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

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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Assessment of Wind Energy for Nevada Using Towers and Mesoscale Modeling

ASME 2007 Energy Sustainability Conference ◽

10.1115/es2007-36198 ◽

2007 ◽

Cited By ~ 1

Author(s):

Darko Koracin ◽

Richard L. Reinhardt ◽

Marshall B. Liddle ◽

Travis McCord ◽

Domagoj Podnar ◽

...

Keyword(s):

High Resolution ◽

Wind Energy ◽

Wind Power ◽

Power Density ◽

Mesoscale Model ◽

Horizontal Resolution ◽

Mesoscale Modeling ◽

Annual Cycles ◽

Wind Power Density ◽

Mountainous Regions

The main objectives of the study were to support wind energy assessment for all of Nevada by providing two annual cycles of high-resolution mesoscale modeling evaluated by data from surface stations and towers, estimating differences between these annual cycles and standard wind maps, and providing wind and wind power density statistics at elevations relevant to turbine operations. In addition to the 65 existing Remote Automated Weather Stations in Nevada, four 50-m-tall meteorological towers were deployed in western Nevada to capture long-term wind characteristics and provide database input to verify and improve modeling results. The modeling methodology using Mesoscale Model 5 (MM5) was developed to provide wind and wind power density estimates representing mesoscale effects that include actual synoptic forcing during the two annual cycles (horizontal resolution on the order of 2 and 3 km). The results from the two annual simulation cycles show similar wind statistics with an average difference of less than 100 W/m2. The available TrueWind results for the wind power density at 50 m show greater values of wind power density compared to both MM5-simulated annual cycles for most of the area. However, mainly in the Sierras and the mountainous regions of southern and eastern Nevada, the MM5 simulations indicate greater values for wind power density. The results of this study suggest that the synthesis of the data from a network of tower observations and high-resolution mesoscale modeling is a crucial tool for assessing the wind power density in Nevada and, more generally, other topographically developed areas.

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Case study of the winter 2013/2014 extreme wave events off the west coast of Ireland

Advances in Science and Research ◽

10.5194/asr-15-145-2018 ◽

2018 ◽

Vol 15 ◽

pp. 145-157 ◽

Cited By ~ 4

Author(s):

Jelena Janjić ◽

Sarah Gallagher ◽

Frédéric Dias

Keyword(s):

High Resolution ◽

Mesoscale Model ◽

Wave Model ◽

Horizontal Resolution ◽

Winter Storms ◽

Wavewatch Iii ◽

High Resolution Analysis ◽

Resolution Analysis ◽

Directional Wave

Abstract. Using the third generation WAVEWATCH III wave model in an unstructured formulation, and driven by HARMONIE-AROME mesoscale model hourly winds with a 2.5 km horizontal resolution, we reproduce the winter storms of 2013/2014 and analyse their effect on the western coastline of Ireland. WAVEWATCH III was forced at its ocean boundaries by directional wave spectra obtained from the ECMWF ERA-Interim re-analysis dataset. The wave model has a high resolution grid (up to 225 m resolution in the nearshore) with around 20 000 nodes, producing an abundance of important wave parameters outputted hourly, enabling a high quality, high-resolution analysis of the winter storms of 2013/2014.

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Developing an operational high-resolution hydrometeorological system in a Mediterranean region: predictability analysis of two case studies

10.5194/egusphere-egu2020-14140 ◽

2020 ◽

Author(s):

Luca Furnari ◽

Alfonso Senatore ◽

Linus Magnusson ◽

Giuseppe Mendicino

Keyword(s):

