Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 7 2 2010 10.5194/bg-7-621-2010 http://www.biogeosciences.net/7/621/2010/ http://www.biogeosciences.net/7/621/2010/bg-7-621-2010.html http://www.biogeosciences.net/7/621/2010/bg-7-621-2010.pdf 621 640 2010-02-15 Detection of anthropogenic climate change in satellite records of ocean chlorophyll and productivity S. A. Henson S.Henson@noc.soton.ac.uk J. L. Sarmiento J. P. Dunne L. Bopp I. Lima S. C. Doney J. John C. Beaulieu Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, USA NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France Dept. of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA now at: National Oceanography Centre, Southampton, UK Global climate change is predicted to alter the ocean's biological productivity. But how will we recognise the impacts of climate change on ocean productivity? The most comprehensive information available on its global distribution comes from satellite ocean colour data. Now that over ten years of satellite-derived chlorophyll and productivity data have accumulated, can we begin to detect and attribute climate change-driven trends in productivity? Here we compare recent trends in satellite ocean colour data to longer-term time series from three biogeochemical models (GFDL, IPSL and NCAR). We find that detection of climate change-driven trends in the satellite data is confounded by the relatively short time series and large interannual and decadal variability in productivity. Thus, recent observed changes in chlorophyll, primary production and the size of the oligotrophic gyres cannot be unequivocally attributed to the impact of global climate change. Instead, our analyses suggest that a time series of ~40 years length is needed to distinguish a global warming trend from natural variability. In some regions, notably equatorial regions, detection times are predicted to be shorter (~20–30 years). Analysis of modelled chlorophyll and primary production from 2001–2100 suggests that, on average, the climate change-driven trend will not be unambiguously separable from decadal variability until ~2055. Because the magnitude of natural variability in chlorophyll and primary production is larger than, or similar to, the global warming trend, a consistent, decades-long data record must be established if the impact of climate change on ocean productivity is to be definitively detected. Alheit, J.: Consequences of regime shifts for marine food webs, Int. J. Earth Sci., 98, 261–268, 2009. Anderson, J. L., Balaji, V., Broccoli, A. J., Cooke, W., Delworth, T., Dixon, K., Donner, L. J., Dunne, K. A., Freidenreich, S. M., Garner, S. T., Gudgel, R. G., Gordon, C. T., Held, I. M., Hemler, R. S., Horowitz, L. W., Klein, S. A., Knutson, T. R., Kushner, P. J., Langenhorst, A. R., Lau, N. C., Liang, Z., Malyshev, S. L., Milly, P. C. D., Nath, M. J., Ploshay, J. J., Ramaswamy, V., Schwarzkopf, M. D., Shevlikova, E., Sirutis, J. J., Soden, B. J., Stern, W. F., Thompson, L. A., Wilson, R. J., Wittenberg, A. T., and Wyman, B. L.: The new GFDL global atmosphere and land model AM2-LM2: Evaluation with prescribed SST simulations, J. Climate, 17, 4641–4673, 2004. Antoine, D., Morel, A., Gordon, H. R., Banzon, V. F., and Evans, R. H.: Bridging ocean color observations of the 1980s and 2000s in