Year: 2010
Type: article
Abstract: Recent paleoclimate proxy reconstructions show that tropical surface temperatures may have been as high as 35°–40°C in the Early Cenozoic. Here, we study the tropical atmospheric circulation's response to temperatures in this range using a full‐complexity atmospheric general circulation model (AGCM). We find that when equatorial surface temperatures exceed ∼33°C, the model undergoes a transition to equatorial superrotation, a state with strong annual‐ and zonal‐mean westerlies on the equator. The transition is driven by zonal momentum convergence due to large‐amplitude transient eddies on the equator. These eddies have a structure similar to the observed Madden‐Julian Oscillation (MJO). The model's MJO variability is weaker than observed when simulating the modern climate but increases sharply with temperature, coming to dominate the tropical variability and mean state of the warmest climates.
Source: Geophysical Research Letters
DOI: 10.1029/2010gl043468
Authors: Rodrigo Caballero, Matthew Huber
Institutions: University College Dublin, Purdue University West Lafayette
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: bronze
OpenAlex ID: W1885197434