Doney (2010)

The Growing Human Footprint on Coastal and Open-Ocean Biogeochemistry

Science 328, 1512

Fig. 1 Schematic of human impacts on ocean biogeochemistry either directly via fluxes of material into the ocean (colored arrows) or indirectly via climate change and altered ocean

circulation (black arrows).

S C Doney Science 2010;328:1512-1516

Published by AAAS

ACC = Antarctic Circumpolar Current (55°S)

Westerly winds (50°S) above the ACC push coldfresh surface waters away to the north and draw up warmer, saltier water that is low in O2 and high in nutrients and CO2. Wind and ACC notaligned. Stronger winds drive more upwelling.

The bands of westerly winds separate the warm air in the tropics from the cold air over thepoles. Winds driven by mid-atmosphere temperature gradients. With warming these winds are shifting poleward to be more aligned with the ACC.

Stratospheric ozone influences the temperature gradient.Removing O3 causes cooling.

Toggweiler and Russell (2008) Nature 451, 286

hwww.youtube.comttp:///watch?v=H2mZyCblxS4

Fig. 2 Time series of (top) atmospheric CO2 and surface ocean pCO2 and (bottom) surface ocean pH at the atmospheric Mauna Loa Observatory (MLO) on the island of Hawai‘i and Station ALOHA

in the subtropical North Pacific north of Hawai‘i, 1988–2008.

S C Doney Science 2010;328:1512-1516

Published by AAAS

Ocean Acidification at BATS(Bermuda Atlantic Time Series)

Feely et al (2008)

Coastal Upwelling

Fig. 3 Model estimated deposition fluxes of anthropogenic reactive nitrogen (mol N m−2 year−1) to the ocean surface for oxidized forms (NOy), primarily from fossil fuel combustion sources,

and reduced forms (NHx) primarily from agricultural sources.

S C Doney Science 2010;328:1512-1516

Published by AAAS

Haber ProcessN2 + 3H2 2 NH3At 200 atm and 300°CH2 from CH4

Kim et al (2011) Science 334, 505-509

Changing Ocean Chemistry (and Biology)

N* = N – RN:P x P

Fig. 4 Decadal change in subsurface O2 from 1994 to 2004 along 30°N in the North Pacific with positive values indicating an increase in apparent oxygen utilization (AOU) and a decline in O2 (μmol kg−1); contour plot is overlaid by mixed-layer depths (green line) and potential density

surfaces (pink) (48).

S C Doney Science 2010;328:1512-1516

Published by AAAS

Hypoxia O2 < 60 mmol kg-1 < 5 mmol kg-1

DT = 10 years DAOU DO2

Pb in the North Atlantic at Bermuda (coral and water data)

From Kelly et al (2009) EPSL 283, 93