Mesoscale Wind Research Articles

Chemical and biological investigations on Nidularium innocentii Lemaire

SUMMARY OF COMMUNICATIONS STORMSURGEMODELINGANDFORECASTFORTHESOUTH-WESTERN ATLANTIC OCEAN RicardodeCamargo 1 ,JosephHarari 2 andPedroL.S.Dias 11 Department of Atmospheric Sciences, Institute of Astronomyand Geophysics of University of Sao Paulo. 2 Department of Physical Oceanography, Institute of Oceanogra-phy of University of Sao Paulo.Presented by IgorG.Pacca StormsurgesovertheAtlanticCoastofSouthAmer-ica have important effects in terms of coastal erosion,sediment dynamics and harbor activities, among manyothers. The aim of this project is to present a numeri-cal system for storm surge forecasts in the South-WesternAtlantic Ocean, basically from the northern Argentineanshelf (42 ◦ S) to the Rio de Janeiro coast (21 ◦ S), hereaftercalled SWAO region. The idealized system would be ableto provide disturbances in the surface elevation and shelfcurrents fields related to the passage of meteorologicalsystems over the studied area. It is very important to men-tion the cyclogenetic characteristics of the region of inter-est, which play an important role for storm surge events.Mesoscale meteorological forecasts for the studyarea can be supplied by operational runs of the RegionalAtmospheric Modelling Systems (RAMS) at the Depart-mentofAtmosphericSciencesofUniversityofSaoPaulo.The model assimilates large scale analysed and predictedfields provided by global models (normally NCEP andCPTEC, and occasionally ECMWF) and improves theforecast considering regional aspects in a 32km grid.The oceanic part of the proposed system is basedon the Princeton Ocean Model (POM) simulations for theSWAO area with approximately 10km resolution, whichwillbeforcedbypredictedwindfieldsprovidedbyRAMSas described above. The use of mesoscale wind fields inprevious hindcasting simulations shown better results incomparison to wind fields directly from global models.—( November 19, 1999 ).

Chemical studies on cultivation of Echinodorus grandiflorus (cham. & schl.) mich.

SUMMARY OF COMMUNICATIONS STORMSURGEMODELINGANDFORECASTFORTHESOUTH-WESTERN ATLANTIC OCEAN RicardodeCamargo 1 ,JosephHarari 2 andPedroL.S.Dias 11 Department of Atmospheric Sciences, Institute of Astronomyand Geophysics of University of Sao Paulo. 2 Department of Physical Oceanography, Institute of Oceanogra-phy of University of Sao Paulo.Presented by IgorG.Pacca StormsurgesovertheAtlanticCoastofSouthAmer-ica have important effects in terms of coastal erosion,sediment dynamics and harbor activities, among manyothers. The aim of this project is to present a numeri-cal system for storm surge forecasts in the South-WesternAtlantic Ocean, basically from the northern Argentineanshelf (42 ◦ S) to the Rio de Janeiro coast (21 ◦ S), hereaftercalled SWAO region. The idealized system would be ableto provide disturbances in the surface elevation and shelfcurrents fields related to the passage of meteorologicalsystems over the studied area. It is very important to men-tion the cyclogenetic characteristics of the region of inter-est, which play an important role for storm surge events.Mesoscale meteorological forecasts for the studyarea can be supplied by operational runs of the RegionalAtmospheric Modelling Systems (RAMS) at the Depart-mentofAtmosphericSciencesofUniversityofSaoPaulo.The model assimilates large scale analysed and predictedfields provided by global models (normally NCEP andCPTEC, and occasionally ECMWF) and improves theforecast considering regional aspects in a 32km grid.The oceanic part of the proposed system is basedon the Princeton Ocean Model (POM) simulations for theSWAO area with approximately 10km resolution, whichwillbeforcedbypredictedwindfieldsprovidedbyRAMSas described above. The use of mesoscale wind fields inprevious hindcasting simulations shown better results incomparison to wind fields directly from global models.—( November 19, 1999 ).

