PRACE GEOGRAFICZNE, zeszyt 126 Instytut Geografii i Gospodarki Przestrzennej UJ Kraków 2011, 53 65 Jerzy Radomski, Artur Widawski INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION IN THE SILESIAN UPLAND Abstract: It is well known that the area of investigation is the most densely populated region in Poland, and air is one of the most important environmental elements determining the quality of human life. In spite of the improvement in the aero-sanitary conditions in recent years, the situation in this region is still unfavorable. Although less frequent, there are cases of exceeded air pollution norms, daily norms in particular, which is especially visible in the winter season. The detailed evaluation of the influence of circulation types on the appearance of particular concentrations of pollutants carried out in this work confirmed the predominant influence of individual circulation types synthetic measures of atmospheric circulation on the development of air pollution levels in the Silesian Upland. Daily immission data and three calendars of circulation types allowed the authors to present mutual relations between the considered variables in detail. Key words: atmospheric circulation, immission, calendar of the circulation types, SO 2, Silesian Upland Słowa kluczowe: cyrkulacja atmosferyczna, imisja, kalendarz typów cyrkulacji, SO 2, Wyżyna Śląska Introduction The Silesian Upland is the best illustration of an area that was subject to strong anthropopression in Poland. The wasteful economy of the 1970s, characterized by a dynamic development in industry and urbanization, was the most strongly reflected in the level of pollutants emitted to the atmosphere. Nowadays, when emission is reduced to a remarkable extent, it is extremely important to examine the influence of atmospheric circulation on the sanitary condition of air. The issue discussed in this work is an example of the so-called synoptic meteorology, which evaluates the relation between the weather elements and circulation conditions.
54 PRACE GEOGRAFICZNE, ZESZYT 126 The atmospheric circulation is one of the main factors influencing climate. It plays an important part in modifying the climatic conditions of urban and industrial areas. Apart from its climate-shaping significance, in the region of Upper Silesia it also influences the concentration or dispersion of pollutants. The occurrence of specific pressure systems and air masses either increases or decreases the influence of the anthropogenic factor, the intensity of the urban heat island and the level of atmospheric pollution (Niedźwiedź 1999; Niedźwiedź, Olecki 1994). A map of the Silesian Upland is presented in Figure 1. The area and methods of study Fig. 1. A map of the Upper Silesia showing the Katowice district Ryc. 1. Mapa obszaru Górnego Śląska z zaznaczonym okręgiem katowickim The evaluation of the influence of atmospheric circulation on air pollution was carried out on the basis of mean daily concentrations of sulphur dioxide (SO 2 ) in the 1983 2002 period and circulation types defined for individual days. In order to achieve a thorough, in-depth synoptic analysis three calendars of circulation types were taken into consideration. As the basic calendar of circulation types the authors used a well-known calendar by T. Niedźwiedź (1981) (Table 1), constructed for the area of the Upper Vistula river basin (comprising also the area of study), which consists of 21 circulation types. The abovementioned circulation types were distinguished on the basis of the predominant direction of air advection and the type of pressure system. The calendar includes 16 advective types, 4 types without distinct air advection and 1 undefined type. The work also takes into consideration the objective classification of circulation types by Z. Ustrnul (1997) constructed for individual grid points (Table 2). For the purposes of this work the authors used data for the interchange point at 20 East longitude and 50 North latitude, which best describes the mesoscale circulation conditions of the Silesian Upland. The abovementioned calendar is unique in its simplicity and comprises 18 circulation types, 16 advective (8 cyclonic and 8 anti-cyclonic in accordance with the eight-direction wind rose) and
INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION... 55 Table 1. Inventory of circulation types according to T. Niedźwiedź (1981) Tab. 1. Wykaz typów cyrkulacji T. Niedźwiedzia (1981) 2 non-advective (1 cyclonic and 1 anti-cyclonic). Both calendars of circulation types mentioned above are based on lower synoptic maps and describe mesoscale, low-level atmospheric circulation. Due to the fact that the above-mentioned calendars are mesoscale in character and concentrate only on low-level atmospheric circulation, the authors decided to use a calendar that takes into consideration the advection of air masses in the middle troposphere. That is why the work makes use of the Grosswetterlagen calendar of circulation types (Gerstengarbe, Werner 1993) based on the system created by P. Hess and H. Brezowsky (1952) (Table 3), well-known in Central Europe, for a corresponding period of 1983 2002. It is worth mentioning that the calendar is systematically made available by the German Meteorological Service (Deutscher Wetterdienst) and has been used previously on several occasions in studies based on the Polish data. Its great usefulness, that does not differ much from the usefulness of the local, Polish calendars of circulation types, has thus been confirmed (Piotrowicz 1998; Ustrnul 2000/2001; Ustrnul, Czekierda 2001). It is worth to make use of the division proposed in the Grosswetterlagen because of its macro-circulation character and the possibility
56 PRACE GEOGRAFICZNE, ZESZYT 126 Table 2. Inventory of circulation types according to Z. Ustrnul (1997) Tab. 2. Wykaz typów cyrkulacji Z. Ustrnula (1997) Table 3. The Grosswetterlagen inventory of circulation types (Hess, Brezowsky 1952) Tab. 3. Wykaz typów cyrkulacji Grosswetterlagen (Hess, Brezowsky 1952)
INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION... 57 of relating the results to a larger area, sometimes even beyond Central Europe (Buishand, Brandsma 1997, Keevallik et al. 1999). The study presented below was based on all available daily immission data from daily measurements carried out by the Regional Sanitary and Epidemiological Station in Katowice. Due to the limited length of the work and its aim the evaluation of the influence of particular circulation types has been divided into two basic sequences of data representing separate types of air pollution. The first sequence of measurements comes from the Katowice-Raciborska Street station. This is by far the best environmental monitoring station Table 4. List of stations selected for the calculation of the daily mean air pollution for the study area Tab. 4. Wykaz stacji uwzględnionych przy konstrukcji średniej dobowej wartości zanieczyszczenia powietrza obszaru badań and has the most complete and homogenous observation material in the whole area in question. The second observation sequence was created artificially as a mean for the area derived from selected, best working stations. The choice of stations for the calculation of the mean was based on the representativeness of the measuring station and the number of observations. The list of stations used for the calculation of the daily area mean for pollution is included in Table 4. Distribution of the sulphur dioxide (SO 2 ) concentration In the beginning, the authors concentrated on the distribution of the daily mean concentration of SO 2 on the yearly scale. The analysis shows a great role of the atmospheric circulation in the shaping of this element. According to the classification by T. Niedźwiedź, the highest concentrations of SO 2 occur when the centre of a high pressure system is over southern Poland or in the situation of an anti-cyclonic air advection from SE and S. In the case ofthese three circulation types the daily mean values of SO 2 exceed 50 µg m -3 (Fig. 2). The lowest concentrations occur with the Nc, NWc i Cc types, when they slightly exceed 20 µg m -3. These relations, based on the calendar by T. Niedźwiedź, are also visible in the division by Z. Ustrnul and the Grosswetterlagen classification. In the case of the latter, of course, the diversity within particular types is significant, due to their big total number. As expected, an even bigger diversity in SO 2 concentrations occurs in the winter season. The highest values are observed, as in the whole year, with the Ca, SEa, Sa, types according to the classification by T. Niedźwiedź, when they exceed 80 µg m -3 (Fig. 3). The lowest, slightly exceeding 40 µg m -3, are visible in the case of cyclonic types with an advection of air from N, NW and W. Very similar values, with
58 PRACE GEOGRAFICZNE, ZESZYT 126 Fig. 2. Mean daily SO 2 concentrations in particular circulation types during the whole year over the Silesian Upland (1983 2002) Ryc. 2. Średnie dobowe stężenia SO 2 w roku w poszczególnych typach cyrkulacji na Wyżynie Śląskiej (1983 2002)
INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION... 59 Fig. 3. Mean daily SO 2 concentrations in particular circulation types in winter over the Silesian Upland (1983 2002) Ryc. 3. Średnie dobowe stężenia SO 2 w zimie w poszczególnych typach cyrkulacji na Wyżynie Śląskiej (1983 2002) Explanations: denotes situations with statistically irrelevant number of cases. Objaśnienia: oznacza sytuację synoptyczną ze statystycznie nieistotną liczbą przypadków.
