1. Changes in Ice Sheets and Snow Cover
Finish Chasing Ice
Greenland
Antarctica
Snow Cover Trends
For Next Class: Read IPCC AR5 Ch. 4 (pp )
Exam III on Wednesday!!!

2. Observed Variations in the Cryosphere

3. Greenland and Antarctica
Why are Greenland and Antarctica important in the context of Global Climate Change?

4. Techniques for Monitoring Ice Sheets?

5. The Greenland Ice Sheet is a huge glacier
Photo by Lora Koenig / NASA

6. Greenland Ice Sheet has a maximum thickness of ~3.3 km (2 mi.)
Photo credit: NASA

7. Large Melt Events Occurred in July 2012
Total melt~ 43%
No melt
Melt seen by two or more sensors
Land
Melt seen by only one sensor
Credit: NASA – GSFC & JPL

8. Large Melt Events Occurred in July 2012
Total melt~ 43%
Total melt~ 99%
No melt
Melt seen by two or more sensors
Land
Melt seen by only one sensor
Credit: NASA – GSFC & JPL

9. Large Melt Events Occurred in July 2012
Total melt~ 43%
Total melt~ 99%
Total melt~ 45%
No melt
Melt seen by two or more sensors
Land
Melt seen by only one sensor
Credit: NASA – GSFC & JPL

10. Large Melt Events Occurred in July 2012
Total melt~ 43%
Total melt~ 99%
Total melt~ 45%
Total melt~ 79%
No melt
Melt seen by two or more sensors
Land
Melt seen by only one sensor
Credit: NASA – GSFC & JPL

11. Air Temperature Data from Summit Station, Greenland
Data courtesy of Tom Mefford, NOAA; graphic created by Mike Schnaubelt and Christopher Shuman, UMBC JCET.

12. Emanating from the periphery of the ice sheet are many smaller ice streams and outlet glaciers that drain the main ice sheet and release icebergs into the ocean
Glaciers, such as the Petermann Glacier along the island’s northern margin, drain the interior, returning this water to the sea as icebergs. Meltwater can accelerate the flow of a glacier by lubricating the underside as it scrapes over the rocky terrain. Despite Greenland’s remoteness, large-scale changes to the island’s ice sheet will have global influence. (NASA image by Jesse Allen and Robert Simmon.)
MODIS image 5 July 2003
Earth Observatory

13. Retreat of Jakobshavn Glacier, SW Greenland
18 June 2003 MISR image from NASA/Earth Observatory
NASA/USGS image courtesy of the Science Visualization Studio, at GSFC

14. Retreat of Jakobshavn Glacier, Greenland
Greenland Ice Sheet
Direction of ice flow
Ocean / fjord

16. IPCC AR5

17. IPCC AR5

18. IPCC AR5

19. Causes of Changes in Ice Sheets?

21. Ice Sheet Summary
Total ice loss from both Greenland and Antarctica between 1992 and 2011 was equivalent to 11.7 mm of sea level.
Future destabilization of ice sheets could cause sea level to rise substantially.

22. Seasonal Snow Cover
Montana near Glacier National Park – photo by D.K. Hall taken in early 1990s
Photo credit: D.K. Hall / NASA

23. Snow Cover
Why do we care about snow cover from a climate and societal perspective?

24. Snow and Climate
Snow covers over 40% of the Northern Hemisphere land surface in a typical winter
High albedo and heat capacity of snow cover influence energy exchange with the atmosphere
Can lower temperatures over large areas
Influences regional weather patterns and monsoon strength
Additionally, snow cover represents a key indicator of climate change

25. Snow Mapping from Space in 1962

26. Satellite Snow-Cover Products
Feb. 2004
28 Dec. 2010
MODIS monthly snow-cover map
Northeastern U.S. MODIS swath fractional snow-cover map
IMS
12 Feb. 2012
National Ice Center (NIC) snow-cover map

27. Snow in North Carolina 14 February 2010 Cape Hatteras
The view from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on February 14, 2010, shows snow extending to the Outer Banks. Harkers Island received 8.8 inches of snow, reported CNN. The snow fell in a winter storm that moved across the southern United States from Texas to the Atlantic Coast on February
Harkers Is.
MODIS Rapid Response Team

28. Snow in the Sierra Nevada, Calif.
1 October 2004
NASA/MODIS

29. Snow Cover in North America Sept. 2002 – Jun. 2003
North Carolina
MODIS SVS / NASA

30. Northern Hemisphere monthly average snow extents for the past three decades*
The graph above shows Northern Hemisphere monthly average snow extents for the past three decades compared the long term average. Most of the highest peaks above the line—times of greater than average snow cover—occurred in the earliest part of the time series; most of the lowest valleys below the line—times of less than average snow extent—have occurred in recent decades.
Reference
Robinson, D.A.: 2012: [Global climate] Northern Hemisphere continental snow cover extent  [in “State of the Climate in 2011”]. Bull. Amer. Meteor. Soc., 93 (7), S21–S22.
*compared the long term average
D. Robinson / Rutgers Univ.

31. IPCC AR5

32. Observed Variations in the Cryosphere