Changes in the climate and sea ice of the Northern Hemisphere in the 20th and 21st centuries from data of observations and modeling

The shrinking of the area occupied by sea ice in the Northern Hemisphere accelerated at the end of the 1990s, when the record minima of the summer area were successively noted, and its absolute minimum was observed in September 2007. Such a radical decrease is ahead of the projections of global models and provokes interest in the reliability of model calculations of the future of Arctic sea ice. The results of an analysis of the relation between the warming in the Arctic and the ice extent shrinkage from data of observations and modeling by an ensemble of global climate models are presented.     

Analysis of the influence that climatic variability has on the formation of the total-ozone-content field at extratropical latitudes of the Northern Hemisphere

Having applied the method of discriminant analysis to the TOMS data of satellite sounding of the total ozone content (TOC) in the March months of 1979–2008, the authors could make a new estimate of the TOC field variability in the Northern Hemisphere and interlongitudinal regularities of its changes under the action of climatic variability. The effects of temperature variations in the polar stratosphere, El Niño, and quasi-biennial oscillation (QBO) have proven comparable and reach 80 DU in some regions. The influence of the Arctic Oscillation (AO) reaches 40 DU. The regions of TOC variations and their location and dimensions change depending on the phases of QBO, AO, and El Niño-Southern Oscillation (ENSO). Three regions of increased TOC—over Europe, Eastern Siberia, and the Pacific Ocean—are formed in years with a warm stratosphere. A compensating TOC decrease takes place in the tropics and over Greenland. In the years of El Niño and the easterly QBO phase, the TOC increases over Europe and drops over the central Pacific, as well as to the south from 45° N. The AO controls the ozone growth over most of Eurasia at temperate latitudes and its weak drop over the Atlantic. It was impossible to obtain such quantitative estimates with the use of methods based on an independent analysis of the TOC series at individual points of the coordinate grid. Testing with the Monte Carlo method confirmed that the results obtained are significant with a probability of 95–99.9%.     

Arctic climate changes and possible conditions of Arctic navigation in the 21st century

Assessments of current and expected climatic changes in the Arctic Basin are obtained, including ice-cover characteristics influencing the duration of the navigation season on the Northern Sea Route (NSR) along Eurasia and the Northwest Passage (NWP) along North America. The ability of modern climate models to simulate the average duration of the navigation season and its changes over recent decades is estimated. The duration of the navigation season for the NSR and NWP in the 21st century is estimated using an ensemble of climate models. The assessments differ significantly for the NSR and NWP. Unlike the NSR, the NWP reveals no large changes in the navigation season in the first 30 years of the 21st century. From the multimodel simulations, the expected duration of the navigation period by the late 21st century will be approximately 3 to 6 months for the NSR and 2 to 4 months for the NWP under the moderate anthropogenic SRES-A1B scenario.     

Simulation of modern climate with the new version of the INM RAS climate model

The INMCM5.0 numerical model of the Earth’s climate system is presented, which is an evolution from the previous version, INMCM4.0. A higher vertical resolution for the stratosphere is applied in the atmospheric block. Also, we raised the upper boundary of the calculating area, added the aerosol block, modified parameterization of clouds and condensation, and increased the horizontal resolution in the ocean block. The program implementation of the model was also updated. We consider the simulation of the current climate using the new version of the model. Attention is focused on reducing systematic errors as compared to the previous version, reproducing phenomena that could not be simulated correctly in the previous version, and modeling the problems that remain unresolved.     

