. M., Quaife, T. ORCID: https://orcid.org/0000-0001-6896-4613 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2020) Efficient hyper-parameter determination for regularised linear BRDF parameter retrieval. International Journal of Remote Sensing, 41 (4). pp. 1437-1457. ISSN 1366-5901 doi: https://doi.org/10.1080/01431161.2019.1667552

Tabeart, J. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Waller, J. A. (2020) Improving the condition number of estimated covariance matrices. Tellus A: Dynamic Meteorology & Oceanography, 72 (1). pp. 1-19. ISSN 1600-0870 doi: https://doi.org/10.1080/16000870.2019.1696646

Simonin, D., Waller, J. A., Ballard, S. P., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2019) A pragmatic strategy for implementing spatially correlated observation errors in an operational system: an application to Doppler radial winds. Quarterly Journal of the Royal Meteorological Society, 145 (723). pp. 2772-2790. ISSN 1477-870X doi: https://doi.org/10.1002/qj.3592

Cooper, E. S., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Garcia-Pintado, J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Smith, P. ORCID: https://orcid.org/0000-0003-4570-4127 (2019) Observation operators for assimilation of satellite observations in fluvial inundation forecasting. Hydrology and Earth System Sciences, 23. pp. 2541-2559. ISSN 1027-5606 doi: https://doi.org/10.5194/hess-23-2541-2019

Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Ballard, S. P., Bannister, R. N. ORCID: https://orcid.org/0000-0002-6846-8297, Clark, P. ORCID: https://orcid.org/0000-0003-1001-9226, Cloke, H. L. ORCID: https://orcid.org/0000-0002-1472-868X, Darlington, T., Flack, D. L. A., Gray, S. L. ORCID: https://orcid.org/0000-0001-8658-362X, Hawkness-Smith, L., Husnoo, N., Illingworth, A. J. ORCID: https://orcid.org/0000-0002-5774-8410, Kelly, G. A., Lean, H. W., Li, D., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Nicol, J. C., Oxley, A., Plant, R. S. ORCID: https://orcid.org/0000-0001-8808-0022, Roberts, N. M., Roulstone, I., Simonin, D., Thompson, R. J. and Waller, J. A. (2019) Improvements in forecasting intense rainfall: results from the FRANC (forecasting rainfall exploiting new data assimilation techniques and novel observations of convection) project. Atmosphere, 10 (3). 125. ISSN 2073-4433 doi: https://doi.org/10.3390/atmos10030125

Waller, J. A., Bauernschubert, E., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Potthast, R. ORCID: https://orcid.org/0000-0001-6794-2500 and Simonin, D. (2019) Observation error statistics for Doppler radar radial wind superobservations assimilated into the DWD COSMO-KENDA system. Monthly Weather Review, 147. pp. 3351-3364. ISSN 0027-0644 doi: https://doi.org/10.1175/MWR-D-19-0104.1

Tabeart, J. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Haben, S. A., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Waller, J. A. (2018) The conditioning of least squares problems in variational data assimilation. Numerical Linear Algebra with Applications, 25 (5). e2165. ISSN 1099-1506 doi: https://doi.org/10.1002/nla.2165

Waller, J. A., Garcia-Pintado, J., Mason, D. C. ORCID: https://orcid.org/0000-0001-6092-6081, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2018) Technical note: assessment of observation quality for data assimilation in flood models. Hydrology and Earth System Sciences, 22. pp. 3983-3992. ISSN 1027-5606 doi: https://doi.org/10.5194/hess-22-3983-2018

Cooper, E. S., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Garcia-Pintado, J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127 (2018) Observation impact, domain length and parameter estimation in data assimilation for flood forecasting. Environmental Modelling and Software, 104. pp. 199-214. ISSN 1364-8152 doi: https://doi.org/10.1016/j.envsoft.2018.03.013

Janjic, T., Bormann, N., Bocquet, M., Carton, J. A., Cohn, S. E., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Losa, S. N., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Potthast, R. ORCID: https://orcid.org/0000-0001-6794-2500, Waller, J. A. and Weston, P. (2018) On the representation error in data assimilation. Quarterly Journal of the Royal Meteorological Society, 144 (713). pp. 1257-1278. ISSN 0035-9009 doi: https://doi.org/10.1002/qj.3130

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2018) Treating sample covariances for use in strongly coupled atmosphere-ocean data assimilation. Geophysical Research Letters, 45 (1). pp. 445-454. ISSN 0094-8276 doi: https://doi.org/10.1002/2017gl075534

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2017) Estimating forecast error covariances for strongly coupled atmosphere-ocean 4D-Var data assimilation. Monthly Weather Review, 145 (10). pp. 4011-4035. ISSN 0027-0644 doi: https://doi.org/10.1175/MWR-D-16-0284.1

Waller, J. A., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2017) On diagnosing observation error statistics with local ensemble data assimilation. Quarterly Journal of the Royal Meteorological Society, 143 (708). pp. 2677-2686. ISSN 1477-870X doi: https://doi.org/10.1002/qj.3117

Pinnington, E. M., Casella, E., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Morison, J. I. L., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Wilkinson, M. and Quaife, T. L. ORCID: https://orcid.org/0000-0001-6896-4613 (2017) Understanding the effect of disturbance from selective felling on the carbon dynamics of a managed woodland by combining observations with model predictions. JGR-Biogeosciences, 122 (4). pp. 886-902. ISSN 2169-8961 doi: https://doi.org/10.1002/2017JG003760

Volpi, D., Guemas, V., Doblas-Reyes, F. J., Hawkins, E. ORCID: https://orcid.org/0000-0001-9477-3677 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2017) Decadal climate prediction with a refined anomaly initialisation approach. Climate Dynamics, 48 (5). pp. 1841-1853. ISSN 1432-0894 doi: https://doi.org/10.1007/s00382-016-3176-6

Cordoba, M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Kelly, G. A., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Waller, J. A. (2017) Diagnosing atmospheric motion vector observation errors for an operational high resolution data assimilation system. Quarterly Journal of the Royal Meteorological Society, 143 (702). pp. 333-341. ISSN 1477-870X doi: https://doi.org/10.1002/qj.2925

Delahaies, S., Roulstone, I. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2017) Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application. Geoscientific Model Development, 10 (7). pp. 2635-2650. ISSN 1991-9603 doi: https://doi.org/10.5194/gmd-10-2635-2017

Bonan, B., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Baines, M. J. and Partridge, D. (2017) Data assimilation for moving mesh methods with an application to ice sheet modelling. Nonlinear Processes in Geophysics, 24 (3). pp. 515-534. ISSN 1023-5809 doi: https://doi.org/10.5194/npg-24-515-2017

Pinnington, E. M., Casella, E., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Morison, J. I. L., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Wilkinson, M. and Quaife, T. L. ORCID: https://orcid.org/0000-0001-6896-4613 (2016) Investigating the role of prior and observation error correlations in improving a model forecast of forest carbon balance using Four Dimensional Variational data assimilation. Agricultural and Forest Meteorology, 228-229. pp. 299-314. ISSN 0168-1923 doi: https://doi.org/10.1016/j.agrformet.2016.07.006