High Resolution ◽

Weather Forecasting ◽

Mesoscale Model ◽

Initial Conditions ◽

Horizontal Resolution ◽

Lead Times ◽

Synoptic Conditions ◽

Hydrological Impact ◽

Forecasting System ◽

Modelling System

Given the expected increase in the frequency and intensity of severe weather events due to global warming, improving weather forecasting capability in terms of both spatial resolution and lead times is a key factor for reducing extreme events impact. The climate of the Calabrian peninsula (southern Italy) is dominated by the interactions of the air masses with the surrounding Mediterranean Sea and strongly influenced by its complex steep orography, which often amplifies precipitation amounts worsening ground effects. With the aim of investigating the capability of a state-of-the-art modelling chain to deliver accurate forecasts for civil protection purposes in the Calabria Region, an experimental high-resolution hydrometeorological modelling system has been developed recently at the Department of Environmental Engineering of the University of Calabria, providing forecasts up to the hydrological impact. The system is based on the Advanced Research WRF (ARW) mesoscale model in its version 3.9.1, with two one-way nested domains, the innermost having 2-km resolution. The boundary and initial conditions are provided operationally by the Global Forecasting System (GFS) in its high-resolution version and, for back-analysis purposes, by the European Centre for Medium-range Weather Forecasts&#8217; Integrated Forecasting System (IFS). Finally, to simulate the hydrological impact of the atmospheric forcing, the WRF-Hydro 5.0 modelling system in a one-way mode with a horizontal resolution of 200 m is linked to the system and applied on all the main river networks of the region.The accuracy and efficiency of the system have been tested with two events occurred in Autumn 2019. Though the synoptic conditions showed some significant differences, both the events affected mainly the central part of the region, causing about 230 mm and 200 mm of rainfall in 72 hours, on the 11-13 November 2019 and on the 24-26 November 2019, respectively. The analysis focused particularly on the predictability of the events, evaluating the forecast accuracy by considering lead times from one week early.Preliminary results highlight the ability to forecasts the events well in advance, proved by the comparison of the simulated rainfall with the ground-based observations and the reproduction of the main hydrological signals in the basins affected by the events.

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High-Resolution Climate Change Impact Analysis on Expected Future Water Availability in the Upper Jordan Catchment and the Middle East

Journal of Hydrometeorology ◽

10.1175/jhm-d-13-0153.1 ◽

2014 ◽

Vol 15 (4) ◽

pp. 1517-1531 ◽

Cited By ~ 15

Author(s):

Gerhard Smiatek ◽

Harald Kunstmann ◽

Andreas Heckl

Keyword(s):

Climate Change ◽

High Resolution ◽

Water Availability ◽

Impact Analysis ◽

River Flow ◽

Climate Model ◽

Mesoscale Model ◽

Global Climate Model ◽

Full Range ◽

The Impact

Abstract The impact of climate change on the future water availability of the upper Jordan River (UJR) and its tributaries Dan, Snir, and Hermon located in the eastern Mediterranean is evaluated by a highly resolved distributed approach with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) run at 18.6- and 6.2-km resolution offline coupled with the Water Flow and Balance Simulation Model (WaSiM). The MM5 was driven with NCEP reanalysis for 1971–2000 and with Hadley Centre Coupled Model, version 3 (HadCM3), GCM forcings for 1971–2099. Because only one regional–global climate model combination was applied, the results may not give the full range of possible future projections. To describe the Dan spring behavior, the hydrological model was extended by a bypass approach to allow the fast discharge components of the Snir to enter the Dan catchment. Simulation results for the period 1976–2000 reveal that the coupled system was able to reproduce the observed discharge rates in the partially karstic complex terrain to a reasonable extent with the high-resolution 6.2-km meteorological input only. The performed future climate simulations show steadily rising temperatures with 2.2 K above the 1976–2000 mean for the period 2031–60 and 3.5 K for the period 2070–99. Precipitation trends are insignificant until the middle of the century, although a decrease of approximately 12% is simulated. For the end of the century, a reduction in rainfall ranging between 10% and 35% can be expected. Discharge in the UJR is simulated to decrease by 12% until 2060 and by 26% until 2099, both related to the 1976–2000 mean. The discharge decrease is associated with a lower number of high river flow years.

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A Comparative Evaluation of a Mesoscale Model and Atmospheric Global Circulation Model for Air Quality Simulation: A Multiscale, Multisite Evaluation

ISRN Meteorology ◽

10.5402/2012/826074 ◽

2012 ◽

Vol 2012 ◽

pp. 1-15 ◽

Cited By ~ 2

Author(s):

P. Goswami ◽

J. Baruah

Keyword(s):

