VOCALS: The Dynamics and Modeling of Andes-induced Perturbations and Their Impact on Stratocumulus and Coastal Upwelling

University Corporation For Atmospheric Res, Boulder CO

Investigators

Abstract

This project focuses on the influence of the Andes cordillera on the regional-scale waves and circulations over the Southeast Pacific Ocean, and the interactions of these waves and circulations with the extensive stratocumulus cloud deck and the strong ocean upwelling along the South American coast. The excitation and characteristics of the diurnal subsidence wave in the atmosphere and its impact on the cloud deck as well as the low-level atmospheric jet off the coast of Chile will be investigated using observations from the VOCALS (i.e., VAMOS1 Ocean-Cloud-Atmosphere-Land Study) campaign and a hierarchy of numerical models including the Navy Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). One component of this project is an effort to deepen our understanding of the regional-scale atmospheric dynamics over the Southeast Pacific, using analytical tools, numerical models, and observational data from VOCALS. A second component will provide high-resolution, real-time forecasts to be used for planning field observations during the VOCALS campaign and will strive to improve the forecast skill of for surface winds and stratocumulus cloud cover through comparisons with VOCALS observations. The performance of COAMPS over the Southeast Pacific will be tested in advance of the VOCALS field campaign, and high-resolution forecasts will be provided to optimize observational strategies during the campaign. Subsequently the focus will shift to analyzing the VOCALS observations, using them for model validation, and carrying out in-depth theoretical studies of the regional circulation. The knowledge acquired from this project will be applicable to Earth's other poorly modeled and understood subtropical coastal regions. The modeling effort should lead to improved physical parameterizations and forecast skill for COAMPS, which is used for both operational forecasting and as a community research tool. Improved parameterization schemes will be tested in the widely used WRF (weather research and forecasting) model. Graduate and undergraduate students will participate in this research through an internship program at the Navy Research Laboratory.