scholarly journals Possible Effects of Sea Ice on Concrete Used in Arctic Conditions

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 13
Author(s):  
Vasiola Zhaka ◽  
Ankit Kothari ◽  
Andrzej Cwirzen

The Arctic region is receiving an increasing attention due to the diminishing area of the permanent ice and easing access to various natural resources including especially oil, gas and rare metals. The nearest future will require building a significant number of new harbors and other structures related to sea operations and exploration. Harsh weather conditions including especially extreme freezing temperatures, snowfall and ice formation impose demanding requirements, which must be taken into account while designing, building and maintaining those structures. Concrete is the main construction material used for harbor structures. Unfortunately, the usage of Portland cement, which is the main cementitious binder used for concrete, it involves hardening processes, which are controlled by the hydration reactions. The hydration needs water and temperatures above freezing point, which impose serious limitations in the arctic environment. Furthermore, later exposure to the arctic conditions and especially to ice may impair its long-term durability and thus the sustainability of built structures. The present work focuses on characterization of properties of sea ice forming in harbors located in the Arctic region and on identification of possible implications on concrete material during the construction phase but also in long-term exploitation.

Author(s):  
Shelton G. De Silva

The rapid change in climate conditions, and the present demand for political and commercial interest in the Arctic region will cause considerable implications on the environment, ecosystem, security, and on the social system in the region. Today, governments, scientists and researchers understand that there is a huge gap of knowledge in the Arctic region and this must be addressed prior to development of the region, or there will be devastating environmental consequences in the future. Existing studies concluded by various organizations including Lloyd’s of London, US Geological Survey and other institutes emphasize that in order to ensure sustainable development in the Arctic, it is important to close the existing gap of knowledge by obtaining accurate scientific data, and make available this data to scientists, researchers and policy makers, for them to take sound decisions on both Arctic challenges and future economic opportunities. The scientists understand that existing lack of knowledge is mainly due to insufficient information in the Arctic and the inability to obtain sufficient scientific data to understand the Arctic region in-depth. Main challenges will be, the vast area of the Arctic, inaccessibility to complex and remote areas, long cold dark winters and short summers, rapid changes of weather conditions etc. Presently, existing satellites provide extremely valuable scientific data, however scientists emphasize that this data would be further analyzed (due to inaccuracy) and collaborated with data on actual close observations, physical sea–ice samples, ice core samples, data from surface and bottom of the sea-ice, glacial ice etc. Collecting data from high altitudes using Unmanned Aerial Vehicles are not new to the Arctic region, and have been used for number of years. The AMAP, (Arctic Monitoring and Assessment Program Workshop), Oslo October, 2008, recommended that it is of great importance that scientists use unmanned aerial vehicles in the Arctic to obtain important environment measurements. Further, added to the AMAP work plan for 2011–2013, is to develop safety guidelines and cross-jurisdictional flight pilot projects, to demonstrate the use of unmanned aerial service (UAS) in the Arctic Environmental Monitoring Plan. The Canadian Government also completed the feasibility study to build a “High Arctic Research Station” in the high north to serve the entire world, for scientists to have an opportunity to share data and support the knowledge for researchers to conclude their investigations. The government is further considering purchasing, three large high-altitude Global Hawk drones for Arctic surveillance, and seeking small snowmobiles and remote control aircrafts to monitor the extreme complex landscape of the Arctic. At present, there is no method to obtain accurate surface and atmospheric data in complex and remote areas, and this requirement has become the highest priority and should be addressed urgently. In order to obtain sufficient accurate data from the Arctic surface and atmosphere, EQQUERA Inc. innovated, is designing and developing multipurpose, multifunctional SG EQQ Unmanned Aerial Vehicles that are able to access remote and complex areas in the Arctic, and operate in challengeable weather conditions such as cold long dark nights.


