Environmental Science & Policy 3 (2000) 287 – 294 www.elsevier.nl/locate/envsci Use of earth observation in support of environmental impact assessments: prospects and trends C. Cartalis a,*, H. Feidas b,, M. Glezakou a,, M. Proedrou a,, N. Chrysoulakis a, a Laboratory of Meteorology, Department of Applied Physics, Di6ision of Physics, Uni6ersity of Athens, Panepistimioupolis, Build. PHYS-5, Athens 15784, Greece b Department of Geography, Uni6ersity of Aegean, Har. Trikoupi and Faonos, 81100 Mytilini, Greece Abstract Earth observation (EO) supports the description of prevailing environmental conditions as well as the state of the environment, with good spatial and temporal resolution. In this paper, the potential of satellite imagery to support the requirements of environmental impact assessments (EIA) is examined. An analytical description is given with respect to the use of EO in EIAs in selected thematic/application areas. It is deduced that EO can provide valuable information in support of EIAs, especially with respect to the definition of the state of the environment and the prevailing environmental conditions. © 2000 Elsevier Science Ltd. All rights reserved. Keywords: Environmental impact assessments; Earth observation; Satellites “ 1. Introduction Environmental impact assessments (EIAs) are considered as important tools for the assessment of the impacts induced by human activities. EIAs support the definition of the state of the environment, the estimation of the severity of the impacts, which may result due to a construction work, and the planning of the necessary measures for reducing the impacts as well as for monitoring environmental impacts. EIAs were instituted in USA in 1970 with the National Law of National Environmental Policy Act. Canada and France followed in 1973 and 1975, respectively. In the framework of the policy of the European Union for pollution prevention, Directive 85/337 and its amendment 99/11 defined the terms and conditions for the execution of EIAs. The structure of an EIA is as follows, “ Name and kind of construction or activity “ Summary * Corresponding author. Tel.: +30-1-7276843; fax: 7295281. E-mail address: ckartali@atlas.cc.uoa.gr (C. Cartalis). +30-1- Geographical position — Extent — administrative subordination “ Description of the current state of the environment “ Description of the construction or activity “ Appraisal and assessment of environmental impacts “ Suggestions for the rectification of environmental impacts “ Plan for environmental monitoring. The description of the current state of the environment is accompanied by general maps (wide area maps) as well as by detailed maps of the area of interest. Following, an extensive description should be given on, “ the natural environment (ecosystems, terrain, meteorological and hydrological data, flora and fauna); “ the anthropogenic environment of the area (settlements, productive sectors — natural resources, existent substructure); “ the prevailing state of pollution; “ the interaction between the natural and anthropogenic environment. The description of the construction or activity should also refer to alternative solutions, to the phases of the construction, to the water and energy use and to the wastes produced. 1462-9011/00/$ - see front matter © 2000 Elsevier Science Ltd. All rights reserved. PII: S 1 4 6 2 - 9 0 1 1 ( 0 0 ) 0 0 0 9 6 - 4 AVHRR VISSR and VAS GOES7 1–7 1.1 Multispectral Panchromatic 4m 1m 5.8 m Pan IKONOS-1 5–23.5 m LISS III IRS 1c, 1d 30 m and 1 km 20 and 10 m 30 m 1.1 km Spatial resolution AMI-SAR and ATSR-2 XS-Multispectral and PAN-Panchromatic Thematic Mapper AVHRR Sensor ERS-1,2 Meteorology, Oceans, Land, Ice LANDSAT and Snow, Atmospheric dynamics, Water and energy cycles, Atmospheric chemistry Meteorology, Atmospheric SPOT 1,2,3,4 dynamics, Water and energy cycles, Land surface NOAA 12,13,14 NOAA 12,13,14 Meteorology, Atmospheric dynamics, Water and energy cycles MVIRI METEOSAT 5,6,7 2.5–5 Mission Application Sensor Mission Spatial resolution (km) Earth resources Monitoring the atmosphere Table 1 Types and operational functions of selected satellites Land surface, Cartography, Agriculture and forestry, Civil planning and mapping, Digital terrain models, Environmental monitoring Ocean, Land, Ice and Snow, Atmospheric dynamics, Atmospheric chemistry, Environmental monitoring Land surface, Agriculture and forestry Regional geology, Land use studies, Water resources, Vegetation studies, Coastal studies and soils, Cartography Land surface, Cartography Civil planning and mapping, Digital terrain models, Environmental monitoring Oceans, Land surface, Vegetation studies, Environmental monitoring etc. Land, Sea, Natural resources Application 288 C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 2. Capability of earth observation for the assessment of environmental problems Earth observation (EO) has improved, in recent years, its capabilities due to the improved spatial, spectral and radiometric resolution of the satellite sensors. Furthermore, new EO satellites have