High Resolution ◽

Mesoscale Model ◽

Large City ◽

Circulation Model ◽

Urban Pollution ◽

Atmospheric Pollutants ◽

Scale Model ◽

Global Circulation Model ◽

Global Circulation ◽

Meso Scale

Concentrations of atmospheric pollutants are strongly influenced by meteorological parameters like rainfall, relative humidity and wind advection. Thus accurate specifications of the meteorological fields, and their effects on pollutants, are critical requirements for successful modelling of air pollution. In terms of their applications, pollutant concentration models can be used in different ways; in one, short term high resolution forecasts are generated to predict and manage urban pollution. Another application of dynamical pollution models is to generate outlook for a given airbasin, such as over a large city. An important question is application-specific model configuration for the meteorological simulations. While a meso-scale model provides a high-resolution configuration, a global model allows better simulation of large-sale fields through its global environment. Our objective is to comparatively evaluate a meso-scale atmospheric model (MM5) and atmospheric global circulation model (AGCM) in simulating different species of pollutants over different airbasins. In this study we consider four locations: ITO (Central Delhi), Sirifort (South Delhi), Bandra (Mumbai) and Karve Road (Pune). The results show that both the model configurations provide comparable skills in simulation of monthly and annual loads, although the skill of the meso-scale model is somewhat higher, especially at shorter time scales.

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An Efficient Dual-Resolution Approach for Ensemble Data Assimilation and Tests with Simulated Doppler Radar Data

Monthly Weather Review ◽

10.1175/2007mwr2120.1 ◽

2008 ◽

Vol 136 (3) ◽

pp. 945-963 ◽

Cited By ~ 31

Author(s):

Jidong Gao ◽

Ming Xue

Keyword(s):

High Resolution ◽

Data Assimilation ◽

Radial Velocity ◽

Computational Cost ◽

Radar Data ◽

Horizontal Resolution ◽

Velocity Data ◽

Background Error ◽

Cross Covariance ◽

Radial Velocity Data

Abstract A new efficient dual-resolution (DR) data assimilation algorithm is developed based on the ensemble Kalman filter (EnKF) method and tested using simulated radar radial velocity data for a supercell storm. Radar observations are assimilated on both high-resolution and lower-resolution grids using the EnKF algorithm with flow-dependent background error covariances estimated from the lower-resolution ensemble. It is shown that the flow-dependent and dynamically evolved background error covariances thus estimated are effective in producing quality analyses on the high-resolution grid. The DR method has the advantage of being able to significantly reduce the computational cost of the EnKF analysis. In the system, the lower-resolution ensemble provides the flow-dependent background error covariance, while the single-high-resolution forecast and analysis provides the benefit of higher resolution, which is important for resolving the internal structures of thunderstorms. The relative smoothness of the covariance obtained from the lower 4-km-resolution ensemble does not appear to significantly degrade the quality of analysis. This is because the cross covariance among different variables is of first-order importance for “retrieving” unobserved variables from the radar radial velocity data. For the DR analysis, an ensemble size of 40 appears to be a reasonable choice with the use of a 4-km horizontal resolution in the ensemble and a 1-km resolution in the high-resolution analysis. Several sensitivity tests show that the DR EnKF system is quite robust to different observation errors. A 4-km thinned data resolution is a compromise that is acceptable under the constraint of real-time applications. A data density of 8 km leads to a significant degradation in the analysis.

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NAM Model Forecasts of Warm-Season Quasi-Stationary Frontal Environments in the Central United States

Weather and Forecasting ◽

10.1175/2010waf2222394.1 ◽

2010 ◽

Vol 25 (4) ◽

pp. 1281-1292 ◽

Cited By ~ 3

Author(s):

Shih-Yu Wang ◽

Adam J. Clark

Keyword(s):

