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"Recognising ocean acidification in deep time: An evaluation of the evidence for acidification across the Triassic-Jurassic boundary Sarah E. GreeneCorresponding author contact information, 1, E-mail the corresponding author, Rowan C. Martindale1, E-mail the corresponding author, Kathleen A. Ritterbush E-mail the corresponding author, David J. Bottjer E-mail the corresponding author, Frank A. Corsetti E-mail the corresponding author, William M. Berelson E-mail the corresponding author Department of Earth Sciences, University of Southern California, Los Angeles, California, USA 90089 Received 22 July 2011. Accepted 17 March 2012. Available online 5 April 2012. While demonstrating ocean acidification in the modern is relatively straightforward (measure increase in atmospheric CO2 and corresponding ocean chemistry change), identifying palaeo-ocean acidification is problematic. The crux of this problem is that the rock record is a constructive archive while ocean acidification is essentially a destructive (and/or inhibitory) phenomenon. This is exacerbated in deep time without the benefit of a deep ocean record. Here, we discuss the feasibility of, and potential criteria for, identifying an acidification event in deep time. Furthermore, we investigate the evidence for ocean acidification during the Triassic-Jurassic (T-J) boundary interval, an excellent test case because 1) it occurs in deep time, beyond the reach of deep sea drilling coverage; 2) a potential trigger for acidification is known; and 3) it is associated with one of the 'Big Five' mass extinctions which disproportionately affected modern-style invertebrates. Three main criteria suggest that acidification may have occurred across the T-J transition. 1) The eruption of the Central Atlantic Magmatic Province (CAMP) and the associated massive and rapid release of CO2 coincident with the end-Triassic mass extinction provide a suitable trigger for an acidification event (

"Published Online September 22 2011 Science 28 October 2011: Vol. 334 no. 6055 pp. 505-509 DOI: 10.1126/science.1206583 Report Increasing N Abundance in the Northwestern Pacific Ocean Due to Atmospheric Nitrogen Deposition Tae-Wook Kim1, Kitack Lee1,*, Raymond G. Najjar2, Hee-Dong Jeong3, Hae Jin Jeong4 + Author Affiliations 1School of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, 790−784, Korea. 2Department of Meteorology, The Pennsylvania State University, University Park, PA 16802, USA. 3East Sea Fisheries Research Institute, National Fisheries Research and Development Institute, Gangneung, 210-861, Korea. 4School of Earth and Environmental Sciences, Seoul National University, Seoul, 151−747, Korea. ↵*To whom correspondence should be addressed. E-mail: ktl@postech.ac.kr Abstract The relative abundance of nitrate (N) over phosphorus (P) has increased over the period since 1980 in the marginal seas bordering the northwestern Pacific Ocean, located downstream of the populated and industrialized Asian continent. The increase in N availability within the study area was mainly driven by increasing N concentrations and was most likely due to deposition of pollutant nitrogen from atmospheric sources. Atmospheric nitrogen deposition had a high temporal correlation with N availability in the study area (r = 0.74 to 0.88), except in selected areas wherein riverine nitrogen load may be of equal importance. The increase in N availability caused by atmospheric deposition and riverine input has switched extensive parts of the study area from being N-limited to P-limited. "

The term ocean acidification is used to describe the ongoing decrease in ocean pH caused by human CO2 emissions, such as the burning of fossil fuels. It is the little known consequence of living in a high CO2 world, dubbed at the 2009 United Nations Climate Change Conference (COP15) as the "evil twin of climate change". The oceans currently absorb approximately half of the CO2 produced by burning fossil fuel; put simply, climate change would be far worse if it were not for the oceans. However, there is a cost to the oceans - when CO2 dissolves in seawater it forms carbonic acid and as more CO2 is taken up by the oceans surface, the pH decreases, moving towards a less alkaline and therefore more acidic state. Already ocean pH has decreased by about 30% and if we continue emitting CO2 at the same rate by 2100 ocean acidity will increase by about 150%, a rate that has not been experienced for at least 400,000 years. Such a monumental alteration in basic ocean chemistry is likely to have wide implications for ocean life, especially for those organisms that require calcium carbonate to build shells or skeletons. Ocean acidification is a relatively new field of research, with most of the studies having been conducted over the last decade. While it is gaining some attention among policy makers, international leaders and the media, scientists find there is still a lack of understanding.

