NASA reports in Bering Sea Teeming with Ice that “…the Bering Sea has been choking with sea ice. ”
acquired March 19, 2012 download large image (12 MB, JPEG, 6800×8800)
acquired March 19, 2012 download GeoTIFF file (95 MB, TIFF)
acquired March 19, 2012 download Google Earth file (KMZ)
For most of the winter of 2011–2012, the Bering Sea has been choking with sea ice. Though ice obviously forms there every year, the cover has been unusually extensive this season. In fact, the past several months have included the second highest ice extent in the satellite record for the Bering Sea region, according to the National Snow and Ice Data Center (NSIDC).
The natural-color image above shows the Bering Sea and the coasts of Alaska and northeastern Siberia on March 19, 2012. The image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Black lines mark the coastlines, many of which have ice shelves or frozen bays extending beyond the land borders.
NSIDC data indicate that ice extent in the Bering Sea for most of this winter has been between 20 to 30 percent above the 1979 to 2000 average. February 2012 had the highest ice extent for the area since satellite records started. As of March 16, National Weather Service forecasters noted that all of the ice cover in the Bering Sea was first year ice, much of it new and thin—which is typical in the Bering Sea
The accumulation of ice this season has largely been fueled by persistent northerly winds blowing from the Arctic Ocean across the Bering Strait. The local winter weather has been dominated by low-pressure systems—with their counterclockwise circulation—that have brought extensive moisture up from the south to coastal and interior Alaska, while sending cold winds down across the sea to the west.
Those winds pushed Arctic sea ice toward the narrow, shallow strait, where it piled up and formed an ice arch that blocked the flow. As arches fail because of wind stress, large floes of sea ice can move south into the Bering Sea. Ice also has piled up on the north side of St. Lawrence Island, near the mouth of the strait.
South of the strait and the island, those same winds push cold air and cold surface waters to lower latitudes, allowing the ice to grow farther south than usual. The widespread and persistent ice cover in the Bering Sea has posed significant problems for fisherman and for supply ships in the region. The weather driving the ice also brought extreme snowfall events to many parts of Alaska this winter.
The Bering Sea stands in stark contrast to the rest of the Arctic ice cap, where sea ice extent was below average in both January and February. Ice cover was down drastically on the Atlantic Ocean side of the Arctic, including the Kara, Barents, and Laptev Seas, where air temperatures were 4 to 8 degrees Celsius (7 to 14 degrees Fahrenheit) above the norm.
- NASA Earth Observatory (2012, January 22) Sea Ice off Southwestern Alaska.
- National Snow and Ice Data Center (2012, March 6) February ice extent low in the Barents Sea, high in the Bering Sea.
- National Weather Service, Anchorage Forecast Office Alaska Sea Ice Forecast. Accessed March 19, 2012.
NASA image by Rob Simmon based on data from Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC. Caption by Mike Carlowicz, with image interpretation by Walt Meier and Ted Scambos, National Snow and Ice Data Center.
- Aqua – MODIS
The iceman giveth, the iceman taketh away. On the other side of the Arctic, there’s a dearth of sea ice, note the orange extent lines:
National Snow & Ice Data Center (NSIDC) – Click the pic to view at source
So while we have reached near normal levels this year so far, reaching into and staying in the ±1 standard deviation area (light gray):
We still find stories like this, for example in WaPo:
For various reasons, the climate crisis has disappeared from the political dialogue. This is unlikely to change in 2012, unless polar bears put it back on the agenda.
As yes, we need a cuteness campaign to save the Arctic, coming right up from an NGO near you, pay up suckas. What I found even more humorous was that Google News considers The Arctic Institute to be a credible news source:
You may recall from Sea Ice News Volume 3 number 1 and in subsequent comments its was revealed that The Arctic Institute is run out of the family apartment of founder Malte Humpert in Washington, DC and has no actual physical presence. Malte Humpert apparently didn’t like the attention.
…and then there’s this story:
In related news, the sea ice record may be headed for yet another adjustment:
NRL Scientists Optimize Arctic Sea Ice Data Products
Scientists from the U.S. Naval Research Laboratory Marine Geosciences Division are assisting NASA, the US Army Cold Regions Research and Engineering Laboratory (CRREL) and the European Space Agency (ESA) in developing more accurate monitoring and sustainable forecasting of Arctic sea ice.
The NRL team, using a specially equipped de Havilland DHC-6 Twin Otter aircraft (similar to aircraft shown), collect data to aid in the validation and calibration of data captured by the ESA Cryosat-2 satellite.
Recent dramatic changes in the characteristics of the Arctic sea ice cover have sparked interest and concern from a wide range of disciplines. The demand for an improved ability to monitor and forecast changes in sea ice cover is driven by diverse and varying priorities to include socioeconomics, maritime safety and security, and resource management, as well as basic research science.
Satellites provide an important and cost effective platform for instruments designed to monitor basin-wide changes in the volume of ice cover and snow pack depths. The primary focus of NRL and NASA is to collect data to aid in the validation and calibration of these data sets to further optimize instrument suites and the development of predictive sea ice models.
“Our project takes direct aim at this issue by targeting the largest identified contributors to errors in sea ice thickness measurements from airborne and satellite-based instruments,” said Joan Gardner, NRL geologist. “Central to our work is the rare opportunity for a multi-scale approach to mapping the snow depth and sea ice thickness distribution using the most comprehensive set of in situ data collected to date.”
In March 2011, a nine kilometer-long survey line was established on the sea ice cover by CRREL and NRL near the U.S. Navy Arctic Submarine Laboratory ICEX2011 ice camp. It was strategically located to cover a wide range of ice types, including refrozen leads, deformed and un-deformed first year ice, and multiyear ice. A highly concentrated set of in situ measurements of snow depth and ice thickness were taken along the survey line.
