Airborne Observations with a Microwave Sounder during CPEX-AW and CPEX-CV: Observations and Scientific Results

The High Altitude MMIC Sounding Radiometer (HAMSR) has been flying on the NASA DC-8 during NASA’s Convective Processes Experiment – Aerosols and Winds (CPEX-AW) and CPEX – Cabo Verde (CPEX-CV). HAMSR is a cross-track scanning microwave sounder, so during these campaigns, we observed changes in water vapor and temperature not only along the flight track but also across a swath with a width of approximately 50 km.

Using an optimization-based retrieval algorithm that includes scattering components and provides uncertainty estimates, we can make better use of the data concerning clouds and precipitation. It allows us to provide as much information as possible about the vertical structure of temperature and water vapor, especially close to critical areas, like convective cells or areas with precipitation.

Our presentation will explain the new retrieval algorithm and focus on validating the data in clear, cloudy, and precipitating areas. We will also discuss how the data selection criteria and quality control work and how they enable a better use of the data in scientific analysis.

Additionally, we will present scientific results with HAMSR observations during CPEX: we will explain how HAMSR data helps to understand the small-scale thermodynamic conditions and the effect of cold pools and how it can be used to analyze moisture advection by storm systems. Additionally, we will show how Fourier analysis of HAMSR data during CPEX can extract information about convection in the marine boundary layer.

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