Arctic sea ice, primary productivity, and climate change

26 Pages·2014·7.06 MB·English

Arctic Ocean
primary productivity
and climate change
Patricia Matrai
Bigelow Laboratory for Ocean Sciences
with help from many colleagues!
Arctic sea ice loss
Snow cover loss
OCB 2014, WHOI
Ice melt and surface
warming result in
stratification that
prevents vertical
mixing
Low (?) nutrient
supply to surface and
thus low harvestable
nutrients
productivity
Low (?) light supply
through surface
coastal waters
(snow + ice, CDOM,
sediment
suspended solids)
Courtesy P Wassmann
OCB 2014, WHOI
Today’s extreme
SSaammseeea aasmmonooauulnn tt
ooff nnvuuattrrriaiieetnniottnss
disappears
SSaammee
Shhuaabrrvv-ieecssett aabbblolleeo ms
pprrooinddcuurccettaiioosnne?
Time
Wassmann 2011, and those before him
OCB 2014, WHOI
Where is Arctic Primary Production now?
Integrated Annual Net Primary Production (NPP)
(1954-2007 field data at www.nodc.noaa.gov; 1998-2007 satellite data)
Algorithm-estimated NPP based on:
Field Chl SeaWiFS Chl
0-100 gC m-2 yr -1
Hill, Matrai et al. 2013
OCB 2014, WHOI
Net Community Production
30
- =
10
10
5
0
0
NCP / f factor = NPP (or NP?)
(0-200) (0-40) gC m-2 yr-1
Codispoti , Matrai et al. 2013
OCB 2014, WHOI
A biological model applied regionally…
using ocean color and sea ice satellite data
Pan-arctic decadal trend
Open
water
Light!
Annual Field data?
net PP
OCB 2014, WHOI Pabi et al. 2008; Arrigo & van Dijken 2011; Van Dijken & Arrigo 2014
NSIDC
Change in timing of annual Change in June ice
Chl max concentration
Is the light field changing?
We have proxies…
Kahruet al. 2011
With respect to satellite median for: 1997-2009 Chl 1979-2007 ice fraction change yr-1
Clouds and light
(satellite data: 1998-2009)
PAR % yr-1 PAR % yr-1 PP % yr-1
+ clouds = + clouds = PP increase estimated below
Light decrease Light change sea (ice?) surface
(8-20%) (+3 to -3%)
ABOVE JUST BELOW - GIN/Barents Sea
sea (ice) surface sea (ice?) surface
~21-26% reduction
Bélanger et al. 2013 BG
OCB 2014, WHOI