Ship-borne Radar Observations of Organized Convection during the Field Campaign ORCESTRA

The ORganized Convection and Earthcare Studies over the TRopical Atlantic (ORCESTRA) field campaign will occur in the tropical Atlantic in August and September 2024. The overarching goal of ORCESTRA is to better understand the physical mechanisms that control organized tropical convection at the mesoscale, including its influence on the structure and dynamics of the ITCZ, its interaction with tropical waves and disturbances, and its impact on climate and Earth’s radiation budget. ORCESTRA is an international initiative that combines eight different sub-campaigns utilizing seven different ship, aircraft, ground-based, and satellite platforms.

Here we focus on preliminary results from PICCOLO (Process Investigation of Clouds and Convective Organization over the atLantic Ocean), the NSF-funded sub-campaign to deploy the SEA-POL radar on the RV Meteor in coordination with the BOW-TIE ship campaign. SEA-POL is a ship-stabilized scanning C-band radar that measures dual-polarization and provides advanced retrievals of precipitation and its spatial pattern. PICCOLO has four objectives: (1) evaluate process relationships between precipitation, humidity, and organization; (2) use advanced polarimetric radar retrievals to investigate microphysical, dynamical, and radiative characteristics of convection; (3) investigate the importance of radiative processes in driving mesoscale organization; and (4) use novel observational approaches to compute the entropy budget to advance understanding of the impacts of convection on climate. We will present an overview of the convective states observed by SEA-POL during the 6-week cruise along with initial classifications of the structure of the precipitation field and its variability.