ATMOSPHERIC DYNAMICS

Author: JORBA CASELLAS ORIOL.
Year: 2004.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: ETSEIB.
Place of preparation: ETSEIB, EDIFICI H PLANTA 10 Campus SUD.

Summary: The air quality in an area is directly linked with the present weather and dispersive characteristics. Therefore, the study of winds in a region represents a contribution of information they need in order to deepen in various scientific fields. The theme of this thesis deeper knowledge of the wind field in the Iberian Peninsula and the Geographic Area de Catalunya (AGC). As a prelude to the study of wind fields have been identified situations typical weather affecting the region study. It has conducted an extensive literature review of different classifications of synoptic situations typical of the Iberian Peninsula and Catalonia. The survey has been the difficulty of finding a unified classification, which encompasses most of the proposals made so far. Therefore, seeing existing classifications have a high degree of subjectivity has chosen to propose and implement a methodology underdeveloped in the region of study to analyze the flow affecting the Iberian Peninsula from a estadístico.Así, we have implemented an algorithm for clustering of clusters to analyze retro-trayectorias for the Barcelona area. From a database of 5 years retro-trayectorias cinematic of 4 days, calculated with the model Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT), has obtained a set of clusters of retro-trayectorias of similar length and curvature . In order to make a better description of the tropospheric circulation affecting Barcelona, have been analyzed retro-trayectorias for 5500, 3000 and 1500 m asl In Barcelona. The main transport patterns identified 5500 m are classified into flows W, flows NW, SW flows, and recirculaciones regional air masses on Europe and the Mediterranean Sea. It describes the annual distribution of the different patterns of transport. In summer, the flows moderate W SW average troposphere, flows weak W SW to 3000 m, and recirculaciones regional 1500 m characterize transport patterns affecting Barcelona. This pattern generally varies in winter, with increased frequency of advecciones of Wa 5000 m, and an increase in situations of N and NW to 1500 m. Combining the results for 5000 and 1500 m are observed a large number of situations with decoupling between the troposphere and lower average troposfera.A from these results have chosen seven days that are representative of different situations typical weather affecting the Iberian Peninsula defined after flows in the middle and lower troposphere (WW, W-NW, W-wR, SW-wR, R-eR, SW-eR, NW-N). With the implementation of the model numerical weather forecasting mesoscalar 5th generation Mesoscale Model (MM5) have described the winds of these situations for the Iberian Peninsula and the AGC. The simulations have been performed with high horizontal resolution (24 km and 2 km respectively). Los resultados permiten describir las circulaciones y regímenes de vientos que se establecen, y permiten caracterizar las particularidades principales de las mismas. To describe the characteristics of the dispersive and turbulent troposphere, especially the boundary layer, also describes the evolution of the turbulent kinetic energy for each day of study. Of every day presents a pattern with the general characteristics of each situación.Se has made a major effort to quantify the errors in both area and height of the vien 8 coughing and 345 air temperature in the validation of the models. The calculation is made to analyze various statistical error of the model, viewing developments in the same time and space

Author: DIAZ RODRÍGUEZ ANA MARIA.
Year: 2005.
University: LA LAGUNA [www.ull.es].
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: FACULTAD DE FÍSICA.

