Preliminary results from the COLPEX field campaign

The Cold Air Pooling (COLPEX) campaign, aimed at studying processes of cold air pooling in small valleys, came to a close in April 2010. The experiment consisted of an extended observation period from January 2009 to April 2010, punctuated by IOPs during cold pooling events precipitated by clear, calm night time conditions. A comprehensive dataset has been produced for an instrumented valley during this time including a broad range of surface-based atmospheric in-situ measurements using stationary and mobile (automobile) platforms, profile measurements using radiosondes (during IOPs), and a continuously operating Doppler LIDAR and webcam recording within the valley. The observations have been complemented by very high resolution (100 m) numerical simulations using the Met Office Unified Model, simulating the winter 2009-2010 period. Findings based on early analysis of this data will be presented, demonstrating characteristics of cold pools in modest sized valleys and the possibilities the dataset offers for studying the processes involved in their formation.