The first of its kind ICEX survey has proved to be of great value to both NASA and NRL in terms of better understanding the capabilities of airborne and satellite based instruments to measure varying ice types. This will aid in achieving a resolution that is adequate to minimize the degree of uncertainty in models that forecast future conditions and for monitoring decadal variability.
Once the survey line was in place, NASA IceBridge — a six-year NASA mission, and largest airborne survey of Earth’s polar ice ever flown – flew a dedicated mission along the survey line, collecting data with an instrument suite that included the Airborne Topographic Mapper (ATM), a high precision, airborne scanning laser altimeter; the Digital Mapping System (DMS), a nadir viewing digital camera; and the University of Kansas ultra-wideband Frequency Modulated Continuous Wave (FMCW) snow radar. The IceBridge measurements were further leveraged by complementary airborne measurements taken by NRL and submarine ice draft measurements.
“We plan to use this set of data to characterize the error on the IceBridge snow depth and sea ice thickness data products as a function of ice type,” adds Gardner. “These results will also be applied to improve understanding of new sensors.” Sensors include the IceBridge snow radar, NRL radar altimeter and the European Space Agency CryoSat-2 satellite carrying a state-of-the-art Synthetic Aperture Radar (SAR) Interferometer Radar Altimeter, or SIRAL.
Improved understanding of these measurements and their accuracies will allow scientists to develop new algorithms to incorporate this information into regional sea ice models used by the research community. The error estimates will also help tie the Ice, Cloud, and land Elevation Satellite (ICESat) and future ICESat-2 records together.
Remote techniques to monitor sea ice extent in all seasons are well developed – these observations reveal a dramatic decline in summer sea ice extent since 1979, when satellite records became available. Further, they indicate that the decline has been facilitated by a dramatic decrease in the extent of perennial or multiyear ice.
Combined estimates of ice thickness derived from submarine records between 1958 and 2000, and ICESat laser altimetry from 2003 to 2008, provided the longest-term record of sea ice thickness observations. These data suggest a decrease in the mean overall thickness of the sea ice over a region covering about 38 percent of the Arctic Ocean.
The ICESat satellite has been critical to meeting the goals of NASA’s Cryospheric Science Program by providing ice elevation information at continental scales with high spatial resolution. As of October 11, 2009, ICESat stopped collecting science data – increasing the urgency of continued observations during IceBridge missions. ICESat-2 is planned to launch no sooner than 2016.
This work directly addresses priorities to improve the utility of IceBridge data to estimate ice thickness and snow accumulation on Arctic sea ice. Because of its fundamental nature, the results from this research will also contribute to the priorities of improved understanding of the mechanisms controlling sea ice cover. These include quantification of the connections between sea ice, ocean and the atmosphere, and validated and improved predictive models of changes in sea ice cover, especially in the coming century, as well as, implications of these changes to the ocean, atmosphere, surrounding land areas and global system. The proposed work also addresses Arctic-related objectives of the US Navy, the Study of Environmental Arctic Change (SEARCH), and the U.S. Global Climate Change Research Program.
The Marine Geosciences Division conducts a broadly based, multidisciplinary program of scientific research and advanced technology development directed towards maritime and other national applications of geosciences, geospatial information and related technologies. Research includes investigations of basic processes within ocean basins and littoral regions. Models, sensors, techniques and systems are developed to exploit this knowledge for applications to enhance U.S. Navy and Marine Corps systems, plans and operations.
SOURCE: U.S. Naval Research Laboratory Press Release
And finally, we have this essay from Dr. Roy Spencer:
March 22nd, 2012
While the IPCC claims that recent Arctic sea ice declines are the result of human-caused warming, there is also convincing observational evidence that natural cycles in atmospheric circulation patterns might also be involved.
And unless we know how much of the decline is natural, I maintain we cannot know how much is human-caused.
In 2002, a paper was published in the Journal of Climate entitled Response of Sea Ice to the Arctic Oscillation, where the authors (one of whom, Mike Wallace, was a co-discoverer of the AO) shows that changing wind patterns associated with the AO contributed to Arctic sea ice declines from one decade to the next: from 1979-1988 to 1989-1998.
The Arctic Oscillation involves sea level pressure patterns over the Arctic Ocean, North Atlantic, and North Pacific. Since sea ice moves around with the wind (see this movie example), sea level pressure patterns can either expose or cover various sections of the Arctic Ocean.
When there are many winters in a row with high (or low) pressure, it can affect sea ice cover on decadal time scales. Over time, ice can become more extensive and thicker, or less extensive and thinner.
There is a time lag involved in all of this, as discussed in the above paper. So, to examine the potential cumulative effect of the AO, I made the following plot of cumulative values of the winter (December-January-February) AO (actually, their departures from the long-term average) since 1900. I’ve attached a spreadsheet with the data for those interested, updated through this past winter.
Consistent with the analysis in the above-cited paper, the sea ice decline since satellite monitoring began in 1979 was during a period of persistent positive values of the AO index (note the reversed vertical scale). Since the satellite period started toward the end of a prolonged period of negative AO values, this raises the question of whether we just happened to start monitoring Arctic sea ice when it was near peak coverage.
Note that back in the 1920’s, when there were reports of declining sea ice, record warmth, and disappearing glaciers, there was similar AO behavior to the last couple of decades. Obviously, that was before humans could have influenced the climate system in any substantial way.
I won’t go into what might be causing the cyclic pattern in the AO over several decades. My only point is that there is published evidence to support the view that some (or even most?) of the ~20 year sea ice decline up until the 2007 minimum was part of a natural cycle, related to multi-decadal changes in average wind patterns.