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1.
N. D. Tsvetkova V. A. Yushkov A. N. Luk’yanov V. M. Dorokhov H. Nakane 《Izvestiya Atmospheric and Oceanic Physics》2007,43(5):592-598
The extremely cold winter of 2004/2005 was accompanied by an intensive formation of polar stratospheric clouds and a significant chemical destruction of ozone. The results of calculating chemical losses of ozone in the polar cyclone from the SAGE-III satellite data are given. Over the period January 1–March 25, 2005, at the isentropic levels 450–500 K, about 60% of ozone was destroyed. During that winter, the zone of formation of polar stratospheric clouds went down to levels with very low values of potential temperature (down to 350 K), thus resulting in a noticeable destruction of ozone at low altitudes. By March 25, 2005, the chemical losses of total ozone attained 116 ± 10 DU (128 ± 10 DU at the cyclone boundary), which is a recordbreaking value of the Arctic. 相似文献
2.
The search of roAp stars at Mt. Dushak-Erekdag Observatory was started in 1992 using the 0.8 m Odessa telescope equipped with
a two-star high-speed photometer. We have observed more than a dozen stars so far and discovered HD 99563 as roAp star while
BD+8087 is suspected to have rapid oscillations. Negative results of our observations for the search of rapid oscillations
in four stars in NGC 752 are also discussed. 相似文献
3.
S. J. Reid M. Rex P. Von Der Gathen I. Fløisand F. Stordal G. D. Carver A. Beck E. Reimer R. Krüger-Carstensen L. L. De Haan G. Braathen V. Dorokhov H. Fast E. Kyrö M. Gil Z. Lityñska M. Molyneux G. Murphy F. O'Connor F. Ravegnani C. Varotsos J. Wenger C. Zerefos 《Journal of Atmospheric Chemistry》1998,30(1):187-207
In this paper, we show that the rate of ozone loss in both polar and mid-latitudes, derived from ozonesonde and satellite data, has almost the same vertical distribution (although opposite sense) to that of ozone laminae abundance. Ozone laminae appear in the lower stratosphere soon after the polar vortex is established in autumn, increase in number throughout the winter and reach a maximum abundance in late winter or spring. We indicate a possible coupling between mid-winter, sudden stratospheric warmings (when the vortex is weakened or disrupted) and the abundance of ozone laminae using a 23-year record of ozonesonde data from the World Ozone Data Center in Canada combined with monthly-mean January polar temperatures at 30 hPa.Results are presented from an experiment conducted during the winter of 1994/95, in phase II of the Second European Stratospheric And Mid-latitude Experiment (SESAME), in which 93 ozone-enhanced laminae of polar origin observed by ozonesondes at different time and locations are linked by diabatic trajectories, enabling them to be probed twice or more. It is shown that, in general, ozone concentrations inside laminae fall progressively with time, mixing irreversibly with mid-latitude air on time-scales of a few weeks. A particular set of laminae which advected across Europe during mid February 1995 are examined in detail. These laminae were observed almost simultaneously at seven ozonesonde stations, providing information on their spatial scales. The development of these laminae has been modelled using the Contour Advection algorithm of Norton (1994), adding support to the concept that many laminae are extrusions of vortex air. Finally, a photochemical trajectory model is used to show that, if the air in the laminae is chemically activated, it will impact on mid-latitude ozone concentrations. An estimate is made of the potential number of ozone molecules lost each winter via this mechanism. 相似文献
4.
Atkin E. V. Bulatov V.L. Vasiliev O. A. Voronin A. G. Gorbunov N. V. Grebenyuk V. M. Dorokhov V. A. Karmanov D. E. Kovalev I.M. Kudryashov I. A. Kurganov A.A. Merkin M. M. Panov A.D. Podorozhny D. M. Polkov D. A. Porokhovoi S. Yu. Sveshnikova L. G. Tkachev L.G. Tkachenko A. V. Turundaevskiy A. N. Filippov S. B. Shumikhin V. V. 《Astronomy Reports》2019,63(1):66-78
Astronomy Reports - Some results of studies of cosmic rays obtained during the NUCLEON space experiment in 2015–2017 are presented. This experiment was intended for direct measurements of the... 相似文献
5.
Oceanology - New data on the geological structure and genesis of relict bottom relief forms, objects of underwater cultural heritage, and the structure of bottom sediments in the Baltic Sea were... 相似文献
6.
Krek A. V. Paka V. T. Krek E. V. Ezhova E. E. Dorokhov D. V. Kondrashov A. A. Bubnova E. S. Ponomarenko E. P. Bashirova L. D. Kapustina M. V. 《Oceanology》2019,59(5):803-805
Oceanology - The 44th cruise of R/V Akademik Boris Petrov was carried out from October 5 to 30, 2018 in the Baltic Sea and Skagerrak Strait. The studies included investigation of the water column... 相似文献
7.
