Investigation of raindrop breakup and evaporation using Doppler lidar-radar synergy: a feasibility study using MC3E observations
Authors
Pavlos Kollias — Stony Brook University
Wanda Szyrmer — McGill University - Dept. of Atmospheric and Oceanic Science
Frederic Claude Tridon — Polytechnic University of Turin
Alessandro Battaglia — University of Bonn
Edward Luke — Brookhaven National Laboratory
Rob K Newsom — Pacific Northwest National Laboratory
Category
Precipitation
Description
Recent modeling studies have indicated that the evolution of midlatitude precipitating systems critically depends on the parameterization of raindrop breakup (Morrison et al. 2012). Profiling radars have been traditionally been used to study the evolution of the raindrop size distribution (RSD). However, radar observations are sensitive to high moments (6th–7th) of the RSD, while microphysical processes influence and are parameterized as a function of lower moments (0th–3rd) of the RSD. We will demonstrate that the choice of the RSD shape in bulk microphysical schemes can have a large impact on our efforts to evaluate lower moments using radar observations. This raises the question: How can we use remote sensing to evaluate the presence and degree of raindrop breakup?The Midlatitude Continental Convective Cloud Experiment (MC3E), a joint field program involving NASA Global Precipitation Measurement Program and ARM investigators, is the first field campaign conducted using the new Recovery Act ARM instrumentation. As part of the new instrumentation, observations from a profiling Doppler lidar and a multi-frequency profiling radar facility are available. In rain, the Doppler lidar receives coherent backscatter returns from aerosol particles and raindrops (Traumner et al. 2010). When raindrops dominate the Doppler lidar signal, the measurements depend on the 2nd–3rd moment of the RSD. This implies that the Doppler lidar measurements have the potential to be more sensitive than radar observables to raindrop breakup/evaporation. Here, we conduct a feasibility study using MC3E observations, a simple raindrop breakup model and a radar/lidar forward model.
Morrison, H, SA Tessendorf, K Ikeda, and G Thompson. 2012. “Sensitivity of a Simulated Midlatitude Squall Line to Parameterization of Raindrop Breakup.” Monthly Weather Review 140: 2437–2460.
Träumner, K, J Handwerker, A Wieser, and J Grenzhäuser. 2010. “A synergy approach for estimating raindrop size-distributions using Doppler lidar and cloud radar.” Journal of Atmospheric and Oceanic Technology 27: 1095–1100.