Secondary metabolites from Ananas bracteatus Lindley (Bromeliaceae)

SUMMARY OF COMMUNICATIONS STORMSURGEMODELINGANDFORECASTFORTHESOUTH-WESTERN ATLANTIC OCEAN RicardodeCamargo 1 ,JosephHarari 2 andPedroL.S.Dias 11 Department of Atmospheric Sciences, Institute of Astronomyand Geophysics of University of Sao Paulo. 2 Department of Physical Oceanography, Institute of Oceanogra-phy of University of Sao Paulo.Presented by IgorG.Pacca StormsurgesovertheAtlanticCoastofSouthAmer-ica have important effects in terms of coastal erosion,sediment dynamics and harbor activities, among manyothers. The aim of this project is to present a numeri-cal system for storm surge forecasts in the South-WesternAtlantic Ocean, basically from the northern Argentineanshelf (42 ◦ S) to the Rio de Janeiro coast (21 ◦ S), hereaftercalled SWAO region. The idealized system would be ableto provide disturbances in the surface elevation and shelfcurrents fields related to the passage of meteorologicalsystems over the studied area. It is very important to men-tion the cyclogenetic characteristics of the region of inter-est, which play an important role for storm surge events.Mesoscale meteorological forecasts for the studyarea can be supplied by operational runs of the RegionalAtmospheric Modelling Systems (RAMS) at the Depart-mentofAtmosphericSciencesofUniversityofSaoPaulo.The model assimilates large scale analysed and predictedfields provided by global models (normally NCEP andCPTEC, and occasionally ECMWF) and improves theforecast considering regional aspects in a 32km grid.The oceanic part of the proposed system is basedon the Princeton Ocean Model (POM) simulations for theSWAO area with approximately 10km resolution, whichwillbeforcedbypredictedwindfieldsprovidedbyRAMSas described above. The use of mesoscale wind fields inprevious hindcasting simulations shown better results incomparison to wind fields directly from global models.—( November 19, 1999 ).

Mesoscale Wind Field Modifications over the Baltic Sea

For two consecutive days during spring 1997, the windfield over the Baltic Sea has been studied. Thestrength of the geostrophic wind speed is the majordifference in synoptic conditions between these twodays. During both days, the mesoscale wind field overmost of the Baltic Sea is quite heterogeneous; themodifications primarily being caused by the land-seacontrasts. On the day with the weaker wind speed,sea-breeze circulations develop. As a consequence, thewind direction at lower levels is more or lessopposite to the geostrophic over large areas of theBaltic Sea and the surface wind speed decreases withoffshore distance. Wind speed maxima caused by the seabreezes are found along the east coasts in the studiedarea. For the other day, the slow growth of a stableinternal boundary layer over the sea also gives asurface wind speed decrease with offshore distancefrom the coast.

Doppler radar wind data assimilation in mesoscale analysis

The development of efficient remote sensing tools, satellite and ground-based, calls for an integrated use of the newly available data and NWP techniques to produce very-short-range operational forecasts. The Local Analysis and Prediction System (LAPS) has been developed by NOAA-FSL as an integrated system to ingest and analyse meteorological data from different observational sources, i.e. mesonet and regular surface data, radar and profiler data, and satellite imagery. The resulting 3-D data-set contains all relevant meteorological parameters, that is temperature, pressure, humidity, wind, clouds, and other derived variables. Radar data play a key role in accurately describing the mesoscale wind pattern, when no others observational sources are available, particularly at low level where the correlation coefficient between radar analysis vs raob analysis grew at 0.99-0.95. The resulting fields are used in a continuous assimilation cycle with a limited area model for improving the forecast skill over a meso-β domain. The overall system is presented highlighting the impact of Doppler radar data in the reconstruction of missing features and comparing the different scenarios that can be foreseen.

Modeling of photochemical air pollution in the Barcelona area with highly disaggregated anthropogenic and biogenic emissions

The city of Barcelona and its surrounding area, located in the western Mediterranean basin, can reach high levels of O 3 in spring and summertime. To study the origin of this photochemical pollution, a numerical modeling approach was adopted and the episode that took place between 3 and 5 August 1990 was chosen. The main meteorological mesoscale flows were reproduced with the meteorological non-hydrostatic mesoscale model MEMO for 5 August 1990, when weak pressure synoptic conditions took place. The emissions inventory was calculated with the EIM-LEM model, giving highly disaggregated anthropogenic and biogenic emissions in the zone studied, an 80×80 km 2 area around the city of Barcelona. Major sources of VOC were road traffic (51%) and vegetation (34%), while NO x were mostly emitted by road traffic (88%). However, emissions from some industrial stacks can be locally important and higher than those from road traffic. Photochemical simulation with the MARS model revealed that the combination of mesoscale wind flows and the above-mentioned local emissions is crucial in the production and transport of O 3 in the area. On the other hand, the geostrophic wind also played an important role in advecting the air masses away from the places O 3 had been generated. The model simulations were also evaluated by comparing meteorological measurements from nine surface stations and concentration measurements from five surface stations, and the results proved to be fairly satisfactory.

