Continued Permafrost Warming on the Arctic Slope of Alaska,

2014 Update

Gary Clow USGS/INSTAAR

Alaska Climate Divisions

Bieniek et al. (2014)

Statewide Air-Temperature Anomaly

5-yr running ave Bieniek et al. (2014)

dT = +0.9 K

5-yr running ave Bieniek et al. (2014)

Statewide Air-Temperature Anomaly

Arctic Slope Air-Temperature Anomaly

5-yr running ave Bieniek et al. (2014)

Sea Ice Extent

NSIDC/NOAA

Sep-2011

Air temperature reanalyses produced using the WRF model, 3.3-km resolution.

Warm Chukchi sector

Cool Chukchi sector

Cool NPR-A / Warm Arctic NWR

NE wind

A common pattern

Air-Temperature Patterns, Arctic Alaska

• With the juxtaposition of the Chukchi Sea, Beaufort Sea, and Brooks Range, weather and climate patterns are somewhat complicated on the Arctic Slope.

Chukchi Sea

Beaufort Sea ground temps

soil moisture

wind

snow depth

rainfall

air temp

radiation

telemetry USGS Climate-Station Network, Arctic Alaska

GTN-P

+1.63

+1.44

+0.70

+0.87

+0.27

+0.92

°C/decade

Mean-Annual Air-Temperature Trends Stations with at least 10 years of data

Chukchi Sea

Beaufort Sea

+1.63

+1.44

+0.70

+0.87

+0.27

+0.92

°C/decade

Mean-Annual Air-Temperature Trends Stations with at least 10 years of data

Chukchi Sea

Beaufort Sea

Seasonal Air-Temperature Trends Fish Creek 1992-2013

Atmosphere Active Layer (thaws in summer)

Permafrost

30 cm

+1.63 +1.86

+1.44 +1.62

+0.70 +1.48

+0.87 +0.66

na +1.46

+0.27 +0.36

+0.92 +0.65

°C/decade air active layer

Mean-Annual Active-Layer Temperature Trends Stations with at least 10 years of data

Fish Creek 1998-2013 Seasonal Ground-Temperature Trends

Active Layer (10 cm)

Maximum Active-layer Depth

Year

Dep

th (c

m)

Active-layer Freeze-up Date

Day

of Y

ear

Year

Snow Depth

winter trend +10.8 cm / decade

Snow

Dep

th (c

m)

Snow and Active-Layer

Fish Creek

Fish Creek Fish Creek

Chukchi Sea

USGS Deep-Borehole Array Thermal State of Permafrost

Beaufort Sea GTN-P

Chukchi Sea

USGS Deep-Borehole Array Thermal State of Permafrost

Beaufort Sea GTN-P

Permafrost Temperatures: South Meade Well

1980

1981

Permafrost Temperatures: South Meade Well

1983

Permafrost Temperatures: South Meade Well

1984

Permafrost Temperatures: South Meade Well

1989

Permafrost Temperatures: South Meade Well

2002

Permafrost Temperatures: South Meade Well

2007

Permafrost Temperatures: South Meade Well

Permafrost Temperatures: South Meade Well

2012

2012

20-m temps

Permafrost Temperatures: South Meade Well

+2.4°C warming since 1980 +2.9°C warming since 1989

1989 1980

Permafrost Temperatures Deep Borehole Array

ESN, Beaufort Coast +1.8°C

Dep

th (m

) Temperature (°C)

FCK, Coastal Plain

TLK, Chukchi Coast

Dep

th (m

)

Dep

th (m

)

Temperature (°C)

SME, Coastal Plain

Dep

th (m

)

Temperature (°C)

2012

2012

2012 +1.9°C

+2.4°C

2012

+2.9°C

Chukchi Sea

Permafrost Warming since 1990 (20-m depth)

Beaufort Sea

2.8 K

1.8 K 2.1 K

- 4.1

- 6.6

- 6.5 - 6.4

- 6.2

- 6.3

- 7.0 - 7.4

- 7.2 - 6.2

- 5.4

- 7.7

- 2.7 - 1.4

- 3.9

- 4.3

Current Permafrost Temperatures at 20-m Depth

Chukchi Sea

Beaufort Sea

Permafrost

Active Layer

Continuous Permafrost Discontinuous Permafrost

Permafrost Zones Alaska

Permafrost

Active Layer

Continuous Permafrost Discontinuous Permafrost

Tair = -8°C Tg = -5°C

mean-annual

Permafrost Zones Alaska

Current Permafrost Temperatures at 20-m Depth

Discontinuous Permafrost

Chukchi Sea

Beaufort Sea

Summary: • Air temperatures across the Arctic Slope are continuing to warm during the autumn.

• Active-layer temperatures are increasing during all seasons except summer.

- increased autumn air temperatures - thicker cold-season snowpacks

• Permafrost temperatures have warmed 2-3 K since 1990 and are continuing to do so. (1 K / decade)

• The discontinuous permafrost boundary is primed to jump north of the Brooks Range.