Connection between the Tropical Pacific and Indian Ocean and Temperature Anomaly across West Antarctic

Abstract West Antarctic and the Antarctic Peninsula have experienced dramatic warming in austral spring since the 1970s. Using observations and the Community Atmosphere Model version 4 (CAM4), this study explores the physical mechanism by which the tropical Pacific and Indian Ocean temperature anoma...

Full description

Bibliographic Details
Published in:npj Climate and Atmospheric Science
Main Authors: Ping Zhang, Anmin Duan
Format: Article in Journal/Newspaper
Language:English
Published: Nature Portfolio 2023
Subjects:
Environmental sciences
GE1-350
Meteorology. Climatology
QC851-999
Amundsen Sea
Antarctic
Antarctic Peninsula
Austral
Indian
Pacific
The Antarctic
Weddell
Weddell Sea
Antarc*
Online Access:https://doi.org/10.1038/s41612-023-00381-8
https://doaj.org/article/a3788e10733942e882b6587daafd4ce6
Description
Summary:Abstract West Antarctic and the Antarctic Peninsula have experienced dramatic warming in austral spring since the 1970s. Using observations and the Community Atmosphere Model version 4 (CAM4), this study explores the physical mechanism by which the tropical Pacific and Indian Ocean temperature anomaly mode (PIM) affects the dipolar surface air temperature (SAT) anomalies across the West Antarctic in austral spring. The positive phase of the PIM, characterized by positive sea surface temperature anomalies (SSTAs) in the tropical central-eastern Pacific and western Indian Ocean and negative SSTAs in the Maritime Continent, can generate two branches of stationary Rossby wave trains propagating from the tropical central Pacific and southeastern Indian Ocean to the West Antarctic, with an anticyclonic anomaly appearing over the Amundsen Sea. The northerlies advect warmer air to the Ross–Amundsen Seas, but southerlies advect colder air to the Antarctic Peninsula–Weddell Sea, resulting in the dipole of SAT anomalies over the West Antarctic. In this process, the role of tropical central-eastern Pacific SSTAs dominate, and it is amplified by the SSTAs around the Maritime Continent. The SSTAs in the western Indian Ocean combined with the SSTAs over the Maritime Continent further contribute to the western pole of the SAT. Only simulation that includes a prescribed PIM forcing can exactly reproduce the observations of the dipolar SAT response across the West Antarctic, indicating the need to treat the tropical Pacific and Indian Oceans as a unified whole.

Similar Items