THE ANALYSIS OF MOISTURE DEFICIT BASED ON MODIS AND LANDSAT SATELLITE IMAGES. CASE STUDY: THE OLTENIA PLAIN

Satellite images are an important source of information to identify and analyse some hazardous climatic phenomena such as the dryness and drought. These phenomena are characterized by scarce rainfall, increased evapotranspiration and high soil moisture deficit. The soil water reserve depletes to the wilting coefficient, soon followed by the pedological drought which has negative effects on vegetation and agricultural productivity. The MODIS satellite images (Moderate Resolution Imaging Spectroradiometer) allow the monitoring of the vegetation throughout the entire vegetative period, with a frequency of 1-2 days and with a spatial resolution of 250 m, 500 m and 1 km away. Another useful source of information is the LANDSAT satellite images, with a spatial resolution of 30 m. Based on MODIS and Landsat satellite images, were calculated moisture monitoring index such as SIWSI (Shortwave Infrared Water Stress Index). Consequently, some years with low moisture such as 2000, 2002, 2007 and 2012 could be identified. Spatially, the areas with moisture deficit varied from one year to another all over the whole analised period (2000-2012). The remote sensing results was corelated with Standard Precipitation Anomaly, which gives a measure of the severity of a wet or dry event

ENVIRONMENTAL LEVELS AND DISTRIBUTION OF CARBON MONOXIDE IN BUCHAREST URBAN AREA CASE STUDY: 1. 07. 2006 – 31.03.2007

Ambient concentrations of carbon monoxide in the vicinity of or inside urban and industrial areas can substantially exceed environmental background levels and can be detrimental to human health and welfare. In this period of analysis (July 2006 – March 2007), the maximum allowable concentration (MAC) was exceeded especially at Mihai Bravu and Cercul Militar. The accompanying diagrams showing the time evolution and charts revealing the spatial distribution of CO ambient air concentrations (based on GIS techniques) can be useful instruments in identifying the potential risk areas, like the important streets in the center of Bucharest

WEATHER COSTS. CASE STUDY: BLIZZARDS IN ROMANIA DURING THE 2000 – 2012 PERIOD

In mid-latitude regions, blizzards may have serious consequences not only on humans, but also on the environment and the economy. In Romania, blizzards may be produced throughout the country, but due to some local conditions and particularities of the underlying active surface, their intensity, duration and frequency are different; the most exposed and vulnerable areas are: The Romanian Plain (and especially the Baragan Steppe – Plain Area), Moldavia and Dobrogea. This study makes a survey of several blizzard episodes, which occurred during the wintertime of the 2000 – 2012 periods. They have been approached from the point of view of the consequences that this kind of weather phenomenon actually has on the society under meteorological, economic and social aspects; the fact that its aftermath may sometimes be of sizeable proportions, occasionally leading even to loss of human lives, being well-known already

THUNDERSTORMS-RISK FACTORS IN AVIATION. CASE STUDY: AREA OF RESPONSABILITY OF THE BUCHAREST-OTOPENI AERODROME ON 30.06.2009

Thunderstorms are always dangerous weather phenomena for flight safety and, irrespective of their nature, they have a negative impact on all aviation activities. Thunderstorm clouds can generate severe and rapid changes of various meteorological elements (visibility, cloudiness and cloud lower base, wind), sometimes to such a great extent that landing may become impossible. Thunderstorms are serious weather hazards in aviation and may produce great damage and even casualties. One such unfortunate aviation event took place in the vicinity of the Bucharest-Otopeni Aerodrome, on 30.06.2009, when a military aircraft, which was operating a training flight in the responsibility area of the Bucharest - Otopeni military aerodrome, was struck by lightning at local hour 18:20. The present study actually makes an inventory of the extremely hazardous flying conditions, by thoroughly analyzing the relevant weather reports and data, as well as visual and synoptic messages from that very day. All these materials showed that the airdrome of destination was under the influence of an anti-cyclonic ridge, which accounted for the very poor meteorological conditions. On such severe weather, although the crew members tried to avoid the Cumulonimbus clouds in which a severe thunderstorm was developing, the flight was put in danger since the aircraft was struck by lightning, which simply blurred out the radar system and, therefore, landmarks orientation became almost impossible, thus creating false perceptions to the pilots trying hard to stabilize the plane

The Influence of Urban Morphology on the Urban Microclimate.

In this paper, GIS techniques and satellite data are used in order to analyze the impact of the two types of urban design existing in the neighborhoods of Bucharest on the local microclimate. The two types of urban morphology considered are separated in time by a natural event, the earthquake from 1977, a phenomenon that has changed the evolution of urban planning of the city. The stages of the study are: i) geospatial analysis of urban morphology with emphasis on the construction features of each period; ii) spatial analysis of the land surface temperature in correlation with urban morphology, using Landsat satellite images; iii) microclimate simulation using ENVI-met software to highlight the local thermal environment. The analysis of satellite data highlighted higher values of the land surface temperature in neighborhoods built after 1977 compared to ones built before that year. The simulation results highlight the differences of thermal environment between the two categories analyzed, lower values of air and surface temperatures for the neighborhoods built before 1977

Analysing the homogeneity of air temperature, relative air humidity, precipitation and wind data series using ‘Climatol’ and meteorological metadata

