10,000 years of hydrologic variability in Maine

(and North Dakota)

George L. JacobsonMaine SC

12 July 2012

AASC Sandestin, FL

Northern Appalachian/Acadian Ecoregion includes extensive topographic, climatic, and geologic

variability

Plant-hardiness zones reveal the same tight gradient.

Climate Change Institute (formerly Institute for Quaternary and Climate Studies)

The University of MaineOrono, ME

• Climatology/Paleoclimatology• Historic climatology• Terrestrial paleoecology• Paleolimnology• Prehistoric archaeology• Glacial geology and glaciology • Atmospheric chemistry (incl. ice cores)• Geochemistry• Maine State Climatologist (GLJ)

40th Anniversary in 2012

Climate Change InstituteThe University of Maine

Central question:What is the natural variability of the earth’s climate, and what are the underlying mechanisms?

Spring runoff has moved earlier by nearly a month since 1952

Changes in annual flow cycles vary N-S in New England

Krista Ricupero (MS Thesis, University of Maine, 2009); S. Jain advisor.

Atlantic Salmon presence in Maine rivers depends on water conditions (hence climate)

Atlantic salmon present in rivers

wet

dry

Early-Holocene insolation (precession-cycle) produced warm, dry conditions with many fires

in Maine.

wet

dry

Peat chem.Peat chem.

Lake levelsLake levels

Kettle Lake, near Williston, North Dakota

10,000 years of climate, showing moisture variations

blue = moistgreen = intermediatered & orange = dry

Eric C. Grimm et al. (2011) Quaternary Science Reviews 30:2626-2650.

Most extreme drought: 9.25 kaMost extreme drought: 9.25 ka

Analog for coming warm-dry times?

Analog for coming warm-dry times?

Discussion?

Peak Flows on Mousam River

Courtesy of Robert Lent, USGS, Augusta, ME