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Greg Mitchell
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Research Biologist in Photobiology Group at Scripps Institution of Oceanography
Recent PACE-related Publications | See All ►
Optimized Multi-Satellite Merger of Primary Production Estimates in the California Current Using Inherent Optical Properties (2015)
A Synthesis of Light Absorption Properties of the Arctic Ocean: Application to Semianalytical Estimates of Dissolved Organic Carbon Concentrations from Space (2014)
Ocean-Color Radiometry Across the Southern Atlantic and Southeastern Pacific: Accuracy and Remote Sensing Implications (2014)
Light and Nutrient Control of Photosynthesis in Natural Phytoplankton Populations from the Chukchi and Beaufort Seas, Arctic Ocean (2013)

Science Meeting Presentations (4)

Improved Satellite Ocean Color Retrievals of Ocean Inherent Optical Properties and Biogeochemical Properties Utilizing the Capabilities of PACE
Mitchell, B.G., Kahru, M., and Vasilkov, A. (16-Jan-18). Click here to view this presentation with audio.
Improved Satellite Ocean Color Retrievals of Ocean Inherent Optical Properties and Biogeochemical Properties Utilizing the Capabilities of PACE
Mitchell, B.G., Kahru, M., and Vasilkov, A. (17-Jan-17)
Improved Satellite Ocean Color Retrievals of Ocean Inherent Optical Properties and Biogeochemical Properties Utilizing the Capabilities of PACE
Mitchell, G. and Kahru, M. (21-Jan-16)
Improved Satellite Ocean Color Retrievals of Ocean Inherent Optical Properties and Biogeochemical Properties Utilizing the Capabilities of PACE
Mitchell, G. and Kahru, M. (14-Jan-15)

ROSES Proposal

Improved Satellite Ocean Color Retrievals of Ocean Inherent Optical Properties and Biogeochemical Properties Utilizing the Capabilities of PACE
To support algorithm development for PACE, we propose to use a globally diverse and detailed optical and biogeochemical data set to develop new parameterizations of absorption and scattering, to advance our understanding of the scattering phase function, and to assess closure of forward and inverse model predictions compared to measured optical and biogeochemical variables. Our data spans the range of spectral relevance for PACE for ocean retrievals (350-750 nm) and includes inherent and apparent optical properties (IOP, AOP) and the most fundamental biogeochemical parameters of interest for remote sensing of ocean ecology. Contemporary satellite retrievals of several IOP variables (phytoplankton absorption, the sum of detrital and correlated spectral channels on orbit. These limitations restrict retrievals of IOPs at few wavelengths and limit our ability to accurately estimate chlorophyll a, particulate organic carbon, and adg, defined as the sum of soluble absorption and detrital particle absorption (CHLA, POC and adg). Using our global data set, we evaluate in this proposal the performance of current empirical and inverse algorithms demonstrating important limitations that can be greatly improved by the work we propose. Combining our uniquely detailed and global data set with UV-Vis numerical modeling in Hydrolight we propose to develop new parameterizations of relationships between the most important ecological variables that govern upper ocean IOP and AOP over the extended spectral range of PACE (350-750 nm). Due to the improved spectral range and resolution of PACE, we envision an ability to broaden the number of biogeochemical constituents to also include UV-absorbing mycosporine amino acids (MAA), phycobiliproteins (PBP) and particle size distribution (PSD ) that are needed to specify phytoplankton functional groups and plankton ecosystem structure. PSD data will be based on our global observations of Coulter Counter size distributions and flow cytometer (FCYT) analysis. FCYT data will provide important details of phytoplankton functional groups and size distributions, 2 µm. We will analyze our liquid nitrogen archived samples for FCYT, MAA and PBP collected over the past 15 years and integrate these new analytical results to our uniquely detailed and global data base to allow us to pursue our proposed goals. Our goal will be to develop forward models of IOP and AOP as governed by CHLA, POC, adg, MAA, PBP and PSD. We will implement a system of optimization combining Hydrolight code extended to the UV, and our large, detailed and globally distributed measurements, to develop forward radiative transfer models dependent on the expanded set of biogeochemical variables. We will use our optimized data to create synthesized ocean spectral reflectance 350-750 nm that will be combined with our expanded set of biogeochemical observations to develop novel inverse algorithms for PACE (MAA, PBP, Nd), spectral values of IOPs, and more robust algorithms for the heritage retrievals (CHLA, POC, adg). We will also utilize our hyperspectral global ocean phytoplankton absorption, HPLC pigments, MAA, PBP and Nd data to develop improved estimates of phytoplankton functional groups. As we did for SeaWiFS (SeaBAM; O'Reilly et al. 1998), as participants in the PACE Science Team we will evaluate our data, models and satellite algorithms in a collaborative way to contribute to the community goal of robust consensus algorithms for a dramatically expanded set of biogeochemical variables that will be enabled by the capabilities of PACE.