Estimating climate changes in the northern hemisphere in the 21st century under alternative scenarios of anthropogenic forcing

Possible changes in the climate characteristics of the Northern Hemisphere in the 21st century are estimated using a climate model (developed at the Obukhov Institute of Atmospheric Physics (OIAP), Russian Academy of Sciences) under different scenarios of variations in the atmospheric contents of greenhouse gases and aerosols, including those formed at the OIAP on the basis of SRES emission scenarios (group I) and scenarios (group II) developed at the Moscow Power Engineering Institute (MPEI). Over the 21st century, the global annual mean warming at the surface amounts to 1.2?C2.6°C under scenarios I and 0.9?C1.2°C under scenarios II. For all scenarios II, starting from the 2060s, a decrease is observed in the rate of increase in the global mean annual near-surface air temperature. The spatial structures of variations in the mean annual near-surface air temperature in the 21st century, which have been obtained for both groups of scenarios (with smaller absolute values for scenarios II), are similar. Under scenarios I, within the extratropical latitudes, the mean annual surface air temperature increases by 3?C7°C in North America and by 3?C5°C in Eurasia in the 21st century. Under scenarios II, the near-surface air temperature increases by 2?C4°C in North America and by 2?C3°C in Eurasia. An increase in the total amount of precipitation by the end of the 21st century is noted for both groups of scenarios; the most significant increase in the precipitation rate is noted for the land of the Northern Hemisphere. By the late 21st century, the total area of the near-surface permafrost soils of the land of the Northern Hemisphere decreases to 3.9?C9.5 10⁶ km² for scenarios I and 9.7?C11.0 × 10⁶ km² for scenarios II. The decrease in the area of near-surface permafrost soils by 2091?C2100 (as compared to 2001?C2010) amounts to approximately 65% for scenarios I and 40% for scenarios II. By the end of the 21st century, in regions of eastern Siberia, in which near-surface permafrost soils are preserved, the characteristic depths of seasonal thawing amount to 0.5?C2.5 m for scenarios I and 1?C2 m for scenarios II. In western Siberia, the depth of seasonal thawing amounts to 1?C2 m under both scenarios I and II.     

Estimation of changes in characteristics of the climate and carbon cycle in the 21st century accounting for the uncertainty of terrestrial biota parameter values

ensemble simulations with the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS) climate model (CM) for the 21st century are analyzed taking into account anthropogenic forcings in accordance with the Special Report on Emission Scenarios (SRES) A2, A1B, and B1, whereas agricultural land areas were assumed to change in accordance with the Land Use Harmonization project scenarios. Different realizations within these ensemble experiments were constructed by varying two governing parameters of the terrestrial carbon cycle. The ensemble simulations were analyzed with the use of Bayesian statistics, which makes it possible to suppress the influence of unrealistic members of these experiments on their results. It is established that, for global values of the main characteristics of the terrestrial carbon cycle, the SRES scenarios used do not differ statistically from each other, so within the framework of the model, the primary productivity of terrestrial vegetation will increase in the 21st century from 74 ± 1 to 102 ± 13 PgC yr⁻¹ and the carbon storage in terrestrial vegetation will increase from 511 ± 8 to 611 ± 8 PgC (here and below, we indicate the mean ± standard deviations). The mutual compensation of changes in the soil carbon stock in different regions will make global changes in the soil carbon storage in the 21st century statistically insignificant. The global CO₂ uptake by terrestrial ecosystems will increase in the first half of the 21st century, whereupon it will decrease. The uncertainty interval of this variable in the middle (end) of the 21st century will be from 1.3 to 3.4 PgC yr⁻¹ (from 0.3 to 3.1 PgC yr⁻¹). In most regions, an increase in the net productivity of terrestrial vegetation (especially outside the tropics), the accumulation of carbon in this vegetation, and changes in the amount of soil carbon stock (with the total carbon accumulation in soils of the tropics and subtropics and the regions of both accumulation and loss of soil carbon at higher latitudes) will be robust within the ensemble in the 21st century, as will the CO₂ uptake from the atmosphere only by terrestrial ecosystems located at extratropical latitudes of Eurasia, first and foremost by the Siberian taiga. However, substantial differences in anthropogenic emissions between the SRES scenarios in the 21st century lead to statistically significant differences between these scenarios in the carbon dioxide uptake by the ocean, the carbon dioxide content in the atmosphere, and changes in the surface air temperature. In particular, according to the SRES A2 (A1B, B1) scenario, in 2071–2100 the carbon flux from the atmosphere to the ocean will be 10.6 ± 0.6 PgC yr⁻¹ (8.3 ± 0.5, 5.6 ± 0.3 PgC yr⁻¹), and the carbon dioxide concentration in the atmosphere will reach 773 ± 28 ppmv (662 ± 24, 534 ± 16 ppmv) by 2100. The annual mean warming in 2071–2100 relatively to 1961–1990 will be 3.19 ± 0.09 K (2.52 ± 0.08, 1.84 ± 0.06 K).     

