scholarly journals Numerical Simulations of Sea-Breeze Circulations over Northwest Hawaii*

2005 ◽  
Vol 20 (6) ◽  
pp. 827-846 ◽  
Author(s):  
Yongxin Zhang ◽  
Yi-Leng Chen ◽  
Thomas A. Schroeder ◽  
Kevin Kodama
Keyword(s):  
Land Surface ◽  
Onset Time ◽  
Surface Air Temperature ◽  
Sea Breeze ◽  
Horizontal Resolution ◽  
Trade Wind ◽  
Surface Model ◽  
Time Duration ◽  
Sea Breezes ◽  
Model Simulations

Abstract Sea-breeze cases during 23–28 June 1978 over northwest Hawaii are simulated using the National Centers for Environmental Prediction (NCEP) Mesoscale Spectral Model (MSM) coupled with an advanced Land Surface Model (LSM) with 3-km horizontal resolution. Subjective analyses show that except for 27 June, the MSM–LSM-predicted onset time, duration, and vertical extent of the sea breezes agree well with observations. The largest mean absolute errors for surface air temperature occur at the coastal stations under strong trade wind conditions (e.g., 23 and 27 June). The model-simulated rainfall distribution in association with sea-breeze fronts is consistent with observations. Sensitivity tests demonstrate the modulation of sea-breeze behavior by surface properties. High-resolution (1 km) MSM–LSM simulations for 23 and 27 June show improvements over the 3-km MSM–LSM in reproducing the observed sea breezes through a better representation of local terrain and a better simulation of orographically enhanced trades channeling through the Waimea Saddle. Deficiencies noted in the model simulations include 1) sea-breeze speeds are more than 2–3 m s−1 weaker than observations, and 2) horizontal penetration of sea breezes is generally overestimated. These deficiencies in the model simulations are primarily related to two factors: one is the underestimation of the trade wind speeds in the initialization from the NCEP–NCAR reanalysis data that is favoring the farther penetration of the sea breezes, and the other is the uncertainties in the thermal properties of the lava rocks that affect the surface temperature and the sea-breeze speed.

scholarly journals Sensitivity of Simulated Sea Breezes to Initial Conditions in Complex Coastal Regions

2016 ◽  
Vol 144 (4) ◽  
pp. 1299-1320 ◽  
Author(s):  
Kelly Lombardo ◽  
Eric Sinsky ◽  
Yan Jia ◽  
Michael M. Whitney ◽  
James Edson
Keyword(s):  
New England ◽  
Land Surface ◽  
Mesoscale Model ◽  
Initial Conditions ◽  
Sea Breeze ◽  
Horizontal Resolution ◽  
Sea Surface ◽  
Initial Surface ◽  
Sea Breezes ◽  
Mesoscale Simulations

Abstract Mesoscale simulations of sea breezes are sensitive to the analysis product used to initialize the simulations, primarily due to the representation of the coastline and the coastal sea surface temperatures (SSTs) in the analyses. The use of spatially coarse initial conditions, relative to the horizontal resolution of the mesoscale model grid, can introduce errors in the representation of coastal SSTs, in part due to the incorrect designation of the land surface. As a result, portions of the coastal ocean are initialized with land surface temperature values and vice versa. The diurnal variation of the sea surface is typically smaller than over land on meso- and synoptic-scale time scales. Therefore, it is common practice to retain a temporally static SST in numerical simulations, causing initial SST errors to persist through the duration of the simulation. These SST errors influence horizontal coastal temperature and humidity gradients and thereby the development of the sea-breeze circulations. The authors developed a technique to modify the initial surface conditions created from a reanalysis product [North American Regional Reanalysis (NARR)] for simulations of two sea-breeze events over the New England coast to more accurately represent the finescale structure of the coastline and the spatial representation of the coastal land surface and SST. Using this technique, the coastal SST (2-m temperature) RMSE is reduced from as much as 25°–1°C (7°–1°C), contributing to a more accurate propagation of the sea-breeze front. Techniques described in this work may be important for mesoscale simulations and forecasts of other coastal phenomena.

scholarly journals Impacts of a Parameterization Deficiency on Offline and Coupled Land Surface Model Simulations

2003 ◽  
Vol 4 (5) ◽  
pp. 901-914 ◽  
Author(s):  
Yuqiong Liu ◽  
Luis A. Bastidas ◽  
Hoshin V. Gupta ◽  
Soroosh Sorooshian
Keyword(s):  
Land Surface ◽  
Land Surface Model ◽  
Surface Model ◽  
Model Simulations

scholarly journals Prediction of Hub Height Winds over the Plateau Terrain by using WRF /YSU/Noah and Statistical Forecast

