scholarly journals The Influence of the Atlantic Multidecadal Oscillation on the Choco Low-Level Jet and Precipitation in Colombia

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 174 ◽  
Author(s):  
Wilmar Loaiza Cerón ◽  
Rita Valeria Andreoli ◽  
Mary Toshie Kayano ◽  
Rodrigo Augusto Ferreira de Souza ◽  
Charles Jones ◽  
...  
Keyword(s):  
North Atlantic ◽  
Atlantic Multidecadal Oscillation ◽  
Sea Surface ◽  
Tropical Pacific Ocean ◽  
Sea Level Pressure ◽  
Low Level ◽  
Tropical North Atlantic ◽  
Low Level Jet ◽  
The Caribbean ◽  
The Tropical Pacific

This study examines the influence of the Atlantic Multidecadal Oscillation (AMO) on the Choco Low-level Jet (CJ) variations during the 1983–2016 period. Considering the September–November (SON) 925 hPa zonal wind index in the CJ core, a significant breakpoint occurs in 1997 with larger values after 1997. The changes in the CJ and Caribbean Low-Level Jet (CLLJ), and their related ocean-atmospheric patterns and impacts on precipitation over Colombia were analyzed considering separately the 1983–1996 and 1998–2016 periods, which overlap the cold and warm AMO phases, respectively. During the 1998–2016 period, the negative sea surface temperature (SST) anomalies in the tropical Pacific Ocean and the positive ones in the Caribbean Sea and Tropical North Atlantic (TNA) strengthen the CJ and weaken the CLLJ, and moisture is transported into Central and Western Colombia increasing the rainfall there. Our results indicate that part of the CJ strengthening after 1997 was due to a higher percentage of intense CJ events coinciding with La Niña events during the warm AMO and cold Pacific Decadal Oscillation (PDO) background. However, the AMO-related SST and sea level pressure (SLP) variations in the TNA seem to be more crucial in modulating the CJ and CLLJ intensities, such that CJ is weakened (intensified) and CLLJ is intensified (weakened) before (after) 1997. As far as we know, the relations of the CJ and CLLJ intensities to the AMO phases were not examined before and might be useful for modeling studies.

scholarly journals The role of the meridional sea surface temperature gradient in controlling the Caribbean low‐level jet

2017 ◽  
Vol 122 (11) ◽  
pp. 5903-5916 ◽  
Author(s):  
Tito Maldonado ◽  
Anna Rutgersson ◽  
Rodrigo Caballero ◽  
Francesco S. R. Pausata ◽  
Eric Alfaro ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Low Level ◽  
Sea Surface Temperature Gradient ◽  
Low Level Jet ◽  
The Caribbean ◽  
Surface Temperature Gradient

scholarly journals Frequency- or amplitude-dependent effects of the Atlantic meridional overturning on the tropical Pacific Ocean

Ocean Science ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 293-301 ◽  
Author(s):  
G. J. van Oldenborgh ◽  
L. A. te Raa ◽  
H. A. Dijkstra ◽  
S. Y. Philip
Keyword(s):  
Pacific Ocean ◽  
Southern Oscillation ◽  
Atlantic Multidecadal Oscillation ◽  
Meridional Overturning Circulation ◽  
Sea Surface ◽  
Tropical Pacific Ocean ◽  
The Pacific ◽  
Meridional Overturning ◽  
The Pacific Ocean ◽  
The Tropical Pacific

Abstract. Using the ECHAM5/MPI-OM model, we study the relation between the variations in the Atlantic meridional overturning circulation (AMOC) and both the Pacific sea surface temperature (SST) and the El Niño-Southern Oscillation (ENSO) amplitude. In a 17-member 20C3M/SRES-A1b ensemble for 1950–2100 the Pacific response to AMOC variations on different time scales and amplitudes is considered. The Pacific response to AMOC variations associated with the Atlantic Multidecadal Oscillation (AMO) is very small. In a 5-member hosing ensemble where the AMOC collapses due to a large freshwater anomaly, the Pacific SST response is large and in agreement with previous work. Our results show that the modelled connection between AMOC and ENSO depends very strongly on the frequency and/or the modelled amplitude of the AMOC variations. Interannual AMOC variations, decadal AMOC variations and an AMOC collapse lead to entirely different responses in the Pacific Ocean.

scholarly journals Frequency-dependent effects of the Atlantic meridional overturning on the tropical Pacific Ocean

2009 ◽  
Vol 6 (1) ◽  
pp. 477-490 ◽  
Author(s):  
L. A. te Raa ◽  
G. J. van Oldenborgh ◽  
H. A. Dijkstra ◽  
S. Y. Philip
Keyword(s):  
Pacific Ocean ◽  
Southern Oscillation ◽  
Atlantic Multidecadal Oscillation ◽  
Meridional Overturning Circulation ◽  
Sea Surface ◽  
Tropical Pacific Ocean ◽  
The Pacific ◽  
Meridional Overturning ◽  
The Pacific Ocean ◽  
The Tropical Pacific

