The performance of two convective parameterization schemes in a mesoscale model over the Indian region

2006 ◽  
Vol 92 (3-4) ◽  
pp. 175-190 ◽  
Author(s):  
S. S. Vaidya
Keyword(s):  
Mesoscale Model ◽  
Indian Region ◽  
Convective Parameterization ◽  
Parameterization Schemes

scholarly journals Impact of Parameterization of Physical Processes on Simulation of Track and Intensity of Tropical Cyclone Nargis (2008) with WRF-NMM Model

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Sujata Pattanayak ◽  
U. C. Mohanty ◽  
Krishna K. Osuri
Keyword(s):  
Land Surface ◽  
Mesoscale Model ◽  
Initial Conditions ◽  
Surface Wind ◽  
India Meteorological Department ◽  
Heat Fluxes ◽  
Cumulus Convection ◽  
Cyclonic Storm ◽  
Parameterization Schemes ◽  
Cyclone Nargis

The present study is carried out to investigate the performance of different cumulus convection, planetary boundary layer, land surface processes, and microphysics parameterization schemes in the simulation of a very severe cyclonic storm (VSCS) Nargis (2008), developed in the central Bay of Bengal on 27 April 2008. For this purpose, the nonhydrostatic mesoscale model (NMM) dynamic core of weather research and forecasting (WRF) system is used. Model-simulated track positions and intensity in terms of minimum central mean sea level pressure (MSLP), maximum surface wind (10 m), and precipitation are verified with observations as provided by the India Meteorological Department (IMD) and Tropical Rainfall Measurement Mission (TRMM). The estimated optimum combination is reinvestigated with six different initial conditions of the same case to have better conclusion on the performance of WRF-NMM. A few more diagnostic fields like vertical velocity, vorticity, and heat fluxes are also evaluated. The results indicate that cumulus convection play an important role in the movement of the cyclone, and PBL has a crucial role in the intensification of the storm. The combination of Simplified Arakawa Schubert (SAS) convection, Yonsei University (YSU) PBL, NMM land surface, and Ferrier microphysics parameterization schemes in WRF-NMM give better track and intensity forecast with minimum vector displacement error.

scholarly journals Why Does Deep Convection Have Different Sensitivities to Temperature Perturbations in the Lower versus Upper Troposphere?

2018 ◽  
Vol 76 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Yang Tian ◽  
Zhiming Kuang
Keyword(s):  
Water Content ◽  
Vertical Velocity ◽  
Liquid Water ◽  
Deep Convection ◽  
Liquid Water Content ◽  
Cloud Base ◽  
Base Temperature ◽  
Upper Troposphere ◽  
Convective Parameterization ◽  
Parameterization Schemes

Abstract Previous studies have documented that deep convection responds more strongly to above-the-cloud-base temperature perturbations in the lower troposphere than to those in the upper troposphere, a behavior that is important to the dynamics of large-scale moist flows, such as convectively coupled waves. A number of factors may contribute to this differing sensitivity, including differences in buoyancy, vertical velocity, and/or liquid water content in cloud updrafts in the lower versus upper troposphere. Quantifying the contributions from these factors can help to guide the development of convective parameterization schemes. We tackle this issue by tracking Lagrangian particles embedded in cloud-resolving simulations within a linear response framework. The results show that both the differences in updraft buoyancy and vertical velocity play a significant role, with the vertical velocity being the more important, and the effect of liquid water content is only secondary compared to the other two factors. These results indicate that cloud updraft vertical velocities need to be correctly modeled in convective parameterization schemes in order to properly account for the differing convective sensitivities to temperature perturbations at different heights of the free troposphere.

scholarly journals Verification of precipitation forecasts of MM5 model over Epirus, NW Greece, for various convective parameterization schemes

2012 ◽  
Vol 12 (5) ◽  
pp. 1393-1405 ◽  
Author(s):  
O. A. Sindosi ◽  
A. Bartzokas ◽  
V. Kotroni ◽  
K. Lagouvardos
Keyword(s):  
Horizontal Resolution ◽  
Forecast Skill ◽  
Precipitation Forecast ◽  
Meteorological Model ◽  
Convective Parameterization ◽  
Parameterization Schemes ◽  
Mm5 Model ◽  
Convective Parameterization Scheme ◽  
High Precipitation Events ◽  
High Precipitation

Abstract. The mesoscale meteorological model MM5 is applied to 22 selected days with intense precipitation in the region of Epirus, NW Greece. At first, it was investigated whether and to what extend an increased horizontal resolution (from 8 to 2 km) improves the quantitative precipitation forecasts. The model skill was examined for the 12-h accumulated precipitation recorded at 14 meteorological stations located in Epirus and by using categorical and descriptive statistics. Then, the precipitation forecast skill for the 2 km grid was studied: (a) without and (b) with the activation of a convective parameterization scheme. From the above study, the necessity of the use of a scheme at the 2 km grid is assessed. Furthermore, three different convective parameterization schemes are compared: (a) Betts-Miller, (b) Grell and (c) Kain-Fritsch-2 in order to reveal the scheme, resulting in the best precipitation forecast skill in Epirus. Kain-Fritsch-2 and Grell give better results with the latter being the best for the high precipitation events.

Sensitivity of AGCM-simulated regional JJAS precipitation to different convective parameterization schemes

2017 ◽  
Vol 37 (13) ◽  
pp. 4594-4609 ◽  
Author(s):  
Muhammad Azhar Ehsan ◽  
Mansour Almazroui ◽  
Ahmed Yousef ◽  
O'Brien Enda ◽  
Michael K. Tippett ◽  
...  
Keyword(s):  
Convective Parameterization ◽  
Parameterization Schemes

scholarly journals An Alternative Mass Flux Profile in the Kain–Fritsch Convective Parameterization and Its Effects in Seasonal Precipitation

2007 ◽  
Vol 8 (5) ◽  
pp. 1128-1140 ◽  
Author(s):  
Christopher J. Anderson ◽  
Raymond W. Arritt ◽  
John S. Kain
Keyword(s):  
High Resolution ◽  
Mass Flux ◽  
Vertical Profile ◽  
Mesoscale Model ◽  
Horizontal Resolution ◽  
Precipitation Rate ◽  
Dynamical Equations ◽  
Convective Parameterization ◽  
Central United States ◽  
June July

Abstract The authors have altered the vertical profile of updraft mass flux detrainment in an implementation of the Kain–Fritsch2 (KF2) convective parameterization within the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (Penn State–NCAR) Mesoscale Model (MM5). The effect of this modification was to alter the vertical profile of convective parameterization cloud mass (including cloud water and ice) supplied to the host model for explicit simulation by the grid-resolved dynamical equations and parameterized microphysical processes. These modifications and their sensitivity to horizontal resolution in a matrix of experimental simulations of the June–July 1993 flood in the central United States were tested. The KF2 modifications impacted the diurnal cycle of precipitation by reducing precipitation from the convective parameterization and increasing precipitation from more slowly evolving mesoscale processes. The modified KF2 reduced an afternoon bias of high precipitation rate in both low- and high-resolution simulations but affected mesoscale precipitation processes only in high-resolution simulations. The combination of high-resolution and modified KF2 resulted in more frequent and more realistically clustered propagating, nocturnal mesoscale precipitation events and agreed best with observations of the nocturnal precipitation rate.

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