Space-based observations provide synoptic coverage of surface ocean temperature, winds, sea surface height, and color useful to a wide range of oceanographic applications. These measurements are increasingly applied to monitor large-scale environmental and climate processes that can have an impact on important managed marine resources. From observing the development of harmful algal blooms using ocean color to tracking regions of thermal stress that can induce coral bleaching, satellites are routinely used for environmental monitoring. Here, we demonstrate an approach to monitoring changes in sea surface ocean chemistry in response to ocean acidification as applied to the Greater Caribbean Region. The method is based on regionally specific empirical algorithms derived from ongoing ship measurements applied to remotely sensed observables. This tool is important for exploring regional to basinwide trends in ocean acidification on seasonal to interannual time scales.

Gledhill, D.K., R. Wanninkhof, and C.M. Eakin. 2009. Observing ocean acidification from space. Oceanography 22(4):48–59, https://doi.org/10.5670/oceanog.2009.96.

Andersson, A.J., I.B. Kuffner, F.T. Mackenzie, P.L. Jokiel, K.S. Rodgers, and A. Tan. 2009. Net loss of CaCO₃ from a subtropical calcifying community due to seawater acidification: Mesocosm-scale experimental evidence. Biogeosciences 6:1,811–1,823.

Anthony, K.R.N, D.L Kline, G. Diaz-Pulido, S. Dove, and O. Hoegh-Guldberg. 2008. Ocean acidification causes bleaching and productivity loss in coral reef builders. Proceedings of the National Academy of Sciences of the United States of America 105:17,442–17,446.

Balch, W.M., H.R. Gordon, B.C. Bowler, D.T. Drapeau, and E.S. Booth. 2005. Calcium carbonate budgets in the surface global ocean based on MODIS data. Journal of Geophysical Research 110, C07001, doi:10.1029/2004JC002560.

Bates, N.R. 2007. Interannual variability of the oceanic CO₂ sink in the subtropical gyre of the North Atlantic Ocean over the last 2 decades. Journal of Geophysical Research 112, C09013, doi:10.1029/2006JC003759.

Bates, N.R., A. Amat, and A.J. Andersson. In press. The interaction of ocean acidification and carbonate chemistry on coral reef calcification: Evaluating the carbonate chemistry Coral Reef Ecosystem Feedback (CREF) hypothesis on the Bermuda coral reef. Biogeosciences Discussions 6:7,627–7,672.

Behrenfeld, M.J., and P.G. Falkowski. 1997. A consumer’s guide to phytoplankton primary productivity models. Limnology and Oceanography 42(7):1,479–1,491.

Crawley, A., D.L. Kline, S. Dunn, K. Anthony, and S. Dove. 2009. The effect of ocean acidification on symbiont photorespiration and productivity in Acropora formosa. Global Change Biology doi:10.1111/j.1365-2486.2009.01943.x.

De’ath, G., J.M. Lough, and K.E. Fabricius. 2009. Declining coral calcification on the Great Barrier Reef. Science 323:116–119.

Doney, S.C., V.J. Fabry, R.A. Feely, and J.A. Kleypas. 2009. Ocean acidification: The other CO₂ problem. Annual Review of Marine Science 1:169–192, doi:10.1146/annurev.marine.010908.163834.

Eakin, C.M., J.M. Lough, and S.F. Heron. 2009. Climate, weather and coral bleaching. Pp. 41–67 in Coral Bleaching: Patterns, Processes, Causes and Consequences. M.J.H. van Oppen and J.M. Lough, eds, Springer.

Feely, R.A., C.L. Sabine, J.M. Hernandez-Ayon, D. Ianson, and B. Hales. 2008. Evidence for upwelling of corrosive “acidified” water onto the continental shelf. Science 320(5882):1,490–1,492.

Friedrich, T., and A. Oschlies. 2009. Neural network-based estimates of North Atlantic surface pCO₂ from satellite data: A methodological study. Journal of Geophysical Research 114, C03020, doi:10.1029/2007JC004646.

Gattuso, J.-P., M. Frankignoulle, and S.V. Smith. 1999. Measurement of community metabolism and significance in the coral reef CO₂ source-sink debate. Proceedings of the National Academy of Sciences of the United States of America 96(23):13,017–13,022.

Gledhill, D.K., R. Wanninkhof, F.J. Millero, and C.M. Eakin. 2008. Ocean acidification of the Greater Caribbean Region. Journal of Geophysical Research 113, C10031, doi:10.1029/2007JC004629.