been placed in orbit, a fact that improves the temporal resolution considerably. As a result, new measurements are now feasible in thematic areas of high environmental concern. Satellites, to be used potentially in support of EIAs, are divided in two main categories — satellites for the monitoring of atmosphere and earth resources satellites (Table 1). There are many satellites for monitoring each resource; however, only high spatial resolution sensors 289 are mentioned in Table 1. The applications described in Table 1 depend on the technical characteristics of the sensors carried on board the satellites. Table 2 describes analytically the technical characteristics and the applications of the sensors potentially to be supportive of an EIA (Cambel, 1996). The technical characteristics of a satellite sensor are described by means of spatial, spectral and temporal resolution. The spatial resolution expresses the ability of a remotely sensing system to render a sharply defined image (Jensen, 1986). It is also a measure of the smallest separation between two objects that can be resolved by the sensor. Spectral resolution expresses the number of specific wavelength intervals (spectral bands) in the electromagnetic spectrum to which a sensor is sensitive (Jensen, 1986). Finally, temporal resolution gives information on the Table 2 Application and technical characteristics of selected EO instruments Instrument Applications/technical characteristics Spectral channel 0.4–12 mm, spatial resolution\100 m. These can provide cloud amount and cloud top temperature, cloud particle properties, troposheric aerosols, sea and land surface temperature, snow and sea ice cover, Earth surface albedo, vegetation type and large scale structure Imaging multi-spectral (visible, IR) radiometers in geostationary orbit These can provide similar measurements to instruments in low Earth orbit with lesser spatial resolution (\2 km). They also provide an important source of wind measurements based on cloud track measurements Atmospheric (IR) sounders These are designed primarily for atmospheric temperature and humidity measurements in clear sky conditions, but can also make contributions to measurements of trace gas distributions, surface emissivity, snow and ice cover etc. Atmospheric (microwave) sounders These are designed primarily for atmospheric temperature and humidity measurements and complement the IR sounders in being able to give sounding in cloudy conditions. Other applications are the detection of cloud water content, rain etc. High resolution multi-spectral and panchromatic mappers (VIS, IR) Spatial resolution B100 m. Instruments in this category provide information on vegetation type, fine scale landscape structure, extent of lakes and inland bodies of water Ocean colour radiometers Ocean colour measurements are used to infer marine productivity, marine pollution, coastal zone water dynamics etc. Imaging multi-spectral (microwave) radiometers These instruments have a resolution of order 1–30 km depending on operating frequency. Instruments measure the microwave emission of the ocean and land surface modified by atmospheric absorption. Instruments measure water vapour and rainfall (particularly over the oceans) and snow cover Radar altimeters These can provide altitude of the mean ocean, surface wave height, wind speed over the oceans, topography of land, ocean currents etc. Mapping radars This category consists mainly of SARs (Synthetic aperture radar). Mapping radars provide information on vegetation type and cover, topography, sea ice texture. An important advantage is their all weather, day/night capability Lidar (laser) A variety laser based instruments are being developed e.g. for measurement of aerosols, cloud particle properties, altimetry and wind profiles Atmospheric chemistry spectrometers and radiometers (UV, VIS, IR, These examine the chemistry and dynamics of atmospheric trace gas MW) species Rain radar Active microwave instruments are being developed to provide more accurate estimates of rainfall Imaging multi-spectral (visible, IR) radiometers in low Earth orbits 290 C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 Table 3 Thematic areas for which EO can support EIAs Thematic areas Measurements/application Temporal resolution Spatial resolution Land use planning Atmosphere Mapping of urban, industrial agricultural and forested areas 3–16 days 1–30 m Marine environment Natural environment Urban environment Agricultural environment Inland waters Wind direction and intensity, temperature and humidity profiles, general and Four times per day to local circulation patterns every 30 min Detection of dispersion patterns, detection of pollution sources, estimation of 3–16 days chlorophyll concentration in surface waters, sea currents, definition of surface temperature, correlation of coastal to open waters Mapping of wetlands, forests and protected areas; assessment of flora in terms Few-hours to 16 days of type and cover Type and cover, air quality with respect to aerosols, microclimate and heat 