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EN
This paper contains a study of using Ogimet services as a source of meteorological data and the Python language script to streamline data processing. Meteorological data is important in large number of research projects in different disciplines of sciences and technology. In this case, it was used to analyze cloudiness, but it can also be used for energy, hydrology, and environment analyses. Attention has been paid to the total cloudiness variability in an area of the Lower Silesia region in Poland during the time period of 2001–2010 using the data from eight synoptic stations (the data was obtained from the Ogimet service). A very important part of the work constituted Ogimet services as a source of free and easily available meteorological data. The biggest advantage of Ogimet is that the process of obtaining data is very easy and helpful in reducing the time needed to collect the data necessary in the research process. The offered data is free and available via the Internet, but it is raw and general. For these reasons, a Python script language application was made for faster and easier data processing. The script applied in this project has been described in detail in the work. Finally, after processing the data, the daily averages of total cloudiness have been calculated based on the available data for eight meteorological stations. Next, the ten-year average for each day and month have been calculated. The results of the study were compared with works that took a longer data time period of total cloudiness into account.
PL
Artykuł poświęcony jest wykorzystaniu usługi Ogimet jako źródła danych meteorologicznych opisujących zachmurzenie oraz skryptu w języku Python do optymalizacji procesu przetwarzania pozyskanych danych. Dane meteorologiczne są istotne w wielu zagadnieniach badawczych z różnych dyscyplin nauki i techniki. W tym przypadku dane zostały wykorzystane do analizy wielkości zachmurzenia. Z równym powodzeniem opisane narzędzia mogą być wykorzystane w innych dziadzinach, takich jak hydrologia, ochrona środowiska czy energetyka. Zasadniczym elementem pracy jest opis usługi Ogimet jako źródła wolnych i łatwo dostępnych danych meteorologicznych. Największą zaletą serwisu jest prostote i szybkie pozyskiwanie danych. Oferowane dane są bezpłatne i dostępne przez Internet, ale są one surowe i ogólne. Z tego powodu zaproponowano użycie języka skryptowego Python do przetwarzania danych. Skrypt zastosowany w tym projekcie został szczegółowo opisany w pracy. Po przetworzeniu danych, na podstawie dostępnych informacji z ośmiu stacji meteorologicznych, obliczono wartości średnich dobowych całkowitego zachmurzenia. Następnie obliczono średnie dziesięcioletnie dla każdej ze stacji. Wyniki zostały porównane danymi zawartymi w pracach, w których analizowano zachmurzenie w dłuższym okresie.
EN
This work contains information concerning long-wave atmospheric radiation. Artificial neural networks were developed to forecast total mean hourly irradiance based on long-wave atmospheric radiation as cloudiness indicator. It was proved that using this variable in models for forecasting irradiance is wellgrounded. The proof was based on the neural networks sensitivity analysis. It was proved that neural network model is capable to utilize information carried by long wave atmospheric radiation only when the air temperature is provided as additional explanatory variable.
PL
Praca stanowi próbę określenia wpływu cyrkulacji atmosferycznej na kształtowanie wielkości i rodzaju zachmurzenia w zależności od pory roku w Krakowie. Jako źródło danych wykorzystano obserwacje z 12 UTC dokonywane na stacji naukowej Zakładu Klimatologii IG UJ w Krakowie w latach 2004-2008 oraz Kalendarz typów cyrkulacji atmosfery dla Polski Południowej T. Niedźwiedzia z tego samego okresu. Badano związek średniej wielkości zachmurzenia z typami cyrkulacji oraz prawdopodobieństwo wystąpienia wybranych rodzajów chmur (Cirrus, Altocumulus, Stratocumulus, Cumulus). Na podstawie częstości względnej wyznaczono typy cyrkulacji sprzyjające ich wystąpieniu. Zaprezentowana metoda pozwoliła na wykazanie różnic wpływu czynników cyrkulacyjnych kształtujących wielkość i rodzaj zachmurzenia między poszczególnymi porami roku. Wykazała również związek zalegania chmur Stratocumulus z typami antycyklonalnymi cyrkulacji na jesieni, słabszy wpływ czynników cyrkulacyjnych na kształtowanie zachmurzenia i dużą rolę konwekcji latem oraz wpływ adwekcji z sektora południowego generującej sytuacje fenowe na występowanie chmur Cirrus i Altocumulus w zimie i na jesieni.
EN
This study attempts to investigate and describe an influence of atmospheric circulation on forming cloudiness on depending of particular seasons in Krakow. 12 UTC observations from the scientific station of Department of Climatology IG Jagiellonian University in Krakow for the period 2004-2008 and Calendar of circulation types for Southern Poland by T. Niedźwiedź for analogous period were used. The influence of circulation types on average cloud cover was investigated, as well as the probability of occurrence for selected cloud genera (Cirrus, Altocumulus, Stratocumulus, Cumulus). Basing on relative frequency, circulation types favorable for their occurrence were determined. Presented method permitted to identify differences of influence of circulation factors on cloud cover and cloud genera between particular seasons. It also indicated that occurrence of Stratocumulus depends on anticyclonic types, weak influence of circulation factors on forming cloudiness with big role of convection in summer and influence of advection from southern sector generating foehn situations on occurrence Cirrus and Altocumulus clouds in winter and autumn.