Glynn, P.W. 1997. Bioerosion and coral reef growth: A dynamic balance. Pp. 68–95 in Life and Death on Coral Reefs. C. Birkeland, ed., Chapman and Hall, New York.

Hoegh-Guldberg O., P.J. Mumby, A.J. Hooten, R.S. Steneck, P. Greenfield, E. Gomez, C.D. Harvell, P.F. Sale, A.J. Edwards, K. Caldeira, and others. 2007. Coral reefs under rapid climate change and ocean acidification. Science 318:1,737–1,742.

Kalteh, A.M., P. Hjorth, and R. Berndtsson. 2008. Review of the self-organizing map (SOM) approach in water resources: Analysis, modeling and application. Environmental Modeling & Software 23:835–845.

Kawahata, H., A. Suzuki, and K. Goto. 1997. Coral reef ecosystems as a source of atmospheric CO₂: Evidence from pCO₂ measurements of surface waters. Coral Reefs 16:261–266.

Langdon, C., and M.J. Atkinson. 2005. Effect of elevated pCO₂ on photosynthesis and calcification of corals and interactions with seasonal change in temperature/irradiance and nutrient enrichment. Journal of Geophysical Research 110, C09S07, doi:10.1029/2004JC002576.

Langdon, C., T. Takahashi, C. Sweeney, D. Chipman, and J. Goddard. 2000. Effect of carbonate saturation state on the calcification rate of an experimental coral reef. Global Biogeochemical Cycles 14(2):639–654.

Lee, K., L.T. Tong, F.J. Millero, C.L. Sabine, A.G. Dickson, C. Goyet, G.-H. Park, R. Wanninkhof, R.A. Feely, and R.M. Key. 2006. Global relationships of total alkalinity with salinity and temperature in surface waters of the world’s oceans. Geophysical Research Letters 33, L1905, doi:10.1029/2006GL027207.

Lee, K.T., R. Wanninkhof, T. Takahashi, S.C. Doney, and R.A. Feely. 1998. Low interannual variability in recent oceanic uptake of atmospheric carbon dioxide. Nature 396:155–159.

Lefèvre, N., J. Aiken, J. Rutllant, G. Daneri, S. Lavender, T. Smyth. 2002. Observations of pCO₂ in the coastal upwelling off Chile: Spatial and temporal extrapolation using satellite data. Journal of Geophysical Research 107, C6, doi:10.1029/2000JC000395.

Lewis, E., and D.W.R. Wallace. 1998. Program Developed for CO₂ System Calculations. ORNL/CDIAC-105. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, TN.

Lohrenz, S.E., and W.J. Cai. 2006. Satellite ocean color assessment of air-sea fluxes of CO₂ in a river dominated coastal margin. Geophysical Research Letters 33, doi:10.1029/2005GL023942.

Manzello, D.P., J.A. Kleypas, D.A. Budd, C.M. Eakin, P.W. Glynn, and C. Langdon. 2008. Poorly cemented coral reefs of the eastern tropical Pacific: Possible insights into reef development in a high-CO₂ world. Proceedings of the National Academy of Sciences of the United States of America 105(30):10,450–10,455.

Morse, J.W., and R.S. Arvidson. 2002. The dissolution kinetics of major sedimentary carbonate minerals. Earth-Science Reviews 58:51–84.

Morse, J.W., D.K. Gledhill, F.J. Millero. 2006. CaCO₃ precipitation kinetics in waters from the Great Bahama Bank: Implications for the relationship between Bank hydrochemistry and whitings. Geochimica et Cosmochimica Acta 67(15):2,819–2,826.

Nelson, N.B., N.R. Bates, D.A. Siegel, and A.F. Michaels. 2001. Spatial variability of the CO₂ sink in the Sargasso Sea. Deep Sea Research Part II 48:1,801–1,821.

Olsen, A., J.A. Trinanes, and R. Wanninkhof. 2004. Sea-air flux of CO₂ in the Caribbean Sea estimated using in situ and remote sensing data. Remote Sensing of the Environment 89:309–325.

Ono, T., T. Saino, N. Kurita, and K. Sasaki. 2004. Basin-scale extrapolation of shipboard pCO₂ data by using satellite SST and Chla. International Journal of Remote Sensing 25(19):3,803–3,815.

Orr, J.C., V.J. Fabry, O. Aumount, L. Bopp, S.C. Doney, R.A. Feely, A. Gnanadesikan, N. Gruber, A. Ishida, F. Joos, and others. 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437:681–686.