60 PRACE GEOGRAFICZNE, ZESZYT 126 the exception of cyclonic situations with an advection from the southern sector, are visible in the division by Z. Ustrnul. The biggest diversity in circulation types is observed in the case of the Grosswetterlagen types. However, with some types a small number of cases may be the cause of statistically irrelevant means. The analysis of SO 2 in winter with individual types showed cases of differences in the values between the Katowice-Raciborska St. and the mean for the area (Fig. 3). The values for Katowice were higher, which was caused by the location of the station in the very centre of Katowice, where, apart from industry, the concentration is influenced by low-level emission from inefficient local heating systems. They are based on coal contaminated with sulphur, which is the basic energetic resource. The above-mentioned difference between the mean for the area and the measurement results from the Katowice-Raciborska St. is also visible in the other seasons. However, it is small enough to enable a combined analysis concerning the circulation types (the differences generated by circulation types are more remarkable than the differences between the characteristics). In spring the values of SO 2 are much lower than in winter and, on average, constitute about 50% of the winter values (Fig. 4). Their distribution with individual circulation types is very similar to the winter distribution. It means that the role of atmospheric circulation in shaping pollution patterns is very big, and individual circulation types show similar influence in both seasons. According to the classification by T. Niedźwiedź, the highest concentrations, reaching a value of 50 µg m -3, occur with the Ca, Ka and SEa, Sa, Ea types, while the lowest ones with Nc, Cc, NEc and NWc, not exceeding 30 µg m -3. According to the division by Z. Ustrnul, by far the highest values of SO 2 occur with the SEa and SWa types. In summer the concentrations of SO 2 are the lowest in the whole year, reaching an average value of 15 µg m -3 (Fig. 5). Owing to a relatively low level of concentrations, their diversity with particular circulation types is small. The highest values with individual circulation types in all three calendars do not exceed the level of 25 µg m -3. In autumn an increase in daily mean concentrations of SO 2 can be observed again (Fig. 6). Their values reach a level of 50 µg m -3 with the anti-cyclonic circulation types by T. Niedźwiedź: SEa, Sa, Ca and Ka. The lowest concentration values, below 20 µg m -3, occur with the NEa, Nc and Cc types. Similar relations can be observed in the classification by Z. Ustrnul. However, in the Grosswetterlagen division the diversity is bigger. The diversity, apart from the different criteria of these classifications development, may be partly a result of the differences in the number of values of the daily SO 2 concentrations in individual types. As can be seen in figure 5, by far the highest concentrations, reaching 90 100 µg m -3, are observed with the HFz (high pressure system over Fennoscandia, cyclonic) and SEa (south-eastern anti-cyclonic) types. The values of these concentrations are much bigger than the values obtained with other types and classifications. It is possible that such high values are caused by a small number of cases taken into consideration when calculating the mean, especially in the case of the HFz type, where the sample consisted only of 6 elements.
INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION... 61 Fig. 4. Mean daily SO 2 concentrations in particular circulation types in spring over the Silesian Upland (1983 2002) Ryc. 4. Średnie dobowe stężenia SO 2 na wiosnę w poszczególnych typach cyrkulacji na Wyżynie Śląskiej (1983 2002) Explanations: denotes situations with statistically irrelevant number of cases. Objaśnienia: oznacza sytuację synoptyczną ze statystycznie nieistotną liczbą przypadków.
62 PRACE GEOGRAFICZNE, ZESZYT 126 Fig. 5. Mean daily SO 2 concentrations in particular circulation types in summer over the Silesian Upland (1983 2002) Ryc. 5. Średnie dobowe stężenia SO 2 w lecie w poszczególnych typach cyrkulacji na Wyżynie Śląskiej (1983 2002) Explanations: denotes situations with statistically irrelevant number of cases. Objaśnienia: oznacza sytuację synoptyczną ze statystycznie nieistotną liczbą przypadków.
INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION... 63 Fig. 6. Mean daily SO 2 concentrations in particular circulation types in autumn over the Silesian Upland (1983 2002) Ryc. 6. Średnie dobowe stężenia SO 2 w jesieni w poszczególnych typach cyrkulacji na Wyżynie Śląskiej (1983 2002) Explanations: denotes situations with statistically irrelevant number of cases. Objaśnienia: oznacza sytuację synoptyczną ze statystycznie nieistotną liczbą przypadków.
