Introduction

1. 24 24 22 22 20 20 18 18 16 16 14 14 y n i z 12 12 \ o G 10 10 8 8 6 6 25 20 4 4 15 2 2 2 2 4 4 6 6 8 8 10 10 12 12 Months Months Warsaw University of Life Sciences - SGGWDivision of Meteorology and ClimatologyKatarzyna Rozbicka, Grzegorz Majewski, Tomasz RozbickiSeasonal variation of air pollution in Warsaw agglomeration Introduction Long term research shows many substances in the atmosphere are in concentration dangerous for human health and welfare and even for human life. They also are injourious for animal and crops and may lead to climate changes on the Earth. These substances are specified in Directives 96/62WE, 199/30/WE and 2008/50/WE. Troposphere ozone, its precursor nitrogen dioxide and particulate matter are the most dangerous among of mentioned ones. The work presents time and spatial variation of troposphere ozone, nitrogen dioxide and PM10 concentrations and focus on episodes of high level of pollution concentration. High level of pollution concentration are not always inducted by the abrupt increase in emission. Usually the main reason of the episodes is adverse meteorological conditions. Additional matter of this work is to find the most significant factors including meteorological elements contribute to concentration values of pollutants on analyzed area. • Material and method • The research was carried out on the base of air pollution and meteorological data of atmosphere monitoring station situated in Warsaw agglomeration and its surroundings: • Station Krucza str. (MzWarszaKrucza) – situated in city center, close to one of the biggest traffic street of Warsaw; represents city center pollution background • Station Komunikacyjna (MzWarszNiepodlKom) – situated in the city center on the one of the biggest traffic street in Warsaw; represents city center pollution background • Station Ursynów SGGW (MzWarszSGGW) – situated in soutern outskirts of Warsaw within no-dense settlement area in University campus; represents city suburb pollution background • Station Wokalna str. (MzWarszUrsynow) – situated in southern outskirts of Warsaw very close to SGGW station but inside settlement area with tall buildings; represents city suburb pollution background • Station Kondratowicza str. (MzWarszTarKondra) – situated in north-east part of Warsaw inside moderately dense settlement area; represents city pollution background • Station Legionowo (MzLegZegIMGW) – situated outside Warsaw, north of agglomeration; represents city suburb pollution background • Station Granica (MzGranicaKPN) – situated outside the agglomeration in the Kampinoski National Park area; represents regional pollution background • Station Belsk (MzBelskIGPAN) – situated outside the agglomeration; represents regional pollution background • Basic data material includes 1-hourly values of tropospheric ozone concentration (O3), nitrogen dioxide concentration (NO2), particulate matter PM10 concentration and meteorological elements: intense of total solar radiation (T), air temperature (t), relative humidity (f), wind velocity (u). The data concerns the period 2009 – 2011. • The influence of meteorological elements on concentration of analyzed pollutants was stated by the use of correlation and multiple regression analysis. Fig.1. Situation of atmosphere monitoring stations Tab 1. Average values of half-year and year nitrogen dioxide concentration in µg·m-3 Fig.3. (left) Maximum 8-hourly values of troposphere ozone concentration in analyzed stations for the years 2008 – 2011 Critical value of concentration - 120 µgm-3 Ursynów SGGW Fig.4. (left) Average 1-hourly values of nitrogen dioxide, and PM10 (left and up) concentration in analyzed stations of Warsaw agglomeration for the years 2008 - 2011 Hours Hours Hours Hours Hours Hours Hours Months Months Months Months Months Months Months Ursynów SGGW Wokalna Krucza Targówek Legionowo Granica Belsk Fig.5. (left) Average 1-hourly values of troposphere ozone concentration in analyzed stations of Warsaw agglomeration for the years 2008 - 2011 Hours Hours Hours Hours Hours Hours Hours Fig.2. Annual average values of nitrogen dioxide concentration in analyzed stations for the years 2008 - 2011 Months Months Months Months Months Months Months Summary 1. In general conclusion quality of air in Warsaw agglomeration is not satisfactory. Although the decrease in trend of concentration level of pollutants, particularly sulfur dioxide, carbon monoxide, oxides of nitrogen and particulate matter PM10 is positive the excesses over permissible level concentration still occur in case of troposphere ozone, nitrogen dioxide and particulate matter PM10. 2. Episodes of days in which maximum of troposphere ozone concentration is grater than critical value 120 µg∙m-3 are frequent in analyzed period 2008 – 2011 April – August in Warsaw agglomeration. It concerns stations situated in the city center, in the suburb and out off agglomeration. But margin of tolerance (average 25 times a year) was non exceeded. Although in single years number of days with ozone concentration above the critical value occurred for single years. 3. The highest 1-hourly average values of troposphere ozone concentration In the period 2008 – 2012 were recorded for stations off the agglomeration: Granica and Belsk 102,1 and 97,8 µgm-3 respectively. 4.The highest annual average value of nitrogen dioxide concentration in the period 2008 – 2011 is equal to 56,9 g∙m-3 (142% of critical value) and is recorded for city center station (Komunikacyjna) situated near one of the most traffic streets in Warsaw. Lower values of annual concentration were recorded for stations situated in some distatnce of the city center: Targówek and Wokalna 25,5 and 22,2 g∙m-3 respectively (64% and 56% of critical value). The lowest annual average value of nitrogen dioxide concentration occur for stations situated out of agglomeration: Granica (10,1 g∙m-3) and Belsk (10,9 g∙m-3) and it is equal about 25% of critical value. 5. Areas exposed to risk on exceeding of permissible 1-hourly concentration of nitrogen dioxide (200 gm-3) in Warsaw agglomeration regard only to the linear sources of pollution – close proximity of the roads and streets. In case of troposphere ozone concentration areas situated in the suburbs and out of the agglomeration are exposed to risk on exceeding of permissible (120 gm-3). For these areas there is the real danger of photochemical smog formation 6.In case of analyzed days with high level troposphere ozone concentration there is a strong relationship between the concentration of ozone and the considered variables: nitrogen oxides concentration and meteorological elements: air temperature and relative humidity. In case of city center there is no correlation between ozone concentration and relative humidity. 7. Multiple regression equations describing these relationships have high determination coefficients and base on big material of data therefore it permits apply these equations as the forecasting models of high level ozone concentration episodes for Warsaw agglomeration Tab. 2. Regression equations between troposphere ozone concentration and independent variables (nitrogen dioxide concentration, air temperature, relative humidity, wind velocity, total solar radiation and basic statistics of the equations for selected stations Tab. 3. Regression equations between troposphere ozone concentration and independent variables (nitrogen dioxide concentration, air temperature, relative humidity, wind velocity, total solar radiation and basic statistics of the equations for different type of stability of the atmosphere Explanations: O3 – troposphere ozone concentration, NO2 – nitrogen dioxide concentration, t – air temperature, RH – relative humidity,R/Rad2 – correlation/determination coefficient adjusted for degrees of freedom, F – Fisher – Snedecor test value, SEE – standard error of estimation, n – number of cases The research was subsided by the Ministry of Science and Higher Education resources.