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Title: Comparison of observed and simulated spatial patterns of ice microphysical processes in tropical oceanic mesoscale convective systems: Ice Microphysics in Midlevel Inflow

Abstract

To equitably compare the spatial pattern of ice microphysical processes produced by three microphysical parameterizations with each other, observations, and theory, simulations of tropical oceanic mesoscale convective systems (MCSs) in the Weather Research and Forecasting (WRF) model were forced to develop the same mesoscale circulations as observations by assimilating radial velocity data from a Doppler radar. The same general layering of microphysical processes was found in observations and simulations with deposition anywhere above the 0°C level, aggregation at and above the 0°C level, melting at and below the 0°C level, and riming near the 0°C level. Thus, this study is consistent with the layered ice microphysical pattern portrayed in previous conceptual models and indicated by dual-polarization radar data. Spatial variability of riming in the simulations suggests that riming in the midlevel inflow is related to convective-scale vertical velocity perturbations. Finally, this study sheds light on limitations of current generally available bulk microphysical parameterizations. In each parameterization, the layers in which aggregation and riming took place were generally too thick and the frequency of riming was generally too high compared to the observations and theory. Additionally, none of the parameterizations produced similar details in every microphysical spatial pattern. Discrepancies in themore » patterns of microphysical processes between parameterizations likely factor into creating substantial differences in model reflectivity patterns. It is concluded that improved parameterizations of ice-phase microphysics will be essential to obtain reliable, consistent model simulations of tropical oceanic MCSs.« less

Authors:
 [1];  [2]
  1. Department of Atmospheric Sciences, University of Washington, Seattle Washington USA
  2. Department of Atmospheric Sciences, University of Washington, Seattle Washington USA; Pacific Northwest National Laboratory, Richland Washington USA
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1342296
Report Number(s):
PNNL-SA-121277
Journal ID: ISSN 2169-897X; KP1703010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Geophysical Research: Atmospheres; Journal Volume: 121; Journal Issue: 14
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Barnes, Hannah C., and Houze, Robert A. Comparison of observed and simulated spatial patterns of ice microphysical processes in tropical oceanic mesoscale convective systems: Ice Microphysics in Midlevel Inflow. United States: N. p., 2016. Web. doi:10.1002/2016JD025074.
Barnes, Hannah C., & Houze, Robert A. Comparison of observed and simulated spatial patterns of ice microphysical processes in tropical oceanic mesoscale convective systems: Ice Microphysics in Midlevel Inflow. United States. doi:10.1002/2016JD025074.
Barnes, Hannah C., and Houze, Robert A. Mon . "Comparison of observed and simulated spatial patterns of ice microphysical processes in tropical oceanic mesoscale convective systems: Ice Microphysics in Midlevel Inflow". United States. doi:10.1002/2016JD025074.
@article{osti_1342296,
title = {Comparison of observed and simulated spatial patterns of ice microphysical processes in tropical oceanic mesoscale convective systems: Ice Microphysics in Midlevel Inflow},
author = {Barnes, Hannah C. and Houze, Robert A.},
abstractNote = {To equitably compare the spatial pattern of ice microphysical processes produced by three microphysical parameterizations with each other, observations, and theory, simulations of tropical oceanic mesoscale convective systems (MCSs) in the Weather Research and Forecasting (WRF) model were forced to develop the same mesoscale circulations as observations by assimilating radial velocity data from a Doppler radar. The same general layering of microphysical processes was found in observations and simulations with deposition anywhere above the 0°C level, aggregation at and above the 0°C level, melting at and below the 0°C level, and riming near the 0°C level. Thus, this study is consistent with the layered ice microphysical pattern portrayed in previous conceptual models and indicated by dual-polarization radar data. Spatial variability of riming in the simulations suggests that riming in the midlevel inflow is related to convective-scale vertical velocity perturbations. Finally, this study sheds light on limitations of current generally available bulk microphysical parameterizations. In each parameterization, the layers in which aggregation and riming took place were generally too thick and the frequency of riming was generally too high compared to the observations and theory. Additionally, none of the parameterizations produced similar details in every microphysical spatial pattern. Discrepancies in the patterns of microphysical processes between parameterizations likely factor into creating substantial differences in model reflectivity patterns. It is concluded that improved parameterizations of ice-phase microphysics will be essential to obtain reliable, consistent model simulations of tropical oceanic MCSs.},
doi = {10.1002/2016JD025074},
journal = {Journal of Geophysical Research: Atmospheres},
number = 14,
volume = 121,
place = {United States},
year = {Mon Jul 25 00:00:00 EDT 2016},
month = {Mon Jul 25 00:00:00 EDT 2016}
}