V. S. Rakitin

Investigation of the 2010 July–August fires impact on carbon monoxide atmospheric pollution in Moscow and its outskirts, estimating of emissions

We investigate the air pollution in the central European part of Russia during the 2010 summer fires. The results of ground-based (Institute of Atmospheric Physics (IAP), Moscow State University (MSU), and Zvenigorod Scientific Station (ZSS)) and satellite (MOPITT, AIRS, of Terra and Aqua satellites) measurements of the total content and concentration of carbon monoxide (CO), as well as MODIS data on the spatial and temporal distribution of forest and peat fires obtained from Terra and Aqua satellites, are presented. A comparison between similar situations in 2010 and 2002 revealed the causes of higher pollution levels in 2010. The use of trajectory analysis, detailed space imagery, and model calculations made it possible to reveal the location of peat fires and their contribution to the air pollution over the Moscow megalopolis. Fireemission estimates were obtained using two independent methods.

Variations of the total content of carbon monoxide over Moscow megapolis

The results of the carbon monoxide total content measurements over Moscow and Zvenigorod for 2005–2008 are compared with the same data sets for Moscow 1986–2005 and Beijing, 1992–2007. Two identical medium resolution diffraction spectrometers (resolution 0.2 cm−1) with solar tracking system were used. The CO total content measured simultaneously over the city and over Zvenigorod Scientific Station (ZSS) of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (60 km west from Moscow). This method allows to isolate an urban part of CO content. The acoustic locator SODAR LATAN-3 measurements permitted us to study the influence of the carbon monoxide ventilation conditions upon level of pollution. Correlation coefficients between the urban part of CO content and average wind speed for cold and warm seasons were obtained. The data sets analysis showed a preeminent effect of the wind within boundary layer (up to 300 m) over the CO ventilation. The urban part of the CO content hasn’t increased in spite of more than quintuple increase of the motor-vehicles number in Moscow. An increase of the rural CO total column for the 1970–1985 has transformed into its virtually stable amount in between of 1986 to 2000, changed then to a decrease for 2001–2008. We noted the 2008 as “the year of the CO total column minimum” over the past decade. The effect of urban CO sources influence on the CO total column in rural area is small, i.e. on a level of 3% of the total number of measurements. The number of extremal daily values for Moscow is estimated as 5%, and 20% for Beijing.

Determination of carbon monoxide pollution of the atmosphere over Moscow with a spectroscopic method

The results of measurements of the total content of carbon monoxide in an atmospheric column over Moscow and the Zvenigorod Scientific Station (ZSS) are given for the period 1993–2005. The simultaneous measurements of the regional background contents of carbon monoxide over a rural area (ZSS) and over Moscow made it possible to isolate an urban portion of the CO content. The total content of CO over the city varies significantly from day to day from values close to the background value to values that are 2.5–3 times greater than the background value. The number of days with such a CO content is 5% of the total number of measurement days. Such a CO content is most often observed during the cold seasons. During the warm seasons, in most of the cases, slight excesses of the CO background value are observed in the urban atmosphere. Variations in the CO content are determined mainly by wind-velocity variations and temperature inversions. In 2002, the high CO concentrations were due to forest and peatbog fires. On some days, over the ZSS, the concentrations of CO were high as never before. Over this period (12 years), the CO content in the surface air layer over the city did not increase.

Studying the pollution of Moscow and Beijing atmospheres with carbon monoxide and aerosol

The measurements of submicron aerosol and black carbon (BC) surface concentrations, and carbon monoxide (CO) total column in 1992–2012 in Beijing and Moscow are illustrated. The specific features in the long-term variations in the studied impurities in these megacities are discussed. The level of pollution with all three impurities in Beijing is substantially higher than in Moscow. From 1992 to 1999, the monthly means of black carbon and aerosol increased in Beijing. These concentrations substantially decreased beginning from 2000. From 2007 to 2011, black carbon decreased and submicron aerosol increased. In 1996–2003 the urban part of CO total column (TC) in Beijing was on average higher than in 2006–2012 by a factor of 1.4. The anthropogenic part of CO in Moscow decreased in 2006–2012. High aerosol and CO concentrations, comparable with concentrations rather typical of Beijing, were observed in Moscow only during wildfires in 2010. Using the cluster analysis statistical methods, it has been indicated that the main sources of the air pollution in Beijing are located 100–500 km southward.

