Effect of the Late-1990s Change in Tropical Forcing on Teleconnections to the Amundsen–Bellingshausen Seas Region during Austral AutumnSource: Journal of Climate:;2022:;volume( 035 ):;issue: 017::page 5687DOI: 10.1175/JCLI-D-21-0965.1Publisher: American Meteorological Society
Abstract: Tropical sea surface temperature (SST) and associated precipitation, acting as diabatic heat forcing, has far-reaching climatic impacts across the globe through exciting poleward-propagating Rossby waves. It is found that the leading mode of tropical Pacific forcing in austral autumn experiences a significant interdecadal shift from an eastern Pacific (EP) to a central Pacific (CP) type around the late 1990s. More specifically, the EP-type precipitation anomaly mode before 1998 drives a quadrupole-like teleconnection pathway emanating from the tropical Pacific to the Ross Sea and Amundsen–Bellingshausen Seas (ABS) region, whereas the CP-type mode after 1999 excites a Pacific–South American (PSA)-like teleconnection orienting along a great circle. Divergent flows induced by different precipitation anomaly modes primarily determine the generation of Rossby waves by means of the vortex stretching and vorticity advection processes. Furthermore, the synoptic high-frequency transient eddy activity along with its dynamic forcing effect differs greatly before and after 1998/99, contributing to different locations of the teleconnection lobes at mid- to high latitudes. In contrast, the subseasonal low-frequency transient eddy activity exerts a limited influence. Our findings also indicate that the EP-type (CP-type) tropical forcing mode could significantly modulate the zonal displacement (strength) of the Amundsen Sea low, which could lead to distinct climate responses of West Antarctica and the Antarctic Peninsula in austral autumn.
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contributor author | Yuanyuan Guo | |
contributor author | Zhiping Wen | |
contributor author | Yu Zhu | |
contributor author | Xiaodan Chen | |
date accessioned | 2023-04-12T18:45:27Z | |
date available | 2023-04-12T18:45:27Z | |
date copyright | 2022/09/01 | |
date issued | 2022 | |
identifier other | JCLI-D-21-0965.1.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4290193 | |
description abstract | Tropical sea surface temperature (SST) and associated precipitation, acting as diabatic heat forcing, has far-reaching climatic impacts across the globe through exciting poleward-propagating Rossby waves. It is found that the leading mode of tropical Pacific forcing in austral autumn experiences a significant interdecadal shift from an eastern Pacific (EP) to a central Pacific (CP) type around the late 1990s. More specifically, the EP-type precipitation anomaly mode before 1998 drives a quadrupole-like teleconnection pathway emanating from the tropical Pacific to the Ross Sea and Amundsen–Bellingshausen Seas (ABS) region, whereas the CP-type mode after 1999 excites a Pacific–South American (PSA)-like teleconnection orienting along a great circle. Divergent flows induced by different precipitation anomaly modes primarily determine the generation of Rossby waves by means of the vortex stretching and vorticity advection processes. Furthermore, the synoptic high-frequency transient eddy activity along with its dynamic forcing effect differs greatly before and after 1998/99, contributing to different locations of the teleconnection lobes at mid- to high latitudes. In contrast, the subseasonal low-frequency transient eddy activity exerts a limited influence. Our findings also indicate that the EP-type (CP-type) tropical forcing mode could significantly modulate the zonal displacement (strength) of the Amundsen Sea low, which could lead to distinct climate responses of West Antarctica and the Antarctic Peninsula in austral autumn. | |
publisher | American Meteorological Society | |
title | Effect of the Late-1990s Change in Tropical Forcing on Teleconnections to the Amundsen–Bellingshausen Seas Region during Austral Autumn | |
type | Journal Paper | |
journal volume | 35 | |
journal issue | 17 | |
journal title | Journal of Climate | |
identifier doi | 10.1175/JCLI-D-21-0965.1 | |
journal fristpage | 5687 | |
journal lastpage | 5702 | |
page | 5687–5702 | |
tree | Journal of Climate:;2022:;volume( 035 ):;issue: 017 | |
contenttype | Fulltext |