Melting trends over the Greenland ice sheet (1958–2009) from spaceborne microwave data and regional climate models

To study near-surface melt changes over the Greenland ice sheet (GrIS) since 1979, melt extent estimates from two regional climate models were compared with those obtained from spaceborne microwave brightness temperatures using two different remote sensing algorithms. The results from the two models were consistent with those obtained with the remote sensing algorithms at both daily and yearly time scales, encouraging the use of the models for analyzing melting trends before the satellite era (1958–1979), when forcing data is available. Differences between satellite-derived and model-simulated results still occur and are used here to identify (i) biases in the snow models (notably in the albedo parametrization, in the thickness of a snow layer, in the maximum liquid water content within the snowpack and in the snowfall impacting the bare ice appearance in summer) and (ii) limitations in the use of passive microwave data for snowmelt detection at the edge of the ice sheet due to mixed pixel effect (e.g., tundra or rock nearby the ice sheet). The results from models and spaceborne microwave sensors confirm a significant (p-value = 0.01) increase in GrIS surface melting since 1979. The melt extent recorded over the last years (1998, 2003, 2005 and 2007) is unprecedented in the last 50 yr with the cumulated melt area in the 2000's being, on the average, twice that of the 1980's

Rapid loss of firn pore space accelerates 21st century Greenland mass loss

Mass loss from the two major ice sheets and their contribution to global sea level rise is accelerating. In Antarctica, mass loss is dominated by increased flow velocities of outlet glaciers, following the thinning or disintegration of coastal ice shelves into which they flow. In contrast, ∼55% of post‒1992 Greenland ice sheet (GrIS) mass loss is accounted for by surface processes, notably increased meltwater runoff. A subtle process in the surface mass balance of the GrIS is the retention and refreezing of meltwater, currently preventing ∼40% of the meltwater to reach the ocean. Here we force a high‒resolution atmosphere/snow model with a mid‒range warming scenario (RCP4.5, 1970–2100), to show that rapid loss of firn pore space, by >50% at the end of the 21st century, quickly reduces this refreezing buffer. As a result, GrIS surface mass loss accelerates throughout the 21st century and its contribution to global sea level rise increases to 1.7 ±0.5 mm yr−1, more than four times the current value

В. Б. Антонович у листах, спогадах та працях Д. І. Багалія

The previous interglacial (Eemian, 130–114 kyr BP) had a mean sea level highstand 4 to 7 m above the current level, and, according to climate proxies, a 2 to 6 K warmer Arctic summer climate. Greenland ice cores extending back into the Eemian show a reduced depletion in δ18O of about 3‰ for this period, which suggests a significant warming of several degrees over the Greenland ice sheet. Since the depletion in δ18O depends, among other factors, on the condensation temperature of the precipitation, we analyze climatological processes other than mean temperature changes that influence condensation temperature, using output of the regional climate model RACMO2. This model is driven by ERA-40 reanalysis and ECHO-G GCM boundaries for present-day, preindustrial and Eemian climate. The processes that affect the condensation temperature of the precipitation are analyzed using 6-hourly model output. Our results show that changes in precipitation seasonality can cause significant changes of up to 2 K in the condensation temperature that are unrelated to changes in mean temperature

Comparison of the meteorology and surface energy balance at Storbreen and Midtdalsbreen, two glaciers in southern Norway

We compare 5 years of meteorological records from automatic weather stations (AWSs) on Storbreen and Midtdalsbreen, two glaciers in southern Norway, located approximately 120 km apart. The records are obtained from identical AWSs with an altitude difference of 120 m and cover the period September 2001 to September 2006. Air temperature at the AWS locations is found to be highly correlated, even with the seasonal cycle removed. The most striking difference between the two sites is the difference in wind climate. Midtdalsbreen is much more under influence of the large-scale circulation with wind speeds on average a factor 1.75 higher. On Storbreen, weaker katabatic winds are dominant. The main melt season is from May to September at both locations. During the melt season, incoming and net solar radiation are larger on Midtdalsbreen, whereas incoming and net longwave radiation are larger on Storbreen, primarily caused by thicker clouds on the latter. The turbulent fluxes are a factor 1.7 larger on Midtdalsbreen, mainly due to the higher wind speeds. Inter-daily fluctuations in the surface energy fluxes are very similar at the AWS sites. On average, melt energy is a factor 1.3 larger on Midtdalsbreen, a result of both larger net radiation and larger turbulent fluxes. The relative contribution of net radiation to surface melt is larger on Storbreen (76%) than on Midtdalsbreen (66%). As winter snow depth at the two locations is comparable in most years, the larger amount of melt energy results in an earlier disappearance of the snowpack on Midtdalsbreen and 70% more ice melt than on Storbreen. We compare the relative and absolute values of the energy fluxes on Storbreen and Midtdalsbreen with reported values for glaciers at similar latitudes. Furthermore, a comparison is made with meteorological variables measured at two nearby weather stations, showing that on-site measurements are essential for an accurate calculation of the surface energy balance and melt rate

