A study of deep convective systems and their associated anvil cloud properties over the SGP through an integrated analysis of NEXRAD, GOES, and ARM MMCR data
Xiquan Dong — University of Arizona
Patrick Minnis — NASA - Langley Research Center
Min Deng — University of Colorado, Boulder
Baike Xi — University of Arizona
Zhe Feng — Pacific Northwest National Laboratory
Category
Cloud Properties
Description
Cloud radiative forcing of deep convective systems partitioned by a hybrid radar and satellite classification technique.
Cirrus anvil clouds associated with deep convective systems (DCS) are strongly connected to the water budgets of the upper troposphere and have strong influence on climate processes through modulating the atmospheric radiation budget. Feng et al. (2011) have developed an objective classification technique to identify DCS and accurately partition anvil cirrus clouds with parent convective rain cores using a combination of NEXRAD radars and GOES satellite data from two summers (JJA 2009–2010) over the SGP region (8×15° centered at the ARM SCF). There are three steps in this study. First, we have developed an objective classification technique to identify Deep Convective Systems (DCS) and separate their rain core and associated anvil clouds using merged NEXRAD and GOES observations. Second, we have calculated the SW, LW, and NET Cloud Radiative Forcing (CRFs) of different cloud types within DCS (core, anvil) and quantitatively estimate their impact to the TOA radiation budget. The preliminary results have revealed that the averaged total SW CRF is -34 Wm-2 and LW CRF is 22.5 Wm-2, resulting in a net cooling of -11.5 W m-2 during summer months over the SGP region. Of all clouds, DCS clouds contribute 48% in SW CRF, 59% in LW CRF, and 52% in NET CRF. Within DCS, the SW, LW, and NET CRFs contributed from anvil clouds are 26%, 35%, and 30%, respectively. These values are slightly higher than those contributed from DCS core regions (22%, 24%, and 22%). Finally, we will compare the vertical profiles of cloud microphysical properties between DCS anvils and cirrus clouds, such as ice water content and effective diameter, retrieved from ARM SGP radar observations over the ARM SCF. It is our goal that these results can be used to evaluate the climate-model-simulated DCSs, their associated anvil cloud properties, and radiative impact over the midlatitudes.
