The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America
Different circulation types for southern South America are derived from the circulation anomaly maps at 500 hPa corresponding to a 9 year period. The series of daily maps was obtained from the ECWMF reanalysis. These data are particularly useful, since real data, especially the radiosonde network, a...
Main Authors: | , |
---|---|
Format: | Journal/Newspaper |
Language: | unknown |
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.12110/paper_08998418_v23_n5_p541_Bischoff |
id |
ftunibueairesbd:todo:paper_08998418_v23_n5_p541_Bischoff |
---|---|
record_format |
openpolar |
spelling |
ftunibueairesbd:todo:paper_08998418_v23_n5_p541_Bischoff 2023-10-29T02:40:09+01:00 The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America Bischoff, S.A. Vargas, W.M. https://hdl.handle.net/20.500.12110/paper_08998418_v23_n5_p541_Bischoff unknown http://hdl.handle.net/20.500.12110/paper_08998418_v23_n5_p541_Bischoff info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar Circulation patterns Climate variability El Niño-southern oscillation Southern South America Atmospherics Climatology Maps Troposphere Pattern classification technique Weather modification anomaly atmospheric circulation climate variation El Nino-Southern Oscillation extreme event South America JOUR ftunibueairesbd https://doi.org/20.500.12110/paper_08998418_v23_n5_p541_Bischoff 2023-10-05T01:58:40Z Different circulation types for southern South America are derived from the circulation anomaly maps at 500 hPa corresponding to a 9 year period. The series of daily maps was obtained from the ECWMF reanalysis. These data are particularly useful, since real data, especially the radiosonde network, are sparse in this region. The properties to be studied are selected in such a way that they describe different flow conditions over the region, in order to obtain a statistical diagnosis useful for modelling an objective forecast. The circulation types were obtained by a correlation-map-based pattern classification technique. Lund's method is used in this paper to identify the most frequent circulation patterns. The classification method was applied to daily Z anomalies at 500 hPa over the whole record (1980-88). This allows one to analyse the evolution and presence of a particular type over different months and years. The most outstanding circulation-type structures, represented by only eight types, explain about 63% of the total number of cases in the sample. The most frequent type, Type 1 (Z), shows an almost zonal circulation with a strong meridional gradient, associated with a trough in the west of the region. Type 2 (LCE) is represented by a low-pressure system in the centre of the region (approximately at 37°S, 65°W). In general, this type is related to the occurrence of blocking situations in the South Atlantic Ocean and the passage of cold fronts over the region. Types 3 (SW) and 4 (WNW) show a SW and WNW atmospheric circulation over the whole region with a meridional gradient lower than in Type 1. Type 5 (TNS) shows an NW - SE trough axis over the continent. Type 6 (WW) has an intense SW flow over the southern part of the continent. Type 7 (NW) shows a very deep trough to the west of the continent, located over the Pacific Ocean at 80°W and 34°S. The continent is affected by a NW atmospheric circulation. Type 8 (R) represents a ridge over the continent with an intense NW flow in the south. The frequency of ... Journal/Newspaper South Atlantic Ocean Biblioteca Digital FCEN-UBA (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires) |
institution |
Open Polar |
collection |
Biblioteca Digital FCEN-UBA (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires) |
op_collection_id |
ftunibueairesbd |
language |
unknown |
topic |
Circulation patterns Climate variability El Niño-southern oscillation Southern South America Atmospherics Climatology Maps Troposphere Pattern classification technique Weather modification anomaly atmospheric circulation climate variation El Nino-Southern Oscillation extreme event South America |
spellingShingle |
Circulation patterns Climate variability El Niño-southern oscillation Southern South America Atmospherics Climatology Maps Troposphere Pattern classification technique Weather modification anomaly atmospheric circulation climate variation El Nino-Southern Oscillation extreme event South America Bischoff, S.A. Vargas, W.M. The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America |
topic_facet |
Circulation patterns Climate variability El Niño-southern oscillation Southern South America Atmospherics Climatology Maps Troposphere Pattern classification technique Weather modification anomaly atmospheric circulation climate variation El Nino-Southern Oscillation extreme event South America |
description |
Different circulation types for southern South America are derived from the circulation anomaly maps at 500 hPa corresponding to a 9 year period. The series of daily maps was obtained from the ECWMF reanalysis. These data are particularly useful, since real data, especially the radiosonde network, are sparse in this region. The properties to be studied are selected in such a way that they describe different flow conditions over the region, in order to obtain a statistical diagnosis useful for modelling an objective forecast. The circulation types were obtained by a correlation-map-based pattern classification technique. Lund's method is used in this paper to identify the most frequent circulation patterns. The classification method was applied to daily Z anomalies at 500 hPa over the whole record (1980-88). This allows one to analyse the evolution and presence of a particular type over different months and years. The most outstanding circulation-type structures, represented by only eight types, explain about 63% of the total number of cases in the sample. The most frequent type, Type 1 (Z), shows an almost zonal circulation with a strong meridional gradient, associated with a trough in the west of the region. Type 2 (LCE) is represented by a low-pressure system in the centre of the region (approximately at 37°S, 65°W). In general, this type is related to the occurrence of blocking situations in the South Atlantic Ocean and the passage of cold fronts over the region. Types 3 (SW) and 4 (WNW) show a SW and WNW atmospheric circulation over the whole region with a meridional gradient lower than in Type 1. Type 5 (TNS) shows an NW - SE trough axis over the continent. Type 6 (WW) has an intense SW flow over the southern part of the continent. Type 7 (NW) shows a very deep trough to the west of the continent, located over the Pacific Ocean at 80°W and 34°S. The continent is affected by a NW atmospheric circulation. Type 8 (R) represents a ridge over the continent with an intense NW flow in the south. The frequency of ... |
format |
Journal/Newspaper |
author |
Bischoff, S.A. Vargas, W.M. |
author_facet |
Bischoff, S.A. Vargas, W.M. |
author_sort |
Bischoff, S.A. |
title |
The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America |
title_short |
The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America |
title_full |
The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America |
title_fullStr |
The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America |
title_full_unstemmed |
The 500 and 1000 hPa weather circulations and their relationship with some extreme climatic conditions over southern South America |
title_sort |
500 and 1000 hpa weather circulations and their relationship with some extreme climatic conditions over southern south america |
url |
https://hdl.handle.net/20.500.12110/paper_08998418_v23_n5_p541_Bischoff |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_relation |
http://hdl.handle.net/20.500.12110/paper_08998418_v23_n5_p541_Bischoff |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar |
op_doi |
https://doi.org/20.500.12110/paper_08998418_v23_n5_p541_Bischoff |
_version_ |
1781068053893611520 |