Improving Simulations of Convective Systems from TRMM LBA: Easterly and Westerly Regimes

Lang, S.; Tao, W.; Simpson, Joanne; Cifelli, Robert; Rutledge, Steven A.; Olson, William S.; Halverson, Jeffrey B.

doi:10.1175/jas3879.1

Cited by 153 publications

(155 citation statements)

References 81 publications

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“…[8] The four microphysical schemes investigated in this paper include the Goddard bulk single-moment scheme [hereinafter GSFC, Tao and Simpson, 1993;Tao et al, 2003;Lang et al, 2007], the WRF single-moment 6-class scheme [hereinafter WSM6, [Hong and Lim, 2006], the Thompson scheme [hereinafter THOM, Thompson et al, 2008], and the Morrison double-moment scheme [hereinafter MORR, Morrison et al, 2005;Morrison et al, 2009]. Each scheme assumes six categories of water species: water vapor, cloud water, cloud ice, snow, graupel, and rain.…”

Section: Models and Calculationsmentioning

confidence: 99%

Evaluation of cloud microphysics schemes in simulations of a winter storm using radar and radiometer measurements

et al. 2013

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[1] Using observations from a space-borne radiometer and a ground-based precipitation profiling radar, the impact of cloud microphysics schemes in the WRF model on the simulation of microwave brightness temperature (T b ), radar reflectivity, and Doppler velocity (V dop ) is studied for a winter storm in California. The unique assumptions of particles size distributions, number concentrations, shapes, and fall speeds in different microphysics schemes are implemented into a satellite simulator and customized calculations for the radar are performed to ensure consistent representation of precipitation properties between the microphysics schemes and the radiative transfer models. [2] Simulations with four different schemes in the WRF model, including the Goddard scheme (GSFC), the WRF single-moment 6-class scheme (WSM6), the Thompson scheme (THOM), and the Morrison double-moment scheme (MORR), are compared directly with measurements from the sensors. Results show large variations in the simulated radiative properties. General biases of~20 K or larger are found in (polarization-corrected) T b , which is linked to an overestimate of the precipitating ice aloft. The simulated reflectivity with THOM appears to agree well with the observations, while high biases of~5À10 dBZ are found in GSFC, WSM6 and MORR. Peak reflectivity in MORR exceeds other schemes. These biases are attributable to the snow intercept parameters or the snow number concentrations. Simulated V dop values based on GSFC agree with the observations well, while other schemes appear to have a~1 m s -1 high bias in the ice layer. In the rain layer, the model representations of Doppler velocity vary at different sites.Citation: Han, M., S. A. Braun, T. Matsui, and C. R. Williams (2013), Evaluation of cloud microphysics schemes in simulations of a winter storm using radar and radiometer measurements,

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Section: Models and Calculationsmentioning

confidence: 99%

Evaluation of cloud microphysics schemes in simulations of a winter storm using radar and radiometer measurements

et al. 2013

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“…Pastushkov, 1975;Corbosiero and Molinari, 2002;Lang et al, 2007;Ueno, 2007). The delayed initiation of convection is associated with a strong vertical wind shear (e.g.…”

Section: Introductionmentioning

confidence: 99%

Effects of vertical wind shear and cloud radiative processes on responses of rainfall to the large‐scale forcing during pre‐summer heavy rainfall over southern China