Summary: The atmospheric aerosols play a key role in energy balance system Tierra-Atmósfera, introducing even large uncertainties as reflected in the Third Panel on Climate Change. The region of the Canary Islands, because of its geographic location, very close to one of the main sources of natural aerosols, of the Sahara desert. Moreover is under the influence of anthropogenic aerosols transported from the industrial zones in the center of Europe, has far excellent conditions for monitoring and research of the radioactive properties of these atmospheric constituents, and their impact on the levels of solar ultraviolet radiation UV. The spectral range is of particular interest because of its marked biological effect. Therefore, the objective of this work is to reduce the uncertainty associated with atmospheric aerosols in the transmission of UV radiation in the atmosphere. This paper has done a characterization of aerosols in the region of the Canary Islands from the climatology of air masses carrying these atmospheric constituents to the two observatories measure, SCO (28.5Â º N, 16.3Â º W, 52 min) and IZO (28.3Â º N 16.5Â º W, 2367 m). Also considers the physico-chemical properties of aerosols present at these observatories. The classification of air masses is based on the contribution delas main sources of aerosols affecting the region of the Canary Islands in the period 1948-2004. It has developed two new methodology, whose main novelty is the use of time of permanence as geographical area and height. The first one is based on the statistical technique of cluster analysis and the second uses fuzzy logic. Both methods showed similar results, characterizing observatories by air masses that develop over the Atlantic Ocean with the difference in height between the two: air masses taking place in this sector about 2 km (44%) in IZO, and below 2 Km (47%) in SCO. The second group of air masses in the two most important observatories are again air masses that des arrollan on the Atlantic Ocean, but with the difference that IXO what shape maritime below 2 km, with a 21.3% and SCO sea over 2 km, with a 23.2%. The third group is made up of air masses undergoing various sectors (European, African and / or sea), EAM, with an average annual rate of 17.4% in IZO and a 21.8% in SCO. Finally, the conglomerate grouping air masses carrying mineral dust from the African continent, AfD, providing average frequency of occurrence very different in the two observatories: 16.9% in IZO and 8.0% in SCO. They show a clear comprotamiento seasonal in the observatory IZO coming to increase by more than 10% of the cold season in the warm, and conversely in SCO. The peaks of this type of air mass is obtained in agosta for IZO, while they are reached during the months of December and January in SCO. The characterization in IZO has completed measurements of the atmospheric constituents: mineral dust, nitrate, ammonium sulphate and non-marine origin during the period 1995-1998. Using various statistical techniques, non - parametric tests and linear regression analysis, it was found that one quarter conglomerates presented specify different chemistry of these elements. Thus, in conglomerates EAM and MaA species are representative sulphate and nitrate harmonious throughout the period. The conglomerate WTO noted a change in the correlation between different chemical species in the first two years of study (1995-1996) to the last two (1997-1998), where it is possible to find nitrate and ammonium sulphate. Lastly, the conglomerate AfD nitrate is present mainly as nitrate harmonious, while the speciation of No 8 ss- is 15 associated species gaseous pollutants emitted from Europe or Africa with the components of mineral dust. From these results it is possible to assume that the conglomerate AfD a significant fraction of sulfate has been associated with the so thick, where its radioactive properties are less important and must be taken into account when shaping the radiative effect of the same. The physical characterization has been done from the remote sensor measurements: TOMS (Total Ozone Mapping Spectroradiometer) and MODIS (Moderate Resolution Imaging Spectrometer) aboard space platforms belonging to NSA. The first of these sensors provide information on the presence of aerosols in the UV absorbers, which in this region is mainly mineral dust originating on the African continent, and the second gives us the power to attenuation of aerosols in the visible spectral range and infrared (VIS-IR). The analysis of the spatial and temporal variation of these parameters in all the pixels covering the area (27Â º N-30Â º N, 19Â º W-15Â º W), has been 0.04 in OAE and 0.05 in the IAA, which indicates that the distribution of aerosols studies on the region is homogenous. Moreover, the study of the time series of these, from 1978 to 2004 to the IAA and from 2000 to 2004 for the OAE, reveal an increase in recent years of the presence of aerosols during the warm season on the region Canary presenting its peak in July. Moreover, both figures reflect secondary peak in February-March and September-October. The correlation of these parameters air masses allows us to complete the characterization of the same. Thus, majest air transporting mineral dust presents an average maximum of IAA, 1.4 +-0.9m air masses EAM also have a contribution of mineral dust important especially in the hot season, as reflected by its average, 1.1 +-1.0. Finally, the minimum values of this parameter are associated with air masses type MAM in the cold season. The correlation between air masses and OAE has the same behavior: maximum values in July, 0.6 +-0.1 associated with air masses EAM type, and minimum values in maritime air masses, and MAM MAL, with an average of the entire period of 0.1 +-0.0. For monitoring measures solar UV radiation in the region of the Canary Islands have been conducted simultaneous action of solar UV radiation in the range 290-400 nm in both observatories during 2002 and 2003 with two espectrorradiómetros Bentharm. These teams have been subjected to strict quality controls, which has developed a methodology calibration with standard lamps, 100 and 1000 W, being able to evaluate their behavior in various campaigns intercomparison. They have shown they agree with the teams of reference, more than 95% for espectrorradiómetros. Characterization of atmospheric aerosols in this region along with measures of solar UV radiation has allowed an assessment of the radiative forcing of the same. Values mean radiative forcing daily in the region of the Canary Islands in a position to intrusion of African mineral dust are: -1.8 + - 0.6 W/m2 at the observatory IZO and -. 2.3 + - 0.5 W/m2 at the observatory SCO during the cold season, and in the hot season of -2.6 +-1.6 and -3.1 +-1.5 W/m2 at observatories IZO and OCS respectively. It has also evaluated the efficiency of radiative forcing both observatories, giving values of -19.5 Wm-2/500 in IZO during the warm season, and -8.8 +-1.4 Wm-2/550 to -6.8 +-1.5 Wm- 2 / 550 in the warm and cold seasons respectively in SCO. These levels are increased in the case of intrusion of mineral dust in SCO, -14.6 +-4.2 and -13.7 +-2.5 Wm-2/550 in warm and cold seasons respectively. For this type spray also has evaluated the efficiency of forcing per unit of AAR, this being of -2.90 + - 0.63 and -8.2 + - 4.1 Wm-2/IAA in warm and cold seasons respectively. The methodology employed to determine the efficiency of aerosol forcing in the region of the Canary Islands has been implemented measures undertaken during the company VELETA2002 (Grenada) can assess the efficiency of forcing of anthropogenic aerosols weakly absorbent. The instantaneous values found, -1.3 + - 1.2 Wm-2/440, are lower than those found in the case of intrusion of mineral dust -12.8 + - 3.4 Wm-2/470 obtained in Santa Cruz de Tenerife during the warm season. Finally, highlight the values of r radiative forcing found in the absence of mineral dust in the region of the Canary Islands, -1.4 + - 0.3 to -1.8 + - 0.6 W/m2, showing the importance of sea spray in the energy balance of system Tierra-Atmósfera and therefore should be included in climate models.