3–16 days island, road network, emission sources Mapping of cultivation, irrigation patterns 3–16 days Inventory of lakes and rivers frequency a sensor obtains imagery of a particular area (Jensen, 1986). Table 3 describes the thematic areas in which EO can support EIAs; the current capabilities in terms of spatial and temporal resolution are also provided. It can be seen clearly that spatial and temporal resolution varies depended on the thematic area of interest. For instance in the thematic area atmosphere, EO can provide information on the atmospheric circulation patterns of the area of concern with the highest temporal resolution (30 min). Even though spatial resolution seems rather low (1100–5000 m), it is sufficient enough in comparison to the requirements of EIAs at the regional scale. Such information is considered essential in defining the potential of an industrial activity to contribute to the pollution of a neighbouring urban area, as well as in supporting numerical models, which describe the dispersion patterns of pollution loads. An analysis of the spectral resolution of the sensors shows that satellites LANDSAT, SPOT, IRS and especially IKONOS cover the requirements of a EIAs in terms of the thematic areas land and water. Meteorological satellites provide measurements of limited spatial resolution; thus the use of satellite data from meteorological satellites for the investigation of local environmental problems should be supported with ground measurements (Barret and Curtis, 1992). 3. Application of earth observation in environmental impact assessments Following, an analytical description is given with respect to the use of EO in EIAs in selected thematic areas. A description of the type of satellite data to be used in each of these areas and an assessment of their contribution in satisfying the needs and requirements of each application area is also given. 3–16 days 1100 to 5000 m 5–1100 m 20–1100 m 1–30 m 4–30 m 10–30 m 3.1. Land use With the use of EO, images of selected land areas can be obtained on a frequent basis. With the use of these images, land use and cover may be defined by means of photointerpretation and/or digital processing. In particular, on the basis of photointerpretation, the following may be distinguished — arid lands, irrigated land, special cultivations, and agricultural land, forest land (Lillesand and Kiefer, 1994). Digital analysis of satellite images is, in certain cases, very appropriate for recognising and mapping land use and cover. Each pixel (the smaller discrete element in a satellite image) corresponds to a land unit with specific characteristics. In particular, EO may support EIAs through the provision of such information on land features as follows. 1. Vegetation type and cover. EO allows the detection and mapping of the various vegetation types. It also supports the revision of thematic maps, in particular following abrupt changes in the landscape due to fires, construction works, mining activities, reforTable 4 An assessment on the capability of EO to support EIAs given on the scale from 1 to 5 Thematic area Land use and cover Atmosphere Meteorology Marine environment Natural environment Urban environment Agricultural environment Inland waters Capability of EO to support an EIAs (1–5) 4 2 2 3 3 4 3 2 C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 291 Table 5 A summary of the potential of EO to support the phase of an EIA Stage of an EIA Capability of EO to support an EIA Definition of the current state of the en6ironment General and detailed maps of the area of interest Yes Ecosystems Terrain Yes Yes Meteorological and hydrological data Yes Flora Fauna Settlements Yes No Yes Productive sectors Yes (indirectly) Natural resources Yes Marine and coastal environment Pollution Interaction between natural and anthropogenic environment Yes Yes (indirectly) Construction of cost and time effective detailed orthoimages and thematic maps Detection, classification, delimitation and mapping of ecosystems Provision of accurate, high resolution, cost effective and comprehensive topographical databases with indication of changes over time Information on wind speed and direction, temperature, humidity, precipitation, type and frequency of synoptic systems in support of ground based measurements or for areas with insufficient ground based data Detection and mapping of the various vegetation types and cover Considerable information regarding the urban structure (urban cover and type) Indirectly, with the use of thematic urban structure maps derived by processed satellite images Identifying geological structures and sub-surface geometry; identifying minerals, water, gas and oil deposits Turbidity of water, dispersion patterns in the surface waters, sea surface temperature, mapping of bottom topography; coastal changes, coastal erosion Information on aerosols’ distribution, aerosols sources Change detection in satellite images over long periods Description of the construction or acti6ity References to alternative solutions No References to the