Wind retrieval over the ocean using synthetic aperture radar with C-band HH polarization

The high spatial resolution and large coverage of satellite-based synthetic aperture radars (SAR) offers a unique opportunity to derive mesoscale wind fields over the ocean surface, providing high resolution wind fields near the shore. For this purpose, algorithms were developed and tested using the ScanSAR aboard the Canadian satellite RADARSAT-1, operating at C-band with horizontal polarization in transmit and receive. Wind directions are extracted from wind-induced streaks visible on most SAR images. Wind speeds are derived from normalized radar cross sections (NRCS) using empirical models. The models were developed for scatterometers (SCAT) operating at C-band with vertical polarization and must be modified for horizontal polarization. Several available C-band polarization ratios were considered, including theoretical and empirical forms. To verify and improve the algorithm, wind speeds were computed from several RADARSAT-1 ScanSAR images and compared to colocated measurements from the SCAT aboard the European remote sensing satellite ERS-2 and to the results of the Danish high resolution limited area model (HIRLAM). Using the colocated measurements, the polarization ratio was estimated and applied to improve the wind retrieval algorithm. In addition, the main error sources in SAR wind field extraction are discussed with respect to the RADARSAT-1 ScanSAR data. Sensitivity studies were performed under different atmospheric situations using the modified C-band model to compute the errors due to wind direction and inaccuracies in NRCS.

A Cluster Space Calibration Scheme for Synthetic Wind Statistics Calculated with a Mesoscale Model and its Application to Regional Wind Climate Studies

¶A scheme for calibrating an ensemble of wind fields computed by a mesoscale model in order to generate synthetic wind statistics is described. It is based on two main points. The first is to exploit the power of a mesoscale model to determine wind fields over complex terrain for different weather situations classified by cluster analysis. The second is to use all the information in the cluster analysis, i.e., the centroid values as well as the internal standard deviations of the clusters, to determine a cluster space distribution at each grid point in the model domain. The latter makes calibration possible if reliable measurements are available at the position of one of the grid points. The accuracy of the calibration is increased by splitting the cluster spaces into several parts. Combining both the modelled mesoscale wind fields and the method of split cluster spaces leads to a spatial transformation of the calibration from the calibration point to each grid point in the model domain. A validation of the scheme is carried out with measurements at grid points other than the calibration point and reveals remarkable improvements in the accuracy of the model wind statistics, especially with regard to wind speed distributions.

Vertical Interactions in a Nocturnal Multi-Scale Wind System Influenced by Atmospheric Stability in a Coastal Area

The winter wind regime of Goteborg, located on the West coast of Sweden, is composed of three different wind systems besides the ambient wind; a nocturnal low level jet (NLLJ), a winter land breeze (WLB) and an urban heat island circulation (UHIC). An inversion divides the air column into two layers, one between 10 – 50 m and one between 50 – 100 m. The UHIC is located in the lower layer, the WLB in the top layer and the NLLJ above the top layer. The intensity of the interacting processes depends on the stability of each layer as calculated from the bulk Richardson number (BRilow and BRihigh) using continuous data collected during four years (1991 – 94) from two sites (one within and one outside the urban area) and sampled at three levels. In the evening the WLB develops from the ground level and increases in height until after midnight. At about the same time an UHIC develops in the urban area, below the WLB and causing an uplift of the latter. However, at both sites the WLB does not exceed the 100 m level. At this time BRi in both layers are below one resulting in continuous coupling between the WLB, the UHIC layers and the regional wind. Consequently, the exchange of momentum is still effective between all layers and this is highlighted by a change in the wind direction and a regulation of wind-speed to more constant levels. When BRihigh≥1, the layers become frictionally decoupled, as indicated by a return in the wind direction in the top level to the regional wind, and an acceleration of the top wind. The top level then becomes incorporated in to a nocturnal low-level jet (NLLJ) system. The normally acknowledged development of the NLLJ, with a start around sunset, is in this case delayed for several hours at the top level. The reason for this is that there are meso-scale/local wind systems present in layers beneath the jet causing an interaction between the layers. In the morning, when the layers are again coupled the top layer wind is once more influenced by the WLB and therefore changes direction and speed. The local and meso-scale wind systems thus delay the current nocturnal wind development.

