The Convective Processes Experiment (CPEX) investigated convective processes and circulations over tropical waters in a field deployment from May 25-June 24, 2017 in the North Atlantic-Gulf of Mexico-Caribbean Oceanic region. CPEX answered questions about convective storm initiation, organization, growth, and dissipation in a variety of weather conditions. During CPEX, the capture of convective structure and storm winds using wind lidar and dual-frequency precipitation radar measurements was achieved for the first time. Additionally, scientists made groundbreaking observations during Tropical Storm Cindy of tropical storm development. A follow-up study, CPEX-AW, will study deep convection in the InterTropical Convergence Zone (ITCZ) and the dynamics and microphysics of the Saharan Air Layer, African Easterly Waves and Jets, and Tropical Easterly Jet.

The first science objective of CPEX was to improve the understanding of convective processes. These processes include cloud dynamics, downdrafts, cold pools and thermodynamics. In regards to this first objective, CPEX focused on exploring the contributing environmental factors involved in situations of rapid upscale growth of convective systems into large organized mesoscale convective systems. The second science objective of CPEX was to use a comprehensive suite of instrumentation to obtain and then evaluate simultaneous wind, temperature, and moisture profiles in all phases of the convective life cycle. The third science objective of CPEX was to improve the representation of convective and boundary layer processes in modeling. CPEX sought to create an atmosphere-ocean model that could simulate the life cycle of convective systems over tropical oceans.

The NASA DC-8 aircraft was the primary platform used in CPEX. The DC-8 was equipped with a suite of five instruments used to measure profiles for variables such as wind, temperature, and humidity. The Doppler Wind Lidar (DAWN) was used for wind retrievals, and the Doppler Radar (APR-2) was used for convective precipitation structure. Three microwave radiometers - the High Altitude MMIC (Monolithic Microwave Integrated Circuit) Sounding Radiometer (HAMSR), the Microwave Temperature and Humidity Profiler (MTHP), and the Microwave Atmospheric Sounder (MASC) - obtained measurements of temperature, water vapor, and the amount of liquid in the clouds. These microwave radiometers also collected thermodynamic profiles from beneath the DC-8. Additionally, the use of dropsondes allowed for the collection of thermodynamic wind profiles from beneath the aircraft.

CPEX Project Page