Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America
Surface winds along the subtropical west coast of South America are characterized by the quasi-weekly occurrences of low-level jet events. These short lived but intense wind events impact the coastal ocean environment. Hence, identifying long-term trends in the coastal low-level jet (CLLJ) is essent...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-04-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/12/4/465 |
| _version_ | 1797538454367633408 |
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| author | Catalina Aguirre Valentina Flores-Aqueveque Pablo Vilches Alicia Vásquez José A. Rutllant René Garreaud |
| author_facet | Catalina Aguirre Valentina Flores-Aqueveque Pablo Vilches Alicia Vásquez José A. Rutllant René Garreaud |
| author_sort | Catalina Aguirre |
| collection | DOAJ |
| description | Surface winds along the subtropical west coast of South America are characterized by the quasi-weekly occurrences of low-level jet events. These short lived but intense wind events impact the coastal ocean environment. Hence, identifying long-term trends in the coastal low-level jet (CLLJ) is essential for understanding changes in marine ecosystems. Here we use ERA5 reanalysis (1979–2019) and an objective algorithm to track anticyclones to investigate recent changes in CLLJ events off central Chile (25–43 °S). Results present evidence that the number of days with intense wind (≥10 ms<sup>−1</sup>), and the number and duration of CLLJ events have significantly changed off central Chile in recent decades. There is an increase in the number of CLLJ events in the whole study area during winter (June-July-August; JJA), while during summer (December–January–February; DJF) a decrease is observed at lower latitudes (29–34 °S), and an increase is found at the southern boundary of the Humboldt system. We suggest that changes in the central pressures and frequency of extratropical, migratory anticyclones that reach the coast of South America, which force CLLJs, have played an important role in the recent CLLJ changes observed in this region. |
| first_indexed | 2024-03-10T12:31:39Z |
| format | Article |
| id | doaj.art-2740a6d4d49e4e258a1cc6cf1397cdb5 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T12:31:39Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-2740a6d4d49e4e258a1cc6cf1397cdb52023-11-21T14:37:02ZengMDPI AGAtmosphere2073-44332021-04-0112446510.3390/atmos12040465Recent Changes in the Low-Level Jet along the Subtropical West Coast of South AmericaCatalina Aguirre0Valentina Flores-Aqueveque1Pablo Vilches2Alicia Vásquez3José A. Rutllant4René Garreaud5Center for Climate and Resilience Research (CR)2, Santiago 8320000, ChileDepartamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8320000, ChileEscuela de Ingeniería Civil Oceánica, Facultad de Ingeniería, Universidad de Valparaíso, Valparaíso 2340000, ChileDepartamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8320000, ChileMillennium Nucleus Understanding Past Coastal Upwelling Systems and Environmental Local and Lasting Impacts (UPWELL), Agencia Nacional de Investigación y Desarrollo (ANID) Millennium Science Initiative, Coquimbo 1780000, ChileCenter for Climate and Resilience Research (CR)2, Santiago 8320000, ChileSurface winds along the subtropical west coast of South America are characterized by the quasi-weekly occurrences of low-level jet events. These short lived but intense wind events impact the coastal ocean environment. Hence, identifying long-term trends in the coastal low-level jet (CLLJ) is essential for understanding changes in marine ecosystems. Here we use ERA5 reanalysis (1979–2019) and an objective algorithm to track anticyclones to investigate recent changes in CLLJ events off central Chile (25–43 °S). Results present evidence that the number of days with intense wind (≥10 ms<sup>−1</sup>), and the number and duration of CLLJ events have significantly changed off central Chile in recent decades. There is an increase in the number of CLLJ events in the whole study area during winter (June-July-August; JJA), while during summer (December–January–February; DJF) a decrease is observed at lower latitudes (29–34 °S), and an increase is found at the southern boundary of the Humboldt system. We suggest that changes in the central pressures and frequency of extratropical, migratory anticyclones that reach the coast of South America, which force CLLJs, have played an important role in the recent CLLJ changes observed in this region.https://www.mdpi.com/2073-4433/12/4/465coastal windscoastal low-level jetupwelling favorable wind eventsHumboldt upwelling systemERA5 reanalysis |
| spellingShingle | Catalina Aguirre Valentina Flores-Aqueveque Pablo Vilches Alicia Vásquez José A. Rutllant René Garreaud Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America Atmosphere coastal winds coastal low-level jet upwelling favorable wind events Humboldt upwelling system ERA5 reanalysis |
| title | Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America |
| title_full | Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America |
| title_fullStr | Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America |
| title_full_unstemmed | Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America |
| title_short | Recent Changes in the Low-Level Jet along the Subtropical West Coast of South America |
| title_sort | recent changes in the low level jet along the subtropical west coast of south america |
| topic | coastal winds coastal low-level jet upwelling favorable wind events Humboldt upwelling system ERA5 reanalysis |
| url | https://www.mdpi.com/2073-4433/12/4/465 |
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