EN
Meteosat Second Generation is a geostationary satellite, designed to explore atmospherical processes. Main instrument on board MSG is SEVIRI, a 12-channel scanning radiometer, observing the Earth full disk in nominal MSG position at 0° longitude with a horizontal resolution of 3 km at nadir. In this paper one of MSG Cloud Products – Cloud Mask (CMa) was used to analyze cloud detection over Poland. The main objective of Cloud Mask is to discriminate all cloudfree pixels, because correct cloud detection is an important pre-processing step, to use many different MSG products. As the result of this algorithm all pixels are categorized in five categories as cloudy, cloud contaminated, cloud-free, snow/ ice fi lled or no processing. The aim of this study is to compare Cloud Mask data to a standard synoptical observations. Ground observations classified cloudiness in a 9-degree scale (octas) and normalization this different scales was the greatest methodical problem. Base sources was 12 situations cloud cover, represented varied types of cloudiness over Poland, in effect 812 sat-synop observations. This satellite data was compared with ground observations through contingency tables and statistical indicators. The percentage of correct observations for 5x5 pixel matrix equals 27,3. As the results shows, it is visible linear relationship between satellite and synop data with correlation coefficient equals 0.73. Most important effect of this study is to indicate a underestimating satellitebased cloudiness observations. The mean error (satellite-synop) ranging between +0,6 and –1,3 octas, and except cloud free situations, is negative.
EN
The paper presents the relationships between daily sums of global solar radiation and real sunshine duration and separately, mean for a day amount of total cloudiness (computed from three standard observation terms) within 11 May - 31 July period in Felin. This period is approximated to the insolation summer one and is characterised by a long day (at least 15.5) and slight differentiation in time. The relationships were obtained on the basis of mean decade data and a stretch of single days during five seasons (but not successive). They were described with two types of equation regressions: linear and curvilinear (a 2-degree polynomial). Additionally, the same relationships were determined regarding the days without and with precipitation during the examind summer periods. The analysis performed in relation to effectiveness of each of these equations application to estimate daily sums of global solar radiation (the relative and standard errors) showed that better results are obtained from the equations concerning relations of the solar radiation with sunshine duration than cloudiness. It also reveated that to describe both types of the relationships, a polynomial is more effi cient than linear regression (particularly in the case of daily data examination). Moreover, it was stated that determination of these relationships for some specific days (eg. days without precipitation) is appropriate as it allws to estimate the daily sum of solar radiation with smaller errors.
PL
Wielkość zachmurzenia nad Polską (poza obszarem gór) opisano średnimi sezonowymi i rocznymi wielkościami zachmurzenia z 48 stacji synoptycznych, obliczając na ich podstawie średnią obszarową wielkość zachmurzenia w kolejnych latach okresu 1951-2000. Określono wielkości anomalne zachmurzenia, stosując podział zbioru oparty na przedziałach kwantylowych. Za anomalne przyjęto te pory roku i lata, w których wielkość zachmurzenia przekraczała kwantyl 90% lub była mniejsza niż określona przez kwantyl 10%. Dokonano analizy pola ciśnienia nad północnym Atlantykiem i Europą na poziomie morza w porach roku i latach o anomalnych wielkościach zachmurzenia nad Polską. Do opisu ciśnienia atmosferycznego użyto średnich sezonowych i rocznych jego wartości, określonych w odniesieniu do punktów węzłowych siatki z obszaru φ 30°-70°N i λ 40°W-60°E. Krok siatki wynosi 5° szerokości i 10° długości geograficznej. Wskazano obszary wystąpienia największych różnic między średnim ciśnieniem w sezonach i latach o anomalnym zachmurzeniu nad Polską i ciśnieniem średnim wieloletnim (1951-2000).
EN
The cloudiness over Poland (except the mountains) was described using seasonal and annual average cloudiness level records from 48 synoptic stations. These were used as bases for calculating the spatial average cloudiness for consecutive years 1951-2000. Anomalous magnitude of cloudiness was determined using the division of series based on quantile interval. It was assumed that the anomalous seasons and years were the ones, in which the cloudiness exceeded the 90 % quantile or was below the value defined by the 10 % quantile. The analysis of the pressure pattern at the sea level for the North Atlantic and Europe in seasons and years with anomalous cloudiness over Poland was carried out. To describe air pressure pattern, its seasonal and yearly average values were used. The values were taken from the nod-points of the grid from the area φ 30°-70°N and λ 40°W-60°E. The grid span was 5° latitude and 10° longitude. The areas of biggest differences between mean pressure in seasons and years with anomalous cloudiness and long-term pressure records (1951-2000) were denoted.
7
Content available remote Struktura czasowo-przestrzenna zachmurzenia na Pomorzu
EN
The aim of the paper was to characterize the degree of the state of the sky in Pomerania and its time and spatial variability. The average yearly state of the cloudiness in the years 1971-2000 amounted to 5.2° in the scale 0-8°. May was the month of the least cloudiness amounting to 4.4° on average and December was the month of the largest cloudiness equalling 6.0°. There were about 40 clear days and 140 cloudy days in Pomerania during the year. Most of the clear days occurred in May - on average 5.5. The least number of clear days was observed in November - on average 1.3. The highest number of cloudy days was in December, on average about 18; the fewest cloudy days occurred in August, on average about 6. In the years 1971-2000 the number of cloudy days significantly increased in April, June, September and November.
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