Climate scenarios of sea level rise for the northeast Atlantic Ocean: a study including the effects of ocean dynamics and gravity changes induced by ice melt

Here we present a set of regional climate scenarios of sea level rise for the northeast Atlantic Ocean. In this study, the latest observations and results obtained with state-of-the-art climate models are combined. In addition, regional effects due to ocean dynamics and changes in the Earth’s gravity field induced by melting of land-based ice masses have been taken into account. The climate scenarios are constructed for the target years 2050 and 2100, for both a moderate and a large rise in global mean atmospheric temperature (2 °C and 4 °C in 2100 respectively). The climate scenarios contain contributions from changes in ocean density (global thermal expansion and local steric changes related to changing ocean dynamics) and changes in ocean mass (melting of mountain glaciers and ice caps, changes in the Greenland and Antarctic ice sheets, and (minor) terrestrial water-storage contributions). All major components depend on the global temperature rise achieved in the target periods considered. The resulting set of climate scenarios represents our best estimate of twenty-first century sea level rise in the northeast Atlantic Ocean, given the current understanding of the various contributions. For 2100, they yield a local rise of 30 to 55 cm and 40 to 80 cm for the moderate and large rise in global mean atmospheric temperature, respectively. <br/

Mechanisms behind the temporary shutdown of deep convection in the Labrador Sea : lessons from the Great Salinity Anomaly years 1968–71

Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 25 (2012): 6743–6755, doi:10.1175/JCLI-D-11-00549.1.From 1969 to 1971 convection in the Labrador Sea shut down, thus interrupting the formation of the intermediate/dense water masses. The shutdown has been attributed to the surface freshening induced by the Great Salinity Anomaly (GSA), a freshwater anomaly in the subpolar North Atlantic. The abrupt resumption of convection in 1972, in contrast, is attributed to the extreme atmospheric forcing of that winter. Here oceanic and atmospheric data collected in the Labrador Sea at Ocean Weather Station Bravo and a one-dimensional mixed layer model are used to examine the causes of the shutdown and resumption of convection in detail. These results highlight the tight coupling of the ocean and atmosphere in convection regions and the need to resolve both components to correctly represent convective processes in the ocean. They are also relevant to present-day conditions given the increased ice melt in the Arctic Ocean and from the Greenland Ice Sheet. The analysis herein shows that the shutdown was initiated by the GSA-induced freshening as well as the mild 1968/69 winter. After the shutdown had begun, however, the continuing lateral freshwater flux as well as two positive feedbacks [both associated with the sea surface temperature (SST) decrease due to lack of convective mixing with warmer subsurface water] further inhibited convection. First, the SST decrease reduced the heat flux to the atmosphere by reducing the air–sea temperature gradient. Second, it further reduced the surface buoyancy loss by reducing the thermal expansion coefficient of the surface water. In 1972 convection resumed because of both the extreme atmospheric forcing and advection of saltier waters into the convection region.This research was funded by a grant from the NWO/SRON User Support Programme Space Research. FS acknowledges support from OCE- 0850416 and NOAA NA08OAR4310569.2013-04-0

Onderzoek naar bovengrensscenario's voor klimaatverandering voor overstromingsbescherming van Nederland : internationale wetenschappelijke beoordeling

De Deltacommissie heeft een internationaal wetenschappelijk onderzoek laten doen naar de bovengrensscenario’s voor klimaatverandering om Nederland te kunnen beschermen tegen overstromingen. Deze wetenschappelijke visie is gebruikt voor het opstellen van het rapport van de Deltacommissie. Het onderliggende onderzoek baseert zich op de meest recente inzichten van de bovenwaarden en langetermijnprojecties voor de zeespiegelstijging tot 2200 van door het klimaat veroorzaakte zeespiegelstijging, veranderende stormcondities en piekafvoer van de Rij

Statistical analysis of individual tasks on probability theory

Over the years, improving the quality of basic education programs (PLO) in Tomsk Polytechnic University has received increased attention. One of the main objectives of improving the educationalprocess and the PLO is the optimization of procedures for monitoring the quality of the PLO for their continuous improvement. This work contains the results of the statistical analysis of the quality of the tests for monitoring students' probability theory knowledge. The analysis showed a significant difference (not parallel) ofvariants of individual tasks, and on its basis is method for providing parallel tests