phases of the construction No materialisation Reference to the water and energy use and wastes No Assessment of en6ironmental impacts Impacts on the atmosphere Yes (indirectly) Impact on the water resources Yes (indirectly) Impact on the terrain Yes (indirectly) Impacts on the flora Impacts on the fauna Impacts of noise Yes (indirectly) No No Suggestions for the rectification of en6ironmental impacts Plan for the rectification of environmental Yes (indirectly) impacts Monitoring mechanism for defining Yes environmental impacts estation, etc. Such information is considered essential in an EIA, especially in strategic impact assessments, which require information for wider geographic or adjacent areas. With respect to forest cover, EO allows the production of cost efficient thematic maps. In the event of forest fires, the assessment and mapping of burned areas provides Indirectly, e.g. the estimation of the prevailed circulation patterns is essential in defining the potential of an industrial activity to contribute to the pollution of a neighbouring urban area Indirectly, e.g. topographical data may be used as input in models for the prediction of the changes in the drainage for water due to the construction Indirectly, e.g. change detection of landscape topography over time in cases of similar construction or activities may give important information on the impacts of the scheduled construction on the terrain Indirectly, e.g. as above with the use of thematic maps Indirectly, e.g. change detection of land use may be helpful to the rectification plan for the impacts on the landscape Potential in defining environmental impacts on several thematic areas with cost and time efficient acquisition of data, spatial coverage of extended areas and provision of data on a continuous basis valuable information regarding the areas where construction should be prohibited. There is a large number of low-to-high resolution multispectral sensors that may be used to provide data on vegetation type. The Advanced Very High-Resolution Radiometer (AVHRR) and the Thematic Mapper on board NOAA and Landsat satellites, respectively, 292 C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 provide data that can be used to derive vegetation indices. It should be mentioned that the improved spatial resolution of new satellite sensors (Wifs on IRS) combined with the use of Geographic Information Systems, facilitate strongly the assessment of land use and the mapping of forested areas. 2. Landscape topography. EO technique can provide accurate, high resolution, cost effective and comprehensive topographical databases with indication of changes over time. This information may be used in EIAs, among others, for land use mapping in the area of concern, to predict the drainage of water, to define the areas where floods are likely and to detect erosion. In coastal areas, topographic information may be used to detect small changes in the slope of coasts, which may determine whether or not the area of concern is susceptible to flooding. At present, information on landscape topography is obtained primarily from multispectral optical sensors and mapping radars (SAR). The pointing capability of SPOT, for example, allows the production of stereo images from the data gathered on different orbits, which are then used to create digital elevation maps, which give a more accurate depiction of terrain. 3.2. Meteorology EO can monitor the meteorological conditions in areas, for which ground based data are unavailable or insufficient. In other cases, satellite images may operate in a supportive manner to the classical ground based measurements. Meteorological parameters, which may be obtained from EO with a view to support EIAs, are as follows. 1. Wind speed and direction. Accurate information on winds is central to the prediction of the dispersion of atmospheric pollutants, which may be potentially released, for example, by an industrial plant to be constructed. Although the needed resolution in the atmospheric boundary layer is not attainable by EO, at least with existing missions, valuable information can be obtained for the troposphere in terms of the vertical profile of wind speed (NOAA, METEOSAT). It should be mentioned that the accuracy of the latter information is to be improved with the use of sensors in future missions (IASI on METOP1 and AIRS on EOS PM-1). 2. Temperature and humidity. The vertical profiles of temperature and humidity can be obtained through the infrared sounders on board the NOAA satellites. In this case, horizontal resolution ranges from 10 to 100 km, and temporal resolution from 4 to 6 images per day. 3. Precipitation. The definition of the precipitation patterns for extended time periods is important in EIAs. At present, EO can only support such need through the provision of related information (precipitable water, humidity) for rather poor spatial resolution. 