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The field measurements of pH, fugacity of carbon dioxide (fCO2), total inorganic carbon dioxide (TCO2) and total alkalinity (TA) on surface and deep waters from the Atlantic, Indian, Southern and Pacific oceans to determine the pK1, pK2 and pK2-pK1 is examined.

Abstract: Coastal upwelling events in the California Current System can transport subsurface waters with high levels of carbon dioxide (CO2) to the sea surface near shore. As these waters age and are advected offshore, CO2 levels decrease dramatically, falling well below the atmospheric concentration beyond the continental shelf break. In May 2007 we observed an upwelling event off the coast of northern California. During the upwelling event subsurface respiration along the upwelling path added ∼35μmolkg−1 of dissolved inorganic carbon (DIC) to the water as it transited toward shore causing the waters to become undersaturated with respect to Aragonite. Within the mixed layer, pCO2 levels were reduced by the biological uptake of DIC (up to 70%), gas exchange (up to 44%), and the addition of total alkalinity through CaCO3 dissolution in the undersaturated waters (up to 23%). The percentage contribution of each of these processes was dependent on distance from shore. At the time of measurement, a phytoplankton bloom was just beginning to develop over the continental shelf. A box model was used to project the evolution of the water chemistry as the bloom developed. The biological utilization of available nitrate resulted in a DIC decrease of ∼200μmolkg−1, sea surface pCO2 near ∼200ppm, and an aragonite saturation state of ∼3. These results suggest that respiration processes along the upwelling path generally increase the acidification of the waters that are being upwelled, but once the waters reach the surface biological productivity and gas exchange reduce that acidification over time. [Copyright &y& Elsevier]

From an empirical point of view, this article aims at analyzing the role of the Swiss press in a language and culture policy debate regarding the changing status of Italian in quadrilingual Switzerland that took place at the beginning of 2005 following the discontinuation of two Italian chairs at Swiss universities. The issue is practically ignored in French- and German-speaking Switzerland, whereas Italian-language newspapers act as a platform for opinion leaders. The theoretical aim is to apply the framework of pragma-dialectics (van Eemeren & Grootendorst 1984, 1992, 2004) to a language and culture policy debate. The first step is an analysis of the confrontation stage of the debate in order to gain an overview of the issues and standpoints. In a second step, attention is focused on the argumentation stage, where the application of a locus analysis to single arguments of the debate allows the argument-generating mechanism to emerge. This mechanism essentially consists of two components: the topical component, which provides the argument with inferential validity, and the endoxical component, which contributes persuasive power to the argument by embedding it in the common ground shared by the arguer and the decision-maker. Moreover, the locus-analysis provides an efficient instrument for evaluating arguments by means of critical questions. [ABSTRACT FROM AUTHOR]

Marine carbonate system monitoring programs often consist of multiple observational methods that include underway cruise data, moored autonomous time series, and discrete water bottle samples. Monitored parameters include all, or some of the following: partial pressure of CO 2 of the water ( p CO 2w ) and air, dissolved inorganic carbon (DIC), total alkalinity (TA), and pH. Any combination of at least two of the aforementioned parameters can be used to calculate the others. In this study at the Gray's Reef (GR) mooring in the South Atlantic Bight (SAB) we: examine the internal consistency of p CO 2w from underway cruise, moored autonomous time series, and calculated from bottle samples (DIC-TA pairing); describe the seasonal to interannual p CO 2w time series variability and air-sea flux ( F CO 2 ), as well as describe the potential sources of p CO 2w variability; and determine the source/sink for atmospheric p CO 2 . Over the ~8.5 years of GR mooring time series, mooring-underway and mooring-bottle calculated- p CO 2w strongly correlate with r -values > 0.90. p CO 2w and F CO 2 time series follow seasonal thermal patterns; however, seasonal non-thermal processes, such as terrestrial export, net biological production, and air-sea exchange also influence variability. The linear slope of time series p CO 2w increases by 5.2 ± 1.4 µatm y −1 with F CO 2 increasing 51–70 mmol m −2 y −1 . The net F CO 2 sign can switch interannually with the magnitude varying greatly. Non-thermal p CO 2w is also increasing over the time series, likely indicating that terrestrial export and net biological processes drive the long term p CO 2w increase. [ABSTRACT FROM AUTHOR]

Carbon dioxide partial pressure ( p CO 2 ) in surface seawater was continuously recorded every three hours from 18 July 2006 through 31 October 2007 using a moored autonomous p CO 2 (MAPCO 2 ) system deployed on the Gray’s Reef buoy off the coast of Georgia, USA. Surface water p CO 2 (average 373 ± 52 μatm) showed a clear seasonal pattern, undersaturated with respect to the atmosphere in cold months and generally oversaturated in warm months. High temporal resolution observations revealed important events not captured in previous ship-based observations, such as sporadically occurring biological CO 2 uptake during April–June 2007. In addition to a qualitative analysis of the primary drivers of p CO 2 variability based on property regressions, we quantified contributions of temperature, air–sea exchange, mixing, and biological processes to monthly p CO 2 variations using a 1-D mass budget model. Although temperature played a dominant role in the annual cycle of p CO 2 , river inputs especially in the wet season, biological respiration in peak summer, and biological production during April–June 2007 also substantially influenced seawater p CO 2 . Furthermore, sea surface p CO 2 was higher in September–October 2007 than in September–October 2006, associated with increased river inputs in fall 2007. On an annual basis this site was a moderate atmospheric CO 2 sink, and was autotrophic as revealed by monthly mean net community production (NCP) in the mixed layer. If the sporadic short productive events during April–May 2007 were missed by the sampling schedule, one would conclude erroneously that the site is heterotrophic. While previous ship-based p CO 2 data collected around this buoy site agreed with the buoy CO 2 data on seasonal scales, high resolution buoy observations revealed that the cruise-based surveys undersampled temporal variability in coastal waters, which could greatly bias the estimates of air–sea CO 2 fluxes or annual NCP, and even produce contradictory results. [ABSTRACT FROM AUTHOR]

