Weather and Wind Modeling in Egypt Meso-scale Meteorological (Weather Forecast) Modeling Presented By; Atef O. Sherif Aerospace Department Faculty of Engineering Cairo University
Collaborators Hamada Sultan BSc Aerospace Engineering, NARSS Mohamed Abd Elkader, Ahmed Abd Elmoaty MSc, Aerospace Engineering, NARSS Hamdi Kandil PhD, Mechanical Engineering, Alexandria University Basman El Hadidi PhD, Aerospace Engineering, Cairo University Atef Sherif PhD, Aerospace Engineering, Cairo University
Presentation layout
The unfortunate disaster by choice Economic stability Along Nile Branches a disaster What we discovered later!
General overview 1/3 Numerical meteorological models are used to asses air pollution o temperature inversion phenomenon o transport of pollutants/dust (sand storms) micro-climate change due to o natural causes formation of lakes, desertification, etc o man made causes: different land use categories Computational models are enhanced with remotely sensed observations for improvement of land surface modeling and accuracy
General overview 2/3 Climate trends in Eastern Mediterranean Recent numerical experiment suggests that severe deforestation around the Mediterranean in the last 2000 years was a major factor in current dry conditions Attributed to change in albedo, and increased evapo-transpiration Statistical trends from observations (over past 50 years) in the Eastern Mediterranean point to increased summer temperatures decreased winter temperatures reduced annual precipitation However, recent observations suggest that atmospheric sensitivity to land use change occurs locally Appreciable deviations in the semi-arid region of the Negev Desert and Gaza o Negev desert: intensive irrigation and changed albedo o Gaza: drastic population increase has led to a positive statistically significant minimum temperature increase all throughout the year
General overview 3/3 Different Flow Scales Meso-scale meteorology is the study of atmospheric phenomena with typical spatial scales between 10 and 1000 km Examples of meso-scale phenomena include thunderstorms, gap winds, down slope windstorms, land-sea breezes, etc Most weather phenomena that impacts human activity occur on the meso-scale Scale Length Area Locale Micro 1 m - 1 km 1 m² - 1 km² local Meso 1 km - 100 km 1 km² - 100 km² regional Macro (Synoptic) 100 km - 10 000 km 100 km² - 10 000 km² continental Mega > 10 000 km >10 000 km² global
Long Term Objectives Aerodynamic model for airflow for Egypt Boundary layer corrections for urban cities and local land use Assimilation of remotely sensed satellite data to provide physically consistent estimates of the meteorological conditions. Meteorological assessment of air pollution Extreme air pollution events Atmospheric dispersion and transport of gases and particles Modeling long term local meteorological climate changes Due to aggressive land use/land cover change Due to formation of artificial water bodies Investigation of Wind Energy Potentials in Egypt Wind Farm Site operational Planning Statistical vs. Dynamic Forecast
Numerical Weather Models: MM5 & WRF The weather model for Egypt is based on the 5 th generation NCAR/Penn state meso-scale model (MM5) and The Weather Research and Forecast Model, WRF. Both are open source models, Continuously being improved by contributions from users worldwide The two models are designed to simulate and predict meso-scale and regional scale atmospheric circulations.
Meteorological Modeling System Ground observations Assimilated in Model To improve the accuracy of the modeling results Gridded Data obtained from the global solvers to provide Initial and Boundary conditions with resolution up to 1 degree (111 km 2 ) Global Meteorological Data Terrestrial Data & Global Topology MM5 Model Updating The Model Post Processing Boundary Conditions High Resolution Data (One km or Less) Frequently updated (4-6 times daily) Land use / Land Cover Vegetation Fraction Terrain Elevation Soil Type
MODEL ENHANCEMENT AND VALIDATION
Satellite Data Assimilation of Surface Data NDVI Albedo LST/SST
Satellite Data Four Dimensional Data Assimilation ATOVS Temperature Retrieval ATOVS Water-Vapor Retrieval
Four Test Cases Four sets of simulations were performed; FDDA0: The reference case FDDA1: Grid FDDA from FNL. FDDA2: Grid FDDA from ATOVS FDDA3: Grid FDDA from FNL + ATOVS. Comparison of simulations results with surface observations at nine monitoring locations and soundings at five monitoring locations.
Results Vertical temperature profile for the different FDDA Techniques: at Helwan Station Percentage Change in X for FDDA i = 100 X ( FDDAi ) X ( FDDA0 ) X ( FDDA ) 0 FDDA1 is more efficient for research where FNL datasets are available FDDA2 can be used for dynamic analysis of operational predictions. FDDA3 has the maximum time cost and similar gains like FDDA1.
