A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean
International audience A 15-year (1999-2014) homogeneous database from RSMC La Reunion is employed to examine the large-scale characteristics of rapidly intensifying tropical cyclones over the southwest Indian Ocean. To allow for basin inter-comparisons we followed the methodology used by Kaplan and...
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ftmeteofrance:oai:HAL:hal-01290128v1 2024-09-15T18:24:20+00:00 A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean Leroux, Marie-Dominique Meister, Julien Mékies, Dominique Bousquet, Olivier Laboratoire de l'Atmosphère et des Cyclones (LACy) Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France American Meteorological Society San Juan, Puerto Rico 2016-04-17 https://hal.science/hal-01290128 https://hal.science/hal-01290128/document https://hal.science/hal-01290128/file/LEROUX_poster_AMS32_2016.pdf en eng HAL CCSD hal-01290128 https://hal.science/hal-01290128 https://hal.science/hal-01290128/document https://hal.science/hal-01290128/file/LEROUX_poster_AMS32_2016.pdf info:eu-repo/semantics/OpenAccess 32nd Conference on Hurricanes and Tropical Meteorology https://hal.science/hal-01290128 32nd Conference on Hurricanes and Tropical Meteorology, Apr 2016, San Juan, Puerto Rico. , 2016 https://www2.ametsoc.org/ams/index.cfm/meetings-events/ams-meetings/32nd-conference-on-hurricanes-and-tropical-meteorology/ climatology tropical cyclones south-west Indian Ocean rapid intensification rapid decay midget MPI [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] info:eu-repo/semantics/conferenceObject Conference poster 2016 ftmeteofrance 2024-06-25T00:21:55Z International audience A 15-year (1999-2014) homogeneous database from RSMC La Reunion is employed to examine the large-scale characteristics of rapidly intensifying tropical cyclones over the southwest Indian Ocean. To allow for basin inter-comparisons we followed the methodology used by Kaplan and DeMaria (2003; 2010) for Atlantic systems. Rapid intensification (RI) for oceanic tropical systems is statistically defined as a 24-hour intensity change of the maximum surface winds exceeding 15.4 m s-1 (94.4th percentile of the ΔV24 distribution). This is equivalent to the 30-kt official threshold determined for the North Atlantic basin (94th percentile) using 1 min sustained winds, whereas the present study uses WMO standard 10 min average winds. It is shown that 39% of all the 151 tropical systems, 12% that reached the tropical storm stage (34 kts), 73% that reached the tropical cyclone stage (64kts), and all the very intense tropical cyclones (115 kts) underwent RI at least once during their lifetimes. Interestingly, the RI probability distribution as a function of storm initial wind is bimodal with two peaks in the 40-55 kts and 60-75 kts ranges.To better understand and ultimately predict RI, the ERA-Interim dataset is used to determine the large-scale dynamic and thermodynamic conditions that are conducive for RI. Six environmental parameters averaged along the storm track during the 24-h period following the beginning of RI are identified as potential RI predictors. For each of them, statistically significant differences are found between the mean values of the RI and non-RI samples at the 99.9% level using a two-sided t test. RI predictors are, in decreasing order of importance: TC intensification during the previous 12h (DVMXM12), a high upper-level divergence (DIV200), a weak 850-200-hPa vertical wind shear (SHR), a high sea surface temperature in a 200-km radius surrounding the storm center (SST), a weak upper-level cyclonic potential vorticity (on the 350-K isentrope, PV350).A statistical-dynamical ... Conference Object North Atlantic Météo-France: HAL |
institution |
Open Polar |
collection |
Météo-France: HAL |
op_collection_id |
ftmeteofrance |
language |
English |
topic |
climatology tropical cyclones south-west Indian Ocean rapid intensification rapid decay midget MPI [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] |
spellingShingle |
climatology tropical cyclones south-west Indian Ocean rapid intensification rapid decay midget MPI [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] Leroux, Marie-Dominique Meister, Julien Mékies, Dominique Bousquet, Olivier A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean |
topic_facet |
climatology tropical cyclones south-west Indian Ocean rapid intensification rapid decay midget MPI [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] |
description |
International audience A 15-year (1999-2014) homogeneous database from RSMC La Reunion is employed to examine the large-scale characteristics of rapidly intensifying tropical cyclones over the southwest Indian Ocean. To allow for basin inter-comparisons we followed the methodology used by Kaplan and DeMaria (2003; 2010) for Atlantic systems. Rapid intensification (RI) for oceanic tropical systems is statistically defined as a 24-hour intensity change of the maximum surface winds exceeding 15.4 m s-1 (94.4th percentile of the ΔV24 distribution). This is equivalent to the 30-kt official threshold determined for the North Atlantic basin (94th percentile) using 1 min sustained winds, whereas the present study uses WMO standard 10 min average winds. It is shown that 39% of all the 151 tropical systems, 12% that reached the tropical storm stage (34 kts), 73% that reached the tropical cyclone stage (64kts), and all the very intense tropical cyclones (115 kts) underwent RI at least once during their lifetimes. Interestingly, the RI probability distribution as a function of storm initial wind is bimodal with two peaks in the 40-55 kts and 60-75 kts ranges.To better understand and ultimately predict RI, the ERA-Interim dataset is used to determine the large-scale dynamic and thermodynamic conditions that are conducive for RI. Six environmental parameters averaged along the storm track during the 24-h period following the beginning of RI are identified as potential RI predictors. For each of them, statistically significant differences are found between the mean values of the RI and non-RI samples at the 99.9% level using a two-sided t test. RI predictors are, in decreasing order of importance: TC intensification during the previous 12h (DVMXM12), a high upper-level divergence (DIV200), a weak 850-200-hPa vertical wind shear (SHR), a high sea surface temperature in a 200-km radius surrounding the storm center (SST), a weak upper-level cyclonic potential vorticity (on the 350-K isentrope, PV350).A statistical-dynamical ... |
author2 |
Laboratoire de l'Atmosphère et des Cyclones (LACy) Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France American Meteorological Society |
format |
Conference Object |
author |
Leroux, Marie-Dominique Meister, Julien Mékies, Dominique Bousquet, Olivier |
author_facet |
Leroux, Marie-Dominique Meister, Julien Mékies, Dominique Bousquet, Olivier |
author_sort |
Leroux, Marie-Dominique |
title |
A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean |
title_short |
A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean |
title_full |
A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean |
title_fullStr |
A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean |
title_full_unstemmed |
A Climatology of Rapidly Intensifying Tropical Systems over the Southwest Indian Ocean |
title_sort |
climatology of rapidly intensifying tropical systems over the southwest indian ocean |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://hal.science/hal-01290128 https://hal.science/hal-01290128/document https://hal.science/hal-01290128/file/LEROUX_poster_AMS32_2016.pdf |
op_coverage |
San Juan, Puerto Rico |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
32nd Conference on Hurricanes and Tropical Meteorology https://hal.science/hal-01290128 32nd Conference on Hurricanes and Tropical Meteorology, Apr 2016, San Juan, Puerto Rico. , 2016 https://www2.ametsoc.org/ams/index.cfm/meetings-events/ams-meetings/32nd-conference-on-hurricanes-and-tropical-meteorology/ |
op_relation |
hal-01290128 https://hal.science/hal-01290128 https://hal.science/hal-01290128/document https://hal.science/hal-01290128/file/LEROUX_poster_AMS32_2016.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1810464675581657088 |