Air pollution over European Russia and Ukraine under the hot summer conditions of 2010

Variations in the concentrations of both primary (PM₁₀, CO, and NO_x) and secondary (ozone) pollutants in the atmosphere over the Moscow and Kirov regions, Kiev, and Crimea under the conditions of the anomalously hot summer of 2011 are given and analyzed. The concentrations of ozone, PM₁₀, CO, and NO_x in the atmosphere over the Moscow region exceeded their maximum permissible levels almost continuously from late July to late August 2010. The highest level of atmospheric pollution was observed on August 4–9, when the Moscow region was within a severe plume of forest and peatbog fires. The maximum single concentrations of ozone, which exceeded its maximum permissible level two-three times, were accompanied by high concentrations of combustion products: the concentrations of PM₁₀ and CO were also three-seven times higher than their maximum permissible concentrations. The maximum levels of air pollution were observed under the meteorological conditions that were unfavorable for pollution scattering, first of all, at a small vertical temperature gradient in the lower atmospheric boundary layer. The number of additional cases of mortality due to the exceeded maximum permissible concentrations of PM₁₀ and ozone in the atmosphere over Moscow was estimated. Under the weather conditions that were close to those for the Moscow region, the air quality remained mainly satisfactory in the Kirov region, Kiev, and Crimea, which were almost not affected by fires.     

Water-vapor content in the atmosphere over European Russia during the summer 2010 fires

We study the water vapor (WV) content over European Russia (ER) during the period of forest and peatbog fires in July–August 2010 using total column water vapor observations from MODIS instruments (both Aqua and Terra platforms) as well as aerological data and NCEP/NCAR reanalysis. It is found that the spatial distribution of total column water vapor (TCWV) over ER in this period was anomalous, with the WV excess in the north of the territory and its deficit in the south of ER. The relationship between WV variations, atmospheric dynamics and the fire situation is analyzed. Along with the processes of the WV advection and evaporation we evaluate the contribution of pyrogenic emission of WV in spatial-temporal evolution of WV over ER during wildfires. The changes of water vapor at different heights in the troposphere and stratosphere are investigated. The results of a comparative analysis of WV contents during the periods of summertime atmospheric blockings in 1972 and 2010 are also presented. The near-infrared total-column precipitable water MODIS products (L3) are validated by upper-air radiosonde data.     

Investigation of dynamic processes in the period of formation and development of the blocking anticyclone over European Russia in summer 2010

The blocking anticyclone (BA) observed in the summer of 2010 over the European part of Russia led to enormous economical damage, substantially increased the mortality of the population, and had serious negative consequences for human health. Dynamic processes in the troposphere, i.e., wave trains, which could contribute to anticyclone formation and sustenance, are investigated. In order to study these wave trains, three-dimensional Plumb vectors have been calculated and analyzed. It is shown that, in June 2010, three wave trains propagated eastward in the troposphere over the Atlantics. The first two wave trains, having reached Europe, continued to propagate in eastern and southeastern directions. Only the third wave train, upon reaching Europe, continued to propagate toward the northeast and, on June 17–19, entered northwestern Russia. The anticyclone, which started to form on June 18 precisely in this region, subsequently developed into a stable BA observed over European Russia up to mid-August. The propagation direction of the wave trains could change due to the formation of a double structure of the zonal flow in the troposphere. The wave trains are revealed in the middle of June in regions with increased cloudiness over the northwestern part of the Atlantic Ocean and over the northwestern and northern parts of the central United States. Eastwardpropagating wave trains, which could contribute to the intensification of the corresponding BAs that brought anomalously high temperatures to European Russia, were also revealed in July and August of 2010 and 1972. The calculated 10-day backward trajectories are analyzed to determine the character of motions of air particles that penetrated into the anticyclone over the region of Moscow during the 2010 summer in the period of its development.     

Specific features of the 2010 summer heat formation in the European territory of Russia in the context of general climate changes and climate anomalies

Specific features of the extreme summer heat of 2010 in the European part of Russia are analyzed against the background of global and regional climate changes taking into account antropogenic influences and natural anomalies related, in particular, to the El Niño/La Niña phenomena. The tendencies of the characteristics of the activity of blocking anticyclones (blockings) responsible for the formation of drought regimes and the increase in the fire hazard at midlatitudes are estimated in connection with climate changes.     

