Various apparatus of SPbSU Geomodel Center and Atmospheric Physics Department give a possibility to perform the regular monitoring of climate-influencing parameters of the atmosphere and to analyse modern changes of Earth climate and factors its defining (tropospheric temperature and humidity, cloud liquid water content, total content of greenhouse, ozone-depleting and polluting gases, optical and microphysical characteristics of atmospheric aerosols, etc.).
1.1. Ground-based studies of atmospheric gaseous composition (Fourier-spectrometer (FS) Bruker IFS 125 with high spectral resolution) - greenhouse, ozone-depleting and polluting gases
Hyper-spectral ground-based FS-measurements using Bruker IFS 125 HRÑ are carried out at Atmospheric Physics Department from January 2009. Regular measurements of solar radiation absorption spectra in IR range with high resolution (up to 0.005 cm-1) lets us determine contents of 1520 greenhouse, ozone-depleting and polluting gases. Photo and installation scheme of the device used at Peterhof observation station is given in Fig. 1.1. Fig. 1.2 demonstrates some examples of measurements of temporal variations of total content of various gases.
Ground-based measurements of solar radiation spectra with high spectral resolution give a possibility to determine not only total content of various gases, but also elements of vertical distributions. Examples of temporal variations of the ozone content in various atmospheric layers are given in Fig. 1.3.
1. Timofeyev Yu.M., Virolainen Ya.A., Makarova M.V., Poberovsky A.V., Polyakov A.V., Ionov D.V., Osipov S.I., Imkhasin Kh.Kh., 2015: Ground-based spectroscopic measurements of atmospheric gas composition near Saint Petersburg (Russia). J. Molec. Spect. doi: 10.1016/j.jms.2015.12.007.
2. Virolainen Ya.A., Yu.M. Timofeev, A.V. Poberovskii, M. Eremenko, and G. Dufour, 2015: Evaluation of Ozone Content in Different Atmospheric Layers using Ground-Based Fourier Transform Spectrometry. Izvestiya, Atmospheric and Oceanic Physics, 51, 2, 167176.
3. Virolainen Ya.A., Yu.M. Timofeev, A.V. Poberovsky, O. Kirner, and M. Hoepfner, 2015: Chlorine Nitrate in the Atmosphere over St. Petersburg. Izvestiya, Atmospheric and Oceanic Physics, 51, 1, 6068.
4. Polyakov A.V., Yu.M. Timofeev, A.V. Poberovskii, Ya.A. Virolainen, 2015: Consideration of High Surface Concentrations of Hydrochloric Acid Vapors in Ground-Based Spectroscopic Measurements. Atmospheric and Oceanic Optics, 28, 03, 240244.
5. Polyakov A.V., Yu.M. Timofeev, Ya.A. Virolainen, A.V. Poberovskii, 2014: Ground-based measurements of HF total column abundances in the stratosphere near St. Petersburg (20092013). Izvestiya, Atmospheric and Oceanic Physics, 50, 6, 675682.
6. Ionov D.V., M.A. Kshevetskaya, Yu.M. Timofeev, and A.V. Poberovskii, 2013: Stratospheric NO2 Content according to Data from Ground-Based Measurements of Solar IR Radiation. Izvestiya, Atmospheric and Oceanic Physics, 49, 5, 519529.
7. Rakitin A.V., A.V. Poberovskii, Yu.M. Timofeev, M.V. Makarova, and T.J. Conway, 2013: Variations in the Column-Average Dry-Air Mole Fractions of CO2 in the Vicinity of St. Petersburg. Izvestiya, Atmospheric and Oceanic Physics, 49, 3, 271275.
8. Semakin S.G., A.V. Poberovskii, and Yu.M. Timofeev, 2013: Ground-Based Spectroscopic Measurements of the Total Nitric Acid Content in the Atmosphere. Izvestiya, Atmospheric and Oceanic Physics, 49, 3, 294297.
9. Timofeyev Yu., Dmitry Ionov, Maria Makarova, Yana Virolainen, Anatoly Poberovsky, Alexander Polyakov, Hamud Imhasin, Sergey Osipov, Anton Rakitin, Marina Kshevetskaya, 2013: Measurements of Trace Gases at Saint-Petersburg State University (SPbSU) in the Vicinity of Saint-Petersburg, Russia. In Disposal of Dangerous Chemicals in Urban Areas and Mega Cities, NATO Science for Peace and Security Series C: Environmental Security 2013, XV, Barnes, Ian; Rudzinski, Krzysztof J. (Eds.), 346 p., pp. 173184.
10. Poberovskii A.V., 2010: High-resolution ground measurements of the IR spectra of solar radiation. Atmospheric and Oceanic Optics, 23, 2, 161163.
11. Poberovskii A.V. , M.V. Makarova, A.V. Rakitin, D.V. Ionov, and Yu.M. Timofeev, 2010: Variability of the Total Column Amounts of Climate Influencing Gases Obtained from Ground-Based High Resolution Spectroscope measurements. Doklady Earth Sciences, 432, 01, 656658.