M. Rex P. Von Der Gathen G.O. Braathen N.R.P. Harris E. Reimer A. Beck R. Alfier R. Krüger-carstensen M. Chipperfield H. De Backer D. Balis F. O'Connor H. Dier V. Dorokhov H. Fast A. Gamma M. Gil E. Kyrö Z. Litynska I.S. Mikkelsen M. Molyneux G. Murphy S.J. Reid M. Rummukainen C. Zerefos 《Journal of Atmospheric Chemistry》1999,32(1):35-59
The chemically induced ozone loss inside the Arctic vortex during the winter 1994/95 has been quantified by coordinated launches of over 1000 ozonesondes from 35 stations within the Match 94/95 campaign. Trajectory calculations, which allow diabatic heating or cooling, were used to trigger the balloon launches so that the ozone concentrations in a large number of air parcels are each measured twice a few days apart. The difference in ozone concentration is calculated for each pair and is interpreted as a change caused by chemistry. The data analysis has been carried out for January to March between 370 K and 600 K potential temperature. Ozone loss along these trajectories occurred exclusively during sunlit periods, and the periods of ozone loss coincided with, but slightly lagged, periods where stratospheric temperatures were low enough for polar stratospheric clouds to exist. Two clearly separated periods of ozone loss show up. Ozone loss rates first peaked in late January with a maximum value of 53 ppbv per day (1.6 % per day) at 475 K and faster losses higher up. Then, in mid-March ozone loss rates at 475 K reached 34 ppbv per day (1.3 % per day), faster losses were observed lower down and no ozone loss was found above 480 K during that period. The ozone loss in hypothetical air parcels with average diabetic descent rates has been integrated to give an accumulated loss through the winter. The most severe depletion of 2.0 ppmv (60 %) took place in air that was at 515 K on 1 January and at 450 K on 20 March. Vertical integration over the levels from 370 K to 600 K gives a column loss rate, which reached a maximum value of 2.7 Dobson Units per day in mid-March. The accumulated column loss between 1 January and 31 March was found to be 127 DU (36 %). 相似文献
8.
F. Goutail J.-P. Pommereau C. Phillips C. Deniel A. Sarkissian F. Lefèvre E. Kyro M. Rummukainen P. Ericksen S.B. Andersen B.-A. Kaastad-Hoiskar G. Braathen V. Dorokhov V.U. Khattatov 《Journal of Atmospheric Chemistry》1999,32(1):1-34
The total ozone reduction in the Arctic during the winters of 1993/94 and 1994/95 has been evaluated using the ground-based total ozone measurements of five SAOZ spectrometers distributed in the Arctic and from number density profiles of a balloon-borne version of the instrument. The ozone change resulting from transport has been removed using a 3D Chemistry Transport Model (CTM) run without chemistry. A cumulative total ozone depletion at the end of winter in March of 18% ± 4% in 1994 and of 32% ± 4% in 1995 was observed within the polar vortex, and of 15% ± 4% in both years outside the vortex. This evaluation is not sensitive to the vertical transport in the model. The periods, locations and altitudes at which ozone loss occurred were tightly connected to temperatures lower than NAT condensation temperature. The maximum loss was observed at 50 hPa in 1994 and lower, 60-80 hPa, in 1995. Half of the depletion in 1994 and three quarters in 1995 occurred during the early winter, showing that a late final warming is not a prerequisite for large ozone destruction in the northern hemisphere. The timing, the geographical location and the altitude of the ozone losses are well captured by the 3D CTM photochemical model using current chemistry, but its amplitude at low sun during the early winter, is underestimated. The model simulations also capture the early season reductions observed outside the vortex. This suggests that the losses occurred in situ in the early winter, when low temperatures are frequent, and not later in March, when ozone is most reduced inside the vortex, which would be the case if leakage from the vortex was the cause of the depletion. 相似文献
9.
Ulyanova M. O. Sivkov V. V. Bashyrova L. D. Krek A. V. Bubnova E. S. Dorokhov D. V. Dorokhova E. V. Krechik V. A. 《Oceanology》2022,62(1):136-138
Oceanology - During the 56th cruise of the P/V Akademik Ioffe (August 2020) in the Baltic Sea, hypoxia was registered at a water depth of 80 m, hydrogen sulfide in the East Gotland Basin was... 相似文献
10.
Abstract Ground‐based measurements of total ozone were made during the polar night from Arctic stations in the winters of 1987–88 and 1988–89. The measurements were made with automated Brewer ozone spectrophotometers using the moon as a light source. Data were obtained from Alert and Resolute in Canada for both winters and from Heiss Island, USSR, for the second winter. The method of measurement is briefly reviewed and data from the three stations are presented. The ground‐based total ozone measurements are compared with the integrated values derived from ozonesonde profiles. 相似文献