Simulation of changes in global ozone and atmospheric dynamics in the 21st century with the chemistry-climate model SOCOL

The solar climate ozone links (SOCOL) three-dimensional chemistry-climate model is used to estimate changes in the ozone and atmospheric dynamics over the 21st century. With this model, four numerical time-slice experiments were conducted for 1980, 2000, 2050, and 2100 conditions. Boundary conditions for sea-surface temperatures, sea-ice parameters, and concentrations of greenhouse and ozone-depleting gases were set following the IPCC A1B scenario and the WMO A1 scenario. From the model results, a statistically significant cooling of the model stratosphere was obtained to be 4–5 K for 2000–2050 and 3–5 K for 2050–2100. The temperature of the lower atmosphere increases by 2–3 K over the 21st century. Tropospheric heating significantly enhances the activity of planetary-scale waves at the tropopause. As a result, the Eliassen-Palm flux divergence considerable increases in the middle and upper stratosphere. The intensity of zonal circulation decreases and the meridional residual circulation increases, especially in the winter-spring period of each hemisphere. These dynamic changes, along with a decrease in the concentrations of ozone-depleting gases, result in a faster growth of O₃ outside the tropics. For example, by 2050, the total ozone in the middle and high latitudes approaches its model level of 1980 and the ozone hole in Antarctica fills up. The superrecovery of the model ozone layer in the middle and high latitudes of both hemispheres occurs in 2100. The tropical ozone layer recovers far less slowly, reaching a 1980 level only by 2100.     

跨入21世纪的俄罗斯海洋地质的关键性问题

当前一般都认为,人类在21世纪的经济生存在很多方面将建立在世界海洋(首先是大陆架)提供的矿物原料潜在资源的基础上。20世纪 70 年代,注意力主要集中在研究世界海洋矿物原料资源问题上。1982 年在海洋科研方向的影响下,北极地质科学研究所被改造为全苏世界海洋地质学和矿物资源科学研究所。最近10年来确定了主要的矿物原料,即铁锰结核、含钴锰结壳、多金属硫化物和磷钙土。在初期(1975—1987 年)主要的注意力投向了铁锰结核。1974 年在太平洋克拉里昂断裂区第1个铁锰结核矿床的发现和美国对它的要求引起了投机行为。其他国家如法国、德…     

Influence of radiation and circulation factors on climate change in Western Siberia at the end of the 20th century and beginning of the 21st century

An analysis of the air-temperature and atmospheric-pressure fields in Western Siberia is performed based on observations in 1976–2014; a comparison of temperature and pressure variability in two temporal intervals, 1976–2005 and 1985–2014, is carried out. The estimation of contributions from such climate-forming factors as radiation and circulation is performed for the same intervals. It is revealed that an increase in the annual mean ground–air temperature in the investigated region of Western Siberia was still taking place in the period of 1985–2014; however, the warming process was less active than in the 1976–2005 period. Winter months play the largest role in decreasing the temperature growth rate; during these months, the warming process was replaced by a cooling one in the second time interval. It is shown that the circulation factors, that is, the mechanisms described by indices of global circulation, played the dominant role in the period from 1985 to 2014.     