Publications (59)

Kahru, M., Jacox, M.G., Lee, Z., Kudela, R.M., Manzano-Sarabia, M., and Mitchell, B.G. (2015). Optimized Multi-Satellite Merger of Primary Production Estimates in the California Current Using Inherent Optical Properties, J. Mar. Syst., 147, 94-102, doi: 10.1016/j.jmarsys.2014.06.003.
Matsuoka, A., Babin, M., Doxaran, D., Hooker, S.B., Mitchell, B.G., Bélanger, S., and Bricaud, A. (2014). A Synthesis of Light Absorption Properties of the Arctic Ocean: Application to Semianalytical Estimates of Dissolved Organic Carbon Concentrations from Space, Biogeosciences, 11, 3131-3147, doi: 10.519/Bg-Ll-3131-2014.
Rudorff, N.D., Frouin, R., Kampel , M., Goyens, C., Meriaux, X., Schieber, B., and Mitchell, B.G. (2014). Ocean-Color Radiometry Across the Southern Atlantic and Southeastern Pacific: Accuracy and Remote Sensing Implications, Remote Sens. Environ., 149, 13-32, doi: /10.1016/J.Rse.2014.03.029.
Palmer, M.A., Van Dijken, G.L., Mitchell, B.G., Seegers, B.J., Lowry, K.E., Mills, M.M., and Arrigo, K.R. (2013). Light and Nutrient Control of Photosynthesis in Natural Phytoplankton Populations from the Chukchi and Beaufort Seas, Arctic Ocean, Limnol. Oceanogr., 58(6), 2185-2205, doi: 10.4319/lo.2013.58.6.2185.
Kahru, M., Lee, Z.P., Kudela, R.M., Manzano-Sarabia, M., and Mitchell, B.G. (2013). Multi-Satellite Time Series of Inherent Optical Properties in the California Current, Deep-Sea Res., 112, 91-106, doi: 10.1016/J.Dsr2.2013.07.023.
Peloquin, J.A., Swan, C.M., Gruber, N., Vogt, M., Claustre, H., Ras, J., Uitz, J., Barlow, R.G., Behrenfeld, M., Bidagare, R., Dierssen, H., Ditullio, G.R., Fernandez, E., Gallienne, C., Gibb, S., Goericke, R., Harding, L., Head, E., Holligan, P.M., Hooker, S.B., Karl, D., Landry, M., Letelier, R., Llewellyn, C.A., Lomas, M., Lucas, M., Mannino, A., Marty, J.-C., Mitchell, B.G., Muller-Karger, F., Nelson, N., O'Brien, C., Prezelin, B.B., Repeta, D., Smith, W.O., Smythe-Wright, D., Stumpf, R.P., Subramaniam, A., Suzuki, K., Trees, C.C., Vernet, M., Wasmund, N., and Wright, S. (2013). The MAREDAT Global Database of High Performance Liquid Chromatography Marine Pigment Measurements, Earth Syst. Sci. Data, 5, 109-123, doi: 10.5194/Essd-5-109-2013.