The effect of atmospheric circulation on the evolution and radiative forcing of smoke aerosol over European Russia during the summer of 2010

The evolution of smoke plume over European Russia (ER) during the massive forest and peatbog fires of summer 2010 has been studied using observations of aerosol optical depth (AOD) from MODIS instruments (both Aqua and Terra platforms), objective analysis of meteorological fields performed at the Russian Hydrometeorological Research Center, NCEP/NCAR reanalysis, as well as upper air data. A relation between the structure inhomogeneities of the AOD field and regional atmospheric circulation has been found. It is shown that, on August 5–9, 2010, the maximum of smoke pollution did complete turn around Moscow, while remaining at a distance of 200 to 650 km from the megacity. Both regionally averaged shortwave aerosol radiative forcings (ARFs) at the top and the bottom of the atmosphere are estimated for the period of extreme smoke pollution over ER. The spatial distributions of ARF values over the territory of the region and the estimates of the local and spatially distributed thermal effects of smoke aerosol are given. It is shown that, on August 5–9, 2010, the spatial distribution of AOD and the calculated thermal effects of smoke aerosol were in agreement with the spatial distributions of air-temperature anomalies observed in the lower 1.5-km layer of the atmosphere. MODIS’s AOD data obtained during the wildfires were validated by AOD observations from the CIMEL sun photometer operated at the AERONET station Zvenigorod.     

Near bottom variations of turbidity in the St Lawrence estuary

Observations of the turbidity and velocity fields in the near-bottom waters of the St Lawrence estuary were obtained with a package which includes a self-recording attenuance meter and a currentmeter. The latter also measures salinity and temperature. Time series varying in length between 26 h and 26 days, and with repetition rates between one and 15 min are discussed for 3 typical open-channel and nearshore stations. A high-frequency sampling mode provides a means to observe the passage of a frontal disturbance over the bottom during the semi-diurnal cycle. With lower frequency records having lengths of one week to one month, contributions to the turbidity fluctuations due to the spring-neap oscillations, seasonal changes in run-off, and the sudden rise in solid discharge of local tributaries following storms, can be resolved. From turbidity polar diagrams, local onshore sources of particulate suspended matter can be identified. Among other advantages, it is possible from such records to time precisely the occurrence of turbidity peaks in relation to the ebb and flow velocities, to assess the importance of resuspension, and to specify exactly the time rate of change of the turbidity. On the whole, self-recording equipments provide a wealth of information unavailable from more traditional hydrocast sampling techniques.     

Spatial variations of DMS, DMSP and phytoplankton in the Bay of Bengal during the summer monsoon 2001

Data on the distribution of dimethylsulphide (DMS) and dimethylsulphoniopropionate (DMSP) in relation to phytoplankton abundance in different oceanic environments is important to understand the biogeochemistry of DMS, which plays an important role in the radiation balance of the earth. During the summer monsoon of 2001 measurements were made for DMS and DMSPt (total DMSP) together with related biological parameters in the Bay of Bengal. Both DMS and DMSPt were restricted to the upper 40 m of the water column. Diatoms accounted for more than 95% of the phytoplankton and were the major contributors to the DMS and DMSPt pool. The mean concentration of DMS in the upper 40 m was observed to be around 1.8+/-1.9 nM in the study area, while DMSPt concentrations varied between 0.7 nM and 40.2 nM with a mean of 10.4+/-8.2 nM. The observed lower DMSPt in the northern Bay in spite of higher mean primary productivity, chlorophyll a and phytoplankton cell counts seemed to result from grazing. Though salinity divides the Bay into different biogeochemical provinces there is no relation between salinity and DMS or DMSPt. On the other hand DMS was linearly related to chlorophyll a:phaeopigments ratio. The results suggest the need for deeper insight into the role of diatoms in the biogeochemical cycling of DMS.     

Estimation of probable contribution of global warming to the genesis of abnormally hot summers in the European part of Russia

Temperature records for the Russian territory in summer 2010 are presented. The potential role that the current global warming plays in the formation of abnormally hot summers in the European part of Russia is discussed. Although the main reason for the extreme heat wave in 2010 was a quasi-stationary anticyclone blocking westerlies, global warming could also contribute to the observed temperature extremums adversely affecting the biota.     

