Yukon River Basin

Paleolimnology and Carbon Cycling of the Yukon Flats National Wildlife Refuge, Alaska

In 2007 with the assistance of U.S. Fish and Wildlife Service Yukon Flats National Wildlife Refuge, we sampled water and sediments from 10 lakes in the Yukon Flats for geochemical analyses. We plan to evaluate carbon cycling dynamics and are working on identify lakes for future long sediment coring. Click here for more information about the Yukon Flats National Wildlife Refuge.

Regional Atmospheric Circulation Change in the North Pacific from Jellybean Lake

Jellybean Lake is a small, evaporation-insensitive groundwater through-flow lake. Oxygen isotope ratios from sediments appear to be related to changes in North Pacific atmospheric circulation patterns via changes in fractionation of meteoric precipitation as airmasses cross the St. Elias Mountains.

The North Pacific Water Cycle from Mt. Logan and Jellybean Lake

Ice cores stable isotopes from the summit of Mount Logan and Jellybean Lake sediments suggest sudden and persistent shifts in north Pacific circulation patterns at ~A.D. 1840-50 and 800 (1200 BP) from zonal, weak/westward Aleutian Low flow to a more meridional, strong/eastward Aleutian Low. Jellybean Lake data is available on the NOAA WDC for Paleoclimatology Paleolimnology data archive.

Late Holocene Moisture Balance of the Southwest Yukon Territory

Marcella Lake is a small, evaporation-sensitive lake in the semi-arid southwest Yukon. Sediments provide moisture balance information for the last ~4500 years at century time-scales.

Prominent late Holocene changes in effective moisture at ~A.D. 1840-50 and A.D. 800 (1200 BP) occurred simultaneously with changes in Aleutian Low circulation patterns over the Gulf of Alaska indicated by Jellybean Lake. Marcella Lake data is available on the NOAA WDC for Paleoclimatology Paleolimnology data archive.

Holocene Paleohydrology of the Southwest Yukon

Past lake-level variations document changes in effective moisture (precipitation-evaporation). Water levels were reconstructed by multi-proxy analyses of sediment cores from four sites spanning shallow to deep water.

Holocene Paleoclimate of the Central Brooks Range

Tangled Up Lake and Meli Lake, located in the central Brooks Range provide temperature and moisture balance information for the past ~8500 cal yr at century time-scales.

Sediment oxygen isotope analyses from the two sites indicate drier conditions than present prior to ~6000 cal yr B.P. Since then, the region became increasingly wet. Temperatures were mainly cooler than recent times. Tangled Up and Meli Lake data are available on the NOAA WDC for Paleoclimatology Paleolimnology data archive.