1 / 46

INORGANIC CARBON AND ACIDIFICATION DYNAMICS IN WESTERN GULF OF MAINE SURFACE WATERS.

INORGANIC CARBON AND ACIDIFICATION DYNAMICS IN WESTERN GULF OF MAINE SURFACE WATERS. J. Salisbury, D. Vandemark, C. Hunt, S. Shellito (Univ. of New Hampshire) W. R. McGillis (Columbia Univ./LDEO) C. L. Sabine (NOAA/PMEL). Atmospheric carbon dioxide record from Mauna Loa for 1958-2000

vea
Download Presentation

INORGANIC CARBON AND ACIDIFICATION DYNAMICS IN WESTERN GULF OF MAINE SURFACE WATERS.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. INORGANIC CARBON AND ACIDIFICATION DYNAMICS IN WESTERN GULF OF MAINE SURFACE WATERS. J. Salisbury, D. Vandemark, C. Hunt, S. Shellito (Univ. of New Hampshire) W. R. McGillis (Columbia Univ./LDEO) C. L. Sabine (NOAA/PMEL)

  2. Atmospheric carbon dioxide record from Mauna Loa for 1958-2000 by C.D. Keeling and T.P. Whorf http://cdiac.esd.ornl.gov/trends/co2/sio-mlo.htm Average for year 2000 = 369.4ppm

  3. Outline Our place and our observation kit Background on CO2 and acid variability and western GOM Ideas on variability from our data set Coastal acidification Conclusions and questions

  4. Our Science Questions • Is the Gulf of Maine a source or sink of atmospheric CO2? • What are the space/time variability and mechanistic controls of surface pCO2 and subsequent acidification? • Can we apply CO2 and O2 data to support monitoring/prediction of lower trophic status via net ecosystem metabolism estimates? Climate and the Integrated Ocean Observing System ( First of the Seven IOOS Societal Goals ) 1. Improve predictions of climate change and weather and their effects on coastal communities and the nation

  5. UNH COOA study region within NERACOOS

  6. Two monthly cruises since 2004 1) cross-shore out to Wilkinson Basin and 2) along-shore up into the Kennebec River. • Suite of variables: • Optical properties • Phytoplankton pigments (HPLC) • Zooplankton biomass and species • Nutrients and oxygen • Inorganic and organic carbon (pCO2, DIC, TA, pH, DOC) • Temperature • Salinity

  7. COOA monthly Gulf of Maine ecosystem observations 2004 - now, Phys/Bio/Chem UNH R/V Gulf Challenger Profilers for IOPs , AOPs, and CTD Fast-rate pCO2 equilibrator Underway pCO2, oxygen, IOPs, NO3 and CTD Infrared pCO2 gas analyzer

  8. http://www.cooa.unh.edu

  9. Some background: CO2 Reactions with water CO2 (air) -------------------------------------------------- Sea Surface ---- CO2 + H2O  H2CO3 H++ HCO3- 2H+ + CO3= CaCO3 (solid) K*2 K*1 Add Ca++ Note: DIC or CO2 is the sum of CO2(aq), HCO3- and CO32-

  10. Solubility a function of temperature and “salinity” ≈ [Ca++] [CO3--] agaronite Ksp Aragonite saturation state: In simple terms, Ω is a measure of the product of the concentrations of CO32- and Ca2+ ions relative to the amount of aragonite that can be dissolved at a given temperature, salinity and pressure.

