Monday, June 17, 2013

New paper finds the oceans are a net source of CO2

A new paper published in Deep-Sea Research finds the ocean is a net source of CO2 to the atmosphere, the opposite of claims by climate alarmists that the ocean removes CO2 from the atmosphere. According to the authors, "At the [research] site, the ocean is primarily a source of CO2 to the atmosphere, except during strong upwelling events." The paper also notes, "Astor et al.(2005) observed the interactions between physical and biochemical parameters that lead to temporal [over time] variations in fCO2 [CO2 flux from the] sea, finding that even during periods of high production, the CO2 flux between the ocean and the atmosphere decreased but remained positive, i.e. CO2 escaped from the ocean to the atmosphere."

The paper corroborates prior work by SalbyHumlum et alFrölicher et alCho et alCalder et alFrancey et alAhlbeck, Petterssonand others demonstrating that man-made CO2 is not the driver of atmospheric CO2. This new work confirms the primary source of atmospheric CO2 is out-gassing from the oceans, which is due to decreased solubility with increased temperature.

The net transfer of CO2  was from the ocean to atmosphere during the study period from 1996-2009, shown by the positive flux values on vertical axis. The flux only dipped to negative values [net transfer from atmosphere to ocean] during brief periods.

Y.M. Astor et al

We examined the variability of sea surface carbon dioxide fugacity (fCO2sea) and its relation to temperature at the Cariaco Basin ocean time-series location (10°30’N, 64°40’W) for the period from 1996 through 2008. Periods of warm (positive) and cold (negative) anomalies at the station were related to variability in coastal upwelling intensity. A positive temporal trend in monthly-deseasonalized sea surface temperatures (SST) was observed, leading to an overall increase of 1.13°C over 13 years. Surface fCO2 sea displayed significant short-term variation (month to month) with a range of 330 to 445µatm. In addition to a large seasonal range (58±17µatm), deseasonalized fCO2sea data showed an interannual positive trend of 1.77±0.43µatmyear−1. In the Cariaco Basin, positive and negative anomalies of temperature and fCO2sea are in phase. An increase/decrease of 1°C coincides with an increase/decrease of 16–20µatm of fCO2sea. Deseasonalized fCO2 seanormalized to 26.05°C, the mean Cariaco SST, shows a lower rate of increase (0.51±0.49µatmyear−1). Based on these observations, 72% of the increase in fCO2sea in Cariaco Basin between 1996 and 2008 can be attributed to an increasing temperature trend of surface waters, making this the primary factor controlling fugacity at this location. During this period, a decrease in upwelling intensity was also observed. The phytoplankton community changed from large diatom-dominated blooms during upwelling in the late 1990's to blooms dominated by smaller cells in the first decade of the twenty-first century. The average net sea [to] air CO2 flux over the study period is 2.0±2.6molCm−2 year−1 employing the Wanninkhof parameterization, and 2.1±2.5molCm−2 year−1 based on Nightingale's model. To further understand the connection between the changes observed in the Cariaco Basin, the relationships between interannual variability in the temperature anomaly with three modes of climate variability (AMO, NAO and ENSO) were examined.

1 comment:

  1. More evidence in support of this:

    "Stephen Wilde: Evidence that Oceans not Man control CO2 emissions
    Thursday, April 26th 2012, 12:39 PM EDT"

    Most CO2 is found above and downwind of sun warmed ocean surfaces beneath the subtropical high pressure cells.

    Next they'll find that decomposing biological material in the oceans is a source of low Carbon 13 CO2.