Nature ◽  
2003 ◽  
Vol 425 (6961) ◽  
pp. 947-950 ◽  
Author(s):  
Seymour Laxon ◽  
Neil Peacock ◽  
Doug Smith

2012 ◽  
Vol 194 (23) ◽  
pp. 6688-6688 ◽  
Author(s):  
Ye Yin ◽  
Guidong Yue ◽  
Qiang Gao ◽  
Zhiyong Wang ◽  
Fang Peng ◽  
...  

ABSTRACTPedobacter arcticussp. nov. was originally isolated from tundra soil collected from Ny-Ålesund, in the Arctic region of Norway. It is a Gram-negative bacterium which shows bleb-shaped appendages on the cell surface. Here, we report the draft annotated genome sequence ofPedobacter arcticussp. nov., which belongs to the genusPedobacter.


2011 ◽  
Vol 24 (22) ◽  
pp. 5757-5771 ◽  
Author(s):  
Gunilla Svensson ◽  
Johannes Karlsson

Abstract Energy fluxes important for determining the Arctic surface temperatures during winter in present-day simulations from the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset are investigated. The model results are evaluated over different surfaces using satellite retrievals and ECMWF interim reanalysis (ERA-Interim). The wintertime turbulent heat fluxes vary substantially between models and different surfaces. The monthly median net turbulent heat flux (upward) is in the range 100–200 W m−2 and −15 to 15 W m−2 over open ocean and sea ice, respectively. The simulated net longwave radiative flux at the surface is biased high over both surfaces compared to observations but for different reasons. Over open ocean, most models overestimate the outgoing longwave flux while over sea ice it is rather the downwelling flux that is underestimated. Based on the downwelling longwave flux over sea ice, two categories of models are found. One group of models that shows reasonable downwelling longwave fluxes, compared with observations and ERA-Interim, is also associated with relatively high amounts of precipitable water as well as surface skin temperatures. This group also shows more uniform airmass properties over the Arctic region possibly as a result of more frequent events of warm-air intrusion from lower latitudes. The second group of models underestimates the downwelling longwave radiation and is associated with relatively low surface skin temperatures as well as low amounts of precipitable water. These models also exhibit a larger decrease in the moisture and temperature profiles northward in the Arctic region, which might be indicative of too stagnant conditions in these models.


Author(s):  
Andrei Andreevich Kovalev

This article explores the key stages of the development of U.S. policy with regards to Arctic Region. The goal is set to outline the fundamental interests of the United States in the Arctic, as well as analyze the actions aimed at their achievement. The article examines the main priorities in U.S. Arctic policy, namely the protection and preservation of resources and ecosystem in the Arctic Region, scientific study of climatic changes, peculiarities of economic development of Alaska, and national security interests of the state. The questions of interaction of Arctic states with regards to defense cooperation become increasingly relevant. Consideration of the mid-term and long-term prospects of U.S. Arctic policy allowed the author focusing attention on the news aspects of U.S. government actions. Maritime capabilities of the United States in the Arctic waters are views in the context of modern tendencies. The author attempted to trace the prospects for expansion of U.S. influence in the Arctic Region based on the current agenda of 2019.


2018 ◽  
pp. 13-17
Author(s):  
V. I. Baburov ◽  
N. V. Vasileva ◽  
N. V. Ivantsevich

In view of the development of the Arctic Region the problem of aircraft (AC) navigation support under arctic conditions throughout the flight, including the landing stage, acquires special momentum. Given that land-based navigation systems have a limited range which does not cover the Arctic Region and are significantly inferior to satellite radio navigation systems (SRNS), SRNS user navigation equipment (UNE) becomes extremely important for AC navigation and landing. The functioning of SRNS UNE in the polar regions is determined by the characteristics of the satellite signal propagation path under arctic conditions and considerable radio signal reflection from the underlying surface. Multipath errors are of special significance for low satellite elevations. If low satellites are excluded from processing by UNE while maintaining acceptable positioning accuracy, both the integral accuracy rates and accessibility may be improved. The paper analyses the composition and information characteristics of working satellite constellations in integrated GLONASS and pseudolites positioning in the Arctic region of Russia. Our study performed by simulation modelling has established considerable redundancy of working constellations at the nominal value of admissible satellite elevation. This factor has been studied for forming controllable working constellations in aircraft on board navigation and landing complex.


