Data associated with “Adapting the COSP Radar Simulator to Compare GCM Output and GPM Precipitation Radar Observations”
Files
CAM5_for_COSP_README.txt (2.49 KB) README for data use instructions COSP_CAM5_t3.cam.h2.2017-06-01-03600_REFF.nc.gz (782.29 MB) Effective radius variables from CAM5 2° run for 1-30 June 2017 COSP_CAM5_t3.cam.h2.2017-06-01-03600_numconc.nc.gz (3.48 GB) Number concentration variables from CAM5 for 2° run for 1-30 June 2017 COSP_CAM5_t3_CFAD.cam.h2.2017-06-01-03600.nc.tar.gz (1.13 GB) 2° CAM5 file that contains 1-3 June 2017 COSP_CAM5_t3_CFAD.cam.h2.2017-06-04-03600.nc.tar.gz (1.12 GB) 2° CAM5 file that contains 4-6 June 2017
Date
2021
Authors
Riley Dellaripa, Emily M.
Funk, Aaron
Schumacher, Courtney
Bai, Hedanqiu
Spangehl, Thomas
Journal Title
Journal ISSN
Volume Title
Abstract
Comparisons of precipitation between general circulation models (GCMs) and observations are often confounded by a mismatch between model output and instrument measurements, including variable type and temporal and spatial resolution. To mitigate these differences, the radar-simulator Quickbeam within the Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package (COSP) simulates reflectivity from model variables at the sub-grid scale. This work adapts Quickbeam to the dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) satellite. The longer wavelength of the DPR is used to evaluate moderate-to-heavy precipitation in GCMs, which is missed when Quickbeam is used as a cloud radar simulator. Latitudinal and land/ocean comparisons are made between COSP output from the Community Atmospheric Model version 5 (CAM5) and DPR data. Additionally, this work improves the COSP sub-grid algorithm by applying a more realistic, non-deterministic approach to assigning GCM grid box convective cloud cover when convective cloud is not provided as a model output. Instead of assuming a static 5% convective cloud coverage, DPR convective precipitation coverage is used as a proxy for convective cloud coverage. For example, DPR observations show that convective rain typically only covers about 1% of a 2°grid box, but that the median convective rain area increases to over 10% in heavy rain cases. In our CAM5 tests, the updated sub-grid algorithm improved the comparison between reflectivity distributions when the convective cloud cover is provided versus the default 5% convective cloud cover assumption.
Description
This dataset includes the global 2° and 1° CAM5 output variables for June 2017 that were used as input into our version of the COSP simulator package as described in the publication. A README file is included to describe the unix scripts used to prepare the data files for input into COSP.
Department of Atmospheric Science
Department of Atmospheric Science
Rights Access
Subject
CAM5
COSP
GPM
Citation
Associated Publications
Riley Dellaripa, E. M., A. Funk, C. Scumacher, H. Bai, and T. Spangehl, 2021: Adapting the COSP Radar Simulator to Compare GCM Output and GPM Precipitation Radar Observations, J. Atmos. Ocean. Technol., 38,1457-1475. https://doi.org/10.1175/JTECH-D-20-0089.1