Assessment of Planetary Boundary-Layer Schemes in the Weather Research and Forecasting Mesoscale Model Using MATERHORN Field Data

Abstract A polar-optimized version of the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) was developed to fill climate and synoptic needs of the polar science community and to achieve an improved regional performance. To continue the goal of enhanced polar mesoscale modeling, polar optimization should now be applied toward the state-of-the-art Weather Research and Forecasting (WRF) Model. Evaluations and optimizations are especially needed for the boundary layer parameterization, cloud physics, snow surface physics, and sea ice treatment. Testing and development work for Polar WRF begins with simulations for ice sheet surface conditions using a Greenland-area domain with 24-km resolution. The winter month December 2002 and the summer month June 2001 are simulated with WRF, version 2.1.1, in a series of 48-h integrations initialized daily at 0000 UTC. The results motivated several improvements to Polar WRF, especially to the Noah land surface model (LSM) and the snowpack treatment. Different physics packages for WRF are evaluated with December 2002 simulations that show variable forecast skill when verified with the automatic weather station observations. The WRF simulation with the combination of the modified Noah LSM, the Mellor–Yamada–Janjić boundary layer parameterization, and the WRF single-moment microphysics produced results that reach or exceed the success standards of a Polar MM5 simulation for December 2002. For summer simulations of June 2001, WRF simulates an improved surface energy balance, and shows forecast skill nearly equal to that of Polar MM5.

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Evaluating winds and vertical wind shear from Weather Research and Forecasting model forecasts using seven planetary boundary layer schemes

Wind Energy ◽

10.1002/we.1555 ◽

2012 ◽

Vol 17 (1) ◽

pp. 39-55 ◽

Cited By ~ 94

Author(s):

Caroline Draxl ◽

Andrea N. Hahmann ◽

Alfredo Peña ◽

Gregor Giebel

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Wind Shear ◽

Vertical Wind Shear ◽

Vertical Wind ◽

Weather Research And Forecasting ◽

Forecasting Model ◽

Weather Research

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A Review and Evaluation of Planetary Boundary Layer Parameterizations in Hurricane Weather Research and Forecasting Model Using Idealized Simulations and Observations

Atmosphere ◽

10.3390/atmos11101091 ◽

2020 ◽

Vol 11 (10) ◽

pp. 1091

Author(s):

Jun A. Zhang ◽

Evan A. Kalina ◽

Mrinal K. Biswas ◽

Robert F. Rogers ◽

Ping Zhu ◽

...

Keyword(s):

Boundary Layer ◽

Wind Speed ◽

Planetary Boundary Layer ◽

Doppler Radar ◽

Deep Convection ◽

Eddy Diffusivity ◽

Intensity Change ◽

Weather Research And Forecasting ◽

Pbl Scheme ◽

Weather Research

This paper reviews the evolution of planetary boundary layer (PBL) parameterization schemes that have been used in the operational version of the Hurricane Weather Research and Forecasting (HWRF) model since 2011. Idealized simulations are then used to evaluate the effects of different PBL schemes on hurricane structure and intensity. The original Global Forecast System (GFS) PBL scheme in the 2011 version of HWRF produces the weakest storm, while a modified GFS scheme using a wind-speed dependent parameterization of vertical eddy diffusivity (Km) produces the strongest storm. The subsequent version of the hybrid eddy diffusivity and mass flux scheme (EDMF) used in HWRF also produces a strong storm, similar to the version using the wind-speed dependent Km. Both the intensity change rate and maximum intensity of the simulated storms vary with different PBL schemes, mainly due to differences in the parameterization of Km. The smaller the Km in the PBL scheme, the faster a storm tends to intensify. Differences in hurricane PBL height, convergence, inflow angle, warm-core structure, distribution of deep convection, and agradient force in these simulations are also examined. Compared to dropsonde and Doppler radar composites, improvements in the kinematic structure are found in simulations using the wind-speed dependent Km and modified EDMF schemes relative to those with earlier versions of the PBL schemes in HWRF. However, the upper boundary layer in all simulations is much cooler and drier than that in dropsonde observations. This model deficiency needs to be considered and corrected in future model physics upgrades.

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Influence of Karst Landscape on Planetary Boundary Layer Atmosphere: A Weather Research and Forecasting (WRF) Model–Based Investigation

Journal of Hydrometeorology ◽

10.1175/2011jhm1260.1 ◽

2011 ◽

Vol 12 (6) ◽

pp. 1512-1529 ◽

Cited By ~ 9

Author(s):

Ronnie Leeper ◽

Rezaul Mahmood ◽

Arturo I. Quintanar

Keyword(s):

Boundary Layer ◽

Heat Flux ◽

Soil Moisture ◽

Planetary Boundary Layer ◽

Cloud Cover ◽

Weather Research And Forecasting ◽

Simulated Rainfall ◽

Karst Hydrology ◽

Atmospheric Processes ◽

Weather Research

Abstract Karst hydrology provides a unique set of surface and subsurface hydrological components that affect soil moisture variability. Over karst topography, surface moisture moves rapidly below ground via sink holes, vertical shafts, and sinking streams, reducing surface runoff and moisture infiltration into the soil. In addition, subsurface cave blockage or rapid snowmelt over karst can lead to surface flooding. Moreover, regions dominated by karst may exhibit either drier or wetter soils when compared to nonkarst landscape. However, because of the lack of both observational soil moisture datasets to initialize simulations and regional land surface models (LSMs) that include explicit karst hydrological processes, the impact of karst on atmospheric processes is not fully understood. Therefore, the purpose of this study was to investigate the importance of karst hydrology on planetary boundary layer (PBL) atmosphere using the Weather Research and Forecasting Model (WRF). This research is a first attempt to identify the impacts of karst on PBL. To model the influence of karst hydrology on atmospheric processes, soil moisture was modified systematically over the Western Kentucky Pennyroyal Karst (WKYPK) region to produce an ensemble of dry and wet anomaly experiments. Simulations were conducted for both frontal- and nonfrontal-based convection. For the dry ensemble, cloud cover was both diminished downwind of karst because of reduced atmospheric moisture and enhanced slightly upwind as moist air moved into a region of increased convection compared to control simulations (CTRL). Moreover, sensible (latent) heat flux and PBL heights were increased (decreased) compared to CTRL. In addition, the wet ensemble experiments reduced PBL heights and sensible heat flux and increased cloud cover over karst compared to CTRL. Other changes were noted in equivalent potential temperature (θe) and vertical motions and development of new mesoscale circulation cells with alterations in soil moisture over WKYPK. Finally, the location of simulated rainfall patterns were altered by both dry and wet ensembles with the greatest sensitivity to simulated rainfall occurring during weakly forced or nonfrontal cases. Simulated rainfall for the dry ensemble was more similar to the North American Regional Reanalysis (NARR) than CTRL for the nonfrontal case. Furthermore, the initial state of the atmosphere and convective triggers were found to either enhance or diminish simulated atmospheric responses.

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