Research Projects

Dust Modeling and Forecasting over the Arabian Peninsula

Chief Contributor: Naseema Beegum

The single largest contributing factor for the attenuation of solar radiation over the arid and semi-arid regions of Middle East and North Africa (MENA) is the mineral dust. Estimation of the spatio-temporal and vertical distribution of dust in the atmosphere over the UAE region is a necessary step for solar resources modelling. Chemistry Transport Models (CTM) are efficient tools to simulate various pollutants in the ambient air. CHIMERE is one of the powerful regional scale CTMs designed to simulate dust and the concentrations of other chemical species.

CHIMERE model has been set up for the domain covering the UAE region with a spatial resolution of 0.1°x0.1° at hourly intervals with 8 vertical levels from 997 hPa to 500 hPa (which is capable of capturing the long-transport of mineral dust through higher altitudes), for 36 chemical species  including PM10, PM2.5 as well as the dust deposition rates. The model requires meteorological data, boundary conditions, land-use information and emissions. WRF mesoscale model has been interfaced with CHIMERE for meteorological input (such as surface pressure, horizontal wind, specific humidity, liquid water content, temperature, and precipitation). WRF real time simulations at hourly intervals for the same geographical domain have been used to force the simulations.  The boundary conditions for gases are taken from the MOZART and LMD-INCA model, while for aerosols global simulations using GOCART are used. The land use informations required to simulate the model are taken from the GLCF and the GlobCover database. Also USGS soil properties have been used for the soil texture information. Biogenic emission factors required to generate the biogenic emissions are adopted from the MEGAN model parameterizations. Anthropogenic emissions are based on the measurements from a network of observatories over UAE.

Simulation of a dust event occurred on 5th August 2013 is shown below. The comparison between the AOD measured at the AERONET station Mezaira and the simulated dust load shows good mutual correlation.

RECALIBRATION OF HELIOSAT-2 METHOD FOR GHI ESTIMATION IN DUSTY AND HUMID ENVIRONMENTS

Chief Contributor: Yehia Eissa

Heliosat-2 is a well-known model for global horizontal irradiance (GHI) retrievals using visible satellite images. In this study, the cloud index was derived from the high-resolution visible channel of the SEVIRI instrument, onboard Meteosat Second Generation satellite. Monthly Linke turbidity values were used over the ground measurement stations to account for the cloud-free atmospheric conditions. Performance of original Heliosat-2 method for GHI retrieval over the dusty and humid environment of the UAE revealed an underestimation in the estimated GHI results. Therefore, the clear-sky diffuse horizontal irradiance equation in the model was recalibrated to fit the dusty and humid environment of the UAE. After recalibration, the underestimation was eliminated and the model shows promising results in GHI retrievals over the UAE’s environment.

recalibration-of-heliostat

ANN BASED MODEL FOR THE RETRIEVAL OF DIRECT NORMAL, DIFFUSE HORIZONTAL AND GLOBAL HORIZONTAL IRRADIANCES USING SEVIRI IMAGES

Chief Contributor: Yehia Eissa

A statistical model for the prediction of the solar irradiance components at a 15-min temporal resolution and a 3-km spatial resolution was developed. Main inputs to the model are the thermal channels of the SEVIRI instrument, onboard Meteosat Second Generation satellite. The model has been trained using reference data from three ground measurement stations for the full year of 2010 and tested over two independent stations for the full year of 2009. As shown in the scatter plots, the model provides accurate results in DNI, DHI and GHI estimations. Advantages include: producing the DNI, DHI and GHI maps in a near real-time manner (15-min resolution) and deriving annual solar maps. Annual solar maps provide irradiation data showing the solar potential in different areas for siting and performance pre-assessment purposes. Since SEVIRI images are available since 2004, the variability of solar radiation over specific locations can be demonstrated through annual maps for past years.

ann-based-model

UAE SOLAR RESOURCE ATLAS: A PUBLICLY-ACCESSIBLE WEB PORTAL

Chief Contributor: Jacinto Estima

A web portal developed to make UAE solar and wind resource maps easily available to end users and stakeholders. It is technology independent based on Open Source technologies and Open Geospatial Consortium (OGC) standards. The platform is constituted by the data source, a server and a web application. The data source is composed by a collection of GeoTIFF images. The server is based on the GeoServer software and provides maps using OGC specifications, namely Web Map Service (WMS) specification. The web application aims to show the atlas maps over a base map and provide basic data management tools including the possibility to access pixel values and to derive historical histograms of solar and wind resources.

uae-solar-atlas

UAE WIND RESOURCE ASSESSMENT

Chief Contributor: Lee Won-Jung

The UAE wind resource map is produced using GIS, WindPRO and WAsP programs. Several conclusions were derived: wind speed is generally higher during day than night, due to homogenously mixed air across the vertical length of the atmosphere, low height areas have comparable potential to that of high heights in viably tapping wind energy, the maximum wind speed is generated in the north eastern inner region in the UAE, whereas the maximum wind speed potential is mainly derived from coastal areas.

uae-wind-assesment

REAL-TIME VISULIZATION OF DUST EMISSIONS OVER UAE USING SEVIRI SATELLITE DATA AND AERONET GROUND BASED MEASURMENTS

Chief Contributor: Nada K. Al Meqbali

An improved model for dust detection over the UAE using Spinning Enhanced Visible and Infrared Imager (SEVIRI) data is produced based on Artificial Neural Network (ANN) and Canonical Correlation Analysis (CCA) methods, which estimates the Aerosol Optical Thickness (AOT) at 500 nm wavelength and compares with corresponding ground based measurements derived from the Aerosol Robotic Network (AERONET). Both images present a better distinction of the dust from other atmospheric features (i.e. clouds) compared to visualizations generated using the SEVIRI RGB Index, with model-1 results showing slightly better dust visualization capability than model-2.

realtime-dust-emissions

DUST MONITORING OVER THE UAE USING THE MSG/SEVIRI THERMAL BANDS

Chief Contributor: Imen Gherboudj

The estimation of temporal and spatial distribution of aerosol load in the atmosphere, expressed often by the Aerosol Optical Thickness (AOT), has become indispensable to many applications such as atmospheric correction of satellites images, human health monitoring, assessment of surface UV radiance, solar energy management, etc. Our methodology consists of developing a model based on the collected dataset constituted by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) thermal observations (8.7, 10.8 and 11.0μm) and the AERONET ground based measurements of different stations spread over different landscape of the UAE.

MSG/SEVIRI thermal bands:

2004-2012: each 15min, resolution 3km 

AERONET ground measurements

2004-2010: specific periods

 

 

SOLAR TECHNOLOGY ASSESSMENT

Chief Contributor: Arttu Tuomiranta

The performance of all mainstream solar photovoltaic (PV) and concentrated solar power (CSP) technologies is assessed based on the irradiance maps previously developed by the Centre. The parameters to be modeled include energy output, specific yield, capacity factor, and performance ratio. In order to analyze the performance of various PV technologies, a simulation tool is developed. The tool is designed drawing on the current knowledge on the impacts ambient temperature, wind speed, solar spectrum, degradation, tracking, inverter dimensioning, system configuration, and irradiance level and composition have on PV performance. The optimal tilt angles are also determined by means of the tool. The performance of major CSP concentrator technologies is assessed through modeling several real CSP plants representing different technologies by the System Advisor Model (SAM) developed by NREL. The modeled performance indicators of solar power systems are eventually integrated as map data layers in the solar atlas infrastructure.
arttu