Suchergebnisse

The monitoring of tropospheric ozone in world science has recently received considerable attention since ozone in the troposphere is both a greenhouse and a pollutant gas. It also plays an important role in various chemical and photochemical processes. Ground-based measurements can be used to assess the quality and to validate satellite measurements of the global ozone distribution. The time series of ozone tropospheric columns in the 0-8 km layer derived from spectral measurements of the IASI satellite instrument using two different algorithms (IASI_LATMOS and IASI_LISA), as well as from joint measurements by the IASI and GOME-2 instruments (IASI-GOME2) were compared to ground-based measurements using the Bruker IFS 125HR Fourier spectrometer at the NDACC St. Petersburg site for 2009–2021. IASI_LISA and IASI-GOME2 on average overestimate ground-based ozone measurements by 9.8 and 5.1%, respectively, while there is no bias between the IASI_LATMOS and FTIR data. The standard deviations of the differences between ground measurements and the IASI_LISA and IASI_LATMOS data do not exceed 12–13%; for the IASI-GOME2 data they are 24.5%. Ground-based and satellite measurements agree better in spring and summer. Ground-based and IASI_LATMOS demonstrate a statistically significant negative trend in the ozone columns in the 0–8 km layer in the vicinity of St. Petersburg for the period 2012–2021, amounting to –0.71 ± 0.35% per year and –0.60 ± 0.21% per year, respectively.

Tropospheric ozone (TO) is one of the major greenhouse gases and a toxic air pollutant. It plays a key role in various chemical and photochemical processes in the troposphere. Ozone concentrations both at surface level and in free troposphere are measured by various local and remote-sensing methods. The SPBU observational site in Peterhof (NDACC site St. Petersburg) is equipped with the Bruker IFS 125HR Fourier spectrometer used for TO measurements and the Thermo Scientific Model 49i gas analyzer for monitoring surface ozone concentrations (SOC). The temporal variability of TO in the 0–8 km layer for the period from April 2009 to October 2022 and of SOC for the period from 2013 to 2021 has been analyzed. Seasonal cycle of TO and SOC is similar to that of total ozone columns, but it is shifted in time by about 1 and 1.5 months, respectively. The maximum variation of TO from the average value for the period falls on the first half of April ~+16%; a minimum of about –(12–14)% is observed from mid-October to the end of December. In the middle of summer, there is also a slight increase in the TO variation at the level of +(7–8)%. A statistically significant decrease in the TO content by 0.34 ± 0.22% per year was also obtained. Comparison of hourly averaged data on TO with synchronized data of SOC measurements revealed an increase in the correlation coefficient (up to 0.5 or more) between the two values 3–4 hours after local noon in the warm season, accompanied by an increase in SOC. The increase in correlations is in good agreement with the increase in the height of the planet boundary layer.

Atmospheric nitric acid (HNO3) has a significant impact on the formation of the ozone layer; therefore, its content is regularly monitored using various local and remote-sensing methods. We used ground-based measurements of solar IR spectra with a Bruker 125HR Fourier spectrometer to derive information on the HNO3 content at the St.Petersburg observational NDACC site in Peterhof. The HNO3 time series obtained showed a pronounced seasonal cycle with a maximum in winter and early spring and a minimum in summer and early autumn. The averaged seasonal variations in nitric acid varied from –30 to +60% for the 0–15 km layer, from –25 to +25% for the 15–50 km layer, and from –25 to +30% for total columns. For 2009–2022 measurement period, no statistically significant trend was found in the time series considered. Comparison of HNO3 stratospheric columns with independent satellite measurements by the MLS and ACE-FTS instruments showed their qualitative and quantitative agreement; the correlation coefficient between ground-based and satellite measurements totals 0.88–0.93. Time series on the vertical structure of the atmospheric nitric acid measured at the St.Petersburg site can be used both to analyze the state of the ozonosphere and to validate satellite measurements and refine the parameters of atmospheric models.

The results of studying spatial-temporal CO2 variations near St. Petersburg during 2014–2017 based on satellite measurements (OSO-2 satellite), ground-based spectroscopic and local measurements are presented. According to satellite data the full amplitude of the spatial-temporal variations for the average CO2 mixing ratio (XCO2) amounted to 57.7 ppm (over 14%). The maximal XCO2 spatial variations during one day of observations (17.03.2015) were 46.8 ppm (more than 10%). Comparison of CO2 satellite and ground-based spectroscopic measurements has shown that ground-based measurements in the NDACC observing system after correction of systematic differences from the TCCON system can be used for validation of satellite measurements. Ground-based local measurements of the near-surface CO2 mixing ratio at Peterhof do not correlate with either spectroscopic ground-based or satellite measurements due to both mesoscale CO2 variations and significantly different spatial averaging kernels of direct and remote measurements.

The main results of scientific research and development in the field of atmospheric radiation in Russia for the period 2019–2022 are considered The main attention is paid to research in the field of radiative transfer theory, atmospheric spectroscopy, radiation climatology, aerosol and radiation forcing, remote sensing of the atmosphere and surface, interpretation of satellite measurements Lists of major publications in these areas for this period are provided.