Register      Login
Environmental Chemistry Environmental Chemistry Society
Environmental problems - Chemical approaches
RESEARCH FRONT

Where to now? A synthesis of current views of the CLAW hypothesis

Jill M. Cainey A D , Herman Sievering B and Greg P. Ayers C
+ Author Affiliations
- Author Affiliations

A Cape Grim Baseline Air Pollution Station, Bureau of Meteorology, Smithton, Tas. 7330, Australia.

B INSTAAR-an Earth & Environmental System Science Institute, University of Colorado, Boulder, CO, USA.

C CSIRO Marine and Atmospheric Research, Aspendale, Vic. 3195, Australia.

D Corresponding author. Email: J.Cainey@bom.gov.au

Environmental Chemistry 4(6) 406-409 https://doi.org/10.1071/EN07082
Submitted: 1 November 2007  Accepted: 12 November 2007   Published: 6 December 2007

Abstract. The CLAW hypothesis was published 20 years ago, building on suggestions that the sulfur cycle provided a natural feedback mechanism whereby plankton in the ocean had a role in modifying climate by providing the precursors for cloud condensation nuclei, which leads to the formation of high albedo clouds.

In this issue, the 10 preceding articles represent the opinions of several leading scientists working on various aspects of the CLAW hypothesis and here we synthesise these varied opinions to answer the questions: Does the CLAW hypothesis operate as described in the original 1987 publication? and What steps and advances are needed to better understand CLAW and resolve any outstanding areas of difficulty?


References


[1]   R. Charlson , J. Lovelock , M. Andreae , S. Warren , Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate. Nature 1987 , 326,  655.
        | Crossref | GoogleScholarGoogle Scholar |  
        | Crossref |  GoogleScholarGoogle Scholar |  open url image1

[17]   E. K. Bigg , Sources, nature and influence on climate of marine airborne particles. Environ. Chem. 2007 , 4,  155.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[18]   C. Leck , E. K. Bigg , Comparison of sources and nature of the tropical aerosol with summer high Arctic aerosol. Tellus B 2007 , OnlineEarly Article.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[19]   C. D. O’Dowd , Biogenic coastal aerosol production and its influence on aerosol radiative properties. J. Geophys. Res. 2001 , 106,  1545.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[20]   G. Shaw , Essay on the CLAW hypothesis. Environ. Chem. 2007 , 4,  382.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[21]   P. S. Liss , J. E. Lovelock , Climate change, the effect of DMS emissions. Environ. Chem. 2007 , 4,  377.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[22]   N. Meskhidze , A. Nenes , Phytoplankton and cloudiness in the Southern Ocean. Science 2006 , 314,  1419.
        | Crossref | GoogleScholarGoogle Scholar | PubMed |  open url image1

[23]   R. J. Weber , P. H. McMurry , L. Mauldin , D. J. Tanner , F. L. Eisele , F. J. Brechtel , S. M. Kreidenweis , G. L. Kok , A study of new particle formation and growth involving biogenic and trace gases during the First Aerosol Characterization Experiment (ACE-1). J. Geophys. Res. 1998 , 103,  16385.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[24]   C. D. O’Dowd , M. Geever , M. K. Hill , M. H. Smith , S. G. Jennings , New particle formation: nucleation rates and spatial scales in the clean marine coastal environment. Geophys. Res. Lett. 1998 , 25,  1661.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[25]   F. Raes , Entrainment of free tropospheric aerosols as a regulating mechanism for cloud condensation nuclei in the remote marine boundary layer. J. Geophys. Res. 1995 , 100,  2893.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[26]   A. D. Clarke , V. N. Kapustin , F. L. Eisele , R. J. Weber , P. H. McMurry , Particle production near marine clouds: sulfuric acid and predictions from classical binary nucleation. Geophys. Res. Lett. 1999 , 26,  2425.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[27]   S. Archer , Crucial uncertainties in predicting biological control of DMS emission. Environ. Chem. 2007 , 4,  404.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[28]   S. M. Vallina , R. Simó , Re-visiting the CLAW hypothesis. Environ. Chem. 2007 , 4,  384.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[29]   S. M. Vallina , R. Simó , Strong relationship between DMS and the solar radiation dose over the Global Surface Ocean. Science 2007 , 315,  506.
        | Crossref | GoogleScholarGoogle Scholar | PubMed |  open url image1

