1. No category

Biological Ramifications of Climate-Change
Mediated Oceanic Multi-Stressors!
Scott Doney
Woods Hole Oceanographic Institution
Phil Boyd (U. Tasmania), Sinikka Lennartz
(GEOMAR), & David Glover (WHOI)
Southern Ocean Dynamics
& Biogeochemistry
Workshop
Caltech, Feb. 2015
Supported by:
Climate Change
Drivers!
Plankton Response to Multiple Environmental
Drivers!
Boyd & Hutchins, Mar. Ecol. Prog. Series, 2012
Talk Outline!
Earth System Model Projections:
•  multiple stressor trends
•  regional variability
Guide design & interpretation of
field/lab manipulation studies
Surface Warming!
4.0
ΔSST
CESM1(BGC) Δ (2100 – 2000)
2.0
0.0
-1.0
1900
2000
Ensemble of CMIP5 Coupled
Climate-Carbon Models
Bopp et al. Biogeosciences
2013
2100
Moore et al., J. Climate 2013
Boyd et al., Nature Climate
Change 2015
Physical Drivers!
Δ 2100 - 2000
CESM1(BGC)
Moore et al., J. Climate 2013
Boyd et al., Nature Climate
Change 2015
Biogeochemical Drivers!
Δ 2100 - 2000
CESM1(BGC)
Moore et al., J. Climate 2013
Boyd et al., Nature Climate
Change 2015
Present-Day Southern Ocean Iron Budget Terms!
Divergence/
Convergence
terms for:
•  Horizontal
advection
•  Vertical
advection
•  Mixing
•  External
forcing
dust &
sediments
Positive is net
source
Misumi et al. Biogeosciences 2014
Net Primary Productivity!
8%
Δ NPP
ΔNPP
0%
10%
20%
1900
2000
2100
Bopp et al. Biogeosciences 2013
Declining Seasonal Sea-ice along Peninsula!
3.3
months
shorter
2.6 months
longer
(1979/80 – 2010/11)
Stammerjohn et al.
Geophysical Research Letters
2012
Sharon Stammerjohn U Colorado Boulder
Ecological Changes to Retreating Sea-Ice!
Decadal Change in
Surface Chlorophyll
Montes et al.
Science (2009)
-Sea ice melt stabilizes upper ocean and fosters phytoplankton growth
-Long sea ice duration acts as a barrier to light penetration and
prevents growth
Courtesy Zina Deretsky, NSF
Effects on Growth & Community Structure!
Small Phytoplankton
Growth Rate
Diatom
Growth Rate
Marinov et al. Global Biogeochemical Cycles 2013
Ocean Acidification!
0.1
Δsurface
pH
0.0
CESM1(BGC) Δ (2100 – 2000)
-0.2
-0.4
1900
2000
2100
Bopp et al. Biogeosciences 2013
Moore et al., J. Climate 2013
Boyd et al., Nature Climate
Change 2015
Ocean Acidification!
CESM1(BGC)
Moore et al., J. Climate 2013
Boyd et al., Nature Climate
Change 2015
Regional Climate Signals: “Climate Clusters”!
Boyd, Lennartz, Glover & Doney
Nature Climate Change 2015
Global Trends vs. Regional Variation!
ΔpH
ΔFe
global trend
ΔSST
ΔSST
ΔNO3
Nutrients log10([X])
ΔSST
ΔSi(OH)4
ΔSST
Principal Component Analysis (PCA)!
Surface
Stratification
Factor (20%)
T S MLD
Nutrient Factor
(26%)
Fe
PO4
NO3
Temperature-Growth Curves!
Boyd et al.
PLoS One
2013
Interactive Effects of Multiple Environmental Drivers!
Days
Rose et al. Biogeosciences 2009
Boyd, Lennartz, Glover & Doney
Nature Climate Change 2015
Regional Variation in Multiple Stressors!
Bopp et al. Biogeosciences 2013
ΔSST >3.5 K
ΔpH <-0.35
ΔNPP <-100 mgC m-2 y-1
O2 <50
ΔO2 <-50
<-20
<50
mmol m-3
mmol m-3
Talk Outline!
Earth System Model Projections:
•  multiple stressor trends
•  regional variability
Guide design & interpretation of
field/lab manipulation studies