64 PRACE GEOGRAFICZNE, ZESZYT 126 Conclusions The distribution of the sulphur dioxide concentration (SO 2 ) in the Upper Silesia is strongly connected with different circulation types. On the yearly scale the highest concentrations occur with the Ca and SEa and Sa types, when the daily mean values exceed 50 µg m -3. The lowest concentrations occur with the Nc, NWc and Cc types, when they slightly exceed 20 µg m -3. A bigger diversity in the SO 2 concentrations occurs in the winter season. The highest values are observed, as in the whole year, with the Ca, SEa, Sa types, according to the classification by T. Niedźwiedź, when they exceed 80 µg m -3. In spring the values of SO 2 are much lower than in winter and, on average, constitute about 50% of the winter values. In summer the concentrations of SO 2 are the lowest in the whole year, reaching an average value of 15 µg m -3. In autumn an increase in the daily mean concentrations of SO 2 can be observed again. Their values reach a level of 50 µg m -3 with anti-cyclonic circulation types. Similar relations of the daily concentration of SO 2 with circulation types were observed in the classification by T. Niedźwiedź and Z. Ustrnul. However, in the Grosswetterlagen classification the diversity is bigger. The reason, apart the different criteria of these classifications development, may be partly a result of the differences in the number of values of the daily SO 2 concentrations in individual types. Regardless of circulation types the daily concentration of SO 2 can be modified by the magnitude of SO 2 inflow from other areas like the Ostrava Karvina region and deep temperature inversions as well. References Buishand T.A., Brandsma T., 1997, Comparison of circulation classification schemes for predicting temperature and precipitation in the Netherlands, International Journal of Climatology, 17, 875 889. Gerstengarbe F. W., Werner P.C., 1993, Katalog der Grosswetterlagen Europas nach Paul Hess und Helmuth Brezowski 1881 1992, Berichte des Deutschen Wetterdienstes, 113. Hess P., Brezowsky H., 1952, Katalog der Grosswetterlagen Europas, Ber. Dt. Wetterdienst in US Zone, 33. Keevallik S., Post P., Tuulik J., 1999, European circulation patterns and meteorological situation in Estonia, Theoretical and Applied Climatology, 63, 117 127. Niedźwiedź T., 1981, Sytuacje synoptyczne i ich wpływ na zróżnicowanie przestrzenne wybranych elementów klimatu w dorzeczu Górnej Wisły, Rozprawy habilitacyjne, UJ, Kraków. Niedźwiedź T., 1999, Rola cyrkulacji atmosfery w kształtowaniu przepływu powietrza, przez Bramę Morawską. [In:] M. Leśniok (ed.), Materiały konferencyjne Zanieczyszczenia pyłowe atmosfery, Cieszyn 19 20.11.1999, Polskie Towarzystwo Mineralogiczne, Prace Specjalne, 15, Wydawnictwo Naukowe Akapit, Kraków, 101 109. Niedźwiedź T., Olecki Z., 1994, Wpływ sytuacji synoptycznych na zanieczyszczenia powietrza w Krakowie, [In:] B. Obrębska-Starklowa (ed.), Przemiany środowiska geograficznego i ich skutki, Zeszyty Naukowe UJ, Prace Geograficzne, 96, 55 68.
INFLUENCE OF CIRCULATION TYPES ON THE SO 2 CONCENTRATION... 65 Piotrowicz K., 1998, Wieloletnie zróżnicowanie liczby dni mroźnych i bardzo mroźnych w Krakowie i Pradze, Acta Universitatis Lodziensis, Folia Geographica Physica, 3, 221 229. Ustrnul Z., 1997, Zmienność cyrkulacji atmosfery na półkuli północnej w XX wieku, Materiały Badawcze, Series Meteorologia, 27, IMGW, Warszawa. Ustrnul Z., 2000/2001, Kalendarze typów cyrkulacji próba oceny, Annales UMCS, Sectio B, Lublin, 55/56, 42, 347 356. Ustrnul Z., Czekierda D., 2001, Circulation background of the atmospheric precipitation in the Central Europe (based on the Polish example), Meteorologische Zeitschrift, 10, 2, 901 908. Wpływ typów cyrkulacji na stężenie SO 2 na Wyżynie Śląskiej Streszczenie Na Wyżynie Śląskiej w ostatnich latach można zauważyć poprawę stanu sanitarnego powietrza, lecz w dalszym ciągu jest on niekorzystny. Znacznie rzadziej, niż poprzednio zdarzają się przekroczenia dopuszczalnych norm (głównie dobowych), co szczególnie widoczne jest w okresie zimowym. Przeprowadzona w opracowaniu szczegółowa ocena wpływu cyrkulacji atmosferycznej na występowanie określonego stężenia zanieczyszczeń potwierdziła dominujący wpływ poszczególnych typów cyrkulacji na kształtowanie się wielkości zanieczyszczenia powietrza na Wyżynie Śląskiej. W przebiegu wieloletnim najwyższe wartości koncentracji SO 2 we wszystkich analizowanych klasyfikacjach występowały przy typach Ca, SEa oraz Sa, kiedy to średnie dobowe wartości przekraczały 50 µg m -3. Najniższe wartości koncentracji SO 2 występowały przy typach Nc, NWc oraz Cc, kiedy to średnie dobowe wartości nieznacznie przekraczały 20 µg m -3. Uwzględnienie danych o imisji z rozdzielczością dobową oraz trzech kalendarzy typów cyrkulacji pozwoliło na szczegółowe przedstawienie wzajemnych zależności pomiędzy rozważanymi zmiennymi. Jerzy Radomski Undergraduate School of Technology (Wyższa Szkoła Techniczna) Rolna 43, 40 555 Katowice, Poland jerzyradomski@tlen.pl Artur Widawski University of Silesia, Faculty of Earth Sciences Department of Climatology Będzińska 60, 41 200 Sosnowiec, Poland artur.widawski@us.edu.pl