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Ice Mass Balance Buoy
An ice mass balance buoy (IMB) allows scientists studying sea ice to measure its temperature and the evolution of its interfaces remotely. The autonomous mass balance buoys usually consist of a data controller module and a temperature string. Some ice mass balance buoys also include Echo sounding, acoustic sounders above and below ice measuring the positions of the snow-ice and ice-water interfaces. Types The main types of ice mass balance buoys include * The Cold Regions Research and Engineering Laboratory, CRREL-Dartmouth College, Dartmouth Ice Mass Balance (IMB) Buoy * Snow and Ice Mass Balance Array (SIMBA) from Scottish Association for Marine Science, SAMS * Seasonal Ice Mass Balance buoy (SIMB-1,2,3) The CRREL-Dartmouth Ice Mass Balance Buoy (IMB) includes two ice-facing acoustic rangefinders, a vertical temperature string, and air temperature and pressure sensors. These sensors are connected to a non-floating satellite-connected transmission package. Seasonal Ice Mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Core
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers (for shallow holes) or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old. The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core. The proportions of different oxygen and hydrogen isotopes provide information about ancient temperatures, and the air trapped in tiny bubbles can be analysed to determine the level of atmospheric gases such as carbon dioxide. Since heat flow in a large ice sheet is very slow, the borehole temperature is another indicator of temperature in the past. These data can be combined to find the climate m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciology
Glaciology (; ) is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice. Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, climatology, meteorology, hydrology, biology, and ecology. The impact of glaciers on people includes the fields of human geography and anthropology. The discoveries of water ice on the Moon, Mars, Europa and Pluto add an extraterrestrial component to the field, which is referred to as "astroglaciology". Overview A glacier is an extended mass of ice formed from snow falling and accumulating over a long period of time; glaciers move very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of accumulation, as in continental glaciers. Areas of study within glaciology include glacial history and the reconstruction of past glaciation. A glaciologist is a person who studies glaciers. A glaci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
False Bottom (sea Ice)
False bottom is a form of sea ice that forms at the interface between meltwater and seawater via the process of Double diffusive convection, double-diffusive convection of heat and salt. Characteristics False bottoms have been observed under drifting Arctic sea ice, under land-fast ice in Greenland, and at Ward Hunt Ice Shelf. Being located under ice, false bottoms are not easy to investigate, and the current observations are quite variable. For example, the areal coverage of false bottoms was 50% at the drifting station Charlie in 1959, 15% during Surface Heat Budget of the Arctic Ocean, SHEBA expedition in 1998 and 20% during MOSAiC Expedition, MOSAiC expedition in 2020. Both physical modelling and in situ observations suggest that false bottoms may decrease Arctic sea ice decline, sea ice melt up to 8%. Meanwhile, measurements from manual ice thickness gauges in Fram Strait in the summer of 2020 showed a nearly 50% reduction in bottom ice melt due to false bottoms. The sali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Ridge (ice)
A pressure ridge, when consisting of ice, is a linear pile-up of sea ice fragments formed in pack ice by accumulation in the convergence between floes. Such a pressure ridge develops in an ice cover as a result of a stress regime established within the plane of the ice. Within sea ice expanses, pressure ridges originate from the interaction between floes,A ''floe'' is any individual piece of sea ice larger than . as they collide with each other.http://nsidc.org/cryosphere/seaice/index.html .Weeks, W. F. (2010) ''On sea ice''. University of Alaska Press, Fairbanks, 664 p. Currents and winds are the main driving forces, but the latter are particularly effective when they have a predominant direction. Pressure ridges are made up of angular ice blocks of various sizes that pile up on the floes. The part of the ridge that is above the water surface is known as the ''sail''; that below it as the ''keel''.These terms also apply for any floating ice feature, such as icebergs. Pressure rid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Ice Concentration
Sea ice concentration is a useful variable for climate scientists and nautical navigators. It is defined as the area of sea ice relative to the total at a given point in the ocean. This article will deal primarily with its determination from remote sensing measurements. Significance Sea ice concentration helps determine a number of other important climate variables. Since the albedo of ice is much higher than that of water, ice concentration will regulate insolation in the polar oceans. When combined with ice thickness, it determines several other important fluxes between the air and sea, such as salt and fresh-water fluxes between the polar oceans (see for instance bottom water) as well as heat transfer between the atmosphere. Maps of sea ice concentration can be used to determine ice area and ice extent, both of which are important markers of climate change. Ice concentration charts are also used by navigators to determine potentially passable regions—see icebreaker. Meth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transpolar Drift Stream