2017 ◽  
Vol 21 (1) ◽  
pp. 37 ◽  
Author(s):  
Hua Deng ◽  
Yan Li ◽  
Yingchao Zhang ◽  
Hou Zhou ◽  
Peipei Cheng ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Numerical Weather Prediction ◽  
Land Surface ◽  
Weather Prediction ◽  
Horizontal Resolution ◽  
Least Square ◽  
Support Vector ◽  
Surface Model ◽  
Short Term ◽  
Numerical Weather

The forecast of wind energy is closely linked to the prediction of the variation of winds over very short time intervals. Four wind towers located in the Inner Mongolia were selected to understand wind power resources in the compound plateau region. The mesoscale weather research and forecasting combining Yonsei University scheme and Noah land surface model (WRF/YSU/Noah) with 1-km horizontal resolution and 10-min time resolution were used to be as the wind numerical weather prediction (NWP) model. Three statistical techniques, persistence, back-propagation artificial neural network (BP-ANN), and least square support vector machine (LS-SVM) were used to improve the wind speed forecasts at a typical wind turbine hub height (70 m) along with the WRF/YSU/Noah output. The current physical-statistical forecasting techniques exhibit good skill in three different time scales: (1) short-term (day-ahead); (2) immediate-short-term (6-h ahead); and (3) nowcasting (1-h ahead). The forecast method, which combined WRF/YSU/Noah outputs, persistence, and LS-SVM methods, increases the forecast skill by 26.3-49.4% compared to the direct outputs of numerical WRF/YSU/Noah model. Also, this approach captures well the diurnal cycle and seasonal variability of wind speeds, as well as wind direction. Predicción de vientos en una altiplanicie a la altura del eje con el esquema de la Universidad Yonsei/Modelo Superficie Terrestre Noah y la predicción estadísticaResumenLa estimación de la energía eólica está relacionada con la predicción en la variación de los vientos en pequeños intervalos de tiempo. Se seleccionaron cuatro torres eólicas ubicadas al interior de Mongolia para estudiar los recursos eólicos en la complejidad de un altiplano. Se utilizó la investigación climática a mesoscala y la combinación del esquema de la Universidad Yonsei con el Modelo de Superficie Terrestre Noah (WRF/YSU/Noah), con resolución de 1km horizontal y 10 minutos, como el modelo numérico de predicción meteorológica (NWP, del inglés Numerical Weather Prediction). Se utilizaron tres técnicas estadísticas, persistencia, propagación hacia atrás en redes neuronales artificiales y máquina de vectores de soporte-mínimos cuadrados (LS-SVM, del inglés Least Square Support Vector Machine), para mejorar la predicción de la velocidad del viento en una turbina con la altura del eje a 70 metros y se complementó con los resultados del WRF/YSU/Noah. Las técnicas de predicción físico-estadísticas actuales tienen un buen desempeo en tres escalas de tiempo: (1) corto plazo, un día en adelante; (2) mediano plazo, de seis días en adelante; (3) cercano, una hora en adelante. Este método de predicción, que combina los resultados WRF/YSU/Noah con los métodos de persistencia y LS-SVM incrementa la precisión de predicción entre 26,3 y 49,4 por ciento, comparado con los resultados directos del modelo numérico WRF/YSU/Noah. Además, este método diferencia la variabilidad de las estaciones y el ciclo diurno en la velocidad y la dirección del viento.

scholarly journals A Numerical Study of “Hijikawa-Arashi”: A Thermally Driven Gap Wind Visualized by Nocturnal Fog

2019 ◽  
Vol 58 (6) ◽  
pp. 1293-1307
Author(s):  
Junshi Ito ◽  
Toshiyuki Nagoshi ◽  
Hiroshi Niino
Keyword(s):  
Land Surface ◽  
Numerical Study ◽  
Sea Breeze ◽  
Early Morning ◽  
Horizontal Resolution ◽  
Local Wind ◽  
The Seto Inland Sea ◽  
Thermally Driven ◽  
Fine Resolution ◽  
Autumn And Winter

AbstractA renowned local wind in Japan, “Hijikawa-Arashi,” is a thermally driven nocturnal gap wind accompanied by fog. The wind is visually identified by the fog along the valley of the Hijikawa River between the Ozu basin and the Seto Inland Sea during the early morning in autumn and winter. A fine-resolution numerical model is employed to reproduce the main observed features of Hijikawa-Arashi. A vertical resolution of 10 m or less at the lowest level is required to express the nocturnal radiative cooling of the land that is required for fog formation in the basin, and fine horizontal resolution is necessary to express a realistic valley through which the fog is advected to the sea. Multiple hydraulic jumps accompanied by supercritical flow occur because of the complex topography. Both moisture transport by the sea breeze during the daytime and evaporation from the land surface are important for accumulating moisture to produce the fog.