Errors are inherent in all measurement activity, and meteorology is no exception. Homogenization of climatological series to eliminate disturbances often contained in them, due to changes in the conditions of observations, is a mandatory process to increase the reliability of studies of climate variability derived from their analysis. The “Climatol” R package is devoted to the problem of homogenizing climatological data series in order to remove the perturbations produced e.g. by changes in the conditions of observation or in the nearby environment, to allow the series to reflect the climatic variations. As it is known, changes in the location of meteorological observatories, changes in instrumentation (from classic equipment to automated sensors) or in shelters intended to protect sensors from solar radiation, or even changes in the environment (land uses, new constructions, etc.) are alterations that can not be attributed to changes in the climate. Such information regarding this changes are known as “metadata”. In this paper the “Climatol” method was used for air temperature, relative air humidity, precipitation and wind daily data homogenization for the period since 1961 till 2015 at Cluj-Napoca, Oradea, Satu Mare and Vlădeasa 1800 meteorological stations. With the help of metadata, the results were validated and changes in statistical parameters of meteorological data string were identified, for the analysed meteorological parameters, due to the relocation of the meteorological platforms, changes of the meteorological equipment and changes of the measuring methodology

THERMAL DIFFERENCES WITHIN BUCHAREST TOWN AREA CASE STUDY: 01.07.2006-31.03.2007

The thermal differences within the Bucharest town-area, as presented in a case study based on hourly measurements in seven fixed-site monitoring stations, made from 01.07.2006 to 31.03.2007, have clearly revealed the town’s thermal superiority over the open spaces around it, even if they are lying at similar or at lower altitudes. The town’s heat surplus, which is mainly due to the various building materials, the density and height of buildings, the orientation of main traffic avenues, the distribution of parks and lakes etc., gets more evident during the warm season. Besides, the thermometrical determinations that have been simultaneously performed at two different height levels (2 and 10 m-high above ground surface) of the seven fixed-site monitoring stations show clear differences of air heating processes, mostly due to the different interaction patterns between solar radiation and the underlying active layer

LAND SURFACE TEMPERATURES ESTIMATED ON GROUNDOBSERVED DATA AND SATELLITE IMAGES, DURING THE VEGETATION PERIOD IN THE OLTENIA PLAIN

The purpose of this study is to analyze the land surface temperatures by using climatological and remote sensing data during the vegetation period in the Oltenia Plain. The data used in this study refer both to climatological data (namely monthly and seasonal air and soil temperatures), and to remote sensing data delivered by MODIS Land Surface Temperature (LST), with a spatial resolution of 1 km. The analyzed period spans from 2000 to 2013 and the vegetation period considered is April-September. As main results, there were observed four years with high temperatures, namely 2000 (20.4oC-air T, 24.6oC soil T, and 26oC LST), 2003 (20.2oC air T, 23.9oC soil T and 24.5oC LST), 2007 (20.5oC air T, 24.3oC soil T and 25oC LST) and 2012 (21.3oC air T, 25.7oC soil T and 26.5oC LST). The correlations between air temperature, soil temperature and LST were statisticaly significant. The diference between air temperature and soil temperature values ranked within 3-4oC, while the difference between soil temperature and land surface temperature obtained from MODIS images was about 0.8oC. Spatially, the highest temperatures were recorded on the Leu-Rotunda Field, the Caracal Plain and the Nedeia Field, and pretty high variations of observed temperatures seemed to depend on vegetation cover. The MODIS images represent one of the most important types of satellite data available for free, which can be successfully used in determining the climatic parameters and can help to predict the changes in plant activity, due to weather phenomena

Minimum air temperatures going to extremes in Brașov city (Romania)

Brașov is the largest city in the Romanian Carpathians, being located inside the largest low-lying area in the country and exposed to western climatic influences, with well-defined local features, especially in the cold season, when many thermal extremes may occur. The main objective of this study was to analyze the minimum air temperatures and highlight their extreme values over the 1980-2015 period. The climatic data were collected from the Brașov-Ghimbav meteorological station and a set of specific indices, generically called as indices of extremes and climate change by the WMO’s Expert Team on Climate Change Detection and Indices (ETCCDI), were subsequently calculated. The resulting quantitative assessments of minimum air-temperature variations in the above mentioned area has also proved that they can be useful tools in calculating other derived technical parameters which may be relevant for the design and onset of heating or cooling installations, in order to maintain a comfortable indoor climate in residential buildings

Meteorological Elements Used in the Numerical Forecast of PM10 Over the Romanian Territory

Pollutants in large amounts may not only cause severe health problems and damage crops, but may also represent one of the main causes of global warming. Air quality numerical models are very useful tools in forecasting air pollutants transport and spread. Consequently, this paper analyzes the regional concentration of PM10 (a geographical domain representative of Romania’s territory), by using the numerical air quality forecasting model: WRF-CHEM version 3.5. The respective model has been applied on a Romania-centered upon geographical area, for both the two months representative of the warm and cold seasons (June and January 2013, respectively), at a spatial resolution of 10 km, with a 24 hours’ anticipation. For the WRF-CHEM chemistry module to be initiated, values of PM10 emissions were extracted from the TNO (Nederlandse Organisatie voor toegepast natuurwetenschappelijk onderzoek, www.tno.nl) database for 2009. The meteorological parameters required by the weather forecast model were obtained from the numerical output of the ECMWF (www.ecmwf.int) global model. All these meteorological parameters are very important for air quality simulations, especially wind profiles, which are very important assessment tools since they determine where pollutants are transported, and air-temperature as it may largely influence the speed of chemical reactions in the atmosphere. The vertical diffusion is strongly linked to the height of the mixing layer and influences the exchange between the ground layers and the open troposphere. In order to highlight the quality of the numerical forecasts for PM10 from the WRF-CHEM model, the results obtained were compared to the measurements obtained through gravimetric methods (average daily values of PM10). Hence, specific measurements were provided by the National Environmental Protection Agency (ANPM)