P. N. Antokhin

Joint radiosonde and doppler lidar measurements of wind in the atmospheric boundary layer

Results of joint measurements of height profiles of wind velocity and direction by the Stream Line pulse coherent Doppler lidar and RS92-SGP radiosonde in Tomsk from 23 to 27 of September, 2013, are presented. It has been established that wind profiles can be retrieved up to heights from 400 to 1100 m depending on the aerosol concentration in the atmospheric boundary layer from lidar data measured at an elevation angle of 45°. It is shown that the coefficient of correlation between lidar and radiosonde measurements of wind velocity and direction is equal to 0.97. The mathematical expectation and standard deviation of the difference between estimates for the wind velocity and direction from the radiosonde and lidar data amount to 0.1 and 0.7 m/s, respectively, for the velocity and 0.8° and 4°, respectively, for the wind direction.

Optik-É AN-30 Aircraft Laboratory for Studies of the Atmospheric Composition

AbstractThe scientific instrumental complex of the Optik-E AN-30 aircraft laboratory developed at the Institute of Atmospheric Optics of the Siberian Branch of the Russian Academy of Sciences is described in detail. Specifications of the main units of the instrumental complex are presented. Special attention is given to the metrological support of measurements of the atmospheric parameters. Experimental capabilities of the aircraft laboratory are illustrated by the results obtained in recent flights over various regions of the Russian Federation.

The Blocking Role of the Ural Mountains in the Transborder Transfer of Impurities from Europe to Asia

Distribution of impurities over the region abutting the Ural Mountains is analyzed with the purpose of searching for traces of western European emissions over the territory of Siberia. It is shown that transborder transfer of impurities from Europe to Asia along direct trajectories (along a circle of latitude) from west to east is possible only in the free troposphere, in a layer higher than 2 km. Within the limits of the atmospheric boundary layer, the transfer of impurities from Europe to Siberia is probable only along trajectories rounding the Urals from north or south.

Control of the Dynamics of Tropospheric Ozone through the Stratosphere

We consider two possible mechanisms of stratospheric control of the ozone concentration and dynamics in the troposphere. The first mechanism is implemented through the total-ozone-caused modulation of the ultraviolet radiative flux, incoming to the troposphere and initiating therein the photochemical processes. The second mechanism acts through direct transport of stratospheric ozone, which will “trigger” the photolysis and initiate these same processes of ozone generation, but now in the troposphere. Both of these mechanisms of stratospheric ozone control of the near-ground ozone concentration are shown to be apparent near Tomsk. It is noteworthy that the control via ultraviolet flux determines the amplitude modulation, and the transport from the stratosphere to the troposphere drives the temporal modulation.

Atmospheric blockings in Western Siberia. Part 1. Detection features, objective criteria, and their comparison

Based on the NCEP/NCAR and ERA-Interim reanalysis archives, we investigated different methods to detect atmospheric blocking events in Western Siberia. Two criteria were studied that are based on calculating meridional gradients of the 500 hPa height and potential temperature at the dynamic tropopause. A situation is considered blocking, when it features a gradient inversion of the investigated characteristics. Additionally, we performed a synoptic analysis of individual blocking events.

Structure of aerosol fields of the atmospheric boundary layer according to aerosol and Doppler lidar data during passage of atmospheric fronts

The paper presents the results of complex observations of the atmospheric boundary layer dynamics performed at the Fonovaya Observatory of the Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, in September 2013, with the use of remote sensing facilities, i.e., aerosol and Doppler lidars. The structure of aerosol and wind fields in the period of occurrence of internal buoyancy waves and low-level jet streams in the boundary layer is considered.

The impact of atmospheric blocking on spatial distributions of summertime precipitation over Eurasia

The correlation of precipitation anomalies over Eurasia with atmospheric blocking events was examined with ERA Interim reanalysis data. We found that, regardless of the frequency of the atmospheric blocking events, they significantly affect the distribution of rainfall over all Eurasian regions in summer, due to both the change in the westerly transport and the dominant dipole blocking structure. It is important that, depending on the blocking positions in Asia, there are heavy rainfalls in an arid zone which includes Kazakhstan, Mongolia, Northern China, and the Trans-Baikal Territory.

Atmospheric Blockings in Western Siberia. Part 2. Long-term Variations in Blocking Frequency and Their Relation with Climatic Variability over Asia

This paper studies the long-term variability of frequency of atmospheric blockings over Western Siberia in 1948–2015 based on the data of three reanalysis projects. We revealed a decreasing blocking frequency for eight of twelve months. However, since the estimated trends of blocking frequency are small comparing to the significant amplitude of interannual variations, we proposed to divide the entire studied period into several quasi-decadal intervals that differ both in the amplitude of interannual fluctuations of blocking frequency and in trends. The effect of Western Siberian blockings imposed on synoptic and climatic variability of meteorological parameters in Asia was studied. The study demonstrated that in summer teleconnection patterns in temperature and precipitation fields are of the close sign-alternating structure; this indirectly indicates that in Western Siberia the blocking is a part of a large-scale wave mechanism. Like the Ural blockings, the blockings occurring over Western Siberia affect meteorological characteristics within the East Asian monsoon area. In winter time they contribute to lower surface temperature and decreased precipitation in Southeast Asia. In summer during blocking events over Western Siberia, precipitation increases in the East Asian monsoon area.

Comparison of WRF-CHEM Chemical Transport Model Calculations with Aircraft Measurements in Norilsk

The results of WRF-CHEM model simulation of dispersal of anthropogenic emissions from the Norilsk industrial zone are verified against data of aircraft sensing performed in August 2004. It is shown that the WRF-CHEM v3.5.1 model configuration selected adequately reproduces the meteorological parameters obtained during the 2004 measurement campaign. The model-derived distributions of the concentrations of sulfur anhydride and ozone and mass concentration of aerosol qualitatively reproduce those retrieved from data of aircraft sensing. Quantitative estimates showed that the standard errors for sulfur dioxide, PM2.5 mass concentration, and ozone, calculated for three flights, had been 23 ppb, 2.6 μg/m3, and 9.8 ppb, respectively. These discrepancies may be due to incorrect specification of the initial and boundary conditions, inaccurate specification of anthropogenic emissions, and limitations in the aerosol and chemical descriptions.

Vertical Distributions of Gaseous and Aerosol Admixtures in Air over the Russian Arctic

Data on the vertical distribution of gaseous and aerosol composition of air, measured onboard the Tu-134 Optic airborne laboratory in October 2014 over the Kara Sea and coastal areas of the Russian Arctic, are presented. We revealed the specific features of the altitude distributions of CO2 and aerosol over the Kara Sea as compared to continental conditions. No significant deviations from continental distributions are found for CH4, CO, and O3.