4. Type and frequency of synoptic systems. Conventional synoptic maps in conjunction with METEOSAT images provide the type and motion characteristics of the weather systems in the area under consideration. Such information, if processed for extended time periods, may allow an overview of the general circulation patterns in the atmosphere in the area of concern; thus significant information may be obtained with respect to the dispersion and diffusion patterns of the lower troposphere. 3.3. Assessment of pollution loads EO has limited application in the assessment of air quality in urban areas, with the exception of the distribution of aerosols (e.g. dust or sulphate particles). The use of satellite data/images may also be supportive for dispersion and diffusion modelling, in terms of the following, 1. Definition of the sources of aerosols as well as of the spatial distribution and extent of the concentrations of aerosols. In particular, LANDSAT and SPOT images have proved useful in providing information on the horizontal distribution and on the sources of aerosols. Such information in conjunction with ground measurements and synoptic maps support the classification of the conditions, which allow the development of atmospheric pollution episodes. 2. Definition of such parameters as albedo, topography, and ground temperature. 3.4. Urban studies EO can provide considerable information regarding the urban structure (urban cover and type) mainly with the use of Landsat-TM, SPOT-XS and IRS images which allow the production of maps at scales from 1:25 000 to 1:50 000. The improved spatial resolution (1–4 m) of new missions (IKONOS) dramatically increase the potential of EO to support urban studies. A particular application, which is strongly benefited by EO, is the study of the microclimatic conditions with special emphasis given in the heat island phenomenon. Landsat images in the thermal infrared are effectively used to provide a microclimatic map of the urban area, with satisfactory spatial resolution (120 m). A considerable difficulty is the invariant passage time of the satellite (i.e. at the same local time) over the study area, a fact, which constitutes a problem with respect to the study of the heat island within the day. Alternatively, NOAA-AVHRR data in the thermal infrared may be used; in this case, the temporal resolution is improved C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 (four images per day) at the expense of the spatial resolution, which is significantly reduced (1100 m). It should be mentioned that the use of data from ATSR on ERS-1 strongly facilitates the study of heat islands (Hyoun-Young, 1993). 3.5. Assessment of the quality of marine and surface waters EO can support EIAs in terms of information on turbidity of water, the dispersion patterns in the surface waters, the mapping of bottom topography as well as the extent of coastal erosion. Mapping of chlorophyll content, as well as the study of the interaction between coastal shallow waters and the open sea can also be benefited greatly by EO (Foster et al., 1994). EO can support the study of lakes and rivers with respect to the level and degree of eutrophication (Davies and Mofor, 1993). The satellite sensors, which are considered supportive for this application, are Thematic Mapper on Landsat, AVHRR on NOAA, CZCS on Nimbus 7 (which is, however, not in operation). Recently, the use of the infrared radiometer ATSR-2 and the mapping radar SAR on ERS-2 has proved highly successful. 4. Policy implications A critical issue is whether the use of EO in EIAs may have policy implications, in particular, whether it may influence or support a policy maker in his tasks. Overall, it may be said that a policy maker is supported, on the basis of the information provided in earlier sections, in the selection of the source and the type of satellite images, which may allow a rapid and rather detailed view of the area concerned. In this way, such decisions as pre-selection of the area, initial characterisation of the area (e.g. ecologically sensitive, urbanised, degraded, etc.), definition of specific in-situ investigations, and rejection of the area may be considerably supported. At a second stage, and depending on the characteristics of the area and the scale of the planned intervention, a policy maker is guided with respect to the selection of the appropriate source of satellite images for the thorough detailed examination of the area (e.g. Meteosat images for the meteorological examination of an area, which is planned to host a heavy industry or a Landsat. Thematic Mapper image for the examination of the land cover characteristics of the area concerned). 