scholarly journals Impacts of land surface model and land use data on WRF model simulations of rainfall and temperature over Lake Tana Basin, Ethiopia

Heliyon ◽  
2019 ◽  
Vol 5 (9) ◽  
pp. e02469 ◽  
Author(s):  
Achenafi Teklay ◽  
Yihun T. Dile ◽  
Dereje H. Asfaw ◽  
Haimanote K. Bayabil ◽  
Kibruyesfa Sisay
Keyword(s):  
Land Use ◽  
Land Surface ◽  
Wrf Model ◽  
Land Surface Model ◽  
Surface Model ◽  
Lake Tana ◽  
Model Simulations ◽  
Lake Tana Basin

Preliminary Results of Simulation of SOCRATES period with Global System for Atmospheric Modeling

2020 ◽  
Author(s):  
Marat Khairoutdinov ◽  
Christopher Bretherton
Keyword(s):  
Land Surface ◽  
Weather Forecasting ◽  
Storm Track ◽  
Land Surface Model ◽  
Cloud Microphysics ◽  
Horizontal Resolution ◽  
Atmospheric Modeling ◽  
Surface Model ◽  
Grid Spacing ◽  
Reanalysis Dataset

<p>The global version of the cloud-resolving System for Atmospheric Modeling (SAM) is used to simulate the global evolution of clouds and precipitation during the SOCRATES field campaign In Feb 2018 with particular focus on the Southern Ocean storm track region. The model has nonuniform horizontal resolution, which ranges from 4-km horizontal grid spacing over the Tropics up to 2-3 km isotropic grid-spacing over mid-latitudes. It includes a realistic topography and comprehensive land-surface model. The sea-surface temperature and sea ice are prescribed from observations. The results of two types of simulations are presented, weather-forecasting and observed-weather-nudged over 24-hour time scale; for the latter, hourly ERA5 reanalysis dataset is used. The cloud properties are compared to the SOCRATES observations. The sensitivity of the results to the choice of cloud microphysics, from simple single-moment to double-moment, is also discussed.</p>

scholarly journals Integration of Lidar Data into a Coupled Mesoscale–Land Surface Model: A Theoretical Assessment of Sensitivity of Urban–Coastal Mesoscale Circulations to Urban Canopy Parameters

2012 ◽  
Vol 29 (3) ◽  
pp. 328-346 ◽  
Author(s):  
Michael Carter ◽  
J. Marshall Shepherd ◽  
Steve Burian ◽  
Indu Jeyachandran
Keyword(s):  
Urban Environment ◽  
Land Surface ◽  
Urban Canopy ◽  
Vertical Motion ◽  
Sea Breeze ◽  
Surface Model ◽  
Lidar Data ◽  
Mesoscale Circulations ◽  
The Impact ◽  
Urban Weather

Abstract Urban–coastal circulations affect urban weather, dispersion and transport of pollutants and contaminants, and climate. Proper characterization and prediction of thermodynamic and dynamic processes in such environments are warranted. A new generation of observation and modeling systems is enabling unprecedented characterization of the three-dimensionality of the urban environment, including morphological parameters. Urban areas of Houston, Texas, are classified according to lidar-measured building heights and assigned typical urban land surface parameters appropriate to each classification. The lidar data were degraded from 1 m to the model resolution (1 km) with the goal of evaluating the impact of degraded resolution urban canopy parameters (UCPs) and three-dimensionality on the coastal–urban mesoscale circulations in comparison to typical two-dimensional urban slab approaches. The study revealed complex interactions between the sea breeze and urban heat island and offers a novel diagnostic tool, the bulk Richardson shear number, for identifying shallow mesoscale circulation. Using the Advanced Research Weather Research and Forecasting model (ARW-WRF) coupled to an atmosphere–land surface–urban canopy model, the authors simulated a theoretical sea-breeze day and confirmed that while coastal morphology can itself lead to complex sea-breeze front structures, including preferred areas of vertical motion, the urban environment can have an impact on the evolution of the sea-breeze mesoscale boundary. The inclusion of lidar-derived UCPs, even at degraded resolution, in the model’s land surface representation can lead to significant differences in patterns of skin surface temperature, convergence, and vertical motion, which have implications for many aspects of urban weather.