Some aspects of boundary layer evolution in Mexico City

Measurements of chemical species and meteorological parameters were made at a site located 440 m above the mean basin level of Mexico City, over a two-week period in November during Project Azteca. Data from three of the stations of Mexico City's air quality monitoring network (Red Automática de Monitoreo Ambiental, RAMA) were also used to estimate the dilution in concentration experienced by pollutants as they are transported upslope during the course of the day. Both carbon monoxide and sulfur dioxide show a dilution of up to 50%, while ozone is usually more concentrated at the elevated site. These comparisons clearly highlight the intrinsic differences between primary and secondary gases, which are supported also by time–space, cross correlation analysis. The thermal mesoscale wind circulation dominates concentrations of pollutants at the research site: upslope during the day and downslope during the night. The data present clear evidence that downslope flows during the night contribute to ozone concentration at basin sites.

The Influence of Mesoscale Features of the Sea Surface Temperature Distribution on Marine Boundary Layer Winds off the Scotian Shelf during the Superstorm of March 1993

Abstract This paper studies the mesoscale wind field during the blizzard of March 1993 off the east coast of North America and examines the influence of the sea surface temperature distribution on surface winds. Can the Gulf Stream and its meanders, by its strong influence on the marine boundary layer, generate mesoscale features in the wind field? Numerical simulations of the storm are carried out using the MC2, a fully elastic nonhydrostatic model. Simulations are conducted at different resolutions (50, 25, 10, 5, and 2 km) with both detailed and smoothed SST fields, so as to examine the influence of these parameters on the marine boundary layer winds. Results from these numerical simulations are compared with surface observations from buoys. The study reveals some mesoscale features in the wind field caused by the Gulf Stream’s meanders and the warm eddies of the SST field. In a stable boundary layer, the meanders shaped a 50–55-kt (26–28 m s−1) band of winds in a general 40–45-kt (21–23 m s−1) wind fi...

High-Resolution Wind Fields within the Inner Core and Eye of a Mature Tropical Cyclone from GOES 1-min Images

Mesoscale wind fields have been determined for a mature hurricane with high spatial and temporal resolution, continuity, and coherency. These wind fields, near the tropopause in the inner core and at low levels inside the eye, allow the evolution of mesoscale storm features to be observed. Previously, satellite-derived winds near hurricanes have been determined only at some distance from the eye over a typical time period of 1–2 h. Hurricane reconnaissance aircraft take 30 min to 1 h to complete an inner-core pattern. With the long observation periods of these previous methods, steady-state conditions must be assumed to give a complete description of the observed region. With the advent of 1-min interval imagery, and fourfold improvement of image dynamic range from NOAA's current generation of GOES satellites, there is a new capability to measure inner-core tropical cyclone wind fields near the tropopause and within the eye, enabling mesoscale dynamical processes to be inferred. These measurements give insights into the general magnitude and structure of the hurricane vortex, along with very detailed measurements of the cloud-top wind's variations in response to convective outbursts. This paper describes the new techniques used to take advantage of the GOES satellite improvements that, in turn, allowed the above innovations to occur. The source of data for this study is a nearly continuous 12-h sequence of 1-min visible images from NOAA GOES-9 on 6 September 1995. These images are centered on Hurricane Luis with maximum winds of 120 kt (CAT4) when it was 250 km northeast of Puerto Rico. A uniform distribution of long-lived cirrus debris with detailed structure is observed in the central dense overcast (CDO), which has been tracked using the 1-min images. The derived wind field near the tropopause at approximately 15 km in the CDO region has a strong closed circulation with speeds up to 25 m s−1, which pulses in response to the convective outbursts in the eye wall. Cloud displacements are computed at every pixel in every image, resulting in a quarter-million u–v winds in each of 488 hurricane images observed at 1- to 4-min intervals over 12 h. For analysis and presentation, these ultradense wind fields are reduced to 8- or 16-km grids using a 7-min time base by smoothing displacement vectors in space and time. Cloud structures were tracked automatically on a massively parallel processing computer, but with manual spot-checking. Manual tracking has been used to follow CDO structure over long time periods, up to 90 min for a small test sample. Cloud tracking for the wind fields presented here is accomplished using a Massively Parallel Semi-Fluid Motion Analysis (MPSMA) automatic technique. This robust deformable surface-matching algorithm has been implemented on the massively parallel Maspar supercomputer. MPSMA automatic tracking typically follows a feature for 7 min. For this time base the error of these winds is estimated to be 1.5 m s−1. However, systematic navigation and height assignment errors in the moderately sheared hurricane environment must still be considered. Spatial and temporal smoothing of the wind field have been performed to reduce systematic navigation errors and small-scale turbulent noise. The synthesis used here to compute the wind fields gives an order of magnitude reduction in the amount of data presented compared to the amount of data processed. Longer tracking could give higher accuracy but would smooth out the smaller-scale spatial and temporal features that appear dynamically significant. The authors believe that the techniques described in this paper have great potential for further research on tropical cyclones and severe weather as well as in operational use for nowcasting and forecasting. United States and foreign policymakers are urged to augment the GOES, GMS, FY2, and Meteosat geostationary satellite systems with dual imaging systems such that 1-min observations are routinely taken.

