Sensitivity of CONUS Summer Rainfall to the Selection of Cumulus Parameterization Schemes in NU-WRF Seasonal Simulations

Authors

Takamichi Iguchi, University of MarylandFollow
Wei-Kuo Tao, NASA Goddard Space Flight Center
Di Wu, NASA Goddard Space Flight Center
Christa D. Peters-Lidard, NASA Goddard Space Flight Center
Joseph A. Santanello, NASA Goddard Space Flight Center
Eric Kemp, NASA Goddard Space Flight Center
Yudong Tian, University of Maryland at College Park
Jonathan Case, ENSCO, Inc
Weile Wang, NASA Ames Research Center
Robert Ferraro, NASA Jet Propulsion LaboratoryFollow
Duane E. Waliser, NASA Jet Propulsion LaboratoryFollow
Jinwon Kim, California Institute of TechnologyFollow
Huikyo Lee, California Institute of TechnologyFollow
Bin Guan, University of California, Los Angeles
Baijun Tian, NASA Jet Propulsion Laboratory
Paul C. Loikith, Portland State UniversityFollow

Published In

Journal of Hydrometeorology

Document Type

Article

Publication Date

6-2017

Subjects

Clouds, Atmospheric models, Precipitation (Meteorology), Hydrologic cycle

Abstract

This study investigates the sensitivity of daily rainfall rates in regional seasonal simulations over the contiguous United States (CONUS) to different cumulus parameterization schemes. Daily rainfall fields were simulated at 24-km resolution using the NASA-Unified Weather Research and Forecasting (NU-WRF) Model for June–August 2000. Four cumulus parameterization schemes and two options for shallow cumulus components in a specific scheme were tested. The spread in the domain-mean rainfall rates across the parameterization schemes was generally consistent between the entire CONUS and most subregions. The selection of the shallow cumulus component in a specific scheme had more impact than that of the four cumulus parameterization schemes. Regional variability in the performance of each scheme was assessed by calculating optimally weighted ensembles that minimize full root-mean-square errors against reference datasets. The spatial pattern of the seasonally averaged rainfall was insensitive to the selection of cumulus parameterization over mountainous regions because of the topographical pattern constraint, so that the simulation errors were mostly attributed to the overall bias there. In contrast, the spatial patterns over the Great Plains regions as well as the temporal variation over most parts of the CONUS were relatively sensitive to cumulus parameterization selection. Overall, adopting a single simulation result was preferable to generating a better ensemble for the seasonally averaged daily rainfall simulation, as long as their overall biases had the same positive or negative sign. However, an ensemble of multiple simulation results was more effective in reducing errors in the case of also considering temporal variation.

Description

To the best of our knowledge, this work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government In accordance with 17 U.S.C. 105.

Published 2017 by the American Meteorological Society.

https://doi.org/10.1175/JHM-D-16-0120.1

DOI

10.1175/JHM-D-16-0120.1

Persistent Identifier

http://archives.pdx.edu/ds/psu/21191

Citation Details

Iguchi, T., Tao, W. K., Wu, D., Peters-Lidard, C., Santanello, J. A., Kemp, E., ... & Waliser, D. (2017). Sensitivity of CONUS summer rainfall to the selection of cumulus parameterization schemes in NU-WRF seasonal simulations. Journal of Hydrometeorology, 18(6), 1689-1706.