Waller, J. A., Simonin, D., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Ballard, S. P. (2016) Diagnosing observation error correlations for Doppler radar radial winds in the Met Office UKV model using observation-minus-background and observation-minus-analysis statistics. Monthly Weather Review, 144 (10). pp. 3533-3551. ISSN 0027-0644 doi: https://doi.org/10.1175/MWR-D-15-0340.1

Waller, J. A., Ballard, S. P., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Kelly, G., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Simonin, D. (2016) Diagnosing horizontal and inter-channel observation error correlations for SEVIRI observations using observation-minus-background and observation-minus-analysis statistics. Remote Sensing, 8 (7). 851. ISSN 2072-4292 doi: https://doi.org/10.3390/rs8070581

Bonan, B., Baines, M., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Partridge, D. (2016) A moving-point approach to model shallow ice sheets: a study case with radially symmetrical ice sheets. The Cryosphere, 10 (1). pp. 1-14. ISSN 1994-0424 doi: https://doi.org/10.5194/tc-10-1-2016

Waller, J. A., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2016) Theoretical insight into diagnosing observation error correlations using observation-minus-background and observation-minus-analysis statistics. Quarterly Journal of the Royal Meteorological Society, 142 (694). pp. 418-431. ISSN 1477-870X doi: https://doi.org/10.1002/qj.2661

Bonan, B., Baines, M. J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Partridge, D. (2015) A moving point approach to model shallow ice sheets: a study case with radially-symmetrical ice sheets. The Cryosphere Discussions, 9 (4). pp. 4237-4270. ISSN 1994-0432 doi: https://doi.org/10.5194/tcd-9-4237-2015

Hodyss, D. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2015) The error of representation: basic understanding. Tellus A, 67. 24822. ISSN 1600-0870 doi: https://doi.org/10.3402/tellusa.v67.24822

Waller, J. A., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2014) Estimating correlated observation error statistics using an ensemble transform Kalman filter. Tellus A, 66. 23294. ISSN 1600-0870 doi: https://doi.org/10.3402/tellusa.v66.23294

Waller, J. A., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Eyre, J. R. (2014) Representativity error for temperature and humidity using the Met Office high-resolution model. Quarterly Journal of the Royal Meteorological Society, 140 (681). pp. 1189-1197. ISSN 1477-870X doi: https://doi.org/10.1002/qj.2207

Stewart, L. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Eyre, J. R. and Cameron, J. (2014) Estimating interchannel observation-error correlations for IASI radiance data in the Met Office system. Quarterly Journal of the Royal Meteorological Society, 140 (681). pp. 1236-1244. ISSN 1477-870X doi: https://doi.org/10.1002/qj.2211

Stewart, L. M., Dance, S. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2013) Data assimilation with correlated observation errors: experiments with a 1-D shallow water model. Tellus A, 65. 19546. ISSN 1600-0870 doi: https://doi.org/10.3402/tellusa.v65i0.19546

Freitag, M.A., Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 and Budd, C.J. (2013) Resolution of sharp fronts in the presence of model error in variational data assimilation. Quarterly Journal of the Royal Meteorological Society, 139 (672). pp. 742-757. ISSN 1477-870X doi: https://doi.org/10.1002/qj.2002

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Thornhill, G. D., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Mason, D. C. ORCID: https://orcid.org/0000-0001-6092-6081 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2013) Data assimilation for state and parameter estimation: application to morphodynamic modelling. Quarterly Journal of the Royal Meteorological Society, 139 (671 Part B). pp. 314-327. ISSN 1477-870X doi: https://doi.org/10.1002/qj.1944

Thornhill, G. D., Mason, D. C. ORCID: https://orcid.org/0000-0001-6092-6081, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Forbes, H. R. (2012) Integration of a 3D Variational data assimilation scheme with a coastal area morphodynamic model of Morecambe Bay. Coastal Engineering, 69. pp. 82-96. ISSN 0378-3839 doi: https://doi.org/10.1016/j.coastaleng.2012.05.010

Vetra-Carvalho, S., Dixon, M., Migliorini, S., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Ballard, S. P. (2012) Breakdown of hydrostatic balance at convective scales in the forecast errors in the Met Office Unified Model. Quarterly Journal of the Royal Meteorological Society, 138 (668). pp. 1709-1720. ISSN 1477-870X doi: https://doi.org/10.1002/qj.1925

Haben, S. A., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2011) Conditioning of incremental variational data assimilation, with application to the Met Office system. Tellus Series A: Dynamic Meteorology and Oceanography, 63 (4). pp. 782-792. ISSN 1600-0870 doi: https://doi.org/10.1111/j.1600-0870.2011.00527.x

Haben, S. A., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2011) Conditioning and preconditioning of the variational data assimilation problem. Computers & Fluids, 46 (1). pp. 252-256. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2010.11.025

Vetra-Carvalho, S., Migliorini, S. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2011) Ensemble data assimilation in the presence of cloud. Computers & Fluids, 46 (1). pp. 493-497. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2011.01.033

Baxter, G.M., Dance, S.L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2011) Four-dimensional variational data assimilation for high resolution nested models. Computers & Fluids, 46 (1). pp. 137-141. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2011.01.023

Budd, C.J., Freitag, M.A. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2011) Regularization techniques for ill-posed inverse problems in data assimilation. Computers & Fluids, 46 (1). pp. 168-173. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2010.10.002

Boess, C., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Bunse-Gerstner, A. (2011) State estimation using model order reduction for unstable systems. Computers & Fluids, 46 (1). pp. 155-160. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2010.11.033

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2011) A hybrid data assimilation scheme for model parameter estimation: application to morphodynamic modelling. Computers & Fluids, 46 (1). pp. 436-441. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2011.01.010

Katz, D., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Cullen, M. J. P. and Bannister, R. N. ORCID: https://orcid.org/0000-0002-6846-8297 (2011) Correlations of control variables in variational data assimilation. Quarterly Journal of the Royal Meteorological Society, 137 (656). pp. 620-630. ISSN 1477-870X doi: https://doi.org/10.1002/qj.798 (Part A)

Freitag, M. A., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Budd, C. J. (2010) L1-regularisation for ill-posed problems in variational data assimilation. PAMM - Proceedings in Applied Mathematics and Mechanics, 10 (1). pp. 665-668. ISSN 1617-7061 doi: https://doi.org/10.1002/pamm.201010324

Smith, P. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Baines, M. J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Scott, T. R. (2009) Variational data assimilation for parameter estimation: application to a simple morphodynamic model. Ocean Dynamics, 59 (5). pp. 697-708. ISSN 1616-7341 doi: https://doi.org/10.1007/s10236-009-0205-6

Bannister, R. N. ORCID: https://orcid.org/0000-0002-6846-8297, Katz, D., Cullen, M. J. P., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2008) Modelling of forecast errors in geophysical fluid flows. International Journal for Numerical Methods in Fluids, 56 (8). pp. 1147-1153. ISSN 0271-2091 doi: https://doi.org/10.1002/fld.1618

Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220, Boess, C. and Bunse-Gerstner, A. (2008) Approximate Gauss-Newton Methods for optimal state estimation using reduced-order models. International Journal for Numerical Methods in Fluids, 56 (8). 1367 -1373. ISSN 0271-2091 doi: https://doi.org/10.1002/fld.1629

Pimentel, S., Haines, K. ORCID: https://orcid.org/0000-0003-2768-2374 and Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2008) The Assimilation of Satellite Derived Sea Surface Temperatures into a Diurnal Cycle Model. Journal of Geophysical Research, 113 (C9). C09013. ISSN 0148-0227 doi: https://doi.org/10.1029/2007JC004608

Stewart, L.M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2008) Correlated observation errors in data assimilation. International Journal for Numerical Methods in Fluids, 56 (8). pp. 1521-1527. ISSN 0271-2091 doi: https://doi.org/10.1002/fld.1636

Pimentel, S., Haines, K. ORCID: https://orcid.org/0000-0003-2768-2374 and Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2008) Modeling the diurnal variability of sea surface temperatures. Journal of Geophysical Research, 113 (C11). C11004. ISSN 0148-0227 doi: https://doi.org/10.1029/2007JC004607

Livings, D. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2008) Unbiased Ensemble Square Root Filters. Physica D: Nonlinear Phenomena, 237 (8). pp. 1021-1028. ISSN 0167-2789 doi: https://doi.org/10.1016/j.physd.2008.01.005

Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220, Boess, C. and Bunse-Gerstner, A. (2008) Using model reduction methods within incremental four-dimensional variational data assimilation. Monthly Weather Review, 136 (4). pp. 1511-1522. ISSN 0027-0644 doi: https://doi.org/10.1175/2007MWR2103.1

Watkinson, L.R., Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 and Roulstone, I. (2007) Weak constraints in four-dimensional variational data assimilation. Meteorologische Zeitschrift, 16 (6). pp. 767-776. doi: https://doi.org/10.1127/0941-2948/2007/0249

Gratton, S., Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2007) Approximate Gauss-Newton methods for nonlinear least squares problems. SIAM Journal on Optimization (SIOPT), 18 (1). pp. 106-132. ISSN 1052-6234 doi: https://doi.org/10.1137/050624935

Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2007) Overview: Data assimilation and model reduction. PAMM - Proceedings in Applied Mathematics and Mechanics, 7. pp. 1026501-1056502. ISSN 1617-7061 doi: https://doi.org/10.1002/pamm.200700006

Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Livings, D. M. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2007) Unbiased ensemble square root filters. PAMM - Proceedings in Applied Mathematics and Mechanics, 7 (1). pp. 1026505-1026506. ISSN 1617-7061 doi: https://doi.org/10.1002/pamm.200700603

Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2006) Inner loop stopping criteria for incremental four-dimensional variational data assimilation. Monthly Weather Review, 134. pp. 3425-3435.

Wlasak, M. A., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Roulstone, I. (2006) Use of potential vorticity for incremental data assimilation. Quarterly Journal of the Royal Meteorological Society, 132. pp. 2867-2886. ISSN 1477-870X doi: https://doi.org/10.1256/qj.06.02

Johnson, C., Hoskins, B. J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Ballard, S. P. (2006) A singular vector perspective of 4DVAR: The spatial structure and evolution of baroclinic weather systems. Monthly Weather Review, 134 (11). pp. 3436-3455. ISSN 0027-0644 doi: https://doi.org/10.1175/MWR3243.1

Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Gratton, S. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2005) Approximate iterative methods for variational data assimilation. International Journal For Numerical Methods In Fluids, 47 (10-11). pp. 1129-1135.

Brown, D. E., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Bell, M. J. (2005) Preconditioners for inhomogeneous anisotropic problems in spherical geometry. International Journal For Numerical Methods In Fluids, 47 (10-11). pp. 1213-1219.

Frame, T. H. A. ORCID: https://orcid.org/0000-0001-6542-2173, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Thorpe, A. J. (2005) Structure and evolution of singular vectors in the Eady model. International Journal For Numerical Methods In Fluids, 47 (8-9). pp. 1003-1009.

Watkinson, L. R., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Roulstone, I. (2005) Variational data assimilation for Hamiltonian problems. International Journal For Numerical Methods In Fluids, 47 (10-11). pp. 1361-1367.

Johnson, C., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Hoskins, B. J. (2005) Very large inverse problems in atmosphere and ocean modelling. International Journal for Numerical Methods in Fluids, 47 (8-9). pp. 759-771. ISSN 0271-2091 doi: https://doi.org/10.1002/fld.869

Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Gratton, S. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2005) An investigation of incremental 4D-Var using non-tangent linear models. Quarterly Journal of the Royal Meteorological Society, 131 (606). pp. 459-476. ISSN 1477-870X

Penfold, R., Nordholm, S. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2005) A simple analysis of thermodynamic properties for classical plasmas: I. theory. Journal of Statistical Mechanics: Theory and Experiment, 2005. P06009. ISSN 1742-5468 doi: https://doi.org/10.1088/1742-5468/2005/06/P06009

Johnson, C., Hoskins, B. J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2005) A singular vector perspective of 4D-Var: Filtering and interpolation. Quarterly Journal of the Royal Meteorological Society, 131 (605). pp. 1-19. ISSN 1477-870X doi: https://doi.org/10.1256/qj.03.231

Huddleston, M. R., Bell, M. J., Martin, M. J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2004) Assessment of wind-stress errors using bias corrected ocean data assimilation. Quarterly Journal of the Royal Meteorological Society, 130 (598). pp. 853-871. ISSN 1477-870X

Bell, M. J., Martin, M. J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2004) Assimilation of data into an ocean model with systematic errors near the equator. Quarterly Journal of the Royal Meteorological Society, 130 (598). pp. 873-893. ISSN 1477-870X

Lemos, A. C., Baines, M. J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2004) Upwind solution of singular differential equations arising from steady channel flows. Computers & Fluids, 33 (5-6). pp. 821-827. ISSN 0045-7930 doi: https://doi.org/10.1016/j.compfluid.2003.06.004

Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 and Ballard, S.P. (2003) A comparison of two methods for developing the linearization of a shallow-water model. Quarterly Journal of the Royal Meteorological Society, 129 (589). pp. 1237-1254. ISSN 1477-870X doi: https://doi.org/10.1256/qj.02.75

Owen, T., Duan, G., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Liu, G. (2002) Discussion on 'Robust pole assignment in descriptor linear systems via state feedback' by G.-R. Duan, N.K. Nichols and G.-P. Liu. European Journal of Control, 8 (2). p. 150. ISSN 0947-3580 doi: https://doi.org/10.3166/ejc.8.150-151

Martin, M. J., Bell, M. J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2002) Estimation of systematic error in an equatorial ocean model using data assimilation. International Journal for Numerical Methods in Fluids, 40 (3-4). pp. 435-444. ISSN 0271-2091 doi: https://doi.org/10.1002/fld.298