search of long-term trends, J. Geophys. Res., 110, C06009, doi:10.1029/2004JC002620, 2005. Aumont, O. and Bopp, L.: Globalizing results from ocean in situ iron fertilization studies, Global Biogeochem. Cy., 20, GB2017, doi:10.1029/2005GB002591, 2006. Behrenfeld, M. J., Boss, E., Siegel, D. A., and Shea, D. M.: Carbon-based ocean productivity and phytoplankton physiology from space, Global Biogeochem. Cy., 19, GB1006, doi:10.1029/2004GC002299, 2005. Behrenfeld, M. J. and Falkowski, P. G.: Photosynthetic rates derived from satellite-based chlorophyll concentration, Limnol. Oceanogr., 42, 1–20, 1997. Behrenfeld, M. J., Halsey, K. H., and Milligan, A. J.: Evolved physiological responses of phytoplankton to their integrated growth environment, Philos. T. Roy. Soc. B, 363, 2687–2703, 2008b. Behrenfeld, M. J., O'Malley, R. T., Siegel, D. A., McClain, C. R., Sarmiento, J. L., Feldman, G. C., Milligan, A. J., Falkowski, P. G., Letelier, R. M., and Boss, E. S.: Climate-driven trends in contemporary ocean productivity, Nature, 444, 752–755, 2006. Behrenfeld, M. J. and Siegel, D. A.: Ocean productivity-climate linkages imprinted in satellite observations, IGBP Newsletter, 68, 4–7, 2007. Behrenfeld, M. J., Siegel, D. A., and O'Malley, R. T.: Global ocean phytoplankton and productivity, in: State of the Climate in 2007, eduted by: Levinson, D. H. and Lawrimore, J. H., B. Am. Meteorol. Soc., 89, S56–S61, 2008a. Behrenfeld, M. J., Siegel, D. A., O'Malley, R. T., and Maritorena, S.: Global ocean phytoplankton, B. Am. Met. Soc., 90, S68–S73, 2009. Bopp, L., Aumont, O., Cadule, P., Alvain, S., and Gehlen, M.: Response of diatoms distribution to global warming and potential implications: A global model study, Geophys. Res. Lett., 32, L19606, doi:10.1029/2005GL023653, 2005. Bopp, L., Kohfeld, K. E., and Le Quere, C.: Dust impact on marine biota and atmospheric CO₂ during glacial periods, Paleoceanography, 18, 1046, doi:1010.1029/2002PA000810, 2003. Bopp, L., Monfray, P., Aumont, O., Dufresne, J.-L., Le Treut, H., Madec, G., Terray, L., and Orr, J. C.: Potential impacts of climate change on marine export production, Global Biogeochem. Cy., 15, 81–99, 2001. Boyd, P. W. and Doney, S. C.: Modelling regional responses by marine pelgaic ecosystems to global climate change, Geophys. Res. Lett., 29, 1806, doi:1810.1029/2001GL014130, 2002. Boyd, P. W., Doney, S. C., Strzepek, R., Dusenberry, J., Lindsay, K., and Fung, I.: Climate-mediated changes to mixed-layer properties in the Southern Ocean: assessing the phytoplankton response, Biogeosciences, 5, 847–864, 2008. Brzezinski, M. A., Villareal, T. A., and Lipschultz, F.: Silica production and the contribution of diatoms to new and primary production in the central North Pacific, Mar. Ecol.-Prog. Ser., 167, 89–104, 1998. Carr, M.-E.: Estimation of potential productivity in Eastern Boundary Currents using remote sensing, Deep Sea Res. Pt II, 49, 59–80, 2002. Chavez, F. P., Ryan, J., Lluch-Cota, S. E., and Niquen, M. C.: From anchovies to sardines and back: Multidecadal changes in the Pacific Ocean, Science, 299, 217–221, 2003. Cheung, W. W. L., Lam, B. W. Y., Sarmiento, J. L., Kearney, K., Watson, R., and Pauly, D.: Projecting global marine biodiversity impacts under climate change scenarios, Fish Fish., 10, 235–251, 