scholarly journals Evaluation of nonlocal and local planetary boundary layer schemes in the WRF model

2012 ◽  
Vol 117 (D12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Bo Xie ◽  
Jimmy C. H. Fung ◽  
Allen Chan ◽  
Alexis Lau
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Wrf Model

scholarly journals Estimating Daytime Planetary Boundary Layer Heights over a Valley from Rawinsonde Observations at a Nearby Airport: An Application to the Page Valley in Virginia, United States

2016 ◽  
Vol 55 (3) ◽  
pp. 791-809 ◽  
Author(s):  
Temple R. Lee ◽  
Stephan F. J. De Wekker
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Weather Forecasting ◽  
Wrf Model ◽  
Heat Fluxes ◽  
Weather Research And Forecasting ◽  
Dispersion Modeling ◽  
Blue Ridge Mountains ◽  
Terrain Following ◽  
Regional Reanalysis

AbstractThe planetary boundary layer (PBL) height is an essential parameter required for many applications, including weather forecasting and dispersion modeling for air quality. Estimates of PBL height are not easily available and often come from twice-daily rawinsonde observations at airports, typically at 0000 and 1200 UTC. Questions often arise regarding the applicability of PBL heights retrieved from these twice-daily observations to surrounding locations. Obtaining this information requires knowledge of the spatial variability of PBL heights. This knowledge is particularly limited in regions with mountainous terrain. The goal of this study is to develop a method for estimating daytime PBL heights in the Page Valley, located in the Blue Ridge Mountains of Virginia. The approach includes using 1) rawinsonde observations from the nearest sounding station [Dulles Airport (IAD)], which is located 90 km northeast of the Page Valley, 2) North American Regional Reanalysis (NARR) output, and 3) simulations with the Weather Research and Forecasting (WRF) Model. When selecting days on which PBL heights from NARR compare well to PBL heights determined from the IAD soundings, it is found that PBL heights are higher (on the order of 200–400 m) over the Page Valley than at IAD and that these differences are typically larger in summer than in winter. WRF simulations indicate that larger sensible heat fluxes and terrain-following characteristics of PBL height both contribute to PBL heights being higher over the Page Valley than at IAD.

COMPARISON AND ANALYSIS OF SEVERAL PLANETARY BOUNDARY LAYER SCHEMES IN WRF MODEL BETWEEN CLEAR AND OVERCAST DAYS

2017 ◽  
Vol 60 (2) ◽  
pp. 141-153
Author(s):  
WANG Cheng-Gang ◽  
SHEN Ying-Jie ◽  
LUO Feng ◽  
CAO Le ◽  
YAN Jia-De ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Wrf Model ◽  
Comparison And Analysis

scholarly journals Impacts of the Lowest Model Level Height on the Performance of Planetary Boundary Layer Parameterizations

2012 ◽  
Vol 140 (2) ◽  
pp. 664-682 ◽  
Author(s):  
Hyeyum Hailey Shin ◽  
Song-You Hong ◽  
Jimy Dudhia
Keyword(s):  
Boundary Layer ◽  
Surface Layer ◽  
Planetary Boundary Layer ◽  
Numerical Models ◽  
Wrf Model ◽  
Weather Research And Forecasting ◽  
Implicit Assumption ◽  
Convective Model ◽  
Local Scheme ◽  
Level Height

The lowest model level height z1 is important in atmospheric numerical models, since surface layer similarity is applied to the height in most of the models. This indicates an implicit assumption that z1 is within the surface layer. In this study, impacts of z1 on the performance of planetary boundary layer (PBL) parameterizations are investigated. Three conceptually different schemes in the Weather Research and Forecasting (WRF) model are tested for one complete diurnal cycle: the nonlocal, first-order Yonsei University (YSU) and Asymmetric Convective Model version 2 (ACM2) schemes and the local, 1.5-order Mellor–Yamada–Janjić (MYJ) scheme. Surface variables are sensitive to z1 in daytime when z1 is below 12 m, even though the height is within the surface layer. Meanwhile during nighttime, the variables are systematically altered as z1 becomes shallower from 40 m. PBL structures show the sensitivity in the similar manner, but weaker. The order of sensitivity among the three schemes is YSU, ACM2, and MYJ. The significant sensitivity of the YSU parameterization comes from the PBL height calculation. This is considerably alleviated by excluding the thermal excess term in determining the PBL height when z1 is within the surface layer. The factor that specifies the ratio of nonlocal transport to total mixing is critical to the sensitivity of the ACM2 scheme. The MYJ scheme has no systematic sensitivity, since it is a local scheme. It is also noted that a numerical instability appears accompanying the unrealistic PBL structures when the grid spacing in the surface layer suddenly jumps.