Duan, G.-R., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Liu, G.-P. (2002) Robust pole assignment in descriptor linear systems via state feedback. European Journal of Control, 8 (2). pp. 136-149. ISSN 0947-3580 doi: https://doi.org/10.3166/ejc.8.136-149

Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 and Kautsky, J. (2001) Robust eigenstructure assignment in quadratic matrix polynomials: nonsingular case. SIAM Journal on Matrix Analysis and Applications, 23 (1). pp. 77-102. ISSN 0895-4798 doi: https://doi.org/10.1137/S0895479899362867

Griffith, A. K. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2000) Adjoint methods in data assimilation for estimating model error. Flow, Turbulence and Combustion, 65 (3/4). pp. 469-488. ISSN 1386-6184 doi: https://doi.org/10.1023/A:1011454109203

Bunse-Gerstner, A., Byers, R., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1999) Feedback design for regularizing descriptor systems. Linear Algebra and its Applications, 299 (1-3). pp. 119-151. ISSN 0024-3795 doi: https://doi.org/10.1016/S0024-3795(99)00167-6

Chu, D., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1999) Minimum norm regularization of descriptor systems by mixed output feedback. Linear Algebra and its Applications, 296 (1-3). pp. 39-77. ISSN 0024-3795 doi: https://doi.org/10.1016/S0024-3795(99)00108-1

Gibson, L. P., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Littleboy, D. M. (1998) Bifurcation Analysis of Eigenstructure Assignment Control in a Simple Nonlinear Aircraft Model. Journal of Guidance, Control and Dynamics, 21 (5). pp. 792-798. ISSN (printed) 0731-5090; (electronic) 1533-3884.

Littleboy, D. M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1998) Modal coupling in linear control systems using robust eigenstructure assignment. Linear Algebra and its Applications, 275-276. pp. 359-379. ISSN 0024-3795 doi: https://doi.org/10.1016/S0024-3795(97)10053-2

MacDonald, I., Baines, M., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Samuels, P. G. (1997) Analytic Benchmark Solutions for Open-Channel Flows. Journal of Hydraulic Engineering, 123 (11). p. 1041. ISSN 0733-9429 doi: https://doi.org/10.1061/(ASCE)0733-9429(1997)123:11(1041)

Dainton, M.P., Goldwater, M.H. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1997) Direct Computation of Stochastic Flow in Reservoirs with Uncertain Parameters. Journal of Computational Physics, 130 (2). p. 203. ISSN 0021-9991 doi: https://doi.org/10.1006/jcph.1996.5578

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Regularization of descriptor systems by output feedback. IEEE Transactions on Automatic Control, 39 (8). pp. 1742-1748. ISSN 0018-9286 doi: https://doi.org/10.1109/9.310065

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Stringer, S.M. (1994) The state estimation of flow demands in gas networks from sparse pressure telemetry. Transactions of the Institute of Measurement and Control, 16 (2). pp. 66-74. ISSN 0142-3312 doi: https://doi.org/10.1177/014233129401600203

Byers, R. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1993) On the stability radius of a generalized state-space system. Linear Algebra and its Applications, 188-189. p. 113. ISSN 0024-3795 doi: https://doi.org/10.1016/0024-3795(93)90466-2

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1993) Obituary: Professor Leslie Fox, C. Math., FIMA. The IMA Bulletin, 29. pp. 175-176.

Perrin, N., Sibly, R. M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1993) Optimal growth strategies when mortality and production rates are size-dependent. Evolutionary Ecology, 7 (6). pp. 576-592. ISSN 0269-7653 doi: https://doi.org/10.1007/BF01237822

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1992) Regularization of Descriptor Systems by Derivative and Proportional State Feedback. Siam Journal on Matrix Analysis and Applications, 13 (1). pp. 46-67. ISSN 0895-4798 doi: https://doi.org/10.1137/0613007

Campbell, S. L., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Terrell, W. J. (1991) Duality, observability, and controllability for linear time-varying descriptor systems. Circuits Systems and Signal Processing, 10 (4). pp. 455-470. ISSN 0278-081X doi: https://doi.org/10.1007/BF01194883

Bunse-Gerstner, A., Byers, R., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1991) Numerical computation of an analytic singular value decomposition of a matrix valued function. Numerische Mathematik, 60 (1). pp. 1-39. ISSN 0029-599X doi: https://doi.org/10.1007/BF01385712

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1990) Robust pole assignment in systems subject to structured perturbations. Systems & Control Letters, 15 (5). pp. 373-380. ISSN 0167-6911 doi: https://doi.org/10.1016/0167-6911(90)90060-8

Kautsky, J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Chu, E.K.-W. (1989) Robust pole assignment in singular control systems. Linear Algebra and its Applications, 121. pp. 9-37. ISSN 0024-3795 doi: https://doi.org/10.1016/0024-3795(89)90689-7

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1989) On the numerical integration of a class of singular perturbation problems. Journal of Optimization Theory and Applications, 60 (3). pp. 439-452. ISSN 0022-3239 doi: https://doi.org/10.1007/BF00940347

Petkov, P.H., Christov, N.D., Konstantinov, M.M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1988) Comments, with reply, on "Computational algorithms for pole assignment" by N.K. Nichols. IEEE Transactions on Automatic Control, 33 (9). pp. 892-894. ISSN 0018-9286 doi: https://doi.org/10.1109/9.1328

Barlow, J. L., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Plemmons, R. J. (1988) Iterative Methods for Equality-Constrained Least Squares Problems. SIAM Journal on Scientific and Statistical Computing, 9 (5). pp. 892-906. ISSN 0196-5204 doi: https://doi.org/10.1137/0909061

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1987) Robustness in partial pole placement. IEEE Transactions on Automatic Control, 32 (8). pp. 728-732. ISSN 0018-9286 doi: https://doi.org/10.1109/TAC.1987.1104703

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) On computational algorithms for pole assignment. IEEE Transactions on Automatic Control, 31 (7). pp. 643-645. ISSN 0018-9286 doi: https://doi.org/10.1109/TAC.1986.1104354

Fletcher, L., Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) Eigenstructure assignment in descriptor systems. IEEE Transactions on Automatic Control, 31 (12). pp. 1138-1141. ISSN 0018-9286 doi: https://doi.org/10.1109/TAC.1986.1104189

Kreiss, H.-O., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Brown, D. L. (1986) Numerical Methods for Stiff Two-Point Boundary Value Problems. SIAM Journal on Numerical Analysis (SINUM), 23 (2). pp. 325-368. ISSN 0036-1429 doi: https://doi.org/10.1137/0723023

Barlow, J. L., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Plemmons, R. J. (1986) A conjugate gradient method for the solution of equality constrained least squares problems. SPIE, 696. pp. 23-30. (SPIE Special issue: Advanced Algebra and Architectures for Signal Processing)

Sibly, R., Calow, P. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1985) Are patterns of growth adaptive? Journal of Theoretical Biology, 112 (3). pp. 553-574. ISSN 00225193 doi: https://doi.org/10.1016/S0022-5193(85)80022-9

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1985) Robust multiple eigenvalue assignment by state feedback in linear systems. Linear Algebra and its Role in System Theory, 47. pp. 253-264.