2009a. Cheung, W. W. L., Lam, B. W. Y., Sarmiento, J. L., Kearney, K., Watson, R., Zeller, D., and Pauly, D.: Large-scale redistribution of maximum fisheries catch potential in the global ocean under climate change, Glob. Change Biol., 16, 24–35, 2009b. Collins, W. D., Blackmon, M., Bitz, C. M., Bonan, G. B., Bretherton, C. S., Carton, J. A., Chang, P., Doney, S. C., Hack, J. J., Kiehl, J. T., Henderson, T., Large, W., McKenna, D., and Santer, B. D.: The community climate system model: CCSM3, J. Climate, 19, 2122–2143, 2006. Conkright, M. E., Locarnini, R. A., Garcia, H. E., O'Brien, T. D., Boyer, T. P., Stephens, C., and Antonov, J. I.: World Ocean Atlas 2001: Objective analyses, data statistics and figures, CD-ROM documentation, National Oceanographic Data Center, Silver Spring, MD, 2002. Delworth, T., Broccoli, A. J., Rosati, A., Stouffer, R., Balaji, V., Beesley, J. A., Cooke, W., Dixon, K., Dunne, J. P., Dunne, K. A., Durachta, J. W., Findell, K. L., Ginoux, P., Gnanadesikan, A., Gordon, C. T., Griffies, S. M., Gudgel, R. G., Harrison, M. J., Held, I. M., Hemler, R. S., Horowitz, L. W., Klein, S. A., Knutson, T. R., Kushner, P. J., Langenhorst, A. R., Lee, H. C., Lin, S. J., Lu, J., Malyshev, S. L., Milly, P. C. D., Ramaswamy, V., Russell, J., Schwarzkopf, M. D., Shevlikova, E., Sirutis, J. J., Spelman, M., Stern, W. F., Winton, M., Wittenberg, A. T., Wyman, B. L., Zeng, F., and Zhang, R.: GFDL's CM2 global coupled climate models. Part I: Formulation and simulation characteristics, J. Climate, 19, 643–674, 2006. deYoung, B., Barange, M., Beaugrand, G., Harris, R., Perry, R. I., Scheffer, M., and Werner, F.: Regime shifts in marine ecosystems: detection, prediction and management, Trends Ecol. Evol., 23, 402–409, 2008. Dickinson, R. E., Oleson, K. W., Bonan, G. B., Hoffman, F. M., Thornton, P., Vertenstein, M., Yang, Z.-L., and Zeng, X.: The community land model and its climate statistics as a component of the Community Climate System Model, J. Climate, 19, 2302–2324, 2006. Doney, S. C.: Oceanography – Plankton in a warmer world, Nature, 444, 695–696, 2006. Doney, S. C., Lima, I. D., Feely, R. A., Glover, D. M., Lindsay, K., Mahowald, N., Moore, J. K., and Wanninkhof, R.: Mechanisms governing interannual variability in upper-ocean inorganic carbon system and air-sea CO₂ fluxes: physical climate and atmospheric dust, Deep Sea Res. Pt II, 56, 640–655, 2009a. Doney, S. C., Lima, I. D., Moore, J. K., Lindsay, K., Behrenfeld, M. J., Westberry, T. K., Mahowald, N., Glover, D. M., and Takahashi, T.: Skill metrics for confronting global upper ocean ecosystem-biogeochemistry models against field and remote sensing data, J. Marine Syst., 76, 95–112, 2009b. Doney, S. C., Lindsay, K., Caldeira, K., Campin, J.-M., Drange, H., Dutay, J.-C., Follows, M., Gao, Y., Gnanadesikan, A., Gruber, N., Ishida, A., Joos, F., Madec, G., Maier-Reimer, E., Marshall, J. C., Matear, R., Monfray, P., Mouchet, A., Najjar, R., Orr, J. C., Plattner, G.-K., Sarmiento, J. L., Schlitzer, R., Slater, R., Totterdell, I. J., Weirig, M.