Comparison results of satellite and ground-based spectroscopic measurements of CO, CH4, and CO2 total contents

A significant amount of satellite and ground-based data on the CO, CO2, and CH4 total contents for 2010–2013 was collected, classified, and analyzed. Transition relations between satellite and groundbased data on the content of impurities under study at different measuring sites (NDACC/ GAW and OIAP RAS stations) with different spatial and temporal resolutions have been found. A high correlation between daily average satellite-measured CO contents (AIRS v6 (R2 = 0.48–0.96), IASI MetOp-A (R2 = 0.25–0.86), and MOPITT v6 Joint (R2 = 0.30–0.83) products, averaging over 1° × 1°) and the ground-based solar spectrometers’ data was ascertained for background conditions. In the case of high pollution of the mixing layer, a significant underestimation of the CO total content (by 1.7–4.7 times, depending on the sensor and observation point) by satellite sensors has been noted. Representative transition relations and correlation coefficients (R2 ≥ 0.5) between satellite data on daily average CH4 contents and the data from ground-based diffraction spectrometers of A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS) and Fourier spectrometers of GAW stations have been found only for the AIRS sensor. The best correlation with ground-based measurement data on CO2 (R2 = 0.25 for daily average values, averaging over 1° × 1°) was found for the IASI sensor. The daily average CH4 total contents from the IASI MetOp-A sensor weakly correlate with the ground-based data and with AIRS data.

Severe Wildfires Near Moscow, Russia in 2010: Modeling of Carbon Monoxide Pollution and Comparisons with Observations

The spatial and temporal distributions of the carbon monoxide (CO) concentration were calculated with the Regional Atmospheric Modeling System and Hybrid Particle and Concentration Transport model (RAMS/HYPACT) in the provinces near Moscow during the abnormally hot summer of 2010. The forest, steppe and meadow hot spots were defined by the satellite data MCD14ML (MODIS Terra and Aqua satellite data). The calculations indicated that the surface CO concentrations from the model were two times less than the experimental data obtained from the Moscow State University (MSU) station and Zvenigorod Scientific Station (ZSS). Conversely, the total column CO concentrations obtained from the model were two to three times larger than the experimental values obtained from the Obukhov Institute of Atmospheric Physics (OIAP) and ZSS stations. The vertical transfer of pollutants was overestimated. Tentatively, it could be assumed that an aerosol influence in the model calculations is a reason for the overestimation. The comparisons between the wind speed, temperature and humidity profiles calculated in the model with the data from the standard balloon sounding exhibited good agreement. The CO total column data of the Measurements of Pollution in the Troposphere (MOPITTv5 NIR and TIR/NIR) obtained from the OIAP and ZSS stations appear more realistic than do the MOPITTv4 data. However, the surface MOPITT values of CO concentration for Moscow have the large distinction from the ground measurements. A careful proposal regarding satellite orbit optimization was made, which could improve future spectrometric measurements, such as the MOPITT, Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) measurements.

Carbon monoxide emissions in summer 2010 in the central part of the Russian Plain and estimation of their uncertainties with the use of different land-cover maps

This study is devoted to estimation of carbon monoxide (CO) emissions during the wildfires of the anomalously hot 2010 summer in the central part of the Russian Plain. CO emissions from the forest wildfires have been estimated with use of the Active Fires (AF) (MODIS MCD14ML) and Burned Areas (BA) (MODIS MCD45) methods for AVHRR/UDM, Global Land Cover 2000 (GLC 2000), GlobCover, and MCD12Q1 vegetation maps. A comparison of the vegetation maps and investigation of forest structure dynamics for the period from 2005 to 2009 have been carried out. It is shown that the major uncertainties during the estimation of CO in decreasing order are the following: distinctions in emission-calculation methods, differences in the vegetation maps used, differences in satellite data from Terra and Aqua, and the insufficient registration of forest structure dynamics. For additional comparison of estimations obtained by an independent method with the use of orbital (MOPITT, AIRS, and IASI) and ground-based (Moscow and Zvenigorod) spectroscopic measurements of CO content were presented.

Variations of the carbon monoxide total column and parameters of the atmospheric boundary layer in the center of Moscow

The content of carbon monoxide in the atmosphere over Moscow has been measured from the absorption spectra of solar radiation in the infrared spectral range (2153–2160 cm−1) for the period 1993–2007. A main advantage of the method is a virtual independence of the results averaged over a significant space and atmospheric thickness on local and even relatively large-scale pollution sources. Moreover, the method permits the determination of the characteristics of anthropogenic pollution of the city air by CO by comparison of the measurement of CO content in two observation sites (one is in the city center and another is outside the city). In both the cases, diffraction spectrometers with the resolution 0.2 cm−1 supplied with a sun tracking system were used. From 2005, in the center of Moscow, the parameters of the atmospheric surface layer have continuously been measured using a LATAN-3 acoustic locator. The measurements show that in this period (14 years), the CO content within an air layer polluted by the city did not increase in spite of the threefold increase in the number of automobiles in the city. Thus, the method allows one to determine the trend of air pollution above Moscow. Variations of the CO content are mainly determined by the wind velocity and the presence of temperature inversions. Using the results of the acoustic sounding, a relation between the pollution magnitude and the condition of the impurities has been elucidated. The wind velocity in the surface (to 500 m) layer has the greatest effect on the pollution accumulation in the city atmosphere. For cold and warm seasons, the correlation coefficients of the urban proportion of the CO content with the wind velocity averaged over air layers of various heights are found.

