The current greenland warming, while not yet quite matching the temperatures of 70 years ago walt meier nsidc examination of several proxy records e. The reason for this is that the mean thickness of arctic sea ice is about 3 m, where as the mean thickness of antarctic sea is 1. In march 2017, when arctic sea ice is typically at its maximum winter extent, circling u. A research plane surveying ice thickness in the arctic in august. North american ice center digital data grids from u. On january 17, 19, alone and near starvation, douglas mawson, leader of the australasian antarctic expedition, was hauling a sledge to get back to base camp. Satellite remote sensing of seaice thickness and kinematics.
History books can explain the recent record low of arctic. They also predicted an icefree arctic within one generation. Arctic ice cover, ice thickness and tipping points. As the washington post reported friday emphasis added. A dance with dragons a song of ice and fire, book 5. Historic variations in arctic sea ice is a series that attempts to determine the arctic warming events through the holocene which commenced some 1 years ago. Map showing the rates of mass changes from icesat 20032008 over antarctica. The svalbardbarents sea icesheet historical, current. The challenge we faced was to take information from many sources and many different international teams, and turn it into a unified history of the antarctic ice. Sea ice thickness spatial extent, and open water within sea ice packs can vary rapidly in response to weather and climate. There has been considerable uncertainty over the causes of ice loss in the arctic.
The history of the cold war has focused overwhelmingly on statecraft and military power, an approach that has naturally placed moscow and. The greatest survival story in the history of exploration. In addition to sea ice thickness, the data set provides sea ice freeboard and snow depth on sea ice from in situ measurements taken primarily using auger, coring devices, and electromagnetic em sounding. In 1940, arctic sea ice was also about two meters thick. In this sweeping, timely book, nicholas crane tells the story of britain.
The findings will provide a starting point to further work to discover how ice thickness, as well as extent, is changing. The foreword of the ice is melting was written by jens stoltenberg, norways former prime minister and secretary general of nato. The ice cover of the arctic ocean is considered to be a sensitive indicator of global climate change. The ice forms a huge dome, parted only by uneven peaks of the highest mountains. On the decrease of arctic sea ice volume hilmer 2000. Arctics winter sea ice drops to its lowest recorded level.
Kwok jet propulsion laboratory, california institute of technology, 4800 oak grove drive, pasadena, california 911098099, usa email. The arctic sea ice covers less area in the summer than in the winter. This paper part 2 examines the period of warming 19201940 with a decade long overlap. Ice mission shows precise changes in arctic seaice thickness.
As arctic sea ice shows record decline, scientists prepare. The evidence comes from various sources, such as beach ridges in northern greenland, never unfrozen today, which show evidence of wave action in the past. The story of a basecamp doctor who spends fourteen months at an isolated british research. The purpose of this paper is to recount how the concepts and ideas about the history of the svalbardbarents sea ice sheet reflect the development of glacial theory since the mid19th century, and how paradigm shifts have been brought about as our icesheet reconstructions have become ever more sophisticated and dynamic over time. Thickness evolution of the scandinavian ice sheet during. Some use was made, for the clarification of ambiguities and an extension of the contours, of the maps presented by robin 1975 and crary and others 1962, the latter being based on. Summer ice cover in the arctic is about 50% of winter cover. But this new york times article from 1958 shows that sea ice thickness in 1958 was two meters, same as december, 2018. Still, areas of the continent, like the antarctic peninsula photographed above, have increased their mass loss in the last decades. This book compiles science, natural history, poetry, history, what it feels like to be in antarctica and why people decide to go there to capture the whole story of the white continent. Arctic sea ice the same thickness as 1940 real climate. The arctic sea ice and its related biota are unique, and the yearround persistence of the ice has allowed the development of ice endemic species, meaning species not found anywhere else there are differing scientific opinions about how.
A guest article by florence fetterer, principal investigator at the national snow and ice data centre nsidc in the us sea ice cover in the arctic has undergone a widely reported decline in recent decades. The simulation also reveals some positive trends in the baffin baylabrador sea and north of the canadian archipelago. The perennial ice cover seems to be between 2 and 5 meters at the end of the winter, whereas the seasonal ice cover seems to be less than 2 meters in a. The thickness of the ice can be illustrated by the map below with average data from april 2015. The panarctic ice ocean and modeling system, or piomas, is a leading tool for gauging the thickness of sea ice coverage in the arctic ocean. History books can explain the recent record low of arctic sea ice. One measure is seaice extent which, as the name implies, is a measure of coverage of the ocean where ice covers 15% or more of the surface. Thickness of the antarctic ice cap the physics factbook. Cryosats orbit goes within a couple of degrees of the poles, allowing it to collect much more detailed data than previous earth observing satellites. Nevertheless, the appx ice thickness product is useful in that it provides ice thickness estimates remote sens. Sea ice surrounding antarctica reached a new record high extent this year, covering more of the southern oceans than it has since scientists began a longterm satellite record to map the extent in the late 1970s.
Quite dry in places and did read like a broad scope history book, lots of names, dates and battles with not too much standing out. The study measured ice thickness from october to march, 2007, over more than half of the arctic. Numerical simulations suggest that arctic ice thickness varies primarily on decadal timescales 3,5,6 owing to changes in wind and ocean stresses on. Previously, measurements of antarctic ice thickness were hindered by. This handsome book provides an eclectic collection of essays written in a conversational tone by more than a dozen norwegian authorities representing many different specialties on the high arctic. The improved model setup has led to a slight decrease in the calculated seaice thickness, especially during winter. The greatest ever measured thickness of the antarctic ice is more than 4,770 meters thick. Scientists have produced the first map which shows the changes in the thickness of arctic sea ice through the entire winter season. The arctic ice cap is melting faster than scientists had expected and will shrink 40 percent by 2050 in most. Naval oceanographic office 19531971 dehn charts, noaa alaska ice desk charts for alaska 19531979. The ice thickness was fairly constant for the five winters before this, but it plummeted in the winter after the 2007 minimum, lead author katharine giles told bbc news.
