Accessibility navigation


A comparison of two identification and tracking methods for polar lows

Downloads

Downloads per month over past year

Xia, L., Zahn, M., Hodges, K. I. and Feser, F. (2012) A comparison of two identification and tracking methods for polar lows. Tellus Series A: Dynamic Meteorology and Oceanography, 64. 17196. ISSN 0280-6495

[img]
Preview
Text (Open Access) - Published Version
· Please see our End User Agreement before downloading.

4Mb

To link to this article DOI: 10.3402/tellusa.v64i0.17196

Abstract/Summary

In this study, we compare two different cyclone-tracking algorithms to detect North Atlantic polar lows, which are very intense mesoscale cyclones. Both approaches include spatial filtering, detection, tracking and constraints specific to polar lows. The first method uses digital bandpass-filtered mean sea level pressure (MSLP) fieldsin the spatial range of 200�600 km and is especially designed for polar lows. The second method also uses a bandpass filter but is based on the discrete cosine transforms (DCT) and can be applied to MSLP and vorticity fields. The latter was originally designed for cyclones in general and has been adapted to polar lows for this study. Both algorithms are applied to the same regional climate model output fields from October 1993 to September 1995 produced from dynamical downscaling of the NCEP/NCAR reanalysis data. Comparisons between these two methods show that different filters lead to different numbers and locations of tracks. The DCT is more precise in scale separation than the digital filter and the results of this study suggest that it is more suited for the bandpass filtering of MSLP fields. The detection and tracking parts also influence the numbers of tracks although less critically. After a selection process that applies criteria to identify tracks of potential polar lows, differences between both methods are still visible though the major systems are identified in both.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Science > School of Mathematical and Physical Sciences > National Centre for Earth Observation (NCEO)
Faculty of Science > School of Mathematical and Physical Sciences > Environmental Systems Science Centre
ID Code:28810
Uncontrolled Keywords:cyclone; tracking algorithm; polar lows; spatial filter; North Atlantic
Publisher:Wiley-Blackwell

Download Statistics for this item.

Centaur Editors: Update this record

Page navigation