1.2. Microwave (MW) measurements of tropospheric temperature, humidity profiles, and cloud liquid water content (MW radiometer RPG-HATPRO)
Microwave sounding of the troposhere is performed by the interpretation of ground-based measurements of descending thermal MW radiation (brightness temperatures) in 14 spectral channels of the RPG-HATPRO spectrometer using algorithms and software for solving the relative inverse problem. The device is installed on a tower on a roof of the building of Scientific Research Institute of Physics of SPbSU. Appearance of the device is given in Fig. 1.4.
The device gives a possibility to determine temperature and humidity profiles in the troposphere and cloud liquid water content. Examples of errors of retrieving temperature and humidity profiles in the troposphere (estimated by comparison with radiosonde data) are introduced in Fig. 1.5. These errors are 13 K (up to 5 km) and 1020% for temperature and relative humidity, respectively. Fig. 1.6 illustrates results of microwave sounding of the cloud liquid water content.
1. Kostsov V.S., A.V. Poberovskii, S.I. Osipov, and Yu.M. Timofeev, 2012: Multiparameter Technique for Interpreting Ground-Based Microwave Spectral Measurements in the Problem of Ozone Vertical Profile Retrieval. Atmospheric and Oceanic Optics, 25, 4, 269-275.
2. Zaitsev N.A., Yu.M. Timofeyev, and V.S. Kostsov, 2014: Comparison of Radio Sounding and Ground-Based Remote Measurements of Temperature Profiles in the Troposphere. Atmospheric and Oceanic Optics, 27, 5, 386392.
3. Kostsov V.S., 2015: Retrieving Cloudy Atmosphere Parameters from RPG-HATPRO Radiometer Data. Izvestiya, Atmospheric and Oceanic Physics, 51, 2, 156166.
1.3. Determination of Î3 and NO2 contents by DOAS method
Continuous O3 and NO2 monitoring be means of zenith observations of scattered visible solar radiation using DOAS (Differential Optical Absorption Spectroscopy) started in 2004. Scheme of ground-based and satellite measurements of atmospheric gaseous composition by DOAS method is given in Fig. 1.7. Fig. 1.8 demonstrates seasonal variations of stratospheric ozone at Peterhof from data of DOAS measurements in comparison with satellite OMI measurements.
Mobile spectroscopic studies of tropospheric NO2 near Saint-Petersburg by DOAS method have been performed using the Ocean Optics spectrometer from 2009. In summer 2012 for the first time the mobile experiment with a continuous series of the closed ring measurements on KAD Route was performed. These experiments repeated further in 2014 and 2015. It has allowed to use the corresponding mobile measurements for detrmining the total emission from sources of air pollution of the megalopolis in a ring. Spatial distributions of NO2 for the ring KAD Route received from these mobile measurements in 2015 are schematically given as an example in Fig. 1.9. On the scheme they are combined with results of modeling of dispersion of city air pollution in day of experiment.
1. Ionov D.V., A.V. Poberovskii, 2012: Nitrogen dioxide in the air basin of St. Petersburg: Remote measurements and numerical simulation. Izvestiya, Atmospheric and Oceanic Physics, 48, 4, 373383.
3. Ionov D., A. Poberovskii, 2015: Quantification of NOx emission from St.Petersburg (Russia) using mobile DOAS measurements around entire city. Int. J. Rem. Sensing, 36, 9, 24862502.
1.4. Measurements of optical and microphysical characteristics of atmospheric aerosol (spectrometer CIMEL Electronique 318A)
Studies of atmospheric aerosol content are carried out from March 2013 by the solar photometer CIMEL Electronique 318A, measuring direct and scattered solar radiation in 9 spectral intervals in visible and near-IR spectral range. In fig. 1.10 I In Fig. 1.10 the spectrometer appearance is presented. Interpretation of measurements allows to retrieve the aerosol optical thicknesses (AOT), albedo of single scattering, microphysical parameters of atmospheric aerosol and the total water vapor content using a special international technique.
Temporal AOT variations at various wavelenghts at Peterhof in 20132014 are given in Fig. 1.11. Fig. 1.12 demonstrates temporal variations of aerosol size distribution functions (dN/dR).
Studies of aerosol characteristics are performed in cooperation with Goddard Space Flight Center (B.N. Holben, A. Smirnov, I. Slutsker) and Obukhov Institute of Atmospheric Physics of RAS (M.A. Sviridenkov).
1. Berezin I.A., I.S. Frantsuzova, Yu.M. Timofeev, Ya.A. Virolainen, B.N. Holben, A. Smirnov, I. Slutsker, 2016: Analysis of errors of measuring the total precipitated water in the atmosphere by CIMEL photometer. Izvestiya, Atmospheric and Oceanic Physics, 52 (in press).