Polar ice is sea ice created from the freezing of sea water, ice sheets and glaciers. These in turn are formed from the build up and compaction of fallen snow. Both the ice sheets and glaciers cover vast areas of the Polar Regions. This polar ice is hugely important to our globe and takes up a large part of it. Global sea-ice coverage averages about 25 million kilometers square; this is the area of the entire North America continent.
5 Feb. 2014. Screen, James, and Simmonds, Ian. "Declining Summer Snowfall In The Arctic: Causes, Impacts And Feedbacks." Climate Dynamics 38.11/12 (2012): 2243-56. Academic Search Premier.
“Effects of patchy ocean fertilization on atmospheric carbon dioxide and biological production.” Global Geobiochemical Cycles. 2003. Vol. 17, #2, 19-1 – 19-17. Warner, R. “Marine snow storms: assessing the environmental risks of ocean fertilization.” Carbons & Climate Law Review.
The rising ocean levels are not the only concern regarding the melting ice sheets. As more ice sheets melt large volumes of freshwater is introduced into the ocean, which can cause disturbances in ocean currents. One such threat is the potential loss of the Gulf Stream. If the Gulf Stream is affected by global warming that the weather in Western Europe would have a dramatic weather shift to severely cold weather. O'Hare (2011) states “If weakening in the Gulf Stream occurs gradually over the 21st century, a possible amelioration of the rising temperatures brought about by global warming could occur over the UK and Western Europe.
Journal of Economic Perspectives, Vol. 26(2), 29-56. Sjegren, K. (2013). Climate change fills polar bears with toxins. Retrieved on 20 April 2014 from http://sciencenordic.com/climate-change-fills-polar-bears-toxins Skeptical Science, (2011).
(Gersonde and Zielinski, 2000) As it can be seen, sea-ice plays a huge role in global climate control(as seen in Figure11, paragraph above and shifting westerlies section) thus there is a crucial need to consider sea-ice reconstruction of climatic evolution during the geological past to further understand them and also to determine what was the past climate, and shape of the polar regions. To reconstruct the polar ... ... middle of paper ... ... condition respectively. Dinocyst and planktonic foraminiferal isotopes data were able to conclude that Arctic and Western Europe had suffered retardation of the North Atlantic Circulation. Norgaard-Pedersen et al., 2003 had done a multiproxy analysis of LGM sea ice conditions in the Fram Strait and Central, Eastern Arcic. A combination of sediment composition and flux rates of iceberg rafting and planktonic foraminiferal abundance and isotopic data was used.
Although this phenomenon is not experienced on all regions around the globe, the average temperatures on the globe have increased by 0.7°C since 1900 (Hansen et al., 2006). According to Houghton et al. (2001), fluctuations in glaciers serve as one of the distinctive natural indicators of climate change because of their sensitivity. One of the underlying notions is that fluctuations in glaciers are mainly due to climate change. The original thought is that climate change mainly results in increase in global temperatures and consequently the melting of ice, snow and shifting of glaciers.
Milankovitch's theory in particular is studied and contrasted to these changes in climate. Specifically the trends of obliquity and eccentricity (Lisiecki et al, 2004). Sea-Level Changes Rohling et al (1999) suggest that 'analysis of oxygen isotope stability within calcite foraminiferal shells significantly links to glacial events' and creates further understanding of the mechanism of climate change. Benthonic δ18O foraminifera records from the Northern Hemisphere ice sheet can vary due to shifting sea temperatures, sea ice formation and evaporation (Lisiecki et al, 2004). Using Lisiecki and Raymo 2004 stack, a calculation of the average sea level change from today was surmised as seen in Fig 1.
Mechanical Performance of the Isolated and Perfused Heart of the Haemoglobinless Antarctic Icefish Chionodraco-hamatus (Lonnberg) – Effects of Loading Conditions and Temperature. Philosophical Transactions of the Royal Society of London. 332 (1264):191-198. doi: 10.1098/rstb.1991.0049 . Tota, B., Cerra, M. C., Mazza, R., Pellegrino, D., and Icardo, J. 1997.
How does that work? As land ice from the Antarctic ice shelves melts due to increasing temperatures, it spreads out into the ocean and then rises due to its low density and freezes. The land ice decreases and contributes to the increase in sea ice. The most recent estimate concludes that Antarctic land ice decreased by an average of 70 giga-tonnes per year, with the estimates beginning in 1992 and going to 2011 (King, 2013). The chart to the right shows monthly changes in Antarctic ice mass, in giga-tonnes, measured by NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites from 2003 to 2011 (NASA, nd.).