Results and Discussions
AIR POLLUTION ASSESSMENT
Air Pollution over Greater Cairo The PM10 exceeded the international limits over the year 2003. PM10 increases over Greater Cairo: Khamasin period (April, May) Black cloud period (September, October and November) Khamasin Sand Storm WHO limits Black Cloud Monthly average concentrations of PM 10 (data from 2000 to 2003), EEAA and Sivertsen, 2004
Air Pollution and Temperature Inversion The subsidence temperature inversion is defined as a temperature increase with height produced by the adiabatic warming of a layer of subsiding air. Layer just above subsidence inversions is usually relatively dry compared to the humid, stagnant and polluted layer below the inversion layer. Megacities in valleys in tropical zones are typical culprits High-pressure area north of Egypt, and low wind speed and high humidity are cause of this strong inversion
Parameters Affecting Temperature Inversion GTI (Your morning fog) STI Local topology and land use (affects surface heat fluxes) Surface heat fluxes and land surface type Regional must atmospheric be considered circulations for accurate High pressure system temperature inversion modeling by Water vapor content atmosphere Local topology and land use using a suitable land surface model Four norms to quantify temperature inversion Strength (average temperature gradient across inversion layer) Elevation (from bottom of inversion layer) Thickness Lifetime
Modeling of Temperature Inversion Inversion layer Latitude cross section at Cairo International Airport shows trapped water vapor under inversion layers Water vapor
Evaluation of Temperature Inversion During Air Pollution Episode over Cairo OOOOOOps Longitude Cross section Correlation Coefficient : 0.87 Latitude Cross section Inversion strength versus PM 10 at El Abbassya station EEAA & EIMP operated 42 air quality stations over Egypt to monitor NO 2, SO 2, O 3, CO, PM 10 and total suspended particulate. Inversion elevation versus PM 10 at El Abbassya station
Comparison Between GTI and PM10 over Greater Cairo
Aerosol Optical Depth AOD is used to relative amount of aerosols (solid or liquid) particles suspended in the atmosphere. The MODIS aerosol optical depth product is a measure of how much light airborne particles prevent from passing through a column of atmosphere. AOD AOD Elevation Inversion strength 1 Inversion elevation
Evaluation of Subsidence Temperature Inversion using AOD 25
LOCAL CLIMATE CHANGES
Effects of Land Cover Changes on Egypt Weather Land cover changes modifies fluxes of momentum, heat, water, aerosols, and gases, as well as near surface radiation balances. Each flux modifications affect atmospheric circulation then cause variations in Temperature, Humidity, and Precipitation. Observations suggest that atmospheric sensitivity to land cover change also occurs locally. The Presence Urbanization of Lakes Sprawl in Toshka over Region Delta Northern Sinai After Reclamation
History of Toshka Lakes The Aswan High Dam constructed in Egypt in 1964-1968, created Lake Nasser, with a maximum water level of 183m above sea level. In 1978 Egypt began digging the draining Canal through Toshka valley to allow water levels higher than 178m to be drained off. In the late 1990s, water began flowing through Toshka Valley forming a group of lakes called Toshka lakes. Aswan High Dam Toshka Kalabsha Lakes Embayment Toshka Depression Toshka Valley Nasser Lake Satellite Image represent Showing for Aswan Toshka High Lakes Dam Valley MODIS IKONOS Satellite http://uregina.ca/piwowarj/geog100/images/aswandam_7_29_02.jpe http://veimages.gsfc.nasa.gov/3133/nasser.a2002067.0830.250m.jpg
Formation of Toshka Lakes 1997 1998 1999 2000 http://veimages.gsfc.nasa.gov//1535/toshkalakes.mov
The Effective Distance of the Lakes 530 km 450 km Morning Noon Night
Percentage Change in Water Vapor Content after Adding the Lakes %
2005-03_2005-04 Relation between Water Vapor and precipitations mm Increases in water vapor at 2.5 km elevation induced by Toshka lakes The precipitations amount measured by the TRMM satellite March 2005
Urban Encroachment in Nile Delta Cairo 1965 Cairo 1998
Effect of Urban Sprawl on Vegetated Areas Urban sprawl creates "Urban Heat Islands" Elevated air temperatures over urban areas is retained by man-made materials such as asphalt which store much of the sun's energy Satellite observations indicate average temperature increase in cities from 2.7 to 5.6 o C than surrounding areas. source: U.S. Environmental Protection Agency (http://yosemite.epa.gov/)
Cross Sectional Temperature Changes after Taking the Urban Areas Effects Latitude cross section (B-B) Longitude cross section (A-A)
IMPACT OF THE NILE DELTA URBANIZATION ON THE TEMPERATURE INVERSION OOOOOOps The increase in heat capacity over urban areas and decrease in soil thermal conductivity and soil moisture, increased the total heat flux over urban areas. Land use
Land Reclamation in North of Sinai The trend in the eastern Mediterranean is, increased summer temperature, decreased winter temperature, and reduced annual precipitation. This trend however, exhibits appreciable deviations in semi-arid region of the Negev Desert, and the Gaza strip The NSADP plan to reclaim 400,000 acres
Changes in Temperature and Water Vapor after Adding the Vegetation Temperature differences Water vapor differences (%)
Changes in Velocity at 10m Elevation after adding The Vegetations
Regional Weather modeling: Africa Velocity Vectors
Regional Weather Modeling, MENA: Combined Velocity Vectors and Humidity Distribution
Regional Weather Modeling: Nile Basin Grid : 420x540x32 10Km Grid Pts : 8.6 M Cell Atef O. Sherif Nov.. 12, 2005
Velocity Vector At Elevation 2.7Km National Weather Modeling: Velocity Vectors
National Weather Modeling: Relative Humidity Atef O. Sherif Nov.. 12, 2005
Preliminary investigation at a Wind Farm Site 4- Levels model
Velocity and Power Density
2-Days Simulation Latitude Cross Section
2-Days Simulation Longitudinal Cross Section
Wind Roses At a Wind Farm Site: A Demonstration of Possible Failure of the Statistical Planning Approach 3 days average Operations probable every day Day 1 Operation not an option Day 2 Operation probable Day 3 Operation probable
Conclusions Data assimilation in meteorological models improves accuracy of surface and aloft variables and are essential to predict thermal inversion Prediction of extreme pollution events has been validated Land cover change significantly impacts local meteorological conditions Along the lake shore, diurnal variations decreased by 2 o C with significant sea-breeze around the lake. Velocity is up to 5 m/s. Relative humidity increase by 90% along the lake shores. Urban encroachment in Delta increases average daily temperature by 0.28 degrees Intensive irrigation in North Sinai, results in significant temperature reduction in the cultivated areas Potential for Wind Energy Site Select, Operational Planning is Promising
Future Work
Thank You Thank you for Attention and Patience