Mesoscale wind measurements using recalibrated ERS SAR images

The precision images (PRI) of the synthetic aperture radars (SAR) on board the European Remote Sensing Satellites ERS‐1 and ERS‐2 are used to derive mesoscale wind fields over the ocean. For calculation of the wind speed the C‐band model (CMOD4) is used, which was originally developed by Stoffelen and Anderson [1993] for the European Space Agency (ESA) to derive wind fields from measurements of the wind scatterometer (SCAT). In the case of the ERS‐1/2 SAR the CMOD4 is used to compute the wind speed from the normalized radar backscatter cross section (NRCS) and the incidence angle of the radar beam, both computed from the SAR.PRI data. The third input variable is the wind direction, which is estimated from the wind streaks in the images or from ground truth measurements. The SAR data are affected by a power loss, caused by saturation of the analog to digital converter (ADC) of the SAR. Therefore the images have to be recalibrated. Errors in the derived wind speed are mainly due to ADC saturation and uncertainties of the input wind direction. These errors are estimated for various wind conditions. Mesoscale wind fields computed from ERS‐1/2 SAR.PRI images taken between the Shetland Islands and the west coast of Norway are compared to ground truth measurements and modeled wind fields from the German weather service (DWD). Wind fields of the nonhydrostatic mesoscale model Geesthacht simulation model of the atmosphere (GESIMA) are compared to the derived wind field of the ERS‐1 SAR.PRI image at the island Rügen in the Baltic Sea.

Numerical simulation of daytime mesoscale flow over highly complex terrain: Alps case

The numerical study of mesoscale wind field and dispersion over terrains belonging to large mountain structures (e.g. Alps) poses a number of difficulties. Narrow valleys and steep slopes can considerably determine the temperature and pressure gradients, thus affecting the mesoscale systems in a quite complex manner. The adequate description of the local wind field, incorporating the high variability of the terrain features, is very important when a numerical simulation above highly complex terrain is attempted. The mathematical models used to reproduce the mesoscale flow in such cases must possess, besides the non-hydrostatic option, the ability to resolve the ground irregularities as realistically as possible. The increase of the spatial resolution would improve the terrain representation, but might require a prohibitively large CPU time and computer memory. DELTA-ADREA-DIPCOT is a numerical prediction code system, specifically designed to perform mesoscale wind field and dispersion calculations over terrains of high complexity, using moderate spatial resolution. This is achieved by recognizing subgrid ground features, such as slope and orientation variations, through a ground surface resolution higher than the one used for the atmosphere. The code system is here applied, focusing on the mesoscale meteorological systems over the Alpine mountainous area. The simulation is based on the data obtained in the framework of the TRANSALP Experimental Campaign, on 29 September 1990. The tracer concentration distribution is also examined, mainly as a further support to the meteorological conclusions. The predictions are compared with corresponding measurements and show a favourable agreement.

Influence of Building Areal Density and Roof Shape on the Wind Characteristics Above a Town

Flow characteristics in the lower part of theatmospheric boundary layer developing immediatelyabove building roofs have been studied by physicalmodelling under neutral stratification conditions. Thevertical profiles of velocity, turbulence intensityand Reynolds stress were measured in detail above amodel urban fetch consisting of parallel streetcanyons. Two different street densities and roofshapes were tested. It is found that the influence ofthe buildings on the oncoming wind remains confined towithin three overall building heights above ground.Furthermore, the effect on the wind at roof levelfrom the areal building density is relatively weak, butstrong from the roof shape. Thus, altering roof shapecan have a much more beneficial impact on urban airquality than increasing the spacing betweenbuildings. Moreover, these findings yield a novelmethodology for reliable prediction of urban airquality, by combining numerical mesoscale wind flowmodels with physical street canyon pollutiondispersion models.