United States ◽

Mesoscale Model ◽

Convective Available Potential Energy ◽

Warm Season ◽

Correlation Coefficients ◽

Precipitable Water ◽

Wind Fields ◽

Vapor Flux ◽

Convective Systems ◽

Central United States

Abstract Using a composite procedure, North American Mesoscale Model (NAM) forecast and observed environments associated with zonally oriented, quasi-stationary surface fronts for 64 cases during July–August 2006–08 were examined for a large region encompassing the central United States. NAM adequately simulated the general synoptic features associated with the frontal environments (e.g., patterns in the low-level wind fields) as well as the positions of the fronts. However, kinematic fields important to frontogenesis such as horizontal deformation and convergence were overpredicted. Surface-based convective available potential energy (CAPE) and precipitable water were also overpredicted, which was likely related to the overprediction of the kinematic fields through convergence of water vapor flux. In addition, a spurious coherence between forecast deformation and precipitation was found using spatial correlation coefficients. Composite precipitation forecasts featured a broad area of rainfall stretched parallel to the composite front, whereas the composite observed precipitation covered a smaller area and had a WNW–ESE orientation relative to the front, consistent with mesoscale convective systems (MCSs) propagating at a slight right angle relative to the thermal gradient. Thus, deficiencies in the NAM precipitation forecasts may at least partially result from the inability to depict MCSs properly. It was observed that errors in the precipitation forecasts appeared to lag those of the kinematic fields, and so it seems likely that deficiencies in the precipitation forecasts are related to the overprediction of the kinematic fields such as deformation. However, no attempts were made to establish whether the overpredicted kinematic fields actually contributed to the errors in the precipitation forecasts or whether the overpredicted kinematic fields were simply an artifact of the precipitation errors. Regardless of the relationship between such errors, recognition of typical warm-season environments associated with these errors should be useful to operational forecasters.

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Comparison of high-resolution wind fields extracted from TerraSAR-X SAR imagery with predictions from the WRF mesoscale model

Journal of Geophysical Research Atmospheres ◽

10.1029/2011jc007526 ◽

2012 ◽

Vol 117 (C2) ◽

pp. n/a-n/a ◽

Cited By ~ 13

Author(s):

Donald R. Thompson ◽

Jochen Horstmann ◽

Alexis Mouche ◽

Nathaniel S. Winstead ◽

Raymond Sterner ◽

...

Keyword(s):

High Resolution ◽

Mesoscale Model ◽

Wind Fields ◽

Sar Imagery

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Role of land state in a high resolution mesoscale model for simulating the Uttarakhand heavy rainfall event over India

Journal of Earth System Science ◽

10.1007/s12040-016-0678-x ◽

2016 ◽

Vol 125 (3) ◽

pp. 475-498 ◽

Cited By ~ 11

Author(s):

P V Rajesh ◽

S Pattnaik ◽

D Rai ◽

K K Osuri ◽

U C Mohanty ◽

...

Keyword(s):

High Resolution ◽

Heavy Rainfall ◽

Mesoscale Model ◽

Rainfall Event ◽

Heavy Rainfall Event

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Investigating Hector Convective Development and Microphysical Structure Using High-Resolution Model Simulations, Ground-Based Radar Data, and TRMM Satellite Data

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-13-0107.1 ◽

2014 ◽

Vol 71 (4) ◽

pp. 1353-1370 ◽

Cited By ~ 3

Author(s):

Sabrina Gentile ◽

Rossella Ferretti ◽

Frank Silvio Marzano

Keyword(s):

High Resolution ◽

Conceptual Model ◽

Vertical Structure ◽

Mesoscale Model ◽

Tropical Rainfall Measuring Mission ◽

Sea Breeze ◽

Radar Data ◽

Full Life Cycle ◽

Resolution Model ◽

High Resolution Model

Abstract One event of a tropical thunderstorm typically observed in northern Australia, known as Hector, is investigated using high-resolution model output from the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) observations from a ground-based weather radar located in Berrimah (Australia) and data from the Tropical Rainfall Measuring Mission (TRMM) satellite. The analysis is carried out by tracking the full life cycle of Hector from prestorm stage to the decaying stage. In both the prestorm stage, characterized by nonprecipitating cells, and the triggering stage, when the Hector storm is effectively initiated, an analysis is performed with the aid of high-spatial-and-temporal-resolution MM5 output and the Berrimah ground-based radar imagery. During the mature (“old”) stage of Hector, considering the conceptual model for tropical convection suggested by R. Houze, TRMM Microwave Imager satellite-based data were added to ground-based radar data to analyze the storm vertical structure (dynamics, thermodynamics, and hydrometeor contents). Model evaluation with respect to observations (radar reflectivity and TRMM data) suggests that MM5 performed fairly well in reproducing the dynamics of Hector, providing support to the assertion that the strength of convection, in terms of vertical velocity, largely contributes to the vertical distribution of hydrometeors. Moreover, the stages of the storm and its vertical structure display good agreement with Houze’s aforementioned conceptual model. Finally, it was found that the most important triggering mechanisms for this Hector event are topography, the sea breeze, and a gust front produced by previous convection.

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