5. Conclusions As an overall conclusion, it may be stated that the 293 use of EO can support, to a good extent, EIAs in terms of the requirements of Directive 85/337 and its 1999 amendment (99/11). Table 4 provides an assessment on the capability of EO to support EIAs; the assessment is given on the scale from 1 to 5 (1, minimum, if any, support; 5, maximum support). Finally, Table 5 summarises the potential of EO to support each of the phases of an EIA. In particular, expected benefits from the use of EO data in EIAs are, “ simultaneous assessment of various parameters, with the use of multispectral sensors; “ cost and time efficient acquisition of data, especially for urban areas; “ spatial coverage of extended areas, for which ground measurements are not available; “ provision of data on a constant basis, allowing change detection; “ assessment of the environment at the regional context in the event of major construction works which may have impacts of transregional character. It has to be mentioned that EO should not be considered as the only means for the assessment of the problems connected with the estimation and monitoring of environmental parameters. In fact, EO operates in a complementary manner to the conventional measurement techniques (ground based measurements, soundings, aerial photos etc.) used in the elaboration of an EIA. However, the continuous improvement of EO capabilities implies the enhanced use of satellite images in EIAs. References Barret, E.C., Curtis, L.F., 1992. Introduction to Environmental Remote Sensing. Chapman & Hall, London. Cambel, J.B., 1996. Introduction to Remote Sensing. The Guilford Press. Davies, P.A., Mofor, L.A., 1993. Remote sensing observations and analyses of cooling water discharges from a coastal power station. International Journal of Remote Sensing 14, 253 – 257. Foster, B., Baide, X., Singwai, K., 1994. Modeling suspended particle distribution in near coastal waters using satellite remotely sensed data. International Journal of Remote Sensing 15, 1207–1219. Hyoun-Young, L., 1993. An application of NOAA AVHRR thermal data to the study of urban heat island. Atmospheric Environment 278, 1 – 13. Jensen, R.J., 1986. Introductory Digital Image Processing. Prentice Hall, New Jersey. Lillesand, T., Kiefer, R., 1994. Remote Sensing and Image Interpretation. Wiley, New York. Constantinos Cartalis, Department of Applied Physics, Laboratory of Meteorology, University of Athens, Panepistimioupolis, Build. PHYS-5, Athens, 15784, Greece. Email: ckartali@atlas.cc.uoa.gr, tel.: 294 C. Cartalis et al. / En6ironmental Science & Policy 3 (2000) 287–294 +30-1-7276843; fax: +30-1-7295281. He is an Assistant Professor at the University of Athens (Department of Physics, Division of Applied Physics). He holds a B.Sc. degree in Physics from the University of Athens (1985), M.Sc. in Atmospheric Physics, Master of Engineering in Space Technology, and Ph.D. in Environmental Physics from University of Michigan (1989). He has the courses of Environmental Pollution and Protection, Environmental Management, Climate Change, Physical Meteorology, and Principles and Applications of Satellite Remote Sensing. Haralambos Feidas, Department of Geography, University of Aegean, Har. Trikoupi and Faonos, 81100 Mytilini, Greece. Email: xfeidas@geo.aegean.gr. He is a Lecturer at the University of Aegean (Department of Geography). He holds a Bachelors degree of Physics (1991), Master of Science degree in Meteorology (1994) and Ph.D. in Satellite Meteorology from the University of Athens (1999). He has the courses of Physical Geography, Physical Meteorology, Hydrology, Applications of Satellite Remote Sensing in the Atmosphere, Satellite Meteorology. He has considerable experience in the area of remote sensing and image processing. Maria Glezakou, Department of Applied Physics, Laboratory of Meteorology, University of Athens, Panepistimioupolis, Build. PHYS-5, Athens, 15784, Greece. Tel.: + 30-1-7276843; fax: + 30-17295281. She has a B.Sc. degree in Physics studies (University of Athens 1994) and M.Sc. degree in Environmental Physics (University . of Athens 1998). She is a research scientist at the University of Athens working on the usage of Remote Sensing in Environmental Impact Assessment. Margaritis Proedrou, Department of Applied Physics, Laboratory of Meteorology, University of Athens, Panepistimioupolis, Build. PHYS-5, Athens, 15784, Greece. Tel.: +30-1-7276843; fax: + 30-17295281. He is a Research Scientist at the University of Athens. He holds a B.Sc. degree in Physics from the University of Ioannina (1991) and a M.Sc. in Environmental Physics from the University of Athens (1993). He is a Ph.D. candidate in the Division of Applied Physics of the University of Athens. He has been involved in a number of research projects in the field of environment, meteorology, climatology and EO. He has considerable experience in the area of remote sensing, for the study of climatic characteristics on the basis of satellite and ground data. Nektarios Chrysoulakis, Department of Applied Physics, Laboratory of Meteorology, University of Athens, Panepistimioupolis, Build. PHYS-5, Athens, 15784, Greece. Email: zedd2@atlas.cc.uoa.gr, tel.: +30-1-7276843; fax: + 30-1-7295281. He holds a B.Sc. degree in Physics (1993), and a M.Sc. in Environmental Physics (1995), both from the University of Athens (1995). He is a Ph.D. candidate in the Division of Applied Physics of the University of Athens. He has worked on Satellite Remote Sensing, especially in studies of climate characteristics on the basis of satellite images.