Variation Trend and Characteristics of Anthropogenic CO Column Content in the Atmosphere over Beijing and Moscow

Abstract The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing, China, and Moscow, Russia, during 1992–2012. Some specific variation characteristics and long-term variation trends of the CO column content in the atmosphere in these regions are discussed. An evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992–2012, while for the Moscow region, it decreases yearly by about 1.4% for the same period. High CO concentrations appear quite frequently in Beijing, but much less frequently in Moscow, except during the natural fire events in summer 2010. From back trajectory analysis, the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.

Long-Term Trends of Carbon Monoxide Total Columnar Amount in Urban Areas and Background Regions: Ground- and Satellite-based Spectroscopic Measurements

A comparative study was carried out to explore carbon monoxide total columnar amount (CO TC) in background and polluted atmosphere, including the stations of ZSS (Zvenigorod), ZOTTO (Central Siberia), Peterhof, Beijing, and Moscow, during 1998–2014, on the basis of ground- and satellite-based spectroscopic measurements. Interannual variations of CO TC in different regions of Eurasia were obtained from ground-based spectroscopic observations, combined with satellite data from the sensors MOPITT (2001–14), AIRS (2003–14), and IASI MetOp-A (2010–13). A decreasing trend in CO TC (1998–2014) was found at the urban site of Beijing, where CO TC decreased by 1.14%±0.87% yr−1. Meanwhile, at the Moscow site, CO TC decreased remarkably by 3.73%±0.39% yr−1. In the background regions (ZSS, ZOTTO, Peterhof), the reduction was 0.9%–1.7% yr−1 during the same period. Based on the AIRSv6 satellite data for the period 2003–14, a slight decrease (0.4%–0.6% yr−1) of CO TC was detected over the midlatitudes of Eurasia, while a reduction of 0.9%–1.2% yr−1 was found in Southeast Asia. The degree of correlation between the CO TC derived from satellite products (MOPITTv6 Joint, AIRSv6 and IASI MetOp-A) and ground-based measurements was calculated, revealing significant correlation in unpolluted regions. While in polluted areas, IASI MetOp-A and AIRSv6 data underestimated CO TC by a factor of 1.5–2.8. On average, the correlation coefficient between ground- and satellite-based data increased significantly for cases with PBL heights greater than 500 m.摘要基于1998-2014年期间地基和卫星高光谱辐射测量数据对污染和背景地区的CO总量进行了综合比较研究, 包括了莫斯科郊区ZSS (Zvenigorod)站, 西伯利亚中部ZOTTO站, 圣彼得堡Peterhof站, 北京和莫斯科观测站所代表的附近地区. 利用较长时期的地基高光谱观测结合卫星高光谱观测数据获得了欧亚大陆不同地区的CO柱总量的年际变化特征. 采用的卫星数据有MOPITT (2001–2014), AIRS (2003–2014)和IASI MetOp-A (2010–2013). 观测数据分析表明, 北京都市区的CO柱总量(1998-2014)呈现下降趋势, 年均速率为1.14% ± 0.87%, 而莫斯科地区下降幅度很大, 达到年均3.73% ± 0.39%. 在作为大都市参照的乡村背景地区(如ZSS, ZOTTO, Peterhof), 同期CO柱总量下降趋势为年均0.9%–1.7%. 基于2003-2014年间的AIRSv6卫星数据产品分析发现, 欧亚大陆中纬度地区CO柱总量有小幅度下降, 只有0.4%–0.6% 每年, 而东南亚地区下降幅度较大, 达到0.9%–1.2%每年. 从卫星数据(MOPITTv6, AIRSv6和IASI MetOp-A)的相关性分析看出, 洁净地区的相关性较高, 而对于污染地区, IASI MetOp-A 和AIRSv6 数据严重低估了CO柱总量, 达到1.5–2.8倍. 当大气边界层高度大于500米时, 地基和卫星观测数据的相关系数总体上显著增大.