Influence of volcanic activity on climate change in the past several centuries: Assessments with a climate model of intermediate complexity

The climate model of intermediate complexity developed at the A.M. Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences (IAP RAS CM) is supplemented by a scheme which takes into account the volcanic forcing of climate. With this model, ensemble experiments have been conducted for the 1600s–1900s, in which, along with the volcanic forcing, the anthropogenic forcing due to greenhouse gases and sulfate aerosols and the natural forcing due to variations in solar irradiance were taken into account. The model realistically reproduces the annual mean response of surface air temperature and precipitation to major eruptions both globally and regionally. In particular, the decreases in the annual mean global temperature T _g in the IAP RAS CM after the largest eruptions in the latter half of the 20th century, the Mt. Agung (1963), El Chichon (1982), and Mt. Pinatubo (1991) volcanic eruptions, are 0.28, 0.27, and 0.46 K, respectively, in agreement with estimates from observational data. Moreover, in the IAP RAS CM, the volcanic eruptions result in a general precipitation decrease, especially over land in the middle and high latitudes of the Northern Hemisphere. The seasonal distribution of the response shows good agreement with observations for high-latitude eruptions and worse agreement for tropical and subtropical volcanoes. On interdecadal scales, volcanism leads to variations in T _g on the order of 0.1 K. In numerical experiments with anthropogenic and natural forcings, the model reproduces a general change in surface air temperature over the past several centuries. Taking into account the volcanic forcing, along with that due to variations in solar irradiance, the model has partly reproduced the nonmonotonic global warming for the 20th century.     

经略“21世纪海上丝绸之路”:综合应用平台建设

由于缺乏系统性的基础理论支撑,目前国内外尚无专业的"21世纪海上丝绸之路"综合应用系统,而远洋航海、战略支撑点建设、海洋工程设计、海洋资源开发、防灾减灾等对这方面的需求尤为迫切。文章首先探析"海上丝路"综合应用平台建设的重要性、紧迫性,规划构建涵盖海洋环境、资源、人文、地理、经济、法律案例的综合性"海上丝路"大数据,为国内和国际同行的"海上丝路"研究提供数据基础;进一步以海洋大数据为支撑,融入团队前期系列研究成果,规划构建贴近实用、查询便捷、理论体系完善的"海上丝路"综合应用平台,增强我国的海洋建设能力、海权维护能力、对南海局势的掌控能力,落实国家战略,切实呼应党中央提出的加强"一带一路"学术研究、理论支撑、话语体系的建设要求,为迈向深蓝提供科技支撑、辅助决策,助力人类社会的繁荣进步。     

Fisheries policy, research and the social sciences in Europe: Challenges for the 21st century

Despite evidence of a broadening of the science base for European fisheries policy with the incorporation of an ecosystem approach and increasing use of economic modelling, the contribution of the social sciences to policy related research remains less conspicuous. Progress has occurred in the understanding of institutional structures and the theory of fisheries governance, but analysis of EU funded research in the 6th Framework Programme (2002–2006) points to the absence of social science except in multi-disciplinary projects. The diasporic nature of fisheries social science and the absence of clearly articulated social objectives from fisheries policy are among the more plausible explanations for this unconformity. Prospects for reform of the CFP in 2012—including a redistribution of responsibilities between central and regional institutions—offer enhanced opportunities for the social sciences in interdisciplinary and specialist areas of policy related research. Responding to the challenge will necessitate the building of stronger networks within the family of social sciences and across disciplinary boundaries with the natural and economic sciences.     

Prognostic estimations of the atmospheric ozone content in the first half of the 21st century

New prognostic estimates are obtained for the potential variability of the atmospheric ozone content in the first half of the 21st century. The calculations are based on models of gas composition and general circulation in the lower and middle atmosphere and on the scenarios of the World Meteorological Organization (WMO). It is shown that the rate of ozone content increase will be controlled to a considerable extent by variations in stratospheric temperature. Even though the contents of atmospheric chlorine and bromine are not reduced, contrary to the WMO prediction, and remain at the present-day levels, the continuation of stratospheric cooling will lead to a rapid recovery of the ozone content to its level characteristic of the 1980s. Model experiments on variations in the stratospheric aerosol content have shown that an increase in the aerosol concentration will not affect the rate of ozone recovery in the atmosphere during reduced emissions of chlorine and bromine gases if the stratospheric temperature remains lowered. Numerical experiments have also shown that the simultaneous anthropogenic action on the contents of halogen gases and on the lower-stratosphere temperature can reduce the adverse effects of Freons and halons on the ozone layer.     