Kautsky, J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Van Dooren, P. (1985) Robust pole assignment in linear state feedback. International Journal of Control, 41 (5). p. 1129. ISSN 0020-7179 doi: https://doi.org/10.1080/0020718508961188

Fletcher, L. R., Kautsky, J., Kolka, G. K. G. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1985) Some necessary and sufficient conditions for eigenstructure assignment. International Journal of Control, 42 (6). pp. 1457-1468. ISSN 0020-7179 doi: https://doi.org/10.1080/00207178508933437

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and van Dooren, P. (1984) Robust pole assignment and optimal stability margins. Electronics Letters, 20 (16). pp. 660-661. ISSN 0013-5194 doi: https://doi.org/10.1049/el:19840452

Kautsky, J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Jupp, D. L.B. (1984) Smoothed histogram modification for image processing. Computer Vision, Graphics, and Image Processing, 26 (3). pp. 271-291. ISSN 0734-189X doi: https://doi.org/10.1016/0734-189X(84)90213-5

Birkett, N., Count, B. M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1984) Optimal control problems in tidal power. Water Power and Dam Construction, 36. pp. 37-42.

Norman, G. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1982) Dynamic Market Strategy Under Threat of Competitive Entry: An Analysis of the Pricing and Production Policies Open to the Multinational Company. The Journal of Industrial Economics, 31 (1/2). pp. 153-174. ISSN 0022-1821 doi: https://doi.org/10.2307/2098010 (Given at a symposium on Spatial Competition and the Theory of Differentiated Markets )

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and England, R. (1982) Numerical solution of an elastic boundary layer problem using a multiple shooting technique. Journal of Computational Physics, 46 (3). pp. 369-389. ISSN 0021-9991 doi: https://doi.org/10.1016/0021-9991(82)90021-3

Burghes, D. N., Lyle, S. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1982) Optimal resource depletion: Free end time problems. Optimal Control: Applications and Methods, 3. pp. 283-291.

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1982) Smooth Regrading of Discretized Data. SIAM Journal on Scientific and Statistical Computing, 3 (2). pp. 145-159. ISSN 0196-5204 doi: https://doi.org/10.1137/0903010

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1982) Time-optimal decoupling control problems. International J. of Control.

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1980) Equidistributing Meshes with Constraints. SIAM Journal on Scientific and Statistical Computing, 1 (4). pp. 499-511. ISSN 0196-5204 doi: https://doi.org/10.1137/0901036

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1973) On the Convergence of Two-Stage Iterative Processes for Solving Linear Equations. SIAM Journal on Numerical Analysis (SINUM), 10 (3). pp. 460-469. ISSN 0036-1429 doi: https://doi.org/10.1137/0710040

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Fox, L. (1969) Generalized consistent ordering and the optimum successive over-relaxation factor. Numerische Mathematik, 13 (5). pp. 425-433. ISSN 0029-599X doi: https://doi.org/10.1007/BF02163270

Book or Report Section

Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2016) Correlated observations in data assimilation. In: Mathematical and Algorithmic Aspects of Data Assimilation in the Geosciences. Mathematisches Forschungsinstitut, Oberwolfach Germany, pp. 35-37. doi: https://doi.org/10.4171/OWR/2016/47

Bell, M. J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Martin, M. J. (2016) Application of data assimilation to ocean and climate prediction. In: Aston, P. J., Mulholland, T. J. and Tant, K. M. M. (eds.) UK Success Stories in Industrial Mathematics. Springer International Publishing AG, Switzerland, pp. 3-10. ISBN 9783319254524 doi: https://doi.org/10.1007/978-3-319-25454-8

Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Chu, D. (2015) Regularization of descriptor systems. In: Numerical Algebra, Matrix Theory, Differential-Algebraic Equations and Control Theory. Springer International Publishing, Switzerland, pp. 415-433. ISBN 9783319152592 doi: https://doi.org/10.1007/978-3-319-15260-8_15

Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2010) Mathematical concepts of data assimilation. In: Lahoz, W., Khattatov, B. and Menard, R. (eds.) Data assimilation: making sense of observations. Springer, pp. 13-40. ISBN 9783540747024

Scott, T. R., Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Mason, D.C. ORCID: https://orcid.org/0000-0001-6092-6081, Baines, M.J., Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220, Horsburgh, K.J., Sweby, P.K. ORCID: https://orcid.org/0009-0003-8488-0251 and Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568 (2008) Data assimilation for morphodynamic prediction and predictability. In: Coastal Engineering 2008 Proceedings of the 31st International Conference. World Scientific, pp. 2386-2398. doi: https://doi.org/10.1142/9789814277426_0197

Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Boess, C. and Bunse-Gerstner, A. (2007) Approximate Gauss-Newton methods using reduced order models. In: Proceedings of the Ninth International ICFD Conference on Numerical Methods for Fluid Dynamics, March 26 – 29, 2007. ICFD, Reading.

Stewart, L. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2007) Correlated observation errors in data assimilation. In: Proceedings of the Ninth International ICFD Conference on Numerical Methods for Fluid Dynamics, March 26 – 29, 2007. ICFD, Reading.

Bannister, R. N. ORCID: https://orcid.org/0000-0002-6846-8297, Katz, D., Cullen, M. J. P., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2007) Modelling of forecast errors in geophysical fluid flows. In: Proceedings of the Ninth International ICFD Conference on Numerical Methods for Fluid Dynamics, March 26 – 29, 2007. ICFD, Reading.

Baxter, G. M., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Ballard, S. P. (2007) Towards Multi-scale Data Assimilation for High Resolution Nested Models. In: Proceedings of the Ninth International ICFD Conference on Numerical Methods for Fluid Dynamics, March 26 – 29, 2007. ICFD, Reading.

Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2003) Data Assimilation: Aims and Basic Concepts. In: Swinbank Shutyaev,, R. (ed.) Data Assimilation for the Earth System. Kluwer Academic, pp. 9-20.

Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2003) Treating Model Error in 3-D and 4-D Data Assimilation. In: Swinbank, R., Shutyaev, V. and Lahoz, W.A. (eds.) Data Assimilation for the Earth System. Kluwer Academic, pp. 127-135.

Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220 (2003) The convergence of incremental 4D-Var using non-tangent linear models. In: Cote, J. (ed.) Research activities in atmospheric and oceanic modelling. WMO CAS/JSG Working Group on Numerical Experimentation, 01-17 + 01-18.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2000) Control strategies for maximizing power output from wave energy converters with turbine losses. In: Wave Power – Moving Towards Commercial Viability. Professional Engineering Publishing Ltd, pp. 103-108.

Lawless, A. S., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, Reinmueller, K. and Ballard, S. (2000) A comparison of two methods for deriving the tangent linear model. In: Proceedings of the Third WMO International Symposium on Assimilation of Observations in Meteorology and Oceanography. WWRP Report Series No. 2, WMO/TD (986). World Meteorological Organization, pp. 105-108.

Griffith, A. K. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1998) Adjoint methods for treating model error in data assimilation. In: Numerical Methods for Fluid Dynamics VI. ICFD, Oxford, pp. 335-344.

