| MMS ENVIRONMENTAL STUDIES PROGRAM: ONGOING STUDIES | ||||||
| MMS OCS Region: | Alaska (Physical Oceanography | |||||
| Titl | Mapping and Characterization of Recurring Spring Leads and Landfast Ice in the Beaufort and Chukchi Seas (AK-03-06) | |||||
| Total Cost |
$397,000 |
Period of Performance | FY 2004-2006 | |||
| Conducting Organization | Universaity of Alaska, Fairbanks - Anchorage, AK (Contact: Dr. Hajo Eicken) | |||||
| MMS Contact | ||||||
| MMS Needs Addressed New information on both the temporal and spatial aspects of landfast ice is the foundation for improving the oil spill risk analysis. Monthly winter landfast ice location would be a significant improvement over a seasonal winter location in use today. In addition, this information is useful for validating contingency planning, and for NEPA analysis and documentation for Beaufort Sea Lease Sales and DPP's. The landfast ice project data was recently incorporated into the OSRA for oil spill risk analysis. |
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| Description | ||||||
| Background Spring leads in the Beaufort Sea occur every year to the east of Barrow. The size, frequency, and latitudinal extent of these leads, particularly further east from Barrow, are poorly known. In recent years, we have become aware that the Arctic Ocean, and especially the Beaufort Sea, responds to alternating climate states lasting a few to several years. A primary difference between the two alternating states is a weakening or reversal in the Beaufort gyre. Superimposed on, and interacting with the alternating climate states, is the estimated 40 percent thinning of Arctic ice pack over the last 30 years. The effects of climate state and ice thinning on spring lead characteristics in the Beaufort Sea are unknown. Better information on how spring leads and moving ice pack interact is another issue, because this interaction is the key to how much risk spilled oil encapsulated in pack ice has to localized biota. Bowhead whales migrate past Barrow along these leads and westward, toward the Canadian Beaufort in the spring. The leads are also heavily used by spring migrating waterfowl. Risk from encapsulated oil would be less if the ice pack diverges along the lead lines as opposed to breaking up and crossing the leads. The spatial location of landfast ice on a monthly basis is known in only a very generalized sense as shown in climatic or ice atlases. The new MMS sponsored sea ice atlas is being developed from the Joint Ice Center products, which are at a 25 km grid resolution and are too coarse for the detail needed. The spatial distribution of landfast ice was documented in the Beaufort Sea by Stringer in the mid 1970’s on a seasonal basis. The seaward limit of stable fast ice defines where under-ice pooling of spilled oil might take place and where fast ice conditions apply to design and operation of offshore facilities. It defines the location where no ice movement occurs. It is also the extreme landward boundary of possible whale migration routes during the springtime migration period. |
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| Objectives 1. Document locations of recurring spring leads to the east of Barrow, and their extent across the Alaskan Beaufort Sea. 2. Document temporal and spatial occurrence of shoreward landfast ice line across the Alaskan Beaufort Sea to the Canadian McKenzie Delta. 3. Examine the effect of climate on lead and landfast ice characteristics. 4. Examine the effect of ice thinning on lead and landfast characteristics. 5. Document dominant spring lead/ice pack interaction mode(s). 6. Map average monthly shoreward land fast ice line. |
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| Methods 1. Review and synthesize literature and local information sources. 2. Synthesize and analyze current and historical remote-sensing imagery of recurring spring leads and shoreward landfast ice line. 3. Create geographic information system files summarizing the spatial distribution of spring leads in the Alaskan Beaufort Sea. Provide individual years as well as statistical representation of lead occurrence and distribution. 4. Create geographic information system files showing the monthly distribution of the shoreward landfast ice line across the Alaskan Beaufort Sea to the Canadian McKenzie Delta. 5. Provide individual months per year as well as statistical representation of landfast ice occurrence and distribution. 6. Provide relevant attributes to spatial data for use in a geographic information system. |
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| Current Status The final data deliverable has een provided to MMS. The final report is scheduled to be delivered to MMS by April 2006. |
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| Final Report Due: |
3/30/2006 |
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| Publications: | ||||||
| Affiliated WWW Sites: |
http://mms.gina.alaska.edu/index.html |
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| Revised date: |
March 3, 2006 |
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| ESPIS |
ESPIS - All completed
ESP Studies: |
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