The effect of meteorology on air pollution in Moscow during the summer episodes of 2010

Relations between short-term variations in the concentrations of aerosol (PM₁₀) and carbon monoxide (CO) and meteorological characteristics are considered for the episodes of severe atmospheric pollution in the region of Moscow in the summer of 2010. The assumption is made and substantiated that the observed (in late June) severe aerosol pollution of the atmosphere over Moscow was caused by air masses arrived from soil-drought regions of southern Russia. In August, during the episodes of advection of forest-fire products, the maximum surface concentrations of pollutants were observed in Moscow mainly at 11:00–12:00 under a convective burst into the atmospheric boundary layer and at night in the presence of local wind-velocity maxima or low-level jet streams within the inversion layer. On the basis of results from an analysis of these air-pollution episodes before and after fires, it is concluded that the shearing instability of wind velocity favors the surface-air purification under ordinary conditions and an increase in the surface concentrations of pollutants during their advection (long-range transport, natural-fire plumes, etc.). It is shown that the pollution of the air basin over the megapolis with biomass-combustion products in 2010 led to an increase in the thermal stability of the atmospheric surface layer and in the duration of radiation inversions, as well as to an attenuation of the processes of purification in the urban heat island.     

Aerosol optical thickness and the total carbon monoxide content over the European Russia territory in the 2010 summer period of mass fires: Interrelation between the variation in pollutants and meteorological parameters

The spatial and temporal variabilities of the aerosol optical thickness (AOT) and the total carbon monoxide content (CO) in the period of development and weakening of mass forest and peatbog fires in the European Russia territory (ERT) in the summer of 2010 are investigated from data of the AOT and CO satellite observations. The intensities of aerosol and CO emissions in the period of mass fires and the ratio of the emission factors of aerosol particles and CO are estimated on the basis of calculations of the smoke and CO masses over the ERT. The interrelation between variations in the levels of the regional pollution by combustion products and the variability of meteorological parameters is investigated. Various aspects of the manifestation of radiation effects of aerosols are discussed. The synchronization of weekly signals of the AOT, CO, and meteorological parameters in the period of mass fires is noted.     

夏季台湾浅滩周边水域悬浮物质浊度和叶绿素a荧光分布特征

2004年7~8月在台湾浅滩周边水域进行了两个断面的水体悬浮物浊度、叶绿素a荧光调查,通过对该区域夏季悬浮物质浊度、叶绿素a荧光的分布变化特征研究,结合水文相关要素分析,初步揭示了该区域海洋沉积和再悬浮过程对悬浮体浊度、叶绿素a荧光分布的影响.悬浮物质浊度在近岸与陆架外缘主要受再悬浮作用影响,而浅滩区再悬浮作用不明显;在陆架外缘区浮游植物的聚集作用对浊度有一定的贡献作用,而近岸区则不明显.     

秦皇岛外海夏季溶解氧与pH的变化特征分析

溶解氧(DO)是海洋生物生存不可缺少的要素。随着人类活动的增加,全球近岸海域低氧情况愈发严重,已经成为威胁海洋生态系统健康的重要因素。通过对2017年5-9月秦皇岛外海区域的观测调查,探讨了该海域低氧与酸化的形成机制并计算了月平均耗氧速率。结果表明,5月秦皇岛外海水体混合较为均匀,表、底层DO浓度一致,均大于8 mg/L;6月开始形成密度跃层,与此同时底层DO浓度和pH开始下降;8月底层呈现明显的低氧和酸化状态,DO浓度下降至2～3 mg/L,pH下降至7.8以下;9月随着层化消失,底层水体DO浓度和pH逐渐升高。相关性分析显示,DO和叶绿素a (Chl a)以及pH具有良好的耦合性,说明秦皇岛外海区域的低氧发生过程主要为局地变化。同时表明DO浓度和pH主要受水体中浮游植物的光合作用和有机物有氧分解的影响。通过箱式模型计算得到2017年6-8月密度跃层以下水体及沉积物耗氧速率为951～1 193 mg/(m²·d)[平均为975 mg/(m²·d)]。综合来看,水体分层是秦皇岛外海低氧和酸化发生的先决条件,跃层以下的有机物分解耗氧则是底层水体...     