-F., Yamanaka, Y., and Yool, A.: Evaluating global ocean carbon models: the importance of realistic physics, Global Biogeochem. Cy., 18, GB3017, doi:10.1029/2003GB002150, 2004. Doney, S. C., Lindsay, K., Fung, I., and John, J.: Natural variability in a stable, 1000-year global coupled climate-carbon cycle simulation, J. Climate, 19, 3033–3054, 2006. Dose, V. and Menzel, A.: Bayesian analysis of climate change impacts in phenology, Glob. Change Biol., 10, 259–272, 2004. Dunne, J. P., Armstrong, R. A., Gnanadesikan, A., and Sarmiento, J. L.: Empirical and mechanistic models for the particle export ratio, Global Biogeochem. Cy., 19, GB4026, doi:10.1029/2004GB002390, 2005. Dunne, J. P., Sarmiento, J. L., and Gnanadesikan, A.: A synthesis of global particle export from the surface ocean and cycling through the ocean interior and on the seafloor, Global Biogeochem. Cy., 21, doi:10.1029/2006GB002907, 2007. Edwards, M. and Richardson, A. J.: Impact of climate change on marine pelagic phenology and trophic mismatch, Nature, 430, 881–884, 2004. Eppley, R. W.: Temperature and phytoplankton growth in the sea, Fish. B., 70, 1063–1085, 1972. Fan, S. M., Moxim, W. J., and Levy, H.: Aeolian input of bioavailable iron to the ocean, Geophys. Res. Lett., 33, L07602; doi:07610.01029/02005GL024852, 2006. Field, C. B., Behrenfeld, M. J., Randerson, J. T., and Falkowski, P. G.: Primary production of the biosphere: Integrating terrestrial and oceanic components, Science, 281, 237–240, 1998. Francis, R. C. and Hare, S. R.: Decadal-scale regime shifts in the large marine ecosystems of the North-east Pacific: a case for historical science, Fish. Oceanogr., 3, 279–291, 1994. Francis, R. C., Hare, S. R., Hollowed, A. B., and Wooster, W. S.: Effects of interdecadal climate variability on the oceanic ecosystems of the NE Pacific, Fish. Oceanogr., 7, 1–21, 1998. Friedrichs, M. A. M., Carr, M.-E., Barber, R., Scardi, M., Antoine, D., Armstrong, R. A., Asanuma, I., Behrenfeld, M. J., Buitenhuis, E. T., Chai, F., Christian, J. R., Ciotti, A. M., Doney, S. C., Dowell, M., Dunne, J. P., Gentili, B., Gregg, W. W., Hoepffner, N., Ishizaka, J., Kameda, T., Lima, I. D., Marra, J., Melin, F., Moore, J. K., Morel, A., O'Malley, R. T., O'Reilly, J., Saba, V. S., Schmeltz, M., Smyth, T. J., Tjiputra, J., Waters, K., Westberry, T. K., and Winguth, A.: Assessing the uncertainties of model estimates of primary productivity in the tropical Pacific Ocean, J. Marine Syst., 76, 113–133, doi:10.1016/j.marsys.2008.05.010, 2009. Geider, R. J.: Light and temperature-dependence of the carbon to chlorophyll-a ratio in microalgae and cyanobacteria – Implications for physiology and growth of phytoplankton, New Phytol., 106, 1–34, 1987. Geider, R. J., MacIntyre, H. L., and Kana, T. M.: Dynamic model of phytoplankton growth and acclimation: responses of the balanced growth rate and the chlorophyll a:carbon ratio to light, nutrient-limitation and temperature, Mar. Ecol.-Prog. Ser., 148, 187–200, 1997. Ginoux, P., Chin, M., Tegen, I., Prospero, J. M., Holben, B., Dubovik, O., and Lin, S. J.: Sources and distributions of dust aerosols simulated with the GOCART model, J. Geophys. Res., 106, 20255–20273, 2001. Gnanadesikan, A., Dixon, K., Griffies, S. M., Balaji, V., Barreiro, M., Beesley, J. A., Cooke, W., Delworth, T., Gerdes, R., Harrison, M. J., Held, I. M., Hurlin, W., Lee, H. C., Liang, Z., Nong, G., Pacanowski, R. C., Rosati, A., Russell, J., Samuels, B. L., Song, Q., Spelman, M., Stouffer, R., Sweeney, C. O., Vecchi, G., Winton, M., Wittenberg, A. T., Zeng, F., Zhang, R., and Dunne, J. P.: GFDL's CM2 global coupled