Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model*
An atmospheric GCM coupled to a slab ocean model is used to investigate how temperature and precipitation over South America and Africa affect the annual cycle of the Atlantic ITCZ. The main conclusion of this study is that variations in precipitation and temperature forced by the annual cycle of in...
Main Authors: | , , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
2003
|
Subjects: | |
Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.6442 http://www.atmos.washington.edu/~david/terrestrial.pdf |
id |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.582.6442 |
---|---|
record_format |
openpolar |
spelling |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.582.6442 2023-05-15T17:31:06+02:00 Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* M. Biasutti D. S. Battisti E. S. Sarachik The Pennsylvania State University CiteSeerX Archives 2003 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.6442 http://www.atmos.washington.edu/~david/terrestrial.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.6442 http://www.atmos.washington.edu/~david/terrestrial.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.atmos.washington.edu/~david/terrestrial.pdf text 2003 ftciteseerx 2016-08-28T00:03:16Z An atmospheric GCM coupled to a slab ocean model is used to investigate how temperature and precipitation over South America and Africa affect the annual cycle of the Atlantic ITCZ. The main conclusion of this study is that variations in precipitation and temperature forced by the annual cycle of insolation over the continents are as important as variations in insolation over the ocean and in ocean heat transport convergence in forcing the annual march of the Atlantic ITCZ observed in the control simulation. The processes involved are as follows. The intensity of precipitation over land affects the stability of the atmosphere over the tropical Atlantic Ocean, and thus modulates the intensity of deep convection and convergence in the ITCZ. Both the imposed changes in land precipitation and the subsequent changes in the strength of the ITCZ drive surface wind anomalies, thereby changing the meridional gradient of SST in proximity of the basic-state ITCZ. Finally, atmosphere–ocean feedbacks cause the ITCZ to be displaced meridionally. Seasonal changes in surface temperature in the Sahara also have a strong influence on the position of the Atlantic ITCZ. Cold wintertime temperatures produce high surface pressure anomalies over Africa and into the tropical North Atlantic and drive stronger trade winds, which cool the North Atlantic by evaporation. The coupled interactions between the SST, the wind, and the ITCZ intensify the anomalies in the equatorial region, causing the southward displacement of the ITCZ in boreal spring. 1. Text North Atlantic Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
description |
An atmospheric GCM coupled to a slab ocean model is used to investigate how temperature and precipitation over South America and Africa affect the annual cycle of the Atlantic ITCZ. The main conclusion of this study is that variations in precipitation and temperature forced by the annual cycle of insolation over the continents are as important as variations in insolation over the ocean and in ocean heat transport convergence in forcing the annual march of the Atlantic ITCZ observed in the control simulation. The processes involved are as follows. The intensity of precipitation over land affects the stability of the atmosphere over the tropical Atlantic Ocean, and thus modulates the intensity of deep convection and convergence in the ITCZ. Both the imposed changes in land precipitation and the subsequent changes in the strength of the ITCZ drive surface wind anomalies, thereby changing the meridional gradient of SST in proximity of the basic-state ITCZ. Finally, atmosphere–ocean feedbacks cause the ITCZ to be displaced meridionally. Seasonal changes in surface temperature in the Sahara also have a strong influence on the position of the Atlantic ITCZ. Cold wintertime temperatures produce high surface pressure anomalies over Africa and into the tropical North Atlantic and drive stronger trade winds, which cool the North Atlantic by evaporation. The coupled interactions between the SST, the wind, and the ITCZ intensify the anomalies in the equatorial region, causing the southward displacement of the ITCZ in boreal spring. 1. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
M. Biasutti D. S. Battisti E. S. Sarachik |
spellingShingle |
M. Biasutti D. S. Battisti E. S. Sarachik Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* |
author_facet |
M. Biasutti D. S. Battisti E. S. Sarachik |
author_sort |
M. Biasutti |
title |
Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* |
title_short |
Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* |
title_full |
Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* |
title_fullStr |
Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* |
title_full_unstemmed |
Terrestrial Influence on the Annual Cycle of the Atlantic ITCZ in an AGCM Coupled to a Slab Ocean Model* |
title_sort |
terrestrial influence on the annual cycle of the atlantic itcz in an agcm coupled to a slab ocean model* |
publishDate |
2003 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.6442 http://www.atmos.washington.edu/~david/terrestrial.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
http://www.atmos.washington.edu/~david/terrestrial.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.582.6442 http://www.atmos.washington.edu/~david/terrestrial.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766128412612624384 |