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EUMETSAT SAFNWC (SAF in Support to Nowcasting and Very Short-Range Forecasting) and its applications in meteorology
Šťástka, Jindřich ; Setvák, Martin (advisor) ; Bednář, Jan (referee)
In the present work we study products for processing data from weather satellites named SAFNWC (SAF in Support to Nowcasting and Very Short-Range Forecasting). SAFNWC is one of the most important of EUMETSAT SAFs (dedicated centers of excellence for processing satellite data), delivering both - complex software modules, as well as operational products delivered in real-time to the end users. Main goal of the thesis is to prepare an overview of presently available software modules and their operational products, with emphasis on the MSG data. Second goal, depending on available software modules and support data resources, is to experimentally implement some of the modules in the Czech Hydrometeorological Institute (CHMI).
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Influence of the satellite spatial resolution and scan time on convective storms'overshooting tops detection
Růžičková, Markéta ; Setvák, Martin (advisor) ; Pešice, Petr (referee)
This paper deals with the possibilities of convective storms' overshooting tops detection as seen from satellites. These tops are characterized by a rapid development, their size is only a few kilometres in diameter and they are connected with the presence of hazardous weather. They can be identified as small clusters of very low temperatures in satellite imagery, but this nature depends on the scan time and the scan frequency of the specific satellite and on the other features presence at tops of convective storm. The temporal variability of minimum IR brightness temperatures at the cloud tops of selected convective storms is studied in this paper, namely on the basis of the Meteosat Second Generation (MSG) satellite datasets. But the main emphasis of this work is to analyse the influence of the operative meteorological satellites' spatial resolution on the minimal IR brightness temperature, which is related to height of the cloud top. The datasets acquired by the sensors SEVIRI, AVHRR and MODIS have been chosen for these purposes. Mostly the convective storms that occurred over the Europe in the year 2008 have been diagnosed. The scan time difference must be taken into account when datasets from MSG and the other polar orbit satellites are compared and this difference should be minimal. The minimum IR...
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Convective storms and lower stratospheric moisture
Šťástka, Jindřich ; Setvák, Martin (advisor)
Title: Convective storms and lower stratospheric moisture Author: Jindřich Šťástka Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: The primary focus of this thesis is to diagnose contributions to upper tropo- spheric and lower stratospheric (UTLS) water vapor from convective storms. The first parts of this work introduces two approaches used for a detection of lower stratospheric water vapor above convective storm tops - brightness temperature difference (BTD) technique and EOS MLS measurements. The BTD technique is based on brightness temperature difference between the water vapor absorp- tion and infrared window bands, assuming a thermal inversion above the cloud top level. The most frequently offered explanation of positive BTD values above convective storms is presence of warmer water vapor in the lower stratosphere. Furthermore, so called BTD anomalies were described and it was proposed an algorithm for objective detection of such BTD anomalies. Characteristics of pa- rameters describing BTD, BTD anomaly, infrared window brightness temperature were investigated during storms evolution on dataset of 320 storms from the area of Europe. The analysis of these characteristics proved highly probable conection between positive...
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Convective storms and lower stratospheric moisture
Šťástka, Jindřich ; Setvák, Martin (advisor)
Title: Convective storms and lower stratospheric moisture Author: Jindřich Šťástka Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: The primary focus of this thesis is to diagnose contributions to upper tropo- spheric and lower stratospheric (UTLS) water vapor from convective storms. The first parts of this work introduces two approaches used for a detection of lower stratospheric water vapor above convective storm tops - brightness temperature difference (BTD) technique and EOS MLS measurements. The BTD technique is based on brightness temperature difference between the water vapor absorp- tion and infrared window bands, assuming a thermal inversion above the cloud top level. The most frequently offered explanation of positive BTD values above convective storms is presence of warmer water vapor in the lower stratosphere. Furthermore, so called BTD anomalies were described and it was proposed an algorithm for objective detection of such BTD anomalies. Characteristics of pa- rameters describing BTD, BTD anomaly, infrared window brightness temperature were investigated during storms evolution on dataset of 320 storms from the area of Europe. The analysis of these characteristics proved highly probable conection between positive...
