What Role Do Mountains Play in Shaping Mean and Extreme Hydroclimate? Lessons from a Tropical Cyclone-Permitting AOGCM
Atmospheric and Oceanic Sciences Departmental Seminar Series
presents
What Role Do Mountains Play in Shaping Mean and Extreme Hydroclimate? Lessons from a Tropical Cyclone-Permitting AOGCM
a talk by
Postdoctoral Research Scientist
Lamont-Doherty Earth Observatory, Ocean and Climate Physics
Columbia University, Earth Institute
A classic question in atmospheric dynamics is what role mountains play in shaping both local and remote climate. Some of the first studies performed with Global Climate Models (GCMs) by Syukuro Manabe and colleagues investigated this question, selectively flattening large-scale orographic features (such as the Tibetan Plateau) to investigate effects on the stationary wave pattern and monsoons. Since these early studies, GCMs have increased significantly in resolution and complexity, now allowing dynamic coupling between the atmosphere and ocean and simulating various climatic extremes with much higher fidelity. Here I revisit the effect of mountains on climate using the GFDL GCM CM2.5-FLOR, which is fully atmosphere-ocean coupled with a 50 km atmospheric/land resolution that permits the simulation of tropical cyclones. I explore the influence of three different orographic features on regional climate: 1) the Tian Shan mountains on the climatology of Asian extratropical deserts, 2) the Tibetan Plateau (and related orography) on the Western North Pacific, and 3) gaps in the topography of Central America on the tropical East Pacific. Previously unappreciated influences of these mountains on the climatology of precipitation and the spatial distribution of tropical cyclones will be demonstrated. Additionally, I will show that relatively small orographic features can have quite large climatic influences contingent on their placement relative to the larger-scale circulation.