21世纪初期海上丝绸之路大陆岸线位置变化特征

基于遥感和GIS技术,利用Landsat影像目视解译提取2000和2015年海上丝绸之路大陆岸线数据,从整体、洲际尺度、国家尺度、热点区域和港口城市5个空间尺度分析大陆岸线位置变化特征.结果表明:(1)整体方面,2000年和2015年海上丝绸之路沿线地区岸线扩张和后退的比例(速度)分别约为8.21％(27 m·a–1)...     

Recent climate forcing and physical oceanographic changes in Northern Hemisphere regions: A review and comparison of four marine ecosystems

As part of a project comparing the structure and function of four marine ecosystems off Norway and the United States, this paper examines the oceanographic responses to climate forcing, with emphasis on recent changes. The four Northern Hemisphere ecosystems include two in the Pacific Ocean (Bering Sea and Gulf of Alaska) and two in the Atlantic Ocean (Georges Bank/Gulf of Maine and the Barents/Norwegian Seas). Air temperatures, wind forcing and heat fluxes over the four regions are compared as well as ocean hydrography and sea-ice conditions where seasonal sea ice is found. The long-term interannual variability in air temperatures, winds and net heat fluxes show strong similarity between adjacent ecosystems and within subregions of an ecosystem, but no significant correlations between Pacific and Atlantic ecosystems and few across the Atlantic. In spite of the lack of correlation between climate forcing and ocean conditions between most of the ecosystems, recent years have seen record or near record highs in air and sea temperatures in all ecosystems. The apparent causes of the warming differ. In the Atlantic, they appear to be due to advection, while in the Pacific temperatures are more closely linked to air-sea heat exchanges. Advection is also responsible for the observed changes in salinity in the Atlantic ecosystems (generally increasing salinity in the Barents and Norwegian Seas and decreasing in the Gulf of Maine and Georges Bank) while salinity changes in the Gulf of Alaska are largely related to increased local runoff.     

21世纪初我国水下工程技术亟待开展的若干课题

水下工程技术是海洋高新技术的重要组成部分。本文根据对２０世纪９０年代以来世界水下工程技术发展态势及２１世纪初我国水下工程技术将面临任务的研究分析,系统地提出了为促进我国水下工程技术的发展,在２０１０年前亟待开展的若干重要研究课题。     

Model estimates for the mean gas exchange between the ocean and the atmosphere under the conditions of the present-day climate and its changes expected in the 21st century

Annual mean fluxes of CO₂ and oxygen across the sea surface are estimated with the use of numerical modeling for several regions located in the Gulf Stream and Kuroshio zones. The present-day climatic conditions and the climatic conditions expected in the middle and at the end of the 21st century are considered. Specific features of gas exchange under a strong wind that are associated with gas exchange by bubbles and with changes in the air-water difference of the gas concentrations were taken into account in the calculations. The estimates obtained differ substantially from the results based on the traditional approach, which disregards the above features. A considerable increase in the absorption of CO₂ by the ocean, which is mainly caused by the continuing increase in the CO₂ concentration in the air during its small changes in the ocean, is expected in the 21st century. At the same time, no trends are revealed in the annual mean fluxes of oxygen across the ocean surface. The conclusion is made that, in calculations of CO₂ absorption by the world ocean, it is necessary to take into account both specific features of gas transfer under a strong wind and an increase in the atmospheric concentration of CO₂.     

General forecast of the evolution of the coastal zone of the Eurasian Arctic seas in the 21st century

Principal regularities of the evolution of the Arctic coasts of Eurasia in the 21st century related to the climate warming and sea level rise are assessed. It is stated that the most significant changes may be expected in the most ice-covered seas of the Arctic Ocean, where the area of the ice cover may significantly decrease while the duration of the ice-free periods will grow. Thermoabrasive coasts will be the most subjected to the changes; the rate of their recession will increase 1.5–2.5 fold. The further development of accumulative coasts in the Arctic seas will proceed against the background of a transgression; meanwhile, in the 21st century, one can expect no catastrophic changes such as washing away of coastal accumulative features.