Abstract. Using the ECHAM5/MPI-OM model, we study the relation between the variations in the Atlantic meridional overturning circulation (AMOC) and both the Pacific sea surface temperature (SST) and the El Niño-Southern Oscillation (ENSO) amplitude. In a 17-member 20C3M/SRES-A1b ensemble for 1950–2100 the Pacific response to AMOC variations on different time scales and amplitudes is considered. The Pacific response to AMOC variations associated with the Atlantic Multidecadal Oscillation (AMO) is very small. In a 5-member hosing ensemble where the AMOC collapses due to a large freshwater anomaly, the Pacific SST response is large and in agreement with previous work. Our results show that the modelled connection between AMOC and ENSO depends very strongly on the frequency and/or the amplitude of the AMOC variations. Interannual AMOC variations, decadal AMOC variations and an AMOC collapse lead to with entirely different responses in the Pacific Ocean.

Isolation of sea surface salinity maps on various timescales in the tropical Pacific Ocean

2012 ◽  
Vol 68 (5) ◽  
pp. 687-701 ◽  
Author(s):  
Jian Chen ◽  
Ren Zhang ◽  
Huizan Wang ◽  
Yuzhu An ◽  
Peng Peng ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Tropical Pacific Ocean ◽  
Surface Salinity ◽  
The Tropical Pacific

Influence of the Madden-Julian Oscillation on moisture transport by the Caribbean Low Level Jet during the Midsummer Drought in Mexico

2021 ◽  
Vol 248 ◽  
pp. 105243
Author(s):  
Juliet Perdigón-Morales ◽  
Rosario Romero-Centeno ◽  
Paulina Ordoñez ◽  
Raquel Nieto ◽  
Luis Gimeno ◽  
...  
Keyword(s):  
Moisture Transport ◽  
Madden Julian Oscillation ◽  
Low Level ◽  
Low Level Jet ◽  
The Caribbean

scholarly journals Impact of the Atlantic Warm Pool on the Summer Climate of the Western Hemisphere

2007 ◽  
Vol 20 (20) ◽  
pp. 5021-5040 ◽  
Author(s):  
Chunzai Wang ◽  
Sang-ki Lee ◽  
David B. Enfield
Keyword(s):  
North Atlantic ◽  
Moisture Transport ◽  
Caribbean Sea ◽  
Warm Pool ◽  
Western Hemisphere ◽  
Trade Winds ◽  
The North ◽  
Atlantic Warm Pool ◽  
Tropical North Atlantic ◽  
The Caribbean

Abstract The Atlantic warm pool (AWP) is a large body of warm water that comprises the Gulf of Mexico, the Caribbean Sea, and the western tropical North Atlantic. Located to its northeastern side is the North Atlantic subtropical high (NASH), which produces the tropical easterly trade winds. The easterly trade winds carry moisture from the tropical North Atlantic into the Caribbean Sea, where the flow intensifies, forming the Caribbean low-level jet (CLLJ). The CLLJ then splits into two branches: one turning northward and connecting with the Great Plains low-level jet (GPLLJ), and the other continuing westward across Central America into the eastern North Pacific. The easterly CLLJ and its westward moisture transport are maximized in the summer and winter, whereas they are minimized in the fall and spring. This semiannual feature results from the semiannual variation of sea level pressure in the Caribbean region owing to the westward extension and eastward retreat of the NASH. The NCAR Community Atmospheric Model and observational data are used to investigate the impact of the climatological annual mean AWP on the summer climate of the Western Hemisphere. Two groups of the model ensemble runs with and without the AWP are performed and compared. The model results show that the effect of the AWP is to weaken the summertime NASH, especially at its southwestern edge. The AWP also strengthens the summertime continental low over the North American monsoon region. In response to these pressure changes, the CLLJ and its moisture transport are weakened, but its semiannual feature does not disappear. The weakening of the easterly CLLJ increases (decreases) moisture convergence to its upstream (downstream) and thus enhances (suppresses) rainfall in the Caribbean Sea (in the far eastern Pacific west of Central America). Model runs show that the AWP’s effect is to always weaken the southerly GPLLJ. However, the AWP strengthens the GPLLJ’s northward moisture transport in the summer because the AWP-induced increase of specific humidity overcomes the weakening of southerly wind, and vice versa in the fall. Finally, the AWP reduces the tropospheric vertical wind shear in the main development region that favors hurricane formation and development during August–October.

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