Long-term estimates of parameters of the vertical distribution of cloud layers from atmospheric radiosounding data

Based on the global aerological dataset and on the method for determination of the boundaries and amount of cloudiness using the profiles of temperature and humidity obtained from the atmospheric radiosounding data [23], the estimates are computed for the parameters of atmospheric temperature- humidity separation into cloud and intercloud layers from the surface to the height of 10 km. The base and top of cloud layers and their total thickness and frequency are selected as layering parameters. The computations are based on the data for the observational period of 1964-1998. To specify the spatiotemporal features of atmospheric layering, long-term geographic distributions of mean values and standard deviations of the mentioned parameters are constructed for January and July, and the amplitude of their variations is determined.     

Long-term projection of main parameters of regional climate till the year 3000

The methods are considered to solve the problem of secure isolation of radioactive waste containing long-lived products of nuclear fuel processing with a half-life of tens of thousands years (plutonium etc.). The methodology of long-term projection of average annual surface air temperature and total precipitation is proposed. Taking into account the possible scenarios of the development of the global socioeconomic system, variations due to the anthropogenic impact in average annual temperature at the Northern Hemisphere mid-latitudes for the period till 2300 are estimated. Based on paleoclimatic data, projections of natural trends in global average annual temperature and total precipitation till the year 3000 are developed. Taking into account the anthropogenic component, the projective ranges of these climatic parameters in the Vyatka River basin in 2100-3000 are evaluated.     

Applying the energy- and water balance model for incorporation of the cryospheric component into a climate model. Part II. Modeled mass balance on the green land ice sheet surface

The Greenland ice sheet is a very important potential source of fresh water inflow to the World Ocean under warming climate conditions. Apparently, it was the same during the Last Interglacial 130-115 thousand years ago. In order to quantify input of the Greenland ice sheet to the rise of the global mean sea level in the past or in the future, we include a surface mass balance model block into the Earth System Model. The computational algorithm is based on the calculation of energy balance on the ice sheet surface. The key tuning parameter of the model is the daily amplitude of air surface temperature. It defines the area and the rate of snow or ice melting. The range of possible values of this parameter is determined during a series of numerical experiments. High sensitivity of meltwater runoff volume to surface air temperature amplitude is revealed.     

Environmental conditions of the Laptev Sea region in the late postglacial time

The comparison between the first results of comprehensive micropaleontological analysis (pollen, spores, foraminifera, and ostracods) and those of radiocarbon dating (AMS¹⁴C) for the sediments of the eastern inner shelf of the Laptev Sea (the core collected from depth of 37 m) indicates that considerable changes in natural conditions in the sea and on land coincide in time and refer to the time period of 1500–1700 years B.P. This period is characterized by changes in microfossils: appearance of thermophilic pollen and planktonic foraminifera and increase in total number of benthic foraminifera and ostracods. Intense warming and humidification of the climate reconstructed for this 200-year period promoted the expansion of large-shrub tundra. Summer air temperatures were lower than that in the peak mid-Holocene climatic optimum by 2°–3°C, but 1°C higher than the present-day temperature. An estuary freshwater basin developed: it was strongly affected by river discharge, but North Atlantic waters also intensely penetrated here in short-term intervals. In general, the studied microfossil complex reflects the relatively stable environmental conditions and decrease in seawater salinity in the eastern part of the Laptev Sea shelf during the last 2300 years.     

Shoreline variability of an urban beach fronted by a beachrock reef from video imagery

This contribution presents the results of a study on the shoreline variability of a natural perched urban beach (Ammoudara, N. Crete, Greece). Shoreline variability was monitored in high spatio-temporal resolution using time series of coastal video images and a novel, fully automated 2-D shoreline detection algorithm. Ten-month video monitoring showed that cross-shore shoreline change was, in some areas, up to 8 m with adjacent sections of the shoreline showing contrasting patterns of beach loss or gain. Variability increased in spring/early summer and stabilized until the end of the summer when partial beach recovery commenced. Correlation of the patterns of beach change with wave forcing (as recorded at an offshore wave buoy) is not straightforward; the only discernible association was that particularly energetic waves from the northern sector can trigger changes in the patterns of shoreline variability and that increased variability might be sustained by increases in offshore wave steepness. It was also found that the fronting beachrock reef exerts significant geological control on beach hydrodynamics. Hydrodynamic modelling and observations during an energetic event showed that the reef can filter wave energy in a highly differential manner, depending on its local architecture. In some areas, the reef allows only low-energy waves to impinge on the shoreline, whereas elsewhere penetration of higher waves is facilitated by the low elevation and limited width of the reef or by the presence of an inlet. Wave/reef interaction can also generate complex circulation patterns, including rip currents that appeared to be also constrained by the reef architecture.     

Evaluation of Strength Characteristics of Tropical Black Clay Treated with Locust Bean Waste Ash

An expansive tropical black clay (also known as black cotton soil because the cotton plant thrives well on it) was treated with up to 15 % locust bean waste ash (LBWA) to assess its soil improvement potential. Samples were subjected to index, compaction using three energy levels (British Standard light, BSL, West African Standard, WAS or ‘Intermediate’ and British Standard heavy, BSH), shear strength (unconfined compressive strength, UCS), California bearing ratio, CBR and durability tests. Results obtained show that the natural soil is not suitable for road construction. The maximum dry density (MDD) and optimum moisture content (OMC) decreased and increased, respectively. Regardless of the compactive effort and curing period, strength and durability properties increased with higher LBWA content with the BSL effort recording the best improvement. However, based on durability results, the optimal 12.5 % LBWA treatment of black cotton soil did not satisfy criteria for its use in road construction as a stand alone additive. Also, significant improvement in soil properties was obtained using the BSL compactive effort, which is easily achieved in the field. The benefits of the application include reduction in the cost of soil improvement and the adverse environmental impact of locust bean waste.     

The fluid phase evolution during the formation of carbonatite of the Guli massif: Evidence from the isotope (C,N, Ar) data

The first data on variations of the isotope composition and element ratios of carbon, nitrogen, and argon in carbonatites of different generations and ultrabasic rocks of the Guli massif obtained by the method of step crushing are reported. It is shown that early carbonatite differs significantly from the later ones by the concentration of highly volatile components, as well as by the isotope compositions of carbon (CO₂), argon, and hydrogen (H₂O). The data obtained allow us to conclude that the mantle component predominated in the fluid at the early stages of formation of rocks of the Guli massif, whereas the late stages of carbonatite formation were characterized by an additional fluid source, which introduced atmospheric argon, and most likely a high portion of carbon dioxide with isotopically heavy carbon.     

PGE distribution in deformed lherzolites of the Udachnaya kimberlite pipe (Yakutia)

The results of the first study of the PGE distribution in deformed lherzolites of the Udachnaya kimberlite pipe (Yakutia) are presented here. The complex character of evolution of the PGE composition in the Deformed lherzolites is assumed to be the result of silicate metasomatism. At the first stage, growth in the amount of clinopyroxene and garnet in the rock is accompanied by a decrease in the concentration of the compatible PGE (Os, Ir). During the final stage, the rock is enriched with incompatible PGE (Pt, Pd) and Re possible due to precipitation of submicron-sized particles of sulfides in the interstitial space of these mantle rocks.