  11. CO2 gas flux at air-sea interface Typical parameterization - flux (mmolC/m2/hr) = α* k * (ΔpCO2) α = gas solubility; known quantity f(T,S) k = gas transfer coefficient; an unknown at sea and empirically related to wind speed (U) ΔpCO2 = pCO2atmosphere– pCO2aqueous pCO2 = partial pressure of CO2 gas ~387 Atm

  12. Lower Higher J F M A M J J A S O N D SST NCP (P-R) Wind speed Main variables affecting temporal variability of DIC,  and air-sea exchange in W. Gulf of Maine

  13. The role of river discharge? Influence spring stratification … and impart resistance to mixing …often has a different temperature signature Potential subsides of nutrients, DOC, acid … and deficits of DIC and alkalinity

  14. Observed variability relevant to CO2.

  15. Salinity, temperature and f-chlorophyll GOMOOS Buoy B

  16. Seasonal to interannual pCO2 and air-sea variations

  17. Interesting cases: Do they affect the annual budget? Effect of discharge on the onset and persistence of two spring blooms? (2004 and 2005) Turbulent interruption of a spring bloom (2006) Timing of the fall turnover could be a significant factor influencing the annual CO2 flux (2007).

  18. Case1. Blooms of different duration (2004-2005) Salinity Inflection 3/05/04, SST ~3.0C Persistence 115 days Inflection 2/13/05, SST ~2.0C Persistence 155 days Surface f-chlorophyll ? Salinity and f-chlorophyll at GOMOOS Buoy B

  19. Salisbury et al., 2008

  20. Comparison of conditions (surface 10m) during April 19-June 18 (2004 and 2005) Focus on the productive seasons of 2004 and 2005 Estimate 2004 2005 Average plume (HFW) region area (km2) 17630 23596 Average freshwater volume (km3)* 6.8 39.5 Average DICbio depletion (ml kg-1) -1.27 -13.97 Net DICbio accumulation (mol) in region of interest (plume and non-plume) -0.48E8 -1.33E8 Biologically mediated DIC and air-sea flux Salisbury et al., 2008

  21. Comparison of conditions (surface 10m) during April 19-June 18 (2004 and 2005) Estimate 2004 2005 Average plume (HFW) region area (km2) 17630 23596 Average freshwater volume (km3)* 6.8 39.5 Average DICbio depletion (ml kg-1) -1.27 -13.97 Net DICbio accumulation (mol) in region of interest (plume and non-plume) -0.48E8 -1.33E8 Salisbury et al., 2008

  22. 10m waves Case 2: Patriot’s Day Storm (2006) A serious interruption of the spring bloom

  23. Evidence for storm induced mixing of shallow and deep DIC pools Start of mixing > 20m

  24. Coastal acid dynamics Joe Salisbury, Mark Green, Doug Vandemark, Chris Hunt It’s not just and air-sea issue

  25. Most soils are acidic • Decaying plant material • Weathering of minerals • Atmospheric deposition

  26. Simulation: Hold SST at median SST (16.1º C) Subtract result from original image

  27. Simulation: Hold pCO2 at the mean atmospheric value (384uatm) Subtract result from original image

  28. Simulation: Hold TA at the 90th prctile Subtract result from original image

  29. Saturation state can be very low within River Plumes

  30. Periodic acidification in the Gulf of Maine:

  31. Soft shelled clam calcification

  32. Closing remarks Operational Salinity model Huijie Xue (UMO)

  33. Important stuff I didn’t cover very well • PAR (effect of clouds) • Distribution of PAR in the water (effects of attenuation) • Community dynamics e.g. Phaeocystis has a C:N of 30 (Mykelstad, 1988)

  34. Some conclusions/ questions Several week-to-month (event scale) processes impart lots of interannual variability. W. Gulf is a an overall air-sea source of CO2 but with interannual variability that can swing to a sink (annual flux numbers - unimpressive) Seasonal pCO2 cycle has large swings from spring drawdown to winter ventilation but we are near carbon neutral over the year Freshwater mixing and biology affect 

  35. Some questions • Why aren’t we a big sink for atmospheric CO2? • What role does freshwater play in carbon and acid dynamics? • What role do storms play?

  36. data collection acknowledgments - a regional and local effort UNH/COOA measurement crew: P. Pelletier, B. Soares, D. Brewitt C. Manning R. Jones C. Hunt T. Gregory M. Novak S. Shellito and many more UNH WB transect PIs: J. Campbell R. Morrison J. Salisbury D. Vandemark J. Runge (GMRI) A. Bucklin (Uconn)

More Related