The contrasting dynamics of the buoyancy-forced Lofoten and Greenland Basins

Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(5),(2020): 1227-1244, doi:10.1175/JPO-D-19-0280.1.The Nordic seas are commonly described as a single basin to investigate their dynamics and sensitivity to environmental changes when using a theoretical framework. Here, we introduce a conceptual model for a two-basin marginal sea that better represents the Nordic seas geometry. In our conceptual model, the marginal sea is characterized by both a cyclonic boundary current and a front current as a result of different hydrographic properties east and west of the midocean ridge. The theory is compared to idealized model simulations and shows good agreement over a wide range of parameter settings, indicating that the physics in the two-basin marginal sea is well captured by the conceptual model. The balances between the atmospheric buoyancy forcing and the lateral eddy heat fluxes from the boundary current and the front current differ between the Lofoten and the Greenland Basins, since the Lofoten Basin is more strongly eddy dominated. Results show that this asymmetric sensitivity leads to opposing responses depending on the strength of the atmospheric buoyancy forcing. Additionally, the front current plays an essential role for the heat and volume budget of the two basins, by providing an additional pathway for heat toward the interior of both basins via lateral eddy heat fluxes. The variability of the temperature difference between east and west influences the strength of the different flow branches through the marginal sea and provides a dynamical explanation for the observed correlation between the front current and the slope current of the Norwegian Atlantic Current in the Nordic seas.We thank Ilker Fer and two anonymous reviewers whose comments improved this paper. S. L. Ypma and S. Georgiou were supported by NWO (Netherlands Organisation for Scientific Research) VIDI Grant 864.13.011 awarded to C. A. Katsman. M. A. Spall was supported by National Science Foundation Grants OCE-1558742 and OPP-1822334. E. Lambert is funded by the ERA4CS project INSeaPTION. The model data analyzed in this study are available on request from the corresponding author. This study has been conducted using E.U. Copernicus Marine Service Information. The altimeter products were produced by Ssalto/Duacs and distributed by Aviso+, with support from CNES (https://www.aviso.altimetry.fr).2020-10-2

Morphological Deformities in Anuran Amphibians from the Khoper River Valley in the “Privolzhskaya Lesostep’” Nature Reserve and Adjacent Territories

In summer 2016, we investigated Ostrovtsovskaya Lesostep’ (Penza region, Russia) and caught more than 130 specimens belonging to 4 species of anuran amphibians. We found a symmetric case of “hyperxanthism” of the eyes (a new type of anomaly among amphibians) in one Rana arvalis specimen, one asymmetric amely in Bombina bombina, and 21 specimens of Pelophylax ridibundus (19% of total sample) with deformed fore and hind limbs. We define some anomalies as “Rostand’s anomaly P” (in its extreme manifestations). The potential reasons of the morphological anomalies were discussed

Античные и средневековые городища на дне Иссык-Куля

В статье дается обзор результатов многолетних подводных археологических разведок на озере Иссык-Куль. Приводятся данные по местоположению некоторых затопленных городищ античности и средних веков (Тору-Айгыр, Кара-ой, Чигу). Описываются наиболее интересные артефакты, найденные на дне озера.В статті дається огляд результатів багаторічних підводних археологічних розвідок на озері Іссик-Куль. Наводяться дані про місцезнаходження деяких затоплених городищ античності і середньовіччя (Тору-Айгир, Кара-ой, Чігу). Описуються найцікавіші артефакти, знайдені на дні озера.The article is a review of the results of many years’ underwater archaeological researches at lake Issik Kul. Data about the place of location of some Ancient and Medieval towns (Toru-Aygir, Kara-oy, Chigu) are given. Most interesting artefacts found at the bottom of the lake are described

Application of dynamic priorities for controlling the characteristics of a queuing system

This paper considers the development and modification of an imitation model of a queuing system. The initial model uses the laws of control (discipline of expectation and service) with mixed priorities. The work investigates the model with three types of entities (absolute priority, relative priority and priority-free ones) in the regime of overload, i.e. a system with losses. Verification and validation of the created imitation model confirmed its adequateness and accuracy of received results. The application of dynamic priorities for changing the laws of model control substantially alters certain system characteristics. The creation of the model in MatLab Simulink environment with the use of SimEvents and Stateflow library modules allowed creating a fairly complex queuing system and obtain new interesting results