scholarly journals Optimization of physical schemes in WRF model on cyclone simulations over Bay of Bengal using one-way ANOVA and Tukey’s test

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meenakshi Shenoy ◽  
P. V. S. Raju ◽  
Jagdish Prasad
Keyword(s):  
Boundary Layer ◽  
Tropical Cyclones ◽  
Planetary Boundary Layer ◽  
Bay Of Bengal ◽  
Wrf Model ◽  
India Meteorological Department ◽  
Cloud Microphysics ◽  
Optimal Combination ◽  
Cumulus Convection ◽  
Elimination Method

AbstractEvaluation of appropriate physics parameterization schemes for the Weather Research and Forecasting (WRF) model is vital for accurately forecasting tropical cyclones. Three cyclones Nargis, Titli and Fani have been chosen to investigate the combination of five cloud microphysics (MP), three cumulus convection (CC), and two planetary boundary layer (PBL) schemes of the WRF model (ver. 4.0) with ARW core with respect to track and intensity to determine an optimal combination of these physical schemes. The initial and boundary conditions for sensitivity experiments are drawn from the National Centers for Environmental Prediction (NCEP) global forecasting system (GFS) data. Simulated track and intensity of three cyclonic cases are compared with the India Meteorological Department (IMD) observations. One-way analysis of variance (ANOVA) is applied to check the significance of the data obtained from the model. Further, Tukey’s test is applied for post-hoc analysis in order to identify the cluster of treatments close to IMD observations for all three cyclones. Results are obtained through the statistical analysis; average root means square error (RMSE) of intensity throughout the cyclone period and time error at landfall with the step-by-step elimination method. Through the elimination method, the optimal scheme combination is obtained. The YSU planetary boundary layer with Kain–Fritsch cumulus convection and Ferrier microphysics scheme combination is identified as an optimal combination in this study for the forecasting of tropical cyclones over the Bay of Bengal.

scholarly journals Aerosol Lidar observations and model calculations of the Planetary Boundary Layer evolution over Greece, during the March 2006 Total Solar Eclipse

2007 ◽  
Vol 7 (24) ◽  
pp. 6181-6189 ◽  
Author(s):  
V. Amiridis ◽  
D. Melas ◽  
D. S. Balis ◽  
A. Papayannis ◽  
D. Founda ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Solar Eclipse ◽  
Wrf Model ◽  
Air Quality Model ◽  
Quality Model ◽  
Gaseous Species ◽  
Time Model ◽  
Model Calculations ◽  
Entrainment Zone

Abstract. An investigation of the Planetary Boundary Layer (PBL) height evolution over Greece, during the solar eclipse of 29 March 2006, is presented. Ground based observations were carried out using lidar detection and ranging devices and ground meteorological instruments, to estimate the height of the mixing layer (ML) before, during and after the solar eclipse in northern and southern parts of Greece exhibiting different sun obscuration. Data demonstrate that the solar eclipse has induced a decrease of the PBL height, indicating a suppression of turbulence activity similar to that during the sunset hours. The changes in PBL height were associated with a very shallow entrainment zone, indicating a significant weakening of the penetrative convection. Heat transfer was confined to a thinner layer above the ground. The thickness of the entrainment zone exhibited its minimum during the maximum of the eclipse, demonstrative of turbulence mechanisms suppression at that time. Model estimations of the PBL evolution were additionally conducted using the Comprehensive Air Quality Model with extensions (CAMx) coupled with the Weather Research and Forecasting model (WRF). Model-diagnosed PBL height decrease during the solar eclipse due to vertical transport decay, in agreement with the experimental findings; vertical profiles of atmospheric particles and gaseous species showed an important vertical mixing attenuation.

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