Derivation of aerosol profiles for MC3E convection studies and use in simulations of the 20 May squall line case
AuthorFridlind, Ann M.
van Lier-Walqui, Marcus
Ackerman, Andrew S.
McFarquhar, Greg M.
Poellot, Michael R.
Tomlinson, Jason M.
AffiliationUniv Arizona, Dept Hydrol & Atmospher Sci
MetadataShow full item record
PublisherCOPERNICUS GESELLSCHAFT MBH
CitationDerivation of aerosol profiles for MC3E convection studies and use in simulations of the 20 May squall line case 2017, 17 (9):5947 Atmospheric Chemistry and Physics
Rights© Author(s) 2017. This work is distributed under the Creative Commons Attribution 3.0 License.
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AbstractAdvancing understanding of deep convection microphysics via mesoscale modeling studies of well-observed case studies requires observation-based aerosol inputs. Here, we derive hygroscopic aerosol size distribution input profiles from ground-based and airborne measurements for six convection case studies observed during the Midlatitude Continental Convective Cloud Experiment (MC3E) over Oklahoma. We demonstrate use of an input profile in simulations of the only well-observed case study that produced extensive stratiform outflow on 20 May 2011. At well-sampled elevations between -11 and -23 degrees C over widespread stratiform rain, ice crystal number concentrations are consistently dominated by a single mode near similar to 400 mu m in randomly oriented maximum dimension (D-max). The ice mass at -23 degrees C is primarily in a closely collocated mode, whereas a mass mode near D-max similar to 1000 mu m becomes dominant with decreasing elevation to the -11 degrees C level, consistent with possible aggregation during sedimentation. However, simulations with and without observation-based aerosol inputs systematically overpredict mass peak D-max by a factor of 3-5 and under-predict ice number concentration by a factor of 4-10. Previously reported simulations with both two-moment and sizeresolved microphysics have shown biases of a similar nature. The observed ice properties are notably similar to those reported from recent tropical measurements. Based on several lines of evidence, we speculate that updraft microphysical pathways determining outflow properties in the 20 May case are similar to a tropical regime, likely associated with warm-temperature ice multiplication that is not well understood or well represented in models.
VersionFinal published version
SponsorsOffice of Science (BER), US Department of Energy through UCAR [DE-SC0006988, DE-SC0014065, DE-SC0016476, Z17-90029]; NASA Radiation Sciences Program; US Department of Energy, Office of Science, Office of Biological and Environmental Research, Climate and Environmental Sciences Division; NASA [NNX10AN38G]; NASA Modeling, Analysis and Prediction (MAP) program; NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center; NASA's Center for Climate Simulation (NCCS) at Goddard Space Flight Center