2020 ◽  
pp. 1-67
Author(s):  
Shuoyi Ding ◽  
Bingyi Wu ◽  
Wen Chen

AbstractThe present study investigated dominant characteristics of autumn Arctic sea ice concentration (SIC) interannual variations and impacts of September-October (SO) mean SIC anomalies in the East Siberian-Chukchi-Beaufort (EsCB) Seas on winter Eurasian climate variability. Results showed that the decreased SO EsCB sea ice is favorable for tropospheric warming and positive geopotential height anomaly over the Arctic region one month later through transporting much more heat fluxes to the atmosphere from the open water. When entering the early winter (ND(0)J(1)), enhanced upward propagation of quasi-stationary planetary waves in the mid-high latitudes generates anomalous Eliassen-Palm flux convergence in the upper troposphere, which decelerates the westerly winds and maintains the positive geopotential height anomaly in the Arctic region. This anticyclonic anomaly extends southward into the central-western Eurasia and leads to evident surface cooling there. Two months later, it further develops toward downstream accompanied by a deepened trough, making the northeastern China experience a colder late winter (JFM(1)). Meanwhile, an anticyclonic anomaly over the eastern North Pacific excites a horizontal eastward wave train and contributes to positive (negative) geopotential height anomaly around the Greenland (Europe), favoring negative surface temperature anomaly over western Europe. In addition, the stratospheric polar vortex is also significantly weakened in the wintertime, which is attributed to decreased meridional temperature gradient and decelerated westerly winds provides a favorable condition for much more quasi-stationary planetary waves propagating into the stratosphere. Some major features of atmospheric responses to EsCB sea ice loss are well reproduced in the CAM4 sensitivity experiments.


2019 ◽  
Vol 19 (9) ◽  
pp. 6419-6435 ◽  
Author(s):  
Rashed Mahmood ◽  
Knut von Salzen ◽  
Ann-Lise Norman ◽  
Martí Galí ◽  
Maurice Levasseur

Abstract. Dimethylsulfide (DMS), outgassed from ocean waters, plays an important role in the climate system, as it oxidizes to methane sulfonic acid (MSA) and sulfur dioxide (SO2), which can lead to the formation of sulfate aerosol. Newly formed sulfate aerosol resulting from DMS oxidation may grow by condensation of gases, in-cloud oxidation, and coagulation to sizes where they may act as cloud condensation nuclei (CCN) and influence cloud properties. Under future global warming conditions, sea ice in the Arctic region is expected to decline significantly, which may lead to increased emissions of DMS from the open ocean and changes in cloud regimes. In this study we evaluate impacts of DMS on Arctic sulfate aerosol budget, changes in cloud droplet number concentration (CDNC), and cloud radiative forcing in the Arctic region under current and future sea ice conditions using an atmospheric global climate model. Given that future DMS concentrations are highly uncertain, several simulations with different surface seawater DMS concentrations and spatial distributions in the Arctic were performed in order to determine the sensitivity of sulfate aerosol budgets, CDNC, and cloud radiative forcing to Arctic surface seawater DMS concentrations. For any given amount and distribution of Arctic surface seawater DMS, similar amounts of sulfate are produced by oxidation of DMS in 2000 and 2050 despite large increases in DMS emission in the latter period due to sea ice retreat in the simulations. This relatively low sensitivity of sulfate burden is related to enhanced sulfate wet removal by precipitation in 2050. However simulated aerosol nucleation rates are higher in 2050, which results in an overall increase in CDNC and substantially more negative cloud radiative forcing. Thus potential future reductions in sea ice extent may cause cloud albedos to increase, resulting in a negative climate feedback on radiative forcing in the Arctic associated with ocean DMS emissions.


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