Aerosols Altered Asian Monsoons Summer monsoons provide much of the water for farming on the Indian subcontinent, but the pattern of rain shifted dramatically during the last half of the 20th century. In a study appearing online 29 September in Science, researchers pin the blame on soot and other aerosols from human activities. From 1951 to 1999, central-northern India became drier while Pakistan, northwestern India, and southern India got wetter. To determine whether these changes were due to natural variability or human interference (greenhouse gases or aerosols), climate scientists Massimo Bollasina, Yi Ming, and V. Ramaswamy of the Geophysical Fluid Dynamics Laboratory/NOAA in Princeton, New Jersey, compared the history of rainfall with simulations that singled out each climate "forcing" factor to observe its impact. Although greenhouse gases would have increased rainfall over north-central India, the aerosols, they found, caused the "very pronounced drying trend," Ming says. Here's why: Under normal conditions, the northern hemisphere receives more energy from the sun from June to September; that imbalance drives the ocean-atmosphere circulation that powers the monsoons. But atmospheric aerosols shaded the northern hemisphere relative to the southern hemisphere, altering the energy balance between the two-weakening the circulation and altering where the rain falls.

"Oil Exploration Oil Exploration Gulf Drilling Disaster Triggers Scrutiny of Mediterranean Oil Rush 1. Laura Margottini* A rush to find and extract oil in the Mediterranean Sea is threatening one of the planet's marine biodiversity hot spots, scientists warn. PANTELLERIA, ITALY-This tiny speck in the Mediterranean, home to a few thousand people, seems like one of the most tranquil places in the world. But looks are deceptive. Pantelleria, in the Strait of Sicily halfway between Palermo and Tunis, is close to one of the world's busiest shipping lanes, and of late, its waters have also become the center of a new oil rush. Attracted by Italy's easygoing drilling regulations and low tax on oil extraction, dozens of companies have new plans for exploration and drilling in this part of the Mediterranean Sea. At a recent meeting here,* however, scientists, conservationists, and environmental activists warned that such efforts put several important biodiversity hot spots in danger. An oil disaster like the Deepwater Horizon explosion, which sent oil gushing into the Gulf of Mexico for months, could easily ruin the Mediterranean ecology for a century or longer, some said. The Italian government has recently issued 66 permissions for drilling around its coasts and 25 concessions for exploration. Another 67 applications for exploration are under review. "Italy now represents the region that holds the most exciting and significant long-term opportunities," one company, Northern Petroleum, says on its Web site. The Strait of Sicily is the center of attention, but other biodiversity hot spots, such as the Tremiti Islands in the Adriatic Sea, could soon be explored as well. Italy isn't alone. Tunisia, for example, has granted concessions for oil exploration for most of its Mediterranean waters, without much political opposition. But the areas coveted by oil companies are ecological treasures, researchers and groups such as Greenpeace Italy stress. Last year, the Uni

A major puzzle of paleoclimatology is why, after a long interval of cooling climate, each late Quaternary ice age ended with a relatively short warming leg called a termination. We here offer a comprehensive hypothesis of how Earth emerged from the last global ice age. A prerequisite was the growth of very large Northern Hemisphere ice sheets, whose subsequent collapse created stadial conditions that disrupted global patterns of ocean and atmospheric circulation. The Southern Hemisphere westerlies shifted poleward during each northern stadial, producing pulses of ocean upwelling and warming that together accounted for much of the termination in the Southern Ocean and Antarctica. Rising atmospheric CO2 during southern upwelling pulses augmented warming during the last termination in both polar hemispheres.

"Spatial diversity gradients are a pervasive feature of life on Earth. We examined a global ocean circulation, biogeochemistry, and ecosystem model that indicated a decrease in phytoplankton diversity with increasing latitude, consistent with observations of many marine and terrestrial taxa. In the modeled subpolar oceans, seasonal variability of the environment led to competitive exclusion of phytoplankton with slower growth rates and lower diversity. The relatively weak seasonality of the stable subtropical and tropical oceans in the global model enabled long exclusion time scales and prolonged coexistence of multiple phytoplankton with comparable fitness. Superimposed on the decline in diversity seen from equator to pole were "hot spots" of enhanced diversity in some regions of energetic ocean circulation, which reflected lateral dispersal. "