Wlasak, M. A. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1998) Application of variational data assimilation to the Lorenz equations using the adjoint method. In: Numerical Methods for Fluid Dynamics VI. ICFD, Oxford, pp. 555-562.

Griffith, A. K. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1996) Accounting for Model Error in Data Assimilation using Adjoint Methods. In: Berz, M., Bischof, C., Corliss, G. and Griewank, A. (eds.) Computational Differentiation: Techniques, Applications and Tools. SIAM: Society for Industrial and Applied Mathematics, pp. 195-204.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Crossley, A. (1996) Optimal control of wave energy devices with various power-take-off mechanisms. In: Chakrabarti, S., Pontes, M. T., Maeda, H., Falzarano, J., Schofield, P., Atkins, W. S. and Morrison, D. (eds.) Proceedings of the 15th International Conference on Offshore Mechanics and Arctic Engineering. The American Society of Mechanical Engineers, New York, pp. 143-150.

Neylon, K. J., Baines, M. J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Bi-CGSTAB for advection dominated problems. In: Lewis, J. G. (ed.) Proc. of the Fifth SIAM Conference on Applied Linear Algebra. SIAM, pp. 439-443.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Differential-algebraic equations and control system design. In: Griffith, D. F. and Watson, G. A. (eds.) Numerical Analysis - 1993. Longman Scientific and Technical, pp. 208-224. ISBN 978-047023385-6

Pratt, R. W., Faleiro, L. F. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Longitudinal instrument landing system design using both eigenstructure assignment and classical techniques. In: Proceedings of IMC Symposium on Applications of Multivariable System Techniques. Institute of Measurement and Control, pp. 11-22.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Stringer, S. M. (1994) Observer design for descriptor systems with application to gas dynamical networks. In: Helmke, U., Mennicken, R. and Saurer, J. (eds.) Systems and Networks: Mathematical Theory and Applications. Akademie Verlag, pp. 377-380.

Bell, S. J. G. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Regularization of time-varying descriptor systems by the asvd. In: Lewis, J. (ed.) Proceedings of the 5th SIAM Conference on Applied Linear Algebra. Society for Industrial and Applied Mathematics, Philadelphia, pp. 172-176. ISBN 978-089871336-7

Kautsky, J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Van Dooren, P. M. (1994) Robust pole assignment in linear state feedback. In: Patel, R. V., Laub, A. J. and Van Dooren, P. M. (eds.) Numerical Linear Algebra Techniques for Systems and Control. IEEE Press, pp. 333-356.

Littleboy, D. M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Using eigenstructure assignment for modal decoupling in aircraft problems. In: Lewis, J. (ed.) Applied Linear Algebra. SIAM: Society for Industrial and Applied Mathematics, pp. 196-200.

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1993) Output feedback in descriptor systems. In: Van Dooren, P. and Wyman, B. (eds.) Linear Algebra for Control Theory. Springer Verlag, pp. 43-54.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1993) Phase control in wave energy generation. In: Caratti, G., Lewis, A. T. and Howett, D. (eds.) Wave Energy R&D. Commission of the European Communities, Brussels, pp. 177-182.

Xu, Z. G., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Birkett, N. R. C. (1992) OCTPG3 - A program for hydrodynamic modeling and optimal-control of tidal power schemes. In: Blain, W. R. and Cabrera, E. (eds.) Fluid flow modelling. Computational Mechanics Publications, pp. 497-508. ISBN 9-78156-252127-1

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, Falcao, A. F. d. O. and Pontes, M. T. (1991) Optimal phase control of wave power devices. In: Wave Energy. Institute of Mechanical Engineers, London, pp. 41-46.

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1990) On derivative and proportional feedback design for descriptor systems. In: Kaashoek, M. A., Van Schuppen, J. H. and Ran, A. C. M. (eds.) Signal Processing, Scattering and Operator Theory, and Numerical Methods. Birkhauser, Boston, pp. 437-446.

Hoskin, R. E. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1987) Optimal Strategies for Phase Control of Wave Energy Devices. In: McCormick, M. E. and Kim, Y. C. (eds.) Utilization of Ocean Waves—Wave to Energy Conversion. ASCE: American Society of Civil Engineers, New York, pp. 184-199. ISBN 978-0-87262-624-9 or 0-87262-624-5 (A paper presented at the ASCE Specialty Conference, Utilization of Ocean Waves, held at the Scripps Institution of Oceanography, June 16 and 17, 1986.)

Birkett, N. R. C. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) Optimal control problems in tidal power generation. In: Elliott, C. and McKee, S. (eds.) Industrial Numerical Analysis - Case Histories. Clarendon Press, Oxford, pp. 53-89.

Hoskin, R. E., Count, B. M., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Nicol, D. A. C. (1986) Phase control for the oscillating water column. In: Evans, D. and Falcao, A. F. d. O. (eds.) Hydrodynamics of Ocean Wave-Energy Utilization. Springer-Verlag, pp. 257-268.

Chu, E. K.-w. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) Reliable algorithms for reduced order observer design. In: Byrne, C. and Lindquist, A. (eds.) Computational and Combinatorial Methods in System Theory. Elsevier Press, North Holland, pp. 11-22.

Birkett, N. R. C., Count, B. M., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Nicol, D. A. C. (1985) Optimal control problems in tidal power generation - full estuary model. In: Wacker, H. (ed.) Applied Optimization Techniques in Energy Problems. B G Teubner, Stuttgart, pp. 138-159.

Birkett, N. R. C. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1985) Optimal control problems in tidal power generation - variable geometry/non-linear head flow model. In: Cook, P. (ed.) Proceedings of the Fourth IMA Conference on Control Theory. Academic Press, pp. 269-284.

Chu, E. K.-w., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Kautsky, J. (1985) Robust pole assignment by output feedback. In: Cook, P. (ed.) Proceedings of the Fourth IMA Conference on Control Theory. Academic Press, pp. 137-146.

Kautsky, J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Van Dooren, P. (1984) Numerical methods for inverse eigenvalue problems in algebraic control theory. In: Proceedings of the Centre for Mathematical Analysis. Australian National University, Canberra, pp. 102-106.

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1983) Matrix factorisation and some applications in linear systems. In: Reliable Numerical Procedures in Control System Design. Digest (1983/87). Institution of Electrical Engineers, 5/1-5/3.

Kautsky, J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, Van Dooren, P. and Fletcher, L. (1983) Numerical methods for robust eigenstructure assignment in control system design. In: Numerical Treatment of Inverse Problems for Integral and Differential Equations. Birhauser, Boston, pp. 171-178.

Lyle, S. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1982) On the finite element solution of optimal design problems using transformation techniques. In: Whiteman, J. R. (ed.) The Mathematics of Finite Elements and Applications IV. Academic Press, pp. 183-192.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, Dearden, S. J., Atkinson, P. and Allen, A. J. (1981) Time optimal decoupled control. In: Marshall, J. E., Collins, W. D., Harris, C. J. and Owens, D. H. (eds.) Third International IMA Conference on Control Theory. Academic Press, London, pp. 507-525.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, Petrovic, S. and Burghes, D. N. (1978) Solutions of optimal control problems in economic growth modelling by the finite element method. In: Alarcon, E. and Brebbia, C. A. (eds.) Proceedings of the Second International Conference on Numerical Modelling. Pentreath Press, Madrid, 12.1-12.9.