scholarly journals Copernicus European regional reanalysis

2021 ◽  
Author(s):  
Semjon Schimanke ◽  
Ludvig Isaksson ◽  
Lisette Edvinsson ◽  
Martin Ridal ◽  
Lars Berggren ◽  
...  
Keyword(s):  
Land Surface ◽  
Land Surface Model ◽  
Remote Sensing Data ◽  
Horizontal Resolution ◽  
Surface Model ◽  
Climate Data ◽  
Data Store ◽  
Regional Reanalysis ◽  
Analysis System ◽  
European Regional

<p>The Copernicus European regional reanalysis (https://climate.copernicus.eu/regional-reanalysis-europe) is produced as part of the Copernicus Climate Change Service (C3S). The presentation will introduce the service and its main objectives as well as it will give and overview of available data. Data quality will be demonstrated by comparison with ERA5 and other gridded datasets.</p><p>In the first phase of the service, systems inherited from the FP7 project UERRA (Uncertainties in Ensembles of Regional ReAnalyses, http://www.uerra.eu) were applied extending the UERRA-HARMONIE as well as the MESCAN-SURFEX datasets. These datasets contain analyses of the atmosphere, the surface and the soil. UERRA-HARMONIE is a full model system including a 3D-Var data assimilation scheme for upper air observations and an OI-scheme for surface observations. MESCAN-SURFEX is a complementary 2D surface analysis system interfaced to a land surface model. Data is available for entire Europe at a horizontal resolution of 11 km for UERRA-HARMONIE and at 5.5 km for MESCAN-SURFEX. The systems provide four analyses per day – at 0 UTC, 6 UTC, 12 UTC, and 18 UTC. Between the analyses ranges, forecasts of the systems are available with hourly resolution. More than fifty parameters are available on various level types. Data are available for the period 1961 – July 2019 through Copernicus Climate Data Store (CDS).</p><p>In spring 2020, the service started the production of the next generation regional reanalysis. The successor comprises three components:<br>- CERRA (5.5 km horizontal resolution)<br>- CERRA-EDA (10-member ensemble at 11 km resolution)<br>- CERRA-Land (5.5 km horizontal resolution)</p><p>In addition to the higher resolution, CERRA is more sophisticated than UERRA. For instance, more observations are assimilated into CERRA, in particular remote sensing data. CERRA is produced with 3-hourly cycling and a flow depending part of the B-matrix is derived from CERRA-EDA. The production of CERRA, CERRA-EDA and CERRA-Land will complete in September/October 2021 and data will become available in the CDS shortly thereafter.</p><p>The quality of the regional reanalysis in comparison to ERA5 will be shown with results of the standard HARMONIE-verification package as well as based on certain case studies. For instance, the winter storm Gudrun (January 2005, southern Sweden) will be investigated.</p>

scholarly journals Impacts of boundary layer turbulence and land surface process parameterizations on simulated sea breeze characteristics

2009 ◽  
Vol 27 (6) ◽  
pp. 2303-2320 ◽  
Author(s):  
J.-F. Miao ◽  
K. Wyser ◽  
D. Chen ◽  
H. Ritchie
Keyword(s):  
Boundary Layer ◽  
West Coast ◽  
Land Surface ◽  
Sea Breeze ◽  
Surface Model ◽  
Surface Process ◽  
Vertical Circulation ◽  
Land Surface Process ◽  
Swedish West Coast ◽  
Boundary Layer Turbulence

Abstract. This paper investigates the sensitivity of sea breeze (SB) simulations to combinations of boundary-layer turbulence and land-surface process parameterizations implemented in the MM5 mesoscale meteorological mode for an observed SB case over the Swedish west coast. Various combinations from four different planetary boundary layer (PBL) schemes [Blackadar, Gayno-Seaman (GS), Eta, MRF], and two land surface model (LSM) schemes (SLAB, Noah) with different complexity are designed to simulate a typical SB case over the Swedish west coast. The simulations are conducted using two-way interactively nested grids. Simulated 10-m winds are compared against observed near-surface wind data from the GÖTE2001 campaign to examine the diurnal cycle of wind direction and speed for SB timing. The SB (vertical) circulation is also compared in the different experiments. The results show that the different combinations of PBL and LSM parameterization schemes result in different SB timing and vertical circulation characteristics. All experiments predict a delayed SB. The vertical component of the SB circulation varies in the experiments, among which the GS PBL scheme produces the strongest SB circulation. Evident differences between the SLAB and Noah LSMs are also found, especially in maximum of updraft and downdraft velocities of the SB vertical circulation. The results have significant implications for convective initiation, air quality studies and other environmental problems in coastal areas.

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