climate models. Part II: The baseline ocean simulation, J. Climate, 19, 675–697, 2006. Gregg, W. W., Casey, N. W., and McClain, C. R.: Recent trends in global ocean chlorophyll, Geophys. Res. Lett., 32, L03606, doi:3610.1029/2004GGL021808, 2005. Gregg, W. W., Conkright, M. E., Ginoux, P., O'Reilly, J. E., and Casey, N. W.: Ocean primary production and climate: Global decadal changes, Geophys. Res. Lett., 30, 1809, doi:10.1029/2003GL016889, 2003. Griffies, S. M., Harrison, M. J., Pacanowski, R. C., and Rosati, A.: A technical guide to MOM4, GFDL Ocean Group Technical Report, Princeton, 2004. Hasselmann, K.: Optimal fingerprints for the detection of time dependent climate change, J. Climate, 6, 1957–1971, 1993. Henson, S. A., Dunne, J. P., and Sarmiento, J. L.: Decadal variability in North Atlantic phytoplankton blooms, J. Geophys. Res., 114, doi:10.1029/2008JC005139, C04013, 2009. Henson, S. A. and Thomas, A. C.: Interannual variability in timing of bloom initiation in the California Current System, J. Geophys. Res., 112, doi:10.1029/2006JC003960, C08007, 2007. Hourdin, F., Musat, I., Bony, S., Braconnot, P., Codron, F., Dufresne, J.-L., Fairhead, L., Filiberti, M.-A., Friedlingstein, P., Grandpeix, J.-Y., Krinner, G., Levan, P., Li, Z.-X., and Lott, F.: The LMDZ4 general circulation model: climate performance and sensitivity to parameterized physics with emphasis on tropical convection, Clim. Dynam., 19, 3445–3482, 2006. Irwin, A. J. and Oliver, M. J.: Are ocean deserts getting larger?, Geophys. Res. Lett., 36, L18609, doi:10.1029/2009GL039883, 2009. Iverson, R. L.: Control of marine fish production, Limnol. Oceanogr., 35, 1593–1604, 1990. Joint, I. and Groom, S. B.: Estimation of phytoplankton production from space: current status and future potential of satellite remote sensing, J. Exp. Mar. Biol. Ecol., 250, 233–255, 2000. Kahru, M., Kudela, R., Manzano-Sarabia, M., and Mitchell, B. G.: Trends in primary production in the California Current detected with satellite data, J. Geophys. Res., 114, C02004, doi: 02010.01029/02008JC004979, 2009. Kahru, M. and Mitchell, B. G.: Ocean color reveals increased blooms in various parts of the world, EOS T. Am. Geophys. Un., 89, 170, doi:10.1029/2008EO180002, 2008. Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W. D., Deaven, D., Gandin, L., Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y., Chelliah, M., Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Leetmaa, A., Reynolds, R., Jenne, R., and Joseph, D.: The NCEP/NCAR 40-year reanalysis project, B. Am. Meteorol. Soc., 77, 437–471, 1996. Key, R. M., Kozyr, A., Sabine, C. L., Lee, K., Wanninkhof, R., Bullister, J., Feely, R. A., Millero, F., Mordy, C., and Peng, T.-H.: A global ocean carbon climatology: results from GLODAP, Global Biogeochem. Cy., 18, GB4031, doi:10.1029/2004GB002247, 2004. Krinner, G., Viovy, N., de Noblet, N., Ogee, J., Polcher, J., Friedlingstein, P., Ciais, P., Sitch, S., and Prentice, I. C.: A dynamic global vegetation model for studies of the coupled atmosphere-biosphere system, Global Biogeochem. Cy., 19, GB1015, doi:10.1029/2003GB002199, 2005. Large, W. and Yeager, S.: Diurnal to decadal global forcing for ocean and sea-ice models: The data sets and flux climatologies, National Center for Atmospheric Research, Boulder, Colorado, Technical