The average standard deviation in thickness at the grid points was 50 m, with the higher values being concentrated around the eastern ice sheet margin where the topography is the most extreme. The 20 best books about the arctic and antarctic to read. The grand and terrible polar voyage of the uss jeannette. I think this is the first time that we can definitively say that the bulk overall volume of ice has decreased. In a new study that provides clues about how antarcticas nationsized ross ice shelf might respond to a warming climate, u. To view historical readings please select the monthyear below. In the past couple of days, the media have reported grim melting of ice in the arctic while disgracefully ignoring the history of the region prior to 1979 and explorations of the area as far back as 1903. The latest hockey stick shows that current warming is unprecedented. When ice builds up over a mountain region, it fills the valleys. Thickness evolution of the scandinavian ice sheet during the late weichselian in nordfjord, western norway. About 10 years ago, scientists drilled a 2milelong 3. Much of the ice in the region appears to be thinner than normal. Onice arctic sea ice thickness measurements from 1894 to. Perhaps its their britishness, but as i read this i couldnt help thinking of james burkes science history series connections.
A sobering but urgent and engaging book, a farewell to ice shows us ice s role on our planet, its history, and the true dimensions of the current global crisis, offering readers concrete advice about what they can do, and what must be done. The arctic ice pack undergoes a regular seasonal cycle in which ice melts in spring and summer, reaches a minimum around midseptember, then increases during fall and winter. The world of ice and fire and over 8 million other books are available for amazon kindle. In both 2017 and 2014 the average sea ice thickness in october was 120 cm, with an ice extent around 6 million square kilometres. The most defining feature of the surface of the arctic ocean and adjacent seas is its ice cover, which waxes and wanes with the seasons, and changes in extent and thickness on interannual and longer time scales. Arctic sea ice thickness remained constant during the. The model gives a realistic estimate of the total amount of seaice within the arctic. Thanks to john of cloverdale, wa, australia for this info.
The antarctic ice sheet is one of the two polar ice caps of the earth. One danish team concluded in 2012 that 8,500 years ago the ice extent was less than half of the. The total seaice volume is a product of the seaice concentration and its thichness. Arctic sea ice extent had been shrinking at a relatively modest rate of 34% per decade annually averaged but after 1996 this speeded up to 10% per decade and in summer 2007 there was. Sea ice volume at the end of summer 2017 was comparable with that of 2014 7,400 and 7,600 cubic kilometresrespectively the second highest volume of the cryosat2 record after 20 9,000 cubic kilometres. It covers about 98% of the antarctic continent and is the largest single mass of ice on earth.
The european space agency esa has released the first maps of seaice thickness in the arctic, based on data from the cryosat mission. A new nasa study says that antarctica is overall accumulating ice. The changing face of the arctic the new york times. Antarctic ice thicker than previously thought, study finds. Find the top 100 most popular items in amazon books best sellers. These changes, while driven by climate, themselves affect atmospheric and hydrographic conditions in high latitudes on various time scales e. A new ice thickness and bed data set for the greenland ice.
Discussions about the amount of sea ice in the arctic often confuse two very different measures of how much ice there is. Cache of historical arctic sea ice maps discovered watts. The arctic ice pack is the sea ice cover of the arctic ocean and its vicinity. Until now, that system has gone back only as far as. If youre looking for some great books to support and inspire your history studies, weve devised a list of seven of the best history books out. Observations of seaice thickness and kinematics are essential for understanding changes in. Ice extent, thickness, drift, and duration arctic seaice cover attains its maximum seasonal extent in march and shrinks through spring and summer to a minimum. The decrease has been greatest during summer, with sea ice extent reducing by around 12% per decade since the satellite record began in 1979.
Calculation of alongtrack standard deviations in thickness of the unaveraged data showed a strong correlation with the ice thickness, with the thinner ice. The 30yr linear trend shows a decline of 11% per decade. That is partly because the extent of that variability is so difficult to imagine. Colossal antarctic iceshelf collapse followed last ice age. The decrease is apparent throughout the annual cycle with largest amplitudes from september to december. Today, the seaice concentration ice cover is in general well estimated using satellite products, while the seaice thickness is poor known. Reports of record arctic ice melt disgracefully ignore history. Unified sea ice thickness climate data record sea ice cdr. New arctic ice thickness map maptd a blog about maps. This paper provides an overview of the arctic seaice history spanning multiple climate regimes, from the early cenozoic to present. High interannual variability of sea ice thickness in the. The model has been running continuously since september 1997.
It covers an area of almost 14 million square kilometres 5. How the little ice age changed history the new yorker. In 1958, the new york times reported that arctic ice was about two meters thick, and that people carry a popular misconception that the ice is much thicker than it is. Regionally the strongest thinning of ice thickness occurs in the east siberian sea with magnitudes up to. We summarize the latest results on the rapid changes that are occurring to arctic sea ice thickness and extent, the reasons for them, and the methods being used to monitor the changing ice thickness. Arctic ice a historical viewpoint watts up with that. Arctic ice thickness decreasing, suggests satellite data. Therefore, we have by october, 2016 updated the graphics of seaice thickness and volume using the new and improved data on polarportal and ocean.
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