Location: Guam, Western Pacific     Date: Jan-Feb     Flying hours: 145     Sondes: Nil

CAST - Co-ordinated Airborne Studies in the Tropics

The main focus of the programme is to study the chemical and physical properties of the tropical tropopause layer (TTL) and their impacts in controlling the composition of the UTLS (upper troposhpere, lower stratosphere). Specifically the research mission will focus on the Western Pacific Warm Pool region. In addition convective transport of very short and long-lived chemical species will be measured together with tropospheric moist convective dynamic processes in this important but data sparse region.

The research will be delivered in partnership with NASA through collaboration with the NASA Earth Venture ATTREX1 (Airborne Tropical Tropopause Experiment) mission deploying the NASA Global Hawk unmanned aerial vehicle (UAV). This project will be in support of the NERC programme “Observations and modelling of the tropical tropopause layer”.  We will also be working in collaboration with NCAR's CONTRAST (CONvective TRansport of Active Species in the Tropics) campaign using their GV aircraft.

Objectives

1. Plan and implement a coordinated measurement campaign involving the NASA Global Hawk, NCAR GV, the FAAM BAe146 and balloon-borne sondes in the Tropical Warm Pool region of the West Pacific
2. Measure VSL (very short lived) halocarbons in situ on the 146 along with 2 years of continuous VSL halocarbon measurements at Chuuk and an extension of the ground-based tropical VSL halocarbon measurement network

• Detachment Manager - Mo Smith, FAAM
• Logistics - Doug Anderson, FAAM
• Project Pilot - DFL, Project Ops - Peter Chappell, DFL
• PI  - Neil Harris, University of Cambridge