Reynolds, R.W., N.A. Rayner, T.M. Smith, D.C. Stokes, and W. Wang. 2002. An improved in situ and satellite SST analysis for climate. Journal of Climate 15:1,609–1,625.

Richardson, A.J., C. Risien, and F.A. Shillington. 2003. Using self-organizing maps to identify patterns in satellite imagery. Progress in Oceanography 59:223–239.

Sabine, C.L., R.A. Feely, N. Gruber, R.M. Key, K. Lee, J.L. Bullister, R. Wanninkhof, C.S. Wong, D.W.R. Wallace, B. Tilbrook, and others. 2004. The oceanic sink for anthropogenic CO₂. Science 305:367–371.

Salisbury, J.S, D. Vandemark, A. Mahadevan, B. Jonsson, C.Hunt, J.W. Campbell, and W. McGillis. 2008. Episodic riverine influence on surface DIC in the coastal Gulf of Maine. Estuarine, Coast and Shelf Science 82(1):108–118, doi:10.1016/
j.ecss.2008.12.021

Silverman, J., B. Lazar, L. Cao, K. Caldeira, and J. Erez. 2009. Coral reefs may start dissolving when atmospheric CO₂ doubles. Geophysical Research Letters 36, L05606, doi:10.1029/2008GL036282.

Stephens, M.P., G. Samuels, D.B. Olson, and R.A. Fine. 1995. Sea-air flux of CO₂ in the North Pacific using shipboard and satellite data. Journal of Geophysical Research 100(C7):13,571–13,583.

Suzuki, A., H. Kawahata. 2004. Reef water CO₂ system and carbon production of coral reefs: Topographic control of system-level performance. Pp. 229–248 in Global Environmental Change in the Ocean and on Land. M. Shiyomi et al., eds, Terrapub.

Takahashi, T., R.A. Feely, R. Weiss, R.H. Wanninkhof, D.W. Chipman, S.C. Sutherland, and T.T. Takahashi. 1997. Global air-sea flux of CO₂: An estimate based on measurements of sea-air pCO₂ difference. Proceedings of the National Academy of Sciences of the United States of America 94:8,292–8,299.

Takahashi, T., S.C. Sutherland, R. Wanninkhof, C. Sweeney, R.A. Feely, D.W. Chipman, B. Hales, G. Friederich, F. Chavez, C. Sabine, and others. 2009. Climatological mean and decadal change in surface ocean pCO₂, and net sea-air CO₂ flux over the global oceans. Deep-Sea Research Part II 56(8–10):554–577.

Telszewski, M., A. Chazottes, U. Schuster, A.J. Watson, C. Moulin, D.C.E. Bakker, M. González-Dávila, T. Johannessen, A. Körtzinger, H. Lüger, and others. 2009. Estimating the monthly pCO₂ distribution in the North Atlantic using a self-organizing neural network. Biogeosciences 6:1,405–1,421.

Veron, J.E.N., O. Hoegh-Guldberg, T.M. Lenton, J.M. Lough, D.O. Obura, P. Pearce-Kelly, C.R.C. Sheppard, M. Spalding, M.G. Stafford-Smith, and A.D. Rogers. 2009. The coral reef crisis: The critical importance of < 350 ppm CO₂. Marine Pollution Bulletin 58(10):1,428–1,436, doi:10.1016/
j.marpolbul.2009.09.009.

Wanninkhof, R., A. Olsen, and J. Triñanes. 2007. Air-sea CO₂ fluxes in the Caribbean Sea from 2002–2004. Journal of Marine Systems 66:272–284.

Wilkinson, C., and D. Souter. 2008. Status of Caribbean Coral Reefs after Bleaching and Hurricanes in 2005. Global Coral Reef Monitoring Network, and Reef and Rainforest Research Centre, Townsville, Australia, 152 pp.

Yates, K.K., and R.B. Halley. 2006. CO₃^2– concentration and pCO₂ thresholds for calcification and dissolution on the Molokai reef flat, Hawaii. Biogeosciences 3:1–13.

This is an open access article made available under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately, provide a link to the Creative Commons license, and indicate the changes that were made to the original content. Images, animations, videos, or other third-party material used in articles are included in the Creative Commons license unless indicated otherwise in a credit line to the material. If the material is not included in the article’s Creative Commons license, users will need to obtain permission directly from the license holder to reproduce the material.