Note TN-460+STR, 2004. Large, W. and Yeager, S.: The global climatology of an interannually varying air-sea flux data set, Clim. Dynam., 33, 341–364, 2009. Laws, E. A. and Bannister, T. T.: Nutrient-limited and light-limited growth of Thalassiosira-fluviatilis in continuous culture, with implications for phytoplankton growth in the ocean, Limnol. Oceanogr., 25, 457–473, 1980. Le Quere, C., Raupach, M. R., Canadell, J. G., Marland, G., Bopp, L., Ciais, P., Conway, T. J., Doney, S. C., Feely, R. A., Foster, O., Friedlingstein, P., Gurney, K., Houghton, R. A., House, J. I., Huntingford, C., Levy, P. E., Lomas, M. R., Majkut, J., Metzl, N., Ometto, J. P., Peters, G. P., Prentice, I. C., Randerson, J. T., Running, S. W., Sarmiento, J. L., Schuster, U., Sitch, S., Takahashi, T., Viovy, N., van der Werf, G. R., and Woodward, F. I.: Trends in the sources and sinks of carbon dioxide, Nature Geoscience, 2, 831–836, 2009. Madec, G.: NEMO ocean engine, Note du Pole de modélisation, Institut Pierre-Simon Laplace (IPSL), Paris, No~27, 2008. Madec, G., Delecluse, P., Imbard, M., and Levy, C.: OPA 8.1 ocean general circulation model reference manual, Notes du Pole de modélisation, Institut Pierre-Simon Laplace (IPSL), Paris, No~11, 1998. Madrid, C. R.: The Nimbus 7 users' guide, NASA, Goddard Space Flight Center, 1978. Marra, J., Ho, C., and Trees, C. C.: An alternative algorithm for the calculation of primary productivity from remote sensing data, LDEO #2003-1, Lamont-Doherty Earth Observatory, 2003. Martinez, E., Antoine, D., D'Ortenzio, F., and Gentili, B.: Climate-driven basin-scale decadal oscillations of oceanic phytoplankton, Science, 326, doi:10.1126/science.1177012, 2009. McClain, C. R.: A decade of satellite ocean color observations, Annu. Rev. Mar. Sci., 1, 19–42, 2009. McClain, C. R., Signorini, S. R., and Christian, J. R.: Subtropical gyre variability observed by ocean-color satellites, Deep Sea Res. Pt II, 51, 281–301, 2004. McGowan, J. A., Cayan, D. R., and Dorman, L. M.: Climate-ocean variability and ecosystem response in the northeast Pacific, Science, 281, 210–217, 1998. Michaels, A. F. and Silver, M. W.: Primary production, sinking fluxes and the microbial food web, Deep Sea Res. A, 35, 473–490, 1988. Milutinovic, S., Behrenfeld, M. J., Johannessen, J. A., and Johannessen, T.: Sensitivity of remote sensing-derived phytoplankton productivity to mixed layer depth: Lessons from the carbon-based productivity model, Global Biogeochem. Cy., 23, GB4005, doi:4010.1029/2008GB003431, 2009. Moore, J. K. and Doney, S. C.: Iron availability limits the ocean nitrogen inventory stabilizing feedbacks between marine denitrification and nitrogen fixation, Global Biogeochem. Cy., 21, GB2001, doi:10.1029/2006GB002762, 2007. Moore, J. K., Doney, S. C., and Lindsay, K.: Upper ocean ecosystem dynamics and iron cycling in a global 3-D model, Global Biogeochem. Cy., 18, GB4028, doi:10.1029/2004GB002220, 2004. Moore, J. K., Doney, S. C., Lindsay, K., Mahowald, N., and Michaels, A. F.: Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition, Tellus B, 58, 560–572, 2006. Nakicenovic, N. and Swart, R.: Special Report on Emissions Scenarios. A special report of Working Group III of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, 2000. Polovina, J. J., Howell, E. A., and Abecassis, M.: Ocean's least productive waters are expanding, Geophys. Res. Lett., 35, 3618, doi:3610.1029/2007GL031745, 2008. Raupach, M. R., Marland, G., Ciais, P., Le Quere, C., Canadell, J. G., Klepper, G., and Field, C. B.: Global and regional drivers of accelerating CO2 emissions, Proceedings of the National Academy of Sciences, 104, 10288–10293, 2007. Riley, G. A.: Phytoplankton of the North Central Sargasso Sea, Limnol. Oceanogr., 2, 252–270, 1957. Sarmiento, J. L., Slater, R., Barber, R., Bopp, L., Doney, S. C., Hirst, A. C., Kleypas, J., Matear, R., Mikolajewicz, U., Monfray, P., Soldatov, V., Spall, S. A., and Stouffer, R.: Response of ocean ecosystems to climate warming, Global Biogeochem. Cy., 18, GB3003, doi:3010.1029/2003GB002134, 2004. Schneider, B., Bopp, L., Gehlen, M., Segschneider, J., Frölicher, T. L., Cadule, P., Friedlingstein, P., Doney, S. C., Behrenfeld, M. J., and Joos, F.: Climate-induced interannual variability of marine primary and export production in three global coupled climate carbon cycle models, Biogeosciences, 5, 597–614, 2008. Steinacher, M., Joos, F., Frölicher, T. L., Bopp, L., Cadule, P., Doney, S. C., Gehlen, M., Schneider, B., and Segschneider, J.: Projected 21st century decrease in marine productivity: a multi-model analysis, Biogeosciences Discuss., 6, 7933–7981, 2009. Stone, D. A., Weaver, A. J., and Stouffer, R.: Projection of climate change onto modes of atmospheric variability, J. Climate, 14, 3551–3565, 2001. Sunda, W. G. and Huntsman, S. A.: Iron uptake and growth limitation in oceanic and coastal phytoplankton, Mar. Chem., 50, 189–206, 1995. Sunda, W. G. and Huntsman, S. A.: Interrelated influence of iron, light and cell size on marine phytoplankton growth, Nature, 390, 389–392, 1997. Tagliabue, A., Bopp, L., Aumont, O., and Arrigo, K. R.: Influence of light and temperature on the marine iron cycle: From theoretical to global modeling, Global Biogeochem. Cy., 23, GB2017, doi:2010.1029/2008GB003214, 2009. Takahashi, T., Broecker, W. S., and Langer, S.: Redfield ratio based on chemical data from isopycnal surfaces, J. Geophys. Res., 90, 6907–6924, 1985. Tegen, I. and Fung, I.: Contribution to the atmospheric mineral aerosol load from land surface modification, J. Geophys. Res., 100, 18707–18726, 1995. Thornton, P. E., Doney, S. C., Lindsay, K., Moore, J. K., Mahowald, N., Randerson, J. T., Fung, I., Lamarque, J.-F., Feddema, J. J., and Lee, Y.-H.: Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere-ocean general circulation model, Biogeosciences, 6, 2099–2120, 2009. Tiao, G. C., Reinsel, G. C., Xu, D., Pedrick, J. H., Zhu, X., Miller, A. J., DeLuisi, J. J., Mateer, C. L., and Wuebbles, D. J.: Effects of autocorrelation and temporal sampling schemes on estimates of trend and spatial correlation, J. Geophys. Res., 95, 20507–20517, 1990. Ware, D. M. and Thomson, R. E.: Bottom-up ecosystem trophic dynamics determine fish production in the Northeast Pacific, Science, 308, 1280–1284, 2005. Weatherhead, E. C., Reinsel, G. C., Tiao, G. C., Meng, X.-L., Choi, D., Cheang, W.-K., Keller, T., DeLuisi, J., Wuebbles, D. J., Kerr, J. B., Miller, A. J., Oltmans, S. J., and Frederick, J. E.: Factors affecting the detection of trends: Statistical considerations and applications to environmental data, J. Geophys. Res., 103, 17149–17161, 1998.