Orographic Influence on the Synoptic-Scale Circulations Associated with the Genesis of Hurricane Guillermo (1991)

Abstract The early stages of tropical cyclogenesis in the eastern Pacific Ocean are investigated in this case study, which is focused on the development of the initial circulation that eventually intensified into Hurricane Guillermo (1991). The authors document the synoptic and mesoscale winds from upper-air soundings, satellite imagery, and a gridded analysis. In addition, flight-level observations taken during the Tropical Experiment in Mexico are used. These winds reveal that, prior to the formation of the tropical cyclone, an easterly wave moved over the Caribbean Sea and that the initial circulation developed while the easterly wave was located over the central Caribbean, east of the mountains in Central America. Numerical simulations with the Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model are used to examine the details of the structure of the flow that resulted in the formation of the eastern Pacific circulation. In these simulations, the model is initialized...

Variational Analysis for Airborne Conically Scanned Doppler Lidar to Retrieve Mesoscale Wind Fields

An airborne pulsed Doppler lidar implementing a downlooking conical scan rotating around the vertical axis is under development. The information contained in the measured radial velocities is studied to assess the capacity to retrieve the 3D wind field at mesoscale. First, in the frame of a variational analysis, it is shown that the observations cannot resolve horizontal scales shorter than approximately 5 km. Then, constraints of mass conservation and regularity as well as various boundary conditions are added to improve the resolution. The various constraints are tested on synthetic data. Further, a full analysis scheme is proposed that combines a preanalysis at low resolution followed by a finer resolution analysis. The achievable performances are discussed as well as the main limitations.

Simulation of Nocturnal Drainage Flows Enhanced by Deep Canyons: The Rocky Flats Case

Abstract The DELTA–ADREA (discretization with elements of triangle approach–atmospheric dispersion of pollutants over irregular terrain) numerical prediction model, developed at the National Center for Scientific Research Demokritos, is specifically designed to perform wind field calculations over terrains of high complexity. The numerical model has the capability to handle air–ground interaction processes by describing the ground-surface details while keeping the computation time at a reasonable level. The numerical model is applied here to a high-resolution topographical representation of the region surrounding the Rocky Flats Facility in Colorado, based on a digitized map consisting of approximately 4.8 × 106 points. Wind field calculations over the region are made using the atmospheric experimental data of 4 February 1991, collected by the participants within the Atmospheric Studies in Complex Terrain research program. The numerical predictions indicate strong drainage flows created at different altitudes with interaction between them, resulting in a quite complicated mesoscale wind field during nighttime. Available observations support the predicted flow features.

Application of Over-the-Horizon Radar Observations to Synoptic and Mesoanalysis over the Atlantic

Abstract Over-the-horizon (OTH) radar observations of surface wind direction offer a high-resolution (15 km) resource for synoptic and mesoscale wind field analysis. With horizontal resolution at the lower end of the mesoscale and areal coverage in the synoptic scale, OTH radar has the potential to contribute significantly to the amelioration of the data sparseness that has long plagued over-ocean surface analysis. Because of a twofold ambiguity in the OTH radar algorithm for determining surface wind direction, however, mapping surface wind directions unambiguously would normally require two radars with overlapping coverage. Alternatively, the single-radar ambiguity can be resolved by combining NWP model analyses and incidental surface wind observations with meteorological insight. An approach to the latter, less expensive solution is presented that relies on the classic principles of streamline analysis and an easy-to-use graphical wind field editor developed specifically for this task. A case study demo...

Numerical Simulation of Mesoscale Wind and Clouds over the Kanto Region Using Four-Dimensional Data Assimilation

Numerical simulations of Mesoscale wind fields and cumulus clouds in summer over Kanto region have been performed using RAMS (Regional Atmospheric Modeling System). This non-hydrostatic model include the advanced technique of weather prediction;(1) the microphisics parameterizations;(2) multi-grid nesting;(3) FDDA (Four Dimensional Data Assimilation). A total of three numerical experiments lead the following results.(1) The results of wind fields agree well with AMeDAS data.(2) Local wind fronts and clouds are simulated by nesting grid system.(3) The cloud over central Japanese mountains area agree qualitatively with the image from NOAA.