Kreiss, H. O. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1975) Methods for singular perturbation problems. In: Glowinski, R. and Lions, J. L. (eds.) Computing Methods in Applied Sciences and Engineering II. Academic Press.

Report

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, (2014) A joint state and parameter estimation scheme for nonlinear dynamical systems. Technical Report. Dept of Mathematics & Statistics, University of Reading pp24.

Haben, S. A., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, (2014) Conditioning and preconditioning of the optimal state estimation problem. Mathematics Preprint Series. 2014-08. Technical Report. Dept of Mathematics & Statistics, University of Reading pp21.

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, (2009) Data assimilation for morphodynamic model parameter estimation: a hybrid approach. Mathematics Report . 2/2009. Technical Report. University of Reading, Department of Mathematics

Stewart, L., Cameron, J., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, English , S., Eyre, J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, (2009) Observation error correlations in IASI radiance data. Mathematics Report . 1/2009. Technical Report. University of Reading, Department of Mathematics

Martin, M. J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1999) Treatment of systematic errors in sequential data assimilation. Technical Note. 21. Technical Report. UK Meteorological Office, Ocean Applications Division

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Crossley, A., (1996) Optimal Strategies for the Control of Wave Energy Converters with Various Power-Take-Off Mechanisms. Project Report. The University of Reading pp48. (Part of ... Off-Shore Wave Energy Converters - OWEC-1, Annex III: Float Systems and Mathematical Models, DG XII - JOULE II Project Report)

Dainton, M. P. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1996) Two-phase flow in heterogeneous porous media with uncertain parameters. Working Paper. The University of Reading

Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1995) Mixed Output Feedback for Descriptor Systems. SPC. 95-33. Technical Report. TU-Chemnitz-Zwickau

Greenhow, M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1994) The use of time-domain models for control of OWCs. Project Report. The University of Reading pp13. (Paper 4 of CEC DG XII JOULE Wave Energy Initiative: Wave Energy Converters - Generic Technical Evaluation Study: Annex Report B1 - Device Fundamentals/Hydrodynamics)

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1992) Numerical methods for the regularization of descriptor systems by output feedback. Preprint Series. 987. Technical Report. Institute of Mathematics and Applications

Andrews, T. P., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Xu, Z., (1990) The form of optimal controllers for tidal power generation schemes. Numerical Analysis Technical Report. 8/90. Technical Report. The University of Reading, Reading.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1984) An optimal heat control problem. UCINA Working Report. Working Paper. The University of Reading

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1982) MEAP-1: MATLAB Eigenstructure Assignment Package - Mark 1. Technical Report. Flinders University of South Australia, Finders, Australia.

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1981) PEEK-2: Computer package for LANDSAT image processing. Technical Report. Flinders University of South Australia

Curtis, A. R., Jones, I. P. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1979) DEPACK: A conversational job entry system for differential equation problems at Harwell. Report. AERE Harwell, Harwell.

Fong, C. M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1979) A continuum model of a fishing net. Working Paper. The University of Reading

Curtis, A. R., Jones, I. P. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1977) Numerical solution of ordinary differential equations. Documentation. AERE Harwell

Kreiss, H. O. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, (1975) Numerical methods for singular perturbation problems. Technical Report. Uppsala University, Uppsala.

Conference or Workshop Item

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Hodyss, D. (2015) Understanding the error of representation. In: Workshop on Sensitivity Analysis and Data Assimilation in Meteorology and Oceanography, 1-5 June 2015, Stonewall Resort Roanoke, West Virginia, USA.

Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Baines, M. J., Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568, Mason, D. C. ORCID: https://orcid.org/0000-0001-6092-6081, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Scott, T. R., Sweby, P. K. ORCID: https://orcid.org/0009-0003-8488-0251, Smith, P. and Thornhill, G. D. (2010) Use of data assimilation methods in coastal sediment models. In: Flood Risk from Extreme Events (FREE) Final Science Meeting, 20 October, London. (Unpublished)

Thornhill, G. D., Scott, T. R., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Mason, D. C. ORCID: https://orcid.org/0000-0001-6092-6081, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Baines, M. J., Horsburgh, K. and Sweby, P. K. ORCID: https://orcid.org/0009-0003-8488-0251 (2010) Data assimilation and morphodynamic modelling of Morecambe Bay. In: National Centre for Earth Observation Annual Conference, 28-30 September 2010, Leicester. (Unpublished)

Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Baines, M. J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Scott, T. R. (2009) Variational data assimilation for morphodynamic model parameter estimation. In: Centre for Australian Weather and Climate Research (CAWCR) Workshop on Ensemble Prediction and Data Assimilation, February 2009, Australian Bureau of Meteorology, Melbourne.

Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Baxter, G., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338 and Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 (2009) Issues in high resolution data assimilation. In: The 8th International Workshop on Adjoint Model Applications in Dynamic Meteorology, May 2009, Tannersville, PA, USA.

Thornhill, G. D., Scott, T. R., Smith, P.J., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Mason, D. C. ORCID: https://orcid.org/0000-0001-6092-6081, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220, Baines, M. J., Horsburgh, K.J., Sweby, P. K. ORCID: https://orcid.org/0009-0003-8488-0251 and Lawless, A. S. ORCID: https://orcid.org/0000-0002-3016-6568 (2009) Progress on “Changing coastlines: data assimilation for morphodynamic prediction and predictability”. In: Third NERC FREE Conference, 10-11 September, Plymouth. (Unpublished)

Stewart, L., Cameron, J., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, English, S., Eyre, J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2009) Quantifying observation error correlations in remotely sensed data. In: Centre for Australian Weather and Climate Research (CAWCR) Workshop on Ensemble Prediction and Data Assimilation, February 2009, Australian Bureau of Meteorology, Melbourne,.

Stewart, L., Cameron, J., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, English, S., Eyre, J. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2009) Quantifying observation error correlations in remotely sensed data. In: The 8th International Workshop on Adjoint Model Applications in Dynamic Meteorology, May 2009, Tannersville, PA, USA.

Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Butala, M., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Petrie, R. E. (2009) Stability and localization in the ensemble square root filter. In: The 8th International Workshop on Adjoint Model Applications in Dynamic Meteorology, May 2009, Tannersville, PA, USA.

Smith, P. J., Dance, S. L. ORCID: https://orcid.org/0000-0003-1690-3338, Baines, M. J., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Scott, T. R. (2009) Variational data assimilation for morphodynamic model parameter estimation. In: The 8th International Workshop on Adjoint Model Applications in Dynamic Meteorology, May 2009, Tannersville, PA, USA.

Roulstone, I., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, Wlasak, M. A. and Fletcher, S. J. (2007) Flow dependent transforms. In: The ECMWF Workshop on Flow Dependent Aspects of Data Assimilation, June 2007, ECMWF, Reading, UK.