Kahru, M., Kudela, R., Manzano-Sarabia, M., and Mitchell, B.G. (2012). Trends in the Surface Chlorophyll of the California Current: Merging Data from Multiple Ocean Color Satellites, Deep-Sea Res., 77-80, 89-98, doi: 10.1016/J.Dsr2.2012.04.007.
Arrigo, K.R., Perovich, D.K., Pickart, R.S., Brown, Z.W., Van Dijken, G.L., Lowry, K.E., Mills, M.M., Palmer, M.A., Balch, W.M., Bahr, F., Bates, N.R., Benitez-Nelson, C., Bowler, B., Brownlee, E., Ehn, J.K., Frey, K.E., Garley, R., Laney, S.R., Lubelczyk, L., Mathis, J., Matsuoka, A., Mitchell, B.G., Moore, G.W.K., Ortega-Retuerta, E., Pal, S., Polashenski, C.M., Reynolds, R.A., Scheiber, B., Sosik, H.M., Stephens, M., and Swift, J.H. (2012). Massive Phytoplankton Blooms Under Arctic Sea Ice, Science, 336(6087), 1408, doi: 10.1126/science.1215065.
Nevison, C.D., Keeling, R.F., Kahru, M., Manizza, M., and Mitchell, B.G. (2012). Estimating Net Community Production in the Southern Ocean Based on Atmospheric Potential Oxygen and Satellite Ocean Color Data, Global Biogeochem. Cy., 26(1), GB1020, doi: 10.1029/2011GB004040.
Kahru, M., Di Lorenzo, E., Manzano-Sarabia, M., and Mitchell, B.G. (2012). Spatial and Temporal Statistics of Sea Surface Temperature and Chlorophyll Fronts in the California Current, J. Plankton Res., doi: 10.1093/Plankt/Fbs010.
Kahru, M., Gille, S.T., Murtugudde, R., Strutton, P., Manzano-Sarabia, M., Wang, H., and Mitchell, B.G. (2010). Global Correlations Between Winds and Ocean Chlorophyll, J. Geophys. Res. Oceans, 115(C12), C12040, doi: 10.1029/2010JC006500.
Allison, D.B., Stramski, D., and Mitchell, B.G. (2010). Empirical Ocean Color Algorithms for Estimating Particulate Organic Carbon in the Southern Ocean, J. Geophys. Res., 115(C10), C10044, doi: 10.1029/2009JC006040.
Kahru, M., Brotas, V., Manzano-Sarabia, M., and Mitchell, B.G. (2010). Are Phytoplankton Blooms Occurring Earlier in the Arctic?, Global Change Biol., 17(4), 1733-1739, doi: 10.111/J.1365-2486.2010.02312x.
Allison, D., Stramski, D., and Mitchell, B.G. (2010). Seasonal and Interannual Variability of Particulate Organic Carbon Within the Southern Ocean from Satellite Ocean Color Observation, J. Geophys. Res., 115(C6), C06002, doi: 10.1029/2009JC005347.
Kahru, M., Kudela, R., Manzano-Sarabia, M., and Mitchell, B.G. (2009). Trends In Primary Production in the California Current Detected with Satellite Data, J. Geophys. Res. Oceans, 114(C2), C02004, doi: 10.1029/2008JC004979.
Mitchell, B.G. and Kahru, M. (2009). Bio-Optical Algorithms for ADEOS-2 GLI, J. Remote Sens. Soc. Japan, 29(1), 80-85.
Kahru, M. and Mitchell, B.G. (2008). Ocean Color Reveals Increased Blooms in Various Parts of the World, Eos Trans. AGU, 89(18), 170-170, doi: 10.1029/2008EO180002.
Hiscock, M., Lance, V., Apprill, A., Bidagare, R., Johnson, Z., Mitchell, B.G., Smith, W., and Barber, R. (2008). Photosynthetic Maximum Quantum Yield Increases Are an Essential Component of the Southern Ocean Phytoplankton Response to Iron, P. Natl. Acad. Sci. USA, 105 12, 4775-4780, doi: 10.1073/pnas.0705006105.