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Convective storms and lower stratospheric moisture
Šťástka, Jindřich ; Setvák, Martin (advisor) ; Púčik, Tomáš (referee) ; Zacharov, Petr (referee)
Title: Convective storms and lower stratospheric moisture Author: Jindřich Šťástka Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: The primary focus of this thesis is to diagnose contributions to upper tropo- spheric and lower stratospheric (UTLS) water vapor from convective storms. The first parts of this work introduces two approaches used for a detection of lower stratospheric water vapor above convective storm tops - brightness temperature difference (BTD) technique and EOS MLS measurements. The BTD technique is based on brightness temperature difference between the water vapor absorp- tion and infrared window bands, assuming a thermal inversion above the cloud top level. The most frequently offered explanation of positive BTD values above convective storms is presence of warmer water vapor in the lower stratosphere. Furthermore, so called BTD anomalies were described and it was proposed an algorithm for objective detection of such BTD anomalies. Characteristics of pa- rameters describing BTD, BTD anomaly, infrared window brightness temperature were investigated during storms evolution on dataset of 320 storms from the area of Europe. The analysis of these characteristics proved highly probable conection between positive...
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Cloud-top morphology of convective storms as observed by meteorological satellites
Radová, Michaela ; Setvák, Martin (advisor) ; Pešice, Petr (referee) ; Sokol, Alois (referee)
Title: Cloud-top morphology of convective storms as observed by meteorological satellites Author: Michaela Radová Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: This work focuses on study of features occurring at tops of convective storms, namely embedded warm areas, cold rings, cold-U/Vs and overshooting tops (OTs), mainly from the perspective of satellite observations. We have assembled a database of 104 subjectively detected cold rings and cold-U/Vs from the area of Europe. We discuss relationship between satellite- observed brightness temperature and cloud top height determined from radar measurements for storms with distinct cold-rings. Our results support the hypothesis that the warm area is a consequence of presence of central elevated dome reaching warmer lower stratosphere. Moreover, a storm with transformation of cold ring into cold-U is studied and an elevated plume above storm anvil in the warmer lower stratosphere is found to be a likely explanation of the warm area inside the cold-U. Both analyses confirm that thermal inversion above the tropopause is a necessary prerequisite for occurrence of cold rings and cold-U/Vs. We also propose a method for automated objective determination of spatial characteristics of...
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The exploitation of remote sensing for the analysis and progress of rainfalls
Bližňák, Vojtěch ; Sokol, Zbyněk (advisor) ; Setvák, Martin (referee) ; Pešice, Petr (referee)
The thesis is divided in two parts. The first part deals with the areal distribution of short-term convective rainfalls with regard to the influence of altitude. Precipitation estimates based on combination of rain gauge and radar data are used for this purpose. Statistical tests proved that the areal distribution of hourly convective rainfalls does not depend on altitude. Besides data containing precipitation events only, all measured data were statistically analysed regardless of the fact whether precipitation occurred or not. In this case it was found out that the relationship between hourly rainfall totals and altitude depends on the considered threshold of rainfall totals. When all data were considered, i.e. a threshold value was set to zero, an increase of rainfall totals well correlated with altitude. The dependence slowly disappeared with an increasing threshold. The areal distribution of 6 hour rainfall totals proved higher values in the area of south Bohemia. The most frequent synoptic patterns were northwest cyclonic situations (NWC) and cyclone over the Central Europe (C). The second part of the thesis is focused on satellite data exploitation, as measured by meteorological satellite Meteosat Second Generation, for convective precipitation estimates. The Convective Rainfall Rate (CRR) algorithm,...
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Influence of the satellite spatial resolution and scan time on convective storms'overshooting tops detection
Růžičková, Markéta ; Setvák, Martin (advisor) ; Pešice, Petr (referee)
This paper deals with the possibilities of convective storms' overshooting tops detection as seen from satellites. These tops are characterized by a rapid development, their size is only a few kilometres in diameter and they are connected with the presence of hazardous weather. They can be identified as small clusters of very low temperatures in satellite imagery, but this nature depends on the scan time and the scan frequency of the specific satellite and on the other features presence at tops of convective storm. The temporal variability of minimum IR brightness temperatures at the cloud tops of selected convective storms is studied in this paper, namely on the basis of the Meteosat Second Generation (MSG) satellite datasets. But the main emphasis of this work is to analyse the influence of the operative meteorological satellites' spatial resolution on the minimal IR brightness temperature, which is related to height of the cloud top. The datasets acquired by the sensors SEVIRI, AVHRR and MODIS have been chosen for these purposes. Mostly the convective storms that occurred over the Europe in the year 2008 have been diagnosed. The scan time difference must be taken into account when datasets from MSG and the other polar orbit satellites are compared and this difference should be minimal. The minimum IR...
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