New data about tsunami evidence on Russia’s Pacific coast based on instrumental measurements for 2009–2010

Doklady Earth Sciences -     

Balance of heavy metals in the Volga River delta

The results of many years of geochemical research of aquatic landscapes are presented. Data on the average annual and seasonal concentrations of heavy metals in water and suspended sediments are given. Factors of migration and accumulation of elements in aquatic landscapes are discussed. Masses of heavy metals annually incoming and accumulated in the Volga River delta were calculated.     

A coordinate form for the Sundman surfaces in the general three-body problem

A new coordinate form for the Sundman surfaces is obtained. Singular points of the surfaces are determined and constructed. The Sundman stability is investigated. The Sundman stability of the motion of the Moon in the general three-body problem of the Sun-Earth-Moon is established.     

Simulating of the probability density of sea surface elevations using the Gram-Charlier series

The capabilities and limitations of the simulation of the probability density of rough sea surface elevations using the Gram-Charlier series are analyzed. The data of direct wave measurements at an oceanographic platform in the Black Sea are used in the analysis. The skewness of the sea surface elevation’s distribution depends on the mean slope formed by the dominating waves and on the degree of the wave field development. A weak trend in the variations of the peakedness during the measurements of these parameters is also observed. The estimates of the errors in the peakedness measurements during the construction of the probability density of the sea surface elevations using the first five terms of the Gram-Charlier series are presented.     

Submarine bars on sandy coasts

A brief review of the studies concerning the problem of submarine bars over the past decade is presented. Various types of bars are distinguished, and the mechanisms responsible for the formation thereof are discussed. The short-term (days, weeks) behavior of the bars is described in relation to the changes in the local wave parameters. The bar systems are shown to demonstrate cyclic behavior of two different types on time scales of years and decades. In the former case, the bars arise near the shore, migrate towards the sea, and degrade in the external margin of the coastal zone. The other cycle’s type is characterized by the landward migration of the bars and their welding with a subaerial beach, which results in creating a conveyor delivering material to the beach and eventually to the foredune by Aeolian transport. In the former case, the bar zone behaves as a closed system, while, in the latter, as a transition zone. It is noted that the long-term evolution of a bar system is controlled by a feedback mechanism tending to return the system to the initial state.     

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.     

Emission metrics under the 2 °C climate stabilization target

In multi-gas climate policies such as the Kyoto Protocol one has to decide how to compare the emissions of different greenhouse gases. The choice of metric could have significant implications for mitigation priorities considered under the prospective negotiations for climate mitigation agreements. Several metrics have been proposed for this task with the Global Warming Potential (GWP) being the most common. However, these metrics have not been systematically compared to each other in the context of the 2 °C climate stabilization target. Based on a single unified modeling framework, we demonstrate that metric values span a wide range, depending on the metric structure and the treatment of the time dimension. Our finding confirms the basic salient point that metrics designed to represent different aspects of the climate and socio-economic system behave differently. Our result also reflects a complex interface between science and policy surrounding metrics. Thus, it is important to select or design a metric suitable for climate stabilization based on an interaction among practitioners, policymakers, and scientists.     

Interannual variability of deep convection in the Northwestern Mediterranean simulated with a coupled AORCM

A hindcast experiment of the Mediterranean present-day climate is performed using a fully-coupled Atmosphere–Ocean Regional Climate Model (AORCM) for the Mediterranean basin. The new model, called LMDz-NEMO-Med, is composed of LMDz4-regional as atmospheric component and of NEMOMED8 as oceanic component. This AORCM equilibrates freely, without any flux adjustment, neither in fresh water nor in heat. At its atmospheric lateral boundary conditions, it is driven by ERA-40 data from 1958 to 2001, after a spin-up of 40 years in coupled configuration. The model performance is assessed and compared with available observational datasets. The model skill in reproducing mean state and inter-annual variability of main atmospheric and oceanic surface fields is in line with that of state-of-the-art AORCMs. Considering the ocean behaviour, the inter-annual variations of the basin-scale heat content are in very good agreement with the observations. The model results concerning salt content could not be adequately validated. High inter-annual variability of deep convection in the Gulf of Lion is simulated, with 53 % of convective winters, representative of the present climate state. The role of different factors influencing the deep convection and its inter-annual variability is examined, including dynamic and hydrostatic ocean preconditioning and atmospheric surface forcing. A conceptual framework is outlined and validated in linking the occurrence of deep convection to the efficiency of the integrated surface buoyancy fluxes along the winter season to mix the initially stratified averaged water column down to the convective threshold depth. This simple framework (based only on 2 independent variables) is able to explain 60 % (resp. 69 %) of inter-annual variability of the deep water formation rate (resp. maximum mixed layer depth) for the West Mediterranean Deep Water (WMDW) formation process.     

Mineralized lakes of the Transbaikalia and Northeastern Mongolia: Specific features of occurrence and ore-generating potential

The paper presents a review of shallow lakes on two neighboring territories, Transbaikalia in Russia and Northeastern Mongolia. Five systems of shallow lakes are distinguished in the regions under study: Barguzin, Eravna-Gusinoozersk, Ingoda, Onon-Borzya, and Eastern-Mongolian systems. The shallow lakes are sub-grouped according to common chemical compositions and geochemical evolution types. Characteristics of ground- and surface waters feeding the lakes are considered. Based on results of trace element analyses of water samples from about 200 lakes and more than 100 springs, wells and boreholes, elements that manifest higher concentrations, resulting from evaporation of lacustrine waters, are determined. Prospects of assessment of ore-generating potential of the shallow lakes as ‘liquid ore’ sources in view of commercial extraction of Li, U, REE, and others metals are discussed.