Effect of nutrient amendments on the summer phytoplankton dynamics on the Bering Sea shelf under experimental conditions

Experiments on nutrient and iron amendments were performed with phytoplankton on the eastern shelf of the Bering Sea in June 2000 and August 2001. The nutrient amendments (NO₃, NH₄, SiO₄, NO₃ + SiO₄, NH₄ + SiO₄, and Fe + NO₃) increasing their initial concentrations by ～20 μM were put into test bottles 10 l in volume each. With iron addition (Fe or Fe + NO₃), its concentration increased by 5 nM. The experiments performed showed that the main nutrient that limited the phytoplankton development was nitrogen. Regardless of the composition of the dominant algae in the background community, the amendments caused massive development of diatoms. The intense growth was characteristic for diatoms of both the spring and spring-summer assemblages. At high abundances of Phaeocystis pouchetii or of the coccolithophore Emiliania huxleyi in the natural water, nitrogen-containing amendments caused an intense growth of these species, along with the massive development of diatoms. In the case of the diatom prevalence in the initial sample, the intensities of the utilization of NO₃ and NH₄ in combination with SiO₄ in the course of the experiment were 1.7 and 3 times as high as their intensities with no silicon amendments. Likewise, NO₃ + SiO₄ and NH₄ + SiO₄ mixed amendments caused an increase in the silicon assimilation by a factor of 4–5 as compared to pure silicon amendments. During one of the experimental series in which both diatoms and Phaeocystis pouchetii actively developed, virtually complete nitrogen utilization (90–99.8%) in 4–5 days was observed for both the NO₃ and NH₄. The addition of silicon and iron only caused no significant growth of the phytoplankton abundance. It was assumed that the destruction of the seasonal thermocline and the supply of nutrients into the surface layer as a result of strong wind forcing might cause a phytoplankton bloom in the summer time and result in the much pronounced qualitative and quantitative spatial heterogeneity of the phytoplankton characteristic of the eastern shelf of the Bering Sea.     

Distribution characteristics of zooplankton in the south part of Taiwan Strait in summer

INTRODUCTIONInfluencedbywarmcurrent,upwellingandalongshore(coastal)waters,zooplanktoniscomparativelyabundantinthesouthpartofTaiwanStrait.Inthepast,macroplanktonnetwasadoptedintheecologicalstudyofzooplanktoninthisarea,thuscausingconsiderablelossofeitherspeciesorindividualnumbersofmeso-andmicrozooplanktoninthesurvey.Inthisstudy,mesozooplanktonnetwasusedinthesamplecollection.Itshowsthatmicrozooplanktonandimmatureindividualsofmacro-andmesozooplanktonwereabundant,andthediversityofzooplanktoni…     

Spatial/temporal variations in zooplankton biomass and ecological characteristics of major species in the southern part of the Japan Sea: a review

During the 1990s many studies on zooplankton in the Japan Sea have been carried out. In this review, I have synthesized the study of horizontal distribution, seasonal and annual variations of zooplankton biomass, and ecological characteristics of major component species in the southern Japan Sea, which area is influenced by the warm Tsushima Current. The zooplankton biomass (annual mean) in the southern Japan Sea was lower than in the subarctic Pacific, including the northern Japan Sea, and similar to biomass levels in Kuroshio waters. Temporal variations in zooplankton biomass showed both seasonal and year-to-year components. Seasonal biomass increases to a maximum in spring with a weak secondary peak in autumn. As for long-term changes, 3–6 year cycles were identified, with the dynamics of the surface warm Tsushima Current and the subsurface cold water playing important roles in determining the yearly zooplankton community structure and biomass. Cold water species in the southern Japan Sea had extensive diel vertical migrations whose range is restricted in summer by the development of a thermocline. Among these species, the herbivores Euphausia pacifica and Metridia pacifica encounter a lower food supply, resulting in lower growth rates. The vertical dispersal of epipelagic carnivorous zooplankton such as Sagitta elegans and Themisto japonica to the deep-sea is probably facilitated by reduced interspecific competition. Their interaction with Japan Sea Proper Water, characterized by near-zero temperatures in the meso- and bathypelagic zones suppresses growth rates of the mesopelagic zooplankton. The lack of micronektonic predators in the mesopelagic zone may allow the persistence of slow growing populations.     

