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Evaluating Precipitation Features and Rainfall Characteristics in a Multi-scale Modeling FrameworkCloud and precipitation systems over the tropics and subtropics are simulated with a multi-scale modeling framework (MMF) and compared against the TRMM radar precipitation features (RPFs) product. A methodology, in close analogy to the TRMM RPFs, is developed to analyze simulated cloud precipitating structures from the embedded two-dimensional cloud-resolving models (CRMs) within an MMF. Despite the two-dimensionality of the CRMs, the simulated RPFs population distribution, and horizontal and vertical structure are in good agreement with TRMM observations. However, some deficits are also found in the model simulations. The model tends to overestimate mean convective precipitation rates for RPFs with a size less than 100 km, contributing to the excessive precipitation biases in the warm pool and western Pacific, western and northern India Ocean, and eastern Pacific commonly found in most MMFs. For large features with a size greater than 150 km, both convective and stratiform rain rates are underestimated. The distribution of maximum radar echo top heights as a function of RPF size is well simulated except the model tends to underestimate the occurrence frequency of maximum heights greater than 15 km. The maximum echo top heights for convective cells embedded within large RPFs with a size greater than 150 km are also underestimated. The cyclic lateral boundary with a limited model domain generates artificial occurrences for RPFs with a size close to the model domain size, producing a significant contribution to the total rainfall due to their sizes. This cyclic lateral boundary effect can be easily identified and quantified in both probability and cumulative distribution functions of RPFs. The geophysical distribution of the population of the largest RPFs in the control experiment shows they are mainly located in the Subtropics but also partially contribute to the common MMF biases of excessive precipitation in the Tropics. Sensitivity experiments using CRMs with different domain sizes and different grid spacings show larger domains (higher resolution) tend to shift the RPFs distribution to large (small) sizes. The cyclic lateral boundary biases increase as CRM domain size decreases. The impacts of model horizontal and vertical resolution on simulated convective systems are also investigated.
Document ID
20190034199
Acquisition Source
Goddard Space Flight Center
Document Type
Poster
Authors
Chern, Jiun-Dar (Maryland Univ. College Park, MD, United States)
Tao, Wei-Kuo (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Lang, Stephen E. (Science Systems and Applications, Inc. (SSAI) Lanham, MD, United States)
Li, Xiaowen (Morgan State Univ. Baltimore, MD, United States)
Matsui, Toshihisa (Maryland Univ. College Park, MD, United States)
Date Acquired
December 30, 2019
Publication Date
December 9, 2019
Subject Category
Meteorology And Climatology
Report/Patent Number
GSFC-E-DAA-TN76642
Meeting Information
Meeting: AGU 2019 Fall Meeting
Location: San Francisco, CA
Country: United States
Start Date: December 9, 2019
End Date: December 13, 2019
Sponsors: American Geophysical Union (AGU)
Funding Number(s)
CONTRACT_GRANT: NNX17AE79A
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
NASA Peer Committee

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