Контроль выбросов вспомогательных корпусов АЭС: состояние и пути совершенствования

Произведен анализ состояния системы контроля выбросов через вентиляционные системы СК АЭС с ВВЭР на примере Запорожской АЭС (ЗАЭС)

Optimising finishing pig delivery weight : participatory decision problem analysis

The seemingly straightforward question of optimal pig delivery weight is more complex than meets the eye. Despite abundant research insights, the industry continues to request additional applied scientific decision support on the delivery weight problem. The current objective is to investigate whether and how the complex decision of delivery weight can be reshaped (reframed) into a more tangible and comprehensible system of factors that matter for making the right decision. We used a participatory decision problem analysis, which resulted in modelling blueprints that incorporate factors prioritised by stakeholders for determining optimal delivery weights. How to efficiently organise such a 'problem reframing process' is case-specific: it depends on the objective, the initial problem understanding by the stakeholders, and their learning potential. Efficient co-learning is a prerequisite for successful participatory problem analysis. Our study reveals that the first step in such a process of 'problem reframing' should therefore be to answer the question of how to effectively organise co-learning among stakeholders and researchers, instead of starting with a correct and detailed representation of the problem. Useful guidelines for participatory problem reframing processes are (1) providing sufficient participatory learning steps, (2) having few and clearly defined objectives per learning step, (3) providing adapted learning tools per step, (4) establishing a common language and (5) deliberately choosing stakeholders based on prior knowledge of the problem or its context, potential motivation or incentives to be part of the participatory process step and potential role in up-scaling the co-learning process to a larger group of beneficiaries

Християнство і європейська духовно-культурна ідентичність

Стаття присвячена з’ясуванню ролі і місця християнства у формуванні європейської ідентичності в умовах ціннісної дезорієнтації, дегуманізації людини і суспільства, морального та релігійного хаосу.Статья посвящена выяснению роли и места христианства в формировании европейской идентичности в условиях ценностной дезориентации, дегуманизации человека и общества, морального и религиозного хаоса.The article is devoted to finding out the role and place of christianity in forming of the European identity in the conditions of the valued disorientation, dehumanizing of man and society, moral and religious chaos

Социально-экономические последствия изменения ставок акцизного сбора

Проаналізовано основні тенденції зміни ставок акцизного збору з алкогольних та тютюнових виробів в Україні та запропонована порівняльна характеристика законодавчого забезпечення. Подано оцінку можливих економічних та соціальних наслідків їх підвищення, виявлено як позитивні, так і негативні тенденції, зроблено висновки щодо доцільності змін. Ключові слова: акцизний збір, ставка акцизного збору, підакцизні товари.Проанализированы основные тенденции изменения ставок акцизного сбора с алкогольной продукции и табачных изделий в Украине и предложена сравнительная характеристика законодательного обеспечения. Дана оценка возможных экономических и социальных последствий их повышения, выявлены как положительные, так и отрицательные тенденции, сделаны выводы о целесообразности изменения. Ключевые слова: акцизный сбор, ставка акцизного сбора, подакцизные товары.The basic tendencies in changing of excise duties’ rate, specifically in alcoholic and tobacco products, in Ukraine were analysed, and was shifted the comparison characteristic of the legislative control. The estimation of possible economic and social outcome of the rate increase was made, both negative and positive its tendencies were revealed, and was drawn the conclusion on the expedience of changes. Key words: excise tax, rate of excise duties, items liable to excise duties

Partitioning of melt energy and meltwater fluxes in the ablation zone of the west Greenland ice sheet

We present four years (August 2003–August 2007) of surface mass balance data from the ablation zone of the west Greenland ice sheet along the 67° N latitude circle. Sonic height rangers and automatic weather stations continuously measured accumulation/ablation and near-surface climate at distances of 6, 38 and 88 km from the ice sheet margin at elevations of 490, 1020 and 1520 m a.s.l. Using a melt model and reasonable assumptions about snow density and percolation characteristics, these data are used to quantify the partitioning of energy and mass fluxes during melt episodes. The lowest site receives very little winter accumulation, and ice melting is nearly continuous in June, July and August. Due to the lack of snow accumulation, little refreezing occurs and virtually all melt energy is invested in runoff. Higher up the ice sheet, the ice sheet surface freezes up during the night, making summer melting intermittent. At the intermediate site, refreezing in snow consumes about 10% of the melt energy, increasing to 40% at the highest site. The sum of these effects is that total melt and runoff increase exponentially towards the ice sheet margin, each time doubling between the stations. At the two lower sites, we estimate that radiation penetration causes 20–30% of the ice melt to occur below the surface