Terrestrial versus Oceanic Source of Water Vapor for Monsoon Convection: A New Look at an Old Problem

David Adams, Professor Universidad Nacional Autónoma de México

Abstract for Weekly Colloquium on Thursday, March 9, 2017 at 4 pm in Harshbarger 206 ~ Refreshments at 3:45 pm

Debate on water sources, oceanic versus terrestrial, for North American Monsoon convective precipitation has been reopened.  This debate is far from academic as it has implications for quantifying the importance of land-surface/atmosphere interactions (e.g., moisture recycling) and atmospheric thermodynamic controls on deep convective activity, specifically water vapor “quantity” (i.e. precipitable or column water vapor) versus “quality” (i.e., the vertical profile of water vapor) in deep convective tropical regimes. I´ll briefly review this moisture source debate and put it in a larger context, particularly focusing on our water vapor/deep convection interactions studies in the Amazon and the North American Monsoon.

I´ll wrap up the talk with an overview of the GPS Hydrometeorological Network for northwestern Mexico, a result of the UC MEXUS collaborative project between nine Mexican and U.S. institutions, including the UA.  The Network will consist of 3 eddy-covariance flux towers (a triangular array, 30km separation distance), soil moisture measures, radiosonde launches, all collocated with 3 GPS meteorological stations.  This mesoscale flux network will be contained within a larger scale array of ~10 GPS meteorological sites across northwest Mexico. We will attempt to identify dominant Monsoon moisture sources, quantify surface/vegetation influence on convective activity and attempt to “close”  the local hydrological cycle on the mesoscale.