The Transpolar Drift Stream is a major ocean current of the Arctic Ocean, transporting sea ice from the Laptev Sea and the East Siberian Sea towards Fram Strait. Drift experiments with ships such as the Fram or the Tara expedition showed that the drift takes between two and four years. In 1937, Pyotr Shirshov at the Soviet drift ice station North Pole-1 described this drift. The stream conveys water in roughly two major routes to the northern Atlantic Ocean at a rate of about per day. Primarily wind-driven, it flows roughly from the northern coast of Russia and Alaska, sometimes curving toward the Beaufort Sea before exiting to the Atlantic Ocean. It has been cited as a major factor in the North Atlantic oscillation and Arctic oscillation The Arctic oscillation (AO) or Northern Annular Mode/Northern Hemisphere Annular Mode (NAM) is a weather phenomenon at the Arctic pole north of 20 degrees latitude. It is an important mode of climate variability for the Northern Hemisphe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOSAiC Expedition
The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC, ) expedition was a one-year-long expedition into the Central Arctic (September 2019 - October 2020). For the first time a modern research icebreaker was able to operate in the direct vicinity of the North Pole year round, including the nearly half year long polar night during winter. In terms of the logistical challenges involved, the total number of participants, the number of participating countries, and the available budget, MOSAiC represents the largest Arctic expedition in history. During its one-year-long journey, the central expedition ship, the research icebreaker ''Polarstern'' from Germany's Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), was supported and resupplied by the icebreakers and research vessels ''Akademik Fedorov'' and ''Kapitan Dranitsyn'' (Russia), ''Sonne'' and '' Maria S. Merian'' (Germany) and ''Akademik Tryoshnikov'' (Russia). In addition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Svalbard
Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norway, Norwegian archipelago in the Arctic Ocean. North of continental Europe, mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range from 74th parallel north, 74° to 81st parallel north, 81° north latitude, and from 10th meridian east, 10° to 35th meridian east, 35° east longitude. The largest island is Spitsbergen, followed by Nordaustlandet and . The largest settlement is Longyearbyen. The islands were first used as a base by the Whaling, whalers who sailed far north in the 17th and 18th centuries, after which they were abandoned. Coal mining started at the beginning of the 20th century, and several permanent communities were established. The Svalbard Treaty of 1920 recognizes Norwegian sovereignty, and the 1925 Svalbard Act made Svalbard a full part of the Kingdom of Norway. They also established Svalbard as a free economic zone and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaufort Gyre
The Beaufort Gyre is one of the two major ocean currents in the Arctic Ocean. It is roughly located north of the Alaskan and Canadian coast. In the past, Arctic sea-ice would circulate in the Beaufort gyre up to several years, leading to the formation of very thick multi-year sea-ice. Due to warming temperatures in the Arctic, the gyre has lost an extensive amount of ice, practically turning what used to be a nursery for sea-ice to mature and grow into the thickest and oldest ice of the Arctic Ocean into a "graveyard" for older ice. Dynamical mechanisms Conditions in the Arctic have favored sea ice loss in recent years during the Northern Hemisphere summers. At the end of the 20th century, analyses of increasing Pacific Surface Water temperatures led to the discovery of a connection between these rising temperatures and the onset of severe loss of Arctic sea ice in the Beaufort Sea. A reason for the existence of this link was proposed: "...delayed winter ice formation allows for m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Heat Budget Of The Arctic Ocean
The Surface Heat Budget of the Arctic Ocean (SHEBA) study was a National Science Foundation-funded research project designed to quantify the heat transfer processes that occur between the ocean and the atmosphere over the course of a year in the Arctic Ocean, where the sun is above the horizon from spring through summer and below the horizon the rest of the time. The study was designed to provide data for use in global climate models, which scientists use to study global climate change. Background Ice reflects sunlight more readily than open water. Snow-covered sea ice reflects about 80% of the incident sunlight. Seasonal changes in the Arctic result in clear skies and radiational cooling from snow-covered sea ice in the constantly dark arctic winter. In spring, with the return of sunlight, melt pools begin to form and increase the rate of heat absorption from the sun. In the summer, during constant daylight, clouds form which reflect light to the sky, but impede heat flow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium Satellite Constellation
The Iridium satellite constellation provides L band voice and data information coverage to satellite phones, pagers and integrated transceivers over the entire surface of Earth. Iridium Communications owns and operates the constellation, additionally selling equipment and access to its services. It was conceived by Bary Bertiger, Raymond J. Leopold and Ken Peterson in late 1987 (in 1988 protected by patents Motorola filed in their names) and then developed by Motorola on a fixed-price contract from July 29, 1993, to November 1, 1998, when the system became operational and commercially available. The constellation consists of 66 active satellites in orbit, required for global coverage, and additional spare satellites to serve in case of failure. Satellites are placed in low Earth orbit at a height of approximately and inclination of 86.4°. The nearly polar orbit and communication between satellites via Ka band inter-satellite links provide global service availability (inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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