Changes in Ice Sheets and Snow Cover Snow/Ice Report Greenland Antarctica Snow Cover Trends For Next Class: Read IPCC AR5 Ch. 4 (pp. 323-343)

Observed Variations in the Cryosphere

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

Techniques for Monitoring Ice Sheets?

Greenland Ice Sheet http://en.wikipedia.org/wiki/File:Helicopter_is_taking_off_Greenland_ice_sheet_.jpg Phot credit: Broken Inaglory

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

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

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

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

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

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

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

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

Retreat of Jakobshavn Glacier, SW Greenland 18 June 2003 MISR image from NASA/Earth Observatory http://earthobservatory.nasa.gov/IOTD/view.php?id=5086 NASA/USGS image courtesy of the Science Visualization Studio, at GSFC

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

https://www.youtube.com/watch?v=hC3VTgIPoGU

IPCC AR5

IPCC AR5

IPCC AR5

Causes of Changes in Ice Sheets?

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.

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

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

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

Snow Mapping from Space in 1962

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

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 12-13. Harkers Is. MODIS Rapid Response Team

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

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

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.

Snow-covered area derived from station data (before 1972) and NOAA satellite data (after 1972); the smooth curve shows decadal variations (from Brown, 2000).

IPCC AR5

1988-2004 period was characterized by warmer NH spring conditions and earlier snowmelt

NH Snow Cover extent has been well above normal the past few winters until 2015-16! Especially over the mid-latitudes (35-55 N). Possibly related to the Warm Arctic Cold Continents pattern (Cohen 2010).

Observed Variations in the Cryosphere