Autonomous Aircraft Observations and Analysis of Cross-equatorial Atmospheric Boundary Layer (ABL) Evolution during EPIC2001

Oregon State University, Corvallis OR

Investigators

Abstract

EPIC (Eastern Pacific Investigation of Climate processes in the coupled ocean-atmosphere system) is an activity of the US CLIVAR Program. EPIC 2001 consists of four components focussing on (i) intertropical convergence zone/warm pool phenomena; (ii) cross-equatorial inflow into the intertropical convergence zone; (iii) upper ocean structure and mixing and (iv) an exploratory study of boundary layer cloud properties in the southeasterly tradewind regime. The field phase of EPIC 2001 is scheduled for a 6-week period during the interval Sept 1 to Oct 15, 2001. In addition to the eight awards made by ATM, this collaborative research has awards made by NSF/OCE and NOAA/OGP. During the field phase, the PIs will collect data by small robotic aircraft called aerosondes. The aerosonde measurements will describe the evolution of the vertical structure of winds, temperature, relative humidity and pressure in the latitude-height cross sections from 5S to 5N. These data will make it possible to calculate and interpret budgets of mass, heat, water vapor and momentum in the cross equatorial flow, leading to better understanding of local air-sea interaction, boundary layer clouds, and large-scale dynamics in determining the evolution of cross equatorial atmospheric boundary layer structure. The work is important because it will improve understanding and modeling of climate variability over the eastern tropical Pacific.