Winter Interactions in the Arctic-Where have we been; where are we
now and where are we going?
Jeff Welker, Gus Jespersen, Josh Leffler, Eric Klein, Claudia Czimczik &
Shawn Pedron
Team WinterJace Fahnestock, Michael Jones, Paddy,
Sullivan, Max Lupascu, Kathy Kelsey, Stine Pedersen, Glen Liston, Mathew Sturm, Don Spalinger, Kelly Elder, Joe Sexton, Pertti Alo-
Ala, Kai Loe, Jessica Richter, Steve Oberbauer, Matt Rogers, Heidi Steltzer, Molly Welker,
Adam Csank, Liz Cooper, Torsten Bentzen et al.
Brooks Range, AK, March 2019
Arctic Finland-Pallas: Dec 2016 Toolik Lake AK, Sept. 1995
Svalbard, Feb. 2013 Coldfoot, AK, April 2019
Late 1980’s and early 1990’s it was clear
winter climates were warming
warmer air-more moisture-more snow
Decadal warming from 1971-2001
Winter
Spring
Summer
Fall
“Mike, I think the Arctic community has discovered
Winter”
Terry Chapin,
LAII ARCSS meeting 2000?Bell Harbor, SEA
Winter Climate & Biophysics
SnowAmounts, sources,
timing, distribution, traits
Thermal Consequence
PhysicalConsequence
EcohydrologicConsequence
Biological Consequences
Trace Gases. Microbial
Processes & Mineral Nutrition
Consequences
Vegetationwater sources,
mineral nutrition & forage quality
Caribou & Reindeer
Sea IceStorm TracksClimate
Oscillations
Key Questions about Winter Ecology and Ecosystem Processes
What are magnitudes and patterns of trace gas fluxes in winter, how do they vary across the Arctic, & how are they effected by changes in snow depth?
(CO2 & CH4)
Do changes in winter snow depth carry –over to effect summer
ecosystem processes?(N, H2O, growth, forage quality)
In the beginning in a galaxy far far awayITEX-Coupled Winter and Summer
Changes in Climate (1994)
Fahnestock et al. JGR-Atmos 1998Jones et al. AAAR 1999
Early ITEX years, landscape winter CO2 fluxesWinter C losses can
account fro up to 30-40% of the total
annual ecosystem respiration
Tussock tundra
Polar semi-desert
Toolik Lake, Moist Tussock Tundra site
Thule NW Greenland, Polar Semi-desert site
ITEX Experiments: More winter snow
Tussock tundra
Consequences of deeper snow
warmer soils in winter
added melt water
shortened growing season
deeper active layer thaw
Greater CO2 emissions
Betula nana Salix pulchraOpen=+ snowFilled=ambient snow
Welker et al. 2005 Oikos
B S
Leffler et al. 2016 Oecologia
Winter snow drives Arctic plant
ecophysiologyThule, NW Greenland
Leffler & Welker 2013 ERL
Salix arctica
Sturm et al. BioScience 2005ATLAS Workshop-Vancouver Island,
2003
Winter Climate & Biophysics
SnowAmounts, sources,
timing, distribution, traits
Thermal Consequence
PhysicalConsequence
EcohydrologicConsequence
Biological Consequences
Trace Gases. Microbial
Processes & Mineral Nutrition
Consequences
Vegetationwater sources,
mineral nutrition & forage quality
Caribou & Reindeer
Sea IceStorm TracksClimate
Oscillations
Jespersen et al. Oecologica 2018
Jespersen, Leffler, Oberbauer & Welker; Oecologia 2018
Snow-shrub-Biogeochemical-Ecohydrologic Feedback Model
Old C-Permafrost
Younger C-Active layer
Atmospheric CO2 pool (~700 Pg)
+, -, or =
818 Pg-globally
Schure et al.
Amount and timing of permafrost carbon release in
response to climate warmingTellus 2011
Schaeffer et al.
Greenland Ice Sheet
Ice Ramp (Camp Century and Camp Tuto)
Biocomplexity in the High Arctic: Ancient C emissions from periglacial, polar semi-deserts
Czimczik and Welker, AAAR 2010
Polar stripes in NW Greenland-vegetation is primarily Dryas integrifolia
25,000 yr old arbon in polar semi deserts discovered; is it
being emitted into the modern atmosphere?
Pump
Flowmeter CO2 infrared gas analyzer
out in
Water trap
Isotope CO2 trap
out in
CO2 infrared gas analyzer
CO2
CO2 CO2
CO2
CO2CO2
CO2 CO2
CO2 CO2
CO2
CO2CO2
CO2
CO2 field sampling for
emissions and
production in the soil
Lupascuet al. 2014, 2015, 2016
Thule,NWGreenland
What are the sources and ages of winter respired CO2 from High
Arctic landscapes and how are these influenced by changes in winter
climate (deeper snow)?
Svalbard winter ancient CO2 emissions in response to deep snow
There is evidence that winter respired CO2 from the High Arctic
landscapes is partially composed of ancient C and that winter
emissions are greater where snow is deeper in winter
Lupascu et al. 2018
Blue Light Period-Svalbard
Nature Climate Change (September 2019)
Large loss of CO2 in winter observed across the pan-arctic permafrost region
Sullivan & Welker et al.
2008
Natali et al. 2019
Winter emissions of ancient CNSF EAGER-Czimczik and
Welker
Navigating the New Arctic: Monthly proporations of ancient C emissions as effected by snow depth-Toolik Lake
3 Depths20, 50, 80 cm
Continual Emissions Monthly integrated sampling for 14C
Winter the Final Frontier
Elena, Miquel & Jeff-Ecosystems 2019