Kahru, M., Fiedler, P.C., Gille, S.T., Manzano, M., and Mitchell, B.G. (2007). Sea Level Anomalies Control Phytoplankton Biomass in the Costa Rica Dome Area, Geophys. Res. Lett., 34(22), L22601, doi: 10.1029/2007GL031631.
Kahru, M., Mitchell, B.G. Gille, S.T., Hewes, C.D., and Holm-Hansen, O. (2007). Eddies Enhance Biological Production In the Weddell-Scotia Confluence of the Southern Ocean, Geophys. Res. Let., 34(14), L14603, doi: 10.1029/2007GL030430.
Murakami, H., Sasaoka, K., Hosoda, K., Fukushima, H., Toratani, M., Frouin, R., Mitchell, B.G., Kahru, M., Deschamps, P.Y., Clark, D., Flora, S., Kishino, M., Saitoh, S., Asanuma, I., Tanaka, A., Sasaki, H., Yokouchi, K., Kiyomoto, Y., Saito, H., Dupouy, C., Siripong, A., Matsumura, S., and Ishizaka, J. (2006). Validation of ADEOS-II GLI Ocean Color Products Using In-Situ Observations, J. Oceanogr., 62(3), 373-393, doi: 10.1007/S10872-006-0062-6.
Vasilkov, A.P., Herman, J.R., Ahmad, Z., Kahru, M., and Mitchell, B.G. (2005). Assessment of the Ultraviolet Radiation Field in Ocean Waters from Space-Based Measurements and Full Radiative-Transfer Calculations, Appl. Opt. 44(14), 2863-2869, doi: 10.1364/AO.44.002863.
Holm-Hansen, O., Kahru, M., Hewes, C.D., Kawaguchi, S., Kameda, T., Sushin, V.A., Krasovski, I., Priddle, J., Korb, R., Hewitt, R.P., and Mitchell, B.G. (2004). Temporal and Spatial Distribution of Chlorophyll-A in Surface Waters of the Scotia Sea as Determined by Both Shipboard Measurements and Satellite Data, Deep-Sea Res., 51(12-13), 1323-1331, doi: 10.1016/j.dsr2.2004.06.004.
Kahru, M., Marinone, S.G., Lluch-Cota, S.E., Pares-Sierra, A., and Mitchell, B.G. (2004). Ocean-Color Variability in the Gulf of California: Scales from Days to ENSO, Deep-Sea Res., 51(1-3), 139-146, doi: 10.1016/j.dsr2.2003.04.001.
Carder, K.L., Chen, R.F., Cannizzaro, J.P., Campbell, J.W., and Mitchell, B.G. (2004). Performance of the MODIS Semi-Analytical Ocean Color Algorithm for Chlorophyll-a, Adv. Space Res., 33(7), 1152-1159, doi: 10.1016/S0273-1177(03)00365-X.
Li, L.P., Fukushima, H., Frouin, R., Mitchell, B.G., He, M.X., Uno, I., Takamura, T., and Ohta, S. (2003). Influence of Submicron Absorptive Aerosol on Sea-Viewing Wide Field-of-View Sensor (SeaWiFS)-Derived Marine Reflectance During Aerosol Characterization Experiment (ACE)-Asia, J. Geophys. Res. Atmospheres, 108(D15), 4472, doi: 10.1029/2002JD002776.
Vassilkov, A.P., Herman, J.R., Krotkov, N.A., Kahru, M., Mitchell, B.G., and Hsu, C. (2002). Problems in Assessment of the UV Penetration Into Natural Waters from Space-Based Measurements, Opt. Eng., 41(12), 3019-3027, doi: 10.1117/1.1516822.
Kahru, M. and Mitchell, B.G. (2002). Influence of the El Niño - La Niña Cycle on Satellite-Derived Primary Production in the California Current, Geophys. Res. Lett., 29(17), 1846, doi: 10.1029/2002GL014963.