Spatial and temporal variations of macro-and mesozooplankton community in the Huanghai Sea (Yellow Sea) and East China Sea in summer and winter

The study was conducted during two cruises of June–August 2006 (summer),and January–February 2007 (winter) in the Huanghai (Yellow) Sea and East China Sea.Spatial and temporal variations of zooplankton abundance,biomass and community structure and its relation to currents and water masses over the continental shelf were examined.A total of 584 zooplankton species/taxa and 28 planktonic larvae were identified during the two surveys.Copepods were the most abundant component among these identified groups.Zooplankton abundance and biomass fluctuated widely and showed distinct heterogeneity in the shelf waters.Five zooplankton assemblages were identified with hierarchical cluster analysis during this study,and they were Huanghai Sea Assemblage,Changjiang Estuary Assemblage,Coastal Assemblage,East China Sea Mixed-water Assemblage and East China Sea Offshore Assemblage.Seasonal changes of zooplankton community composition and its geographical distribution were detected,and the locations of the faunistic areas overlap quite well with water masses and current systems.So we suggest that the zooplankton community structure and its changes were determined by the water masses in the Huanghai Sea and East China Sea.The results of this research can provide fundamental information for the long-term monitoring of zooplankton ecology in the shelf of Huanghai Sea and East China Sea.     

Development of the summer breeze circulation in the west part of the Black Sea

On the basis of the results of regional reanalysis of the atmospheric circulation presented with a resolution of 9 km, the process of formation of breezes is studied for the case of weak synoptic background activity in the rectilinear part of the west coast of the Black Sea for the period 01–04.07.2007. It is shown that the gravitational currents, breeze fronts, and intense internal waves are formed under these conditions in the troposphere during the daytime. The Hovm?ller diagrams of the wind velocity and the maps of the vertical sections of potential temperature, vertical velocity of the air masses, and other parameters are presented. On the basis of these diagrams and maps, we obtain quantitative estimates of the wind velocity in the breeze and of the velocity of propagation of the breeze front and compare these estimates with the available literature data.     

Bacterioplankton in the northeastern part of the Black Sea during the summer and autumn of 2005

On the basis of luminescent microscopy using a DAPI dye, the abundance, morphometric characteristics, and biomass of bacteria in the coastal waters off the northeastern part of the Black Sea in 2005 were considered. The material was collected in June, September, and October along the cross section from Golubaya Bay towards the open part of the sea. An analysis of the microorganism development level showed that the bacteria achieved their maximal abundance in September, amounting, in the closest near-shore area, to 2435 × 10³ cells/ml, or 276 mg/m³ of wet weight; the lowest values were characteristic of October. During all the survey periods, coccal forms were prevailing among the microorganisms; regardless of the season, their fraction was maximal at the coastal stations. The greatest prevalence of coccal forms was characteristic of October (83%). The average sizes of the bacterial cells in 2005 varied within 0.073–0.257 μm³. The highest values of the bacterial abundance and biomass, almost in all the cases, were found at coastal stations; with the distance from the coast, a decrease in the bacterioplankton abundance was observed. A comparison of methodically similar data on the concentration of bacteria (dying with acridine orange and DAPI) from 1985 till now shows a trend of the annual growth in the bacterial abundance.     

Spatial and temporal variability of heat content above the thermocline in the tropical Pacific Ocean

Abstract-Heat content of the upper layer above the 20℃ isotherm in the tropical Pacific Ocean isestimated by using the sea temperature data set with a resolution 2°latitude×5°longitude (1980～1993)for the water depths (every 10 m) from 0 m to 400 m, and its temporal and spatial variabilities are an-alyzed. (1) The temporal variability indicates that the total heat in the upper layer of the equatorial Pa-cific Ocean is charcterized by the interannual variability. The time series of the equatorial heat anomaly5 months lead that of the El Nino index at the best positive lag correlation between the two, and theformer 13 months lag behind the latter at their best negative lag correlation. Therefore the equatorialheat content can be used as a better predictor than the El Nino index for a warm or cold event. In addi-tion, it is also found that less heat anomaly in the equator corresponds to the stronger warm events inthe period (1980～1993) and much more heat was accumulated in the 4 years including 1992/1