Assessing and Understanding Extratropical Control on Tropical Climate

Ohio State University, The, Columbus OH

Investigators

Abstract

It has long been recognized that tropical climate and variability can be affected by climate processes in the extratropics. Previous studies on the extratropical impact on the tropics have remained largely qualitative in nature and from the fully coupled ocean-atmosphere perspective. As such, the impact of extratropical climate on tropical climate has remained largely unexplored. The goal of this project is to investigate the extratropical impact on tropical climate with the focus on quantifying extratropical influences of tropical climate and its variability. The project will use a novel modeling approach called Regional Coupled Data Assimilation (RCDA) approach, which combines coupled data assimilation with coupled climate dynamics, to assess and understand the extratropical climate impact on tropical climate for the real world. In RCDA, observations in the extratropics are assimilated in climate models while the tropical ocean-atmosphere processes remain fully coupled. This allows the quantitative assessment and understanding of the extratropical impacts on both tropical climatology and tropical climate variability, such as ENSO. The research team will also explore the extratropical impact on the tropical bias in coupled general circulation models. The funded research represents a systematic study of the extratropical impact on tropical climate and tropical climate variability that combines coupled data assimilation with coupled climate dynamics. This work will develop a new modeling strategy to assess and understand the impact of extratropical climate variability on tropical climatology and climate variability. This understanding will help further improve climate models for climate predictions, future climate projections, and, in turn, their societal impacts. This project will train two graduate students.