Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin
Large-scale environmental variables known to be linked to the formation of tropical cyclones, have previously been used to develop empirical indices as proxies for assessing cyclone frequency from large-scale analyses or model simulations. Here we examine the ability of two recent indices, the Genes...
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American Meteorological Society
2012
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ftncar:oai:drupal-site.org:articles_12280 2023-09-05T13:21:27+02:00 Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin Bruyere, Cindy (author) Holland, Gregory (author) Towler, Erin (author) 2012-12-01 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-334 https://doi.org/10.1175/JCLI-D-11-00619.1 en eng American Meteorological Society Journal of Climate http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-334 doi:10.1175/JCLI-D-11-00619.1 ark:/85065/d7bk1d3s Copyright 2012 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. Text article 2012 ftncar https://doi.org/10.1175/JCLI-D-11-00619.1 2023-08-14T18:39:25Z Large-scale environmental variables known to be linked to the formation of tropical cyclones, have previously been used to develop empirical indices as proxies for assessing cyclone frequency from large-scale analyses or model simulations. Here we examine the ability of two recent indices, the Genesis Potential and the Genesis Potential Index to reproduce observed North Atlantic cyclone annual frequency variations and trends. These skillfully estimate the mean seasonal variation of observed cyclones, but they struggle with reproducing interannual frequency variability and change. Examination of the independent contributions by the four terms that make up the indices finds that potential intensity and shear have significant skill, while moisture and vorticity either do not contribute or degrade the indices capacity to reproduce observed interannual variability. We also find that for assessing basin wide cyclone frequency, averaging indices over the whole basin is less skillful than its application to the general area off the coast of Africa broadly covering the Main Development Region (the MDR). These results point to a revised index, the Cyclone Genesis Index (CGI) comprised of only potential intensity and vertical shear. Application of the CGI averaged over the MDR demonstrates high and significant skill at reproducing interannual variations and trends in all-basin cyclones across both reanalyses. The CGI also provides a more accurate reproduction of seasonal variations than the original GP. Future work applying the CGI to other tropical cyclone basins and to the downscaling of relatively course climate simulations is briefly addressed. Article in Journal/Newspaper North Atlantic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Climate 25 24 8611 8626 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Large-scale environmental variables known to be linked to the formation of tropical cyclones, have previously been used to develop empirical indices as proxies for assessing cyclone frequency from large-scale analyses or model simulations. Here we examine the ability of two recent indices, the Genesis Potential and the Genesis Potential Index to reproduce observed North Atlantic cyclone annual frequency variations and trends. These skillfully estimate the mean seasonal variation of observed cyclones, but they struggle with reproducing interannual frequency variability and change. Examination of the independent contributions by the four terms that make up the indices finds that potential intensity and shear have significant skill, while moisture and vorticity either do not contribute or degrade the indices capacity to reproduce observed interannual variability. We also find that for assessing basin wide cyclone frequency, averaging indices over the whole basin is less skillful than its application to the general area off the coast of Africa broadly covering the Main Development Region (the MDR). These results point to a revised index, the Cyclone Genesis Index (CGI) comprised of only potential intensity and vertical shear. Application of the CGI averaged over the MDR demonstrates high and significant skill at reproducing interannual variations and trends in all-basin cyclones across both reanalyses. The CGI also provides a more accurate reproduction of seasonal variations than the original GP. Future work applying the CGI to other tropical cyclone basins and to the downscaling of relatively course climate simulations is briefly addressed. |
author2 |
Bruyere, Cindy (author) Holland, Gregory (author) Towler, Erin (author) |
format |
Article in Journal/Newspaper |
title |
Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin |
spellingShingle |
Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin |
title_short |
Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin |
title_full |
Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin |
title_fullStr |
Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin |
title_full_unstemmed |
Investigating the use of a Genesis potential index for tropical cyclones in the North Atlantic Basin |
title_sort |
investigating the use of a genesis potential index for tropical cyclones in the north atlantic basin |
publisher |
American Meteorological Society |
publishDate |
2012 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-334 https://doi.org/10.1175/JCLI-D-11-00619.1 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Journal of Climate http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-334 doi:10.1175/JCLI-D-11-00619.1 ark:/85065/d7bk1d3s |
op_rights |
Copyright 2012 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. |
op_doi |
https://doi.org/10.1175/JCLI-D-11-00619.1 |
container_title |
Journal of Climate |
container_volume |
25 |
container_issue |
24 |
container_start_page |
8611 |
op_container_end_page |
8626 |
_version_ |
1776202059722260480 |