Shen

2011

Quart J Royal Meteoro Soc

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The pre-summer heavy rainfall over southern China during 3-8 June 2008 is simulated using a two-dimensional cloud-resolving model. The model is integrated with imposed zonally uniform vertical velocity, zonal wind, horizontal temperature and vapour advection from National Centers for Environmental Prediction (NCEP)/Global Data Assimilation System (GDAS) data. The effects of vertical wind shear and cloud radiative processes on the response of rainfall to largescale forcing are analysed through the comparison of two sensitivity experiments with the control experiment. One sensitivity experiment excludes the large-scale vertical wind shear and the other excludes the cloud radiative effects. During the decay phase of convection, the increase in model domain-mean surface rain-rate resulting from the exclusion of vertical wind shear is associated with the slowdown in the decrease of perturbation kinetic energy due to the exclusion of barotropic conversion from mean kinetic energy to perturbation kinetic energy. The increase in domain-mean rain-rate from the exclusion of cloud radiative effects is related to the enhancement of condensation and associated latent heat as a result of strengthened radiative cooling. The increase in the domain-mean surface rain-rate is mainly associated with the increase of convective rainfall, which is in turn related to the local atmospheric change from moistening to drying. During the onset and mature phases of convection, the domain-mean surface rain-rates are generally insensitive to vertical wind shear and cloud radiative effects whereas convective and stratiform rain-rates are sensitive to vertical wind shear and cloud radiative effects. The decrease in convective rain-rate and the increase in stratiform rain-rate are primarily associated with the enhanced transport of hydrometeor concentration from convective regions to raining stratiform regions. Copyright c 2011 Royal Meteorological Society Key Words: cloud-resolving model simulation; convective and stratiform rain-rates; vertical wind shear; cloud radiative effects; budget analysis

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“…The increase of domain and resolution in general tends to increase the lifetime of individual storms that propagate more slowly. This explains the delay in the peak of the diurnal precipitation (Lang et al 2007). Both in the small and large domain cases, precipitation develops regularly on a diurnal basis, presumably due to the imposed, regular diurnal forcing.…”

Section: Appendix: Sensitivity Testsmentioning

confidence: 93%

“…The GCE model has been tested extensively both in 2D (e.g., Johnson et al 2002) and three-dimensional (3D) configurations (e.g., Tao and Simpson 1989;Lang et al 2007;Zeng et al 2007). In this study, we used the 2D (zonal and vertical) version.…”

Section: Model and Experimentsmentioning

confidence: 99%

Mechanisms of diurnal precipitation over the US Great Plains: a cloud resolving model perspective

et al. 2009

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The mechanisms of summertime diurnal precipitation in the US Great Plains were examined with the two-dimensional (2D) Goddard Cumulus Ensemble (GCE) cloud-resolving model (CRM). The model was constrained by the observed large-scale background state and surface flux derived from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program's Intensive Observing Period (IOP) data at the Southern Great Plains (SGP). The model, when continuously-forced by realistic surface flux and large-scale advection, simulates reasonably well the temporal evolution of the observed rainfall episodes, particularly for the strongly forced precipitation events. However, the model exhibits a deficiency for the weakly forced events driven by diurnal convection. Additional tests were run with the GCE model in order to discriminate between the mechanisms that determine daytime and nighttime convection. In these tests, the model was constrained with the same repeating diurnal variation in the large-scale advection and/or surface flux. The results indicate that it is primarily the surface heat and moisture flux that is responsible for the development of deep convection in the afternoon, whereas the large-scale upward motion and associated moisture advection play an important role in preconditioning nocturnal convection. In the nighttime, high clouds are continuously built up through their interaction and feedback with long-wave radiation, eventually initiating deep convection from the boundary layer. Without these upper-level destabilization processes, the model tends to produce only daytime convection in response to boundary layer heating. This study suggests that the correct simulation of the diurnal variation in precipitation requires that the free-atmospheric destabilization mechanisms resolved in the CRM simulation must be adequately parameterized in current general circulation models (GCMs) many of which are overly sensitive to the parameterized boundary layer heating.

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Improving Simulations of Convective Systems from TRMM LBA: Easterly and Westerly Regimes

Cited by 153 publications

References 81 publications

Evaluation of cloud microphysics schemes in simulations of a winter storm using radar and radiometer measurements

Evaluation of cloud microphysics schemes in simulations of a winter storm using radar and radiometer measurements

Effects of vertical wind shear and cloud radiative processes on responses of rainfall to the large‐scale forcing during pre‐summer heavy rainfall over southern China

Mechanisms of diurnal precipitation over the US Great Plains: a cloud resolving model perspective

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