Scott, T. R., Smith, P. J. ORCID: https://orcid.org/0000-0003-4570-4127, Dance, S.L. ORCID: https://orcid.org/0000-0003-1690-3338, Mason, D.C. ORCID: https://orcid.org/0000-0001-6092-6081, Nichols, N.K. ORCID: https://orcid.org/0000-0003-1133-5220, Baines, M.J., Horsburgh, K., Sweby, P. K. ORCID: https://orcid.org/0009-0003-8488-0251 and Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568 (2007) Progress on Changing coastlines: data assimilation for morphodynamic prediction and predictability. In: 2nd NERC Conference on Flood Risk from Extreme Events (FREE). (Unpublished)

Frame, T. ORCID: https://orcid.org/0000-0001-6542-2173, Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Thorpe, A. J. (2006) Targeting observations using singular vectors. In: The Fourth WMO International Symposium on Assimilation of Observations in Meteorology and Oceanography, 2006.

Lawless, A. ORCID: https://orcid.org/0000-0002-3016-6568, Gratton, S. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2006) An investigation of the convergence of incremental 4D-Var. In: The Fourth WMO International Symposium on Assimilation of Observations in Meteorology and Oceanography, 2006.

Johnson, C., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Hoskins, B. (2006) A singular vector perspective of 4D-Var. In: The Fourth WMO International Symposium on Assimilation of Observations in Meteorology and Oceanography, 2006.

Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Gratton, S. and Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 (2004) Approximate iterative methods for variational data assimilation. In: Proceedings of the ICFD International Conference on Numerical Methods for Fluid Dynamics, Oxford, University of Oxford.

Brown, D.E., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Bell, M.J. (2004) Preconditioners for inhomogeneous anisotropic problems in spherical geometry. In: Proceedings of the ICFD International Conference on Numerical Methods for Fluid Dynamics, University of Oxford.

Frame, T.H.A. ORCID: https://orcid.org/0000-0001-6542-2173, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Thorpe, A. J. (2004) Sensitivity to initial conditions in numerical weather prediction. In: Proceedings of the ICFD International Conference on Numerical Methods for Fluid Dynamics, Oxford, University of Oxford.

Stanton, L.R., Lawless, A.S. ORCID: https://orcid.org/0000-0002-3016-6568, Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Roulstone, I. (2004) Variational data assimilation for Hamiltonian problems. In: Proceedings of the ICFD International Conference on Numerical Methods for Fluid Dynamics, Oxford, University of Oxford.

Johnson, C., Nichols, N. K. ORCID: https://orcid.org/0000-0003-1133-5220 and Hoskins, B. J. (2004) Very large inverse problems in atmosphere and ocean modelling. In: Proceedings of the ICFD International Conference on Numerical Methods for Fluid Dynamics, Oxford, University of Oxford.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2000) Robust eigenstructure assignment in second-order control systems. In: MTNS2000: the Fourteenth International Symposium on the Mathematical Theory of Networks and Systems, 2000, Perpignan, France, pp. 1-6.

Griffith, A. K., Martin, M. J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (2000) Techniques for treating systematic model error in 3D and 4D data assimilation. In: The Third WMO International Symposium on Assimilation of Observations in Meteorology and Oceanography, 2000, pp. 9-12.

Gibson, L. P., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Littleboy, D. M. (1997) Closed loop design for a simple nonlinear aircraft model using eigenstructure assignment. In: AIAA Atmospheric Flight Mechanics Conference , 11-13 August 1997, American Institute of Aeronautics and Astronautics, Reston, Virginia, USA, pp. 746-754.

MacDonald, I., Baines, M. J., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Samuels, P. G. (1995) A new method for the computation of steady open channel trans-critical flow. In: The XXVIth Congress of the International Association for Hydyraulic Research, London.

Faleirot, L. F., Pratt, R. W. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) A comparison between classical techniques and eigenstructure assignment in the design of a longitudinal instrument landing system. In: IEE Colloquium on Multivariable Methods for Flight Control Applications, 1994-05-25, London, UK, 1/1-1/3.

Dainton, M., Goldwater, M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1994) Direct solution of reservoir flow equations with uncertain parameters. In: the Fourth European Conference on the Mathematics of Oil Recovery, 1994, pp. 1-15.

Justino, P. A. P., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and deo Falcano, A. F. (1993) Optimal phase control of OWCs. In: European Wave Energy Symposium, July 1993, Edinburgh, Scotland, pp. 145-149.

Stringer, S. M. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1993) The estimation of flow demands in a linear gas network from sparse pressure telemetry. In: Symposium on Post-graduate Research in Control and Instrumentation, SERC/Institute of Measurement and Control, Nottingham.

Xu, Z. G. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1992) OCTPG: A program for estuary hydrodynamic modelling and optimal control of tidal power schemes. In: HYDROSOFT 92 International Conference, 1992, Valencia.

Xu, Z. G. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1992) A theoretical and numerical investigation of tidal power schemes by non-linear optimal control methods. In: Sixth IMA Conference on Control: Modelling, Computation and Information, 1992, Manchester, pp. 117-123.

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1991) Regularization of descriptor systems. In: 30th IEEE Conference on Decision and Control, 1991.

Bunse-Gerstner, A., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1989) Derivative feedback for descriptor systems. In: IFAC Workshop on System Structure and Control: State-Space and Polynomial Methods, 1989, Prague, Czechoslovakia, pp36. (Availability also from TIB Hannover ... RN 7886(58))

Birkett, N. R. C., Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Nicol, D. A. C. (1987) Dynamic models for optimal control of tidal power schemes. In: ICE Tidal Power Symposium, 1987, London, pp. 33-39.

Kautsky, J. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) Algorithms for Robust Pole Assignment in Singular Systems. In: The American Control Conference, 18-20 June 1986, Seattle WA USA, pp. 433-436.

Hoskin, R. E. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) Latching control of a point absorber. In: n.k.nichols, 1986, The Fluid Engineering Centre, Bedford, pp. 317-330. (Proceedings published by BHRA)

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1986) Robust control system design for generalized state-space systems. In: 25th IEEE Conference on Decision and Control, 1986, pp. 538-540. doi: https://doi.org/10.1109/CDC.1986.267341

Kautsky, J., Jupp, D. L. B. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1981) Image enhancement by smoothed histogram modification. In: LANDSAT 81, Second Australasian Remote Sensing Conference, 1981, Canberra.

Book

Ammar, G., Mehrmann, V. and Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220, eds. (1993) Linear Algebra and its Applications: special issue on Numerical Linear Algebra Methods in Control, Signals and Systems. Linear Algebra and its Applications, 189. Elsevier.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 and Owens, D. H., eds. (1992) The Mathematics of Control Theory. Clarendon Press, pp489. ISBN 978-0198536406

Thesis

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1969) Numerical solution of elliptic differential equations. PhD thesis, Oxford University.

Nichols, N. ORCID: https://orcid.org/0000-0003-1133-5220 (1966) Matrix iterative methods for elliptic differential equations. Other thesis, Oxford University.