Cool Geo-Pic: "Net-net" Global Sea Ice is Shrinking

Today's cool geo-pic is again from NASA's Earth Observatory. It provides a "net-net" comparison of polar ice loss, and comes to the conclusion that global sea ice is still shrinking.

"Cut & Paste" Highlights:
"....Examining 35 years of sea ice data, Parkinson has shown that increases around Antarctica do not make up for the accelerated Arctic sea ice loss of the last decades. Earth has been shedding sea ice at an average annual rate of 35,000 square kilometers (13,500 square miles) since 1979—the equivalent of losing an area of sea ice larger than the state of Maryland every year...."

.... “Even though Antarctic sea ice reached a new record maximum in September 2014, global sea ice is still decreasing,” said Parkinson, who is based at NASA’s Goddard Space Flight Center. “That’s because the decreases in Arctic sea ice far exceed the increases in Antarctic sea ice.....”

".....The line graphs above plot the monthly deviations and overall trends in polar sea ice from 1979 to 2013 as measured by satellites. The top line shows the Arctic, the middle shows Antarctica, and the third line shows the global, combined total. The sparklines at the bottom of the graphs show each year separately, enabling month-to-month comparisons across each year. The thickness of each sparkline indicates the overall growth or loss in sea ice globally. The thinning of the sparklines is indicative of the downward trend in total polar sea ice......"

Full Article:  Despite Antarctic Gains, Global Sea Ice Is Shrinking February 11, 2015
 Click Here

References:

• Parkinson, C.L. (2014) Global Sea Ice Coverage from Satellite Data: Annual Cycle and 35-Yr Trends. Journal of Climate, 27, 9377–9382.
• NASA Earth Observatory (2014, September 24) A Tale of Two Poles.
• NASA Earth Observatory (2014) Antarctic Sea Ice.
• NASA Earth Observatory (2014) Arctic Sea Ice.
• NASA Earth Observatory (2009, April 20) Sea Ice.

Earth Observatory images by Joshua Stevens. Caption by Maria-Jose Viñas and Mike Carlowicz.

Instrument(s): DMSP - SSM/I

Mapping Ice - Arctic and Antarctic Ice Depths

Recently the European Space Agency posted imagery of sea-ice thickness from ESA’s CryoSat mission to both poles of the earth. Here is a link to a nice time series image of ice loss over three decades: http://www.esa.int/SPECIALS/Cryosat/SEMQK4908BE_1.html 

From their site:
" ...CryoSat measures the height of the sea ice above the water line, known as the freeboard, to calculate the thickness. The measurements used to generate this first map of the Arctic were from January and February 2011, as the ice approaches its annual maximum.."

"... For the first time, data from ESA’s CryoSat mission have been used

to map the height of the ice sheet that blankets Antarctica. The preliminary data used here are from February and March 2011... CryoSat's ability to map the edges of the ice sheet is demonstrated by the detail that can be seen of the flow from east Antarctica onto the Ronne-Filchner ice shelf in the west. ... [t]he outer white circle represents the limits of earlier missions and the inner circle shows that CryoSat is collecting data up 88° latitude..."

Full credit to the Map Room for bringing this to my attention.

Cool Geo-Pic: Winter Temperatures and the Arctic Oscillation

This Cool Geo-Pic comes again from NASA's Earth Observatory.  What I find fascinating is that the changes in climate patterns vary by geography, terrain and element (land/water).

Quick "Cut & Paste" Highlights:
" ... Much of the Northern Hemisphere experienced cold land surface temperatures, but the Arctic was exceptionally warm. This weather pattern is a tale-tell sign of the Arctic Oscillation.



The Arctic Oscillation is a climate pattern that influences winter weather in the Northern Hemisphere. It is defined by the pressure difference between air at mid-latitudes (around 45 degrees North, about the latitude of Montreal, Canada or Bordeaux, France) and air over the Arctic. A low-pressure air mass usually dominates the Arctic, and while higher pressure air sits over the mid-latitudes.

This pressure difference generates winds that confine extremely cold air to the Arctic. Sometimes, the pressure systems weaken, decreasing the pressure difference between the Arctic and midlatitudes and allowing chilly Arctic air to slide south while warmer air creeps north..... When the pressure systems are strong, the Arctic Oscillation is positive.... Cold Arctic air chilled the land surface at midlatitudes, while Arctic land, such as Greenland and Alaska, was much warmer than usual...."


Full Article - Click Here





References / Credits:
Climate Prediction Center. (2010, January 8). Arctic Oscillation. National Weather Service, National Oceanic and Atmospheric Administration. Accessed January 8, 2010.


National Snow and Ice Data Center. The Arctic Oscillation. Accessed January 8, 2010.


Wallace, J.M. (2000, July 17). On the Arctic and Antarctic Oscillations. University of Washington. Accessed January 8, 2010.


National Snow and Ice Data Center. (2010, January 5). Extreme negative phase of the Arctic Oscillation yields a warm Arctic. Accessed January 8, 2010.


NASA Earth Observatory image by Kevin Ward, based on data provided by the NASA Earth Observations (NEO) Project. Caption by Holli Riebeek.


Instrument: Terra - MODIS

Cool Geo-Pic: North Pole Sea Ice Minimum 2009

This Cool Geo-Pic comes again from NASA's Earth Observatory. Part of larger series on measuring the loss of one million square miles of polar ice in the Arctic Ocean, it highlights the pace of the ice loss.

Nothing about this is "new to the planet" except for THE RATE OF CHANGE.

Fluctuations in sea level (30 meters lower as recent as 20,000 years ago) - once measured in centuries and millennia are now occurring over decades.


Quick "Cut & Paste" Highlights:
" ... On September 12, 2009, sea ice in the Arctic Ocean most likely reached its minimum extent for 2009, said the National Snow and Ice Data Center. The reach of Arctic sea ice fluctuates through the year, growing in the winter and shrinking through the summer...."

"....This image illustrates the 2009 minimum on September 12, when ice covered 5.10 million square kilometers (2.97 million square miles) of the Arctic Ocean. The average minimum between 1979 and 2000, outlined in yellow, was 6.71 million square kilometers...."

"....The graph illustrates the difference between 2009, 2008, and 2007 sea ice extent and the average extent. Sea ice covered a smaller area in 2009 compared to 2008 until August, at which point ice loss in 2008 surpassed 2009. Neither year came close to 2007, which was low from the start of the melt season. All years were significantly below average...."

"....To see how sea ice has changed since 2000, see the Earth Observatory’s World of Change entry on Arctic Sea Ice...."


Full Article - Click Here


References / Credits:
National Snow and Ice Data Center. (2009, September 17). Arctic sea ice reaches annual minimum extent. Accessed September 18, 2009.

Scott, M. (2009, April 20). Sea Ice. NASA’s Earth Observatory. Accessed September 18, 2009.

NASA images created by Jesse Allen and Rob Simmon, using AMSR-E sea ice concentration data provided courtesy of the National Snow and Ice Data Center. Caption by Holli Riebeek.

Instrument: Aqua - AMSR-E