Arctic Field Projects



Project Title: Collaborative research: Coupled glacial and lacustrine evidence for decadal- to millennial-scale variability in the climatologic Aleutian low, southern Alaska (Award# 0823583)

PI: Axford, Yarrow L (axford@northwestern.edu)
Phone: (847) 467.2268 
Institute/Department: Northwestern University, Earth and Planetary Sciences 
IPY Project? NO
Funding Agency: US\Federal\NSF\GEO\EAR
Program Manager: Dr. Paul Filmer (pfilmer@nsf.gov)
Discipline(s): | Geological Sciences\Climate Change | Geological Sciences\Paleolimnology |

Project Web Site(s):
Institute: http://jan.ucc.nau.edu/~dsk5/S_AK/
NSF_Award_Info: http://www.nsf.gov/awardsearch/showAward.do?AwardN...
Initiative: https://www.arcus.org/

Science Summary:
This project’s overall goal is to reconstruct the low-frequency behavior of the climatological Aleutian Low on decadal to millennial time scales, and to assess how its variability has related to past shifts in the mean state of climate during the Holocene. To confidently reconstruct past climate change, the inter-related processes that control the proxy climate indicators must be well understood. This project will continue on-going monitoring and lake-core-based investigations at nine lakes in southern Alaska with the dual aims of (1) understanding the primary controls on the sedimentary changes, and (2) applying this understanding to generate the highest quality time series of paleoclimate proxies that relate quantitatively to summer temperature and winter precipitation. The investigators recently discovered two lakes that contain annually laminated (varved) sediment. These are among the few varved lakes currently known in Alaska, and they present an opportunity to develop annually resolved time series of past climate variability. In addition to the new laminated lakes, this project will generate complementary records from lakes more suitable for ecologically based proxies, including chironomid and pollen/macrofossil assemblages, and lake-productivity indicators that respond to growing-season temperature. In addition, researchers will analyze oxygen-isotope ratios in diatoms to reconstruct moisture-source variations, and use geomorphic evidence to assess Holocene glacier fluctuations within the lake catchments. The basic study design is to pair a glacial-fed lake (lamination record) with an organic-rich lake (chironomid record) in each of three study areas separated by 2100 km: Adak (middle Aleutian Islands) in the far west, Ahklun Mountains in the southwest, and Chugach Range in the Gulf of Alaska. These three areas straddle the prominent dipole in the influence of the Aleutian Low. The multi-proxy time series will extend through the Holocene, with higher-resolution analyses over two periods that encompass past warm intervals, namely the Holocene thermal maximum, which took place early during the current epoch, and the last 2000 years, which includes the so-called medieval warm period, a key benchmark for 20th century warmth. The broader impacts of this study involve its synergistic activities with resource managers at US Fish and Wildlife Service who are developing a premier environmental monitoring program in the Togiak National Wildlife Refuge, geoscientists at the US Geological Survey's Alaska Volcano Observatory who are striving to assess the frequency of eruptions of Aleutian Arc volcanoes and to identify widespread tephra-stratigraphic markers, and the broader community of multi- and inter-disciplinary scientists aiming to understand the causes and effects of climatic change around the North Pacific, the Arctic, and globally. This project contributes to understanding climatic variability, a key challenge facing society.

Logistics Summary:
This grant supports a collaborative project between 0823522 (Kaufman, NAU) and 0823583 (Axford, CU). The research team will test the hypothesis that decadal- to millennial-scale climate change across southern Alaska is manifested as a shift in the overall strength and position of the Aleutian Low. Logistic details are carried under the record for 0823522 in this database.

For support details, see the record for grant 0823522 in this database.
SeasonField SiteDate InDate Out#People
2009Alaska - Allison Lake0
2009Alaska - Cascade Lake0
2009Alaska - Shadow Bay0
2009Alaska - Upper Togiak Lake0
2010Alaska - Adak Island0
2010Alaska - Allison Lake0
2011Alaska - Cascade Lake0
2011Alaska - Greyling Lake0
2011Alaska - Hallet Lake0
2011Alaska - Shadow Bay0
2011Alaska - Upper Togiak Lake0
2012Alaska - Allison Lake0
2012Alaska - Cascade Lake0
2012Alaska - Shadow Bay0
2012Alaska - Upper Togiak Lake0
 


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Parameters used to generate this report:, Grant# = "0823583", IPY = "ALL" 
     Number of projects returned based on your query parameters = 1
 
ARLSS_ProjectsDetail