Abstract: Continental margin carbon cycling is complex, highly variable over a range of space and time scales, and forced by multiple physical and biogeochemical drivers. Predictions of globally significant air–sea CO2 fluxes in these regions have been extrapolated based on very sparse data sets. We present here a method for predicting coastal surface-water pCO2 from remote-sensing data, based on self organizing maps (SOMs) and a nonlinear semi-empirical model of surface water carbonate chemistry. The model used simple empirical relationships between carbonate chemistry (total dissolved carbon dioxide () and alkalinity (T Alk)) and satellite data (sea surface temperature (SST) and chlorophyll (Chl)). Surface-water CO2 partial pressure (pCO2) was calculated from the empirically-predicted and T Alk. This directly incorporated the inherent nonlinearities of the carbonate system, in a completely mechanistic manner. The model’s empirical coefficients were determined for a target study area of the central North American Pacific continental margin (22–50°N, within 370km of the coastline), by optimally reproducing a set of historical observations paired with satellite data. The model-predicted pCO2 agreed with the highly variable observations with a root mean squared (RMS) deviation of <20μatm, and with a correlation coefficient of >0.8 (r =0.81; r 2 =0.66). This level of accuracy is a significant improvement relative to that of simpler models that did not resolve the biogeochemical sub-regions or that relied on linear dependences on input parameters. Air–sea fluxes based on these pCO2 predictions and satellite-based wind speed measurements suggest that the region is a ∼14TgCyr−1 sink for atmospheric CO2 over the 1997–2005 period, with an approximately equivalent uncertainty, compared with a ∼0.5TgCyr−1 source predicted by a recent bin-averaging and interpolation-based estimate for the same area. [Copyright &y& Elsevier]

Abstract: A climatological mean distribution for the surface water pCO2 over the global oceans in non-El Niño conditions has been constructed with spatial resolution of 4° (latitude) ×5° (longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. Global sea–air CO2 flux based on climatological surface ocean pCO2, and seasonal biological and temperature effects. Deep-Sea Res. II, 49, 1601–1622]. A time-trend analysis using deseasonalized surface water pCO2 data in portions of the North Atlantic, North and South Pacific and Southern Oceans (which cover about 27% of the global ocean areas) indicates that the surface water pCO2 over these oceanic areas has increased on average at a mean rate of 1.5μatmy−1 with basin-specific rates varying between 1.2±0.5 and 2.1±0.4μatmy−1. A global ocean database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Niño periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO2 and the sea-air pCO2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern Oceans are presented. Over the Southern Ocean seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net air–sea CO2 flux is estimated using the sea–air pCO2 difference and the air–sea gas transfer rate that is parameterized as a function of (wind speed)2 with a scaling factor of 0.26. This is estimated by inverting the bomb 14C data using Ocean General Circulation models and the 1979–2005 NCEP-DOE AMIP-II Reanalysis (R-2) wind speed data. The equatorial Pacific (14°N–14°S) is the major source for atmospheric CO2, emitting about +0.48Pg-Cy−1, and the temperate oceans between 14° and 50° in the both hemispheres are the major sink zones with an uptake flux of −0.70Pg-Cy−1 for the northern and −1.05Pg-Cy−1 for the southern zone. The high-latitude North Atlantic, including the Nordic Seas and portion of the Arctic Sea, is the most intense CO2 sink area on the basis of per unit area, with a mean of −2.5tons-Cmonth−1 km−2. This is due to the combination of the low pCO2 in seawater and high gas exchange rates. In the ice-free zone of the Southern Ocean (50°–62°S), the mean annual flux is small (−0.06Pg-Cy−1) because of a cancellation of the summer uptake CO2 flux with the winter release of CO2 caused by deepwater upwelling. The annual mean for the contemporary net CO2 uptake flux over the global oceans is estimated to be −1.6±0.9Pg-Cy−1, which includes an undersampling correction to the direct estimate of −1.4±0.7Pg-Cy−1. Taking the pre-industrial steady-state ocean source of 0.4±0.2Pg-Cy−1 into account, the total ocean uptake flux including the anthropogenic CO2 is estimated to be −2.0±1.0Pg-Cy−1 in 2000. [Copyright &y& Elsevier]

Presents a method for distinguishing the seasonal biological effect on surface-water ρ CO[sub2] from the effect of seasonal temperature changes, and discuss the relative significance of these effects in different regions of the global oceans. Explanation on the climatological distribution of surface-water ρ CO[sub2]; Description on the seasonal variation of ρ CO[sub2] in surface waters; Conclusions.