[30]   S. M. Vallina , R. Simó , S. Gassó , What controls CCN seasonality in the Southern Ocean? A statistical analysis based on satellite-derived chlorophyll and CCN and model-estimated OH radical and rainfall. Global Biogeochem. Cy. 2006 , 20,  GB1014.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[31]   R. A. Cropp , J. M. Norbury , Plankton modelling and CLAW. Environ. Chem. 2007 , 4,  388.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[32]   S. M. Vallina , R. Simó , E. E. Popova , T. R. Anderson , A. Gabric , R. A. Cropp , J. M. Norbury , A dynamic model of ocean sulfur (DMOS) applied to the Sargasso Sea: simulating the dimethylsulfide (DMS) summer paradox. J. Geophys. Res. 2007 , in press.
         open url image1

[33]   M. J. Harvey , The iron CLAW. Environ. Chem. 2007 , 4,  396.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[34]   J. E. Lovelock , L. R. Kump , Failure of climate regulation in a geophysiological model. Nature 1994 , 369,  732.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[35]   J. E. Lovelock , A geophysiologist’s thoughts on the natural sulphur cycle. Philos. Trans. R. Soc. London B 1997 , 352,  143.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[36]   J. L. Sarmiento , R. Slater , R. Barber , L. Bopp , S. C. Doney , A. C. Hirst , J. Kieypas , R. Matear , et al. Response of ocean ecosystems to climate warming. Global Biogeochem. Cy. 2004 , 18,
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[37]   P. W. Boyd , T. Jickells , C. S. Law , S. Blain , E. A. Boyle , K. O. Buesseler , K. H. Coale , J. J. Cullen , et al. Mesoscale iron enrichment experiments 1993–2005: synthesis and future directions. Science 2007 , 315,  612.
        | Crossref | GoogleScholarGoogle Scholar | PubMed |  open url image1

[38]   O. W. Wingenter , K. B. Haase , M. Zeigler , D. R. Blake , F. S. Rowland , B. C. Sive , A. Paulino , R. Thyrhaug , et al. Unexpected consequences of increasing CO2 and ocean acidity on marine production of DMS and CH2ClI: potential climate impacts. Geophys. Res. Lett. 2007 , 34,  L05710.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[39]   S. Norris , I. Brooks , G. de Leeuw , M. H. Smith , M. Moerman , J. Lingard , Eddy covariance measurements of sea spray particles over the Atlantic Ocean. Atmos. Chem. Phys. Discuss. 2007 , 7,  13243.
         open url image1

[40]   S. Alvain , C. Moulin , Y. Dandonneau , H. Loisel , F.-M. Breon , A species-dependent bio-optical model of case I waters for global ocean color processing. Deep-Sea Res. I 2006 , 53,  917.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[41]   G. P. Ayers , J. M. Cainey , The CLAW hypothesis: a review of the major developments. Environ. Chem. 2007 , 4,  366.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[42]   Y. J. Yoon , P. Brimblecombe , Modelling the contribution of sea salt and dimethyl sulfide derived aerosol to marine CCN. Atmos. Chem. Phys. Discuss. 2001 , 1,  93.
         open url image1

[43]   B. Huebert , Do I believe in CLAW? Environ. Chem. 2007 , 4,  375.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[44]   J. M. Cainey , Understanding the origin of clouds. Environ. Chem. 2007 , 4,  141.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[45]   C. D. O’Dowd , M. H. Smith , Physico-chemical properties of aerosols over the Northeast Atlantic: Evidence for wind-speed-related submicron sea-salt aerosol production. J. Geophys. Res. 1993 , 98,  1137.
         open url image1

[46]   M. A. Alexander , J. D. Scott , C. Deser , Processes that influence sea surface temperature and ocean mixed layer depth variability in a coupled model. J. Geophys. Res. 2000 , 105,  16823.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1