Pegau, S., Zanefeld, J.R.V., Mitchell, B.G., Mueller, J.L., Kahru, M., Wieland, J., and Stramska, M. (2002). Inherent Optical Properties: Instruments, Characterizations, Field Measurements and Data Analysis Protocols, In Ocean Optics Protocols For Satellite Ocean Color Sensor Validation, Revision 4, Volume IV, (J.L. Mueller, G.S. Fargion, and C.R. Mcclain, eds.), NASA/TM-2003-211621/Rev4-Vol.IV.
Schwarz, J.N., Kowalczuk, P., Kaczmarek, S., Cota, G.F., Mitchell, B.G., Kahru, M., Chavez, F.P., Cunningham, A., McKee, D., Gege, P., Kishino, M., Phinney, D.A., and Raine, R. (2002). Two Models for Absorption by Coloured Dissolved Organic Matter (CDOM), Oceanologia, 44(2), 209-241.
Loisel, H., Stramski, D., Mitchell, B.G., Fell, F., Fournier-Sicre, V., Lemasle, B., and Babin, M. (2001). Comparison of the Ocean Inherent Optical Properties Obtained from Measurements and Inverse Modeling, Appl. Opt., 40(15), 2384-2397, doi: 10.1364/AO.40.002384.
Reynolds, R.A., Stramski, D., and Mitchell, B.G. (2001). A Chlorophyll-Dependent Semianalytical Reflectance Model Derived from Field Measurements of Absorption and Backscattering Coefficients Within the Southern Ocean, J. Geophys. Res., 106(C4), 7125-7138, doi: 10.1029/1999JC000311.
Kahru, M. and Mitchell, B.G. (2001). Seasonal and Nonseasonal Variability of Satellite-Derived Chlorophyll and Colored Dissolved Organic Matter Concentration in the California Current, J. Geophys. Res. Oceans, 106(C2), 2517-2529, doi: 10.1029/1999JC000094.
Moisan, T.A. and Mitchell, B.G. (2001). UV Absorption by Mycosporine-Like Amino Acids in Phaeocystis Antarctica Karsten Induced by Photosynthetically Available Radiation, Mar. Biol., 138(1), 217-227, doi: 10.1007/s002270000424.
Kahru, M. and Mitchell, B.G. (2000). Influence of the 1997-98 El Niño in the Surface Chlorophyll in the California Current, Geophys. Res. Lett., 27(18), 2937-2940, doi: 10.1029/2000GL011486.
Stramska, M., Stramski, D., Mitchell, B.G. and Mobley, C.D. (2000). Estimation of the Absorption and Backscattering Coefficients from In-Water Radiometric Measurements, Limnol. Oceanogr., 45(3), 628-641, doi: 10.4319/lo.2000.45.3.0628.
Gross, L., Thiria, S., Frouin, R., and Mitchell, B.G. (2000). Artificial Neural Networks for Modeling the Transfer Function Between Marine Reflectance and Phytoplankton Pigment Concentration, J. Geophys. Res. Oceans, 105(C2), 3483-3495, doi: 10.1029/1999JC900278.
O (2000). Ocean Color Chlorophyll a Algorithms For SeaWiFS, OC2, and OC4: Version 4, In SeaWiFS Postlaunch Technical Report Series (Hooker, S.B and Firestone, E.R., eds.), 11, SeaWiFS Postlaunch Calibration and Validation Analyses, Part 3.
Stramski, D., Reynolds, R.A., Kahru, M., and Mitchell, B.G. (1999). Estimation of Particulate Organic Carbon in the Ocean from Satellite Remote Sensing, Science, 285(5425), 239-242, doi: 10.1126/science.285.5425.239.
Nakajima, T., Higurashi, A., Aoki, K., Endoh, T., Fukushima, H., Toratani, M., Mitomi, Y., Mitchell, B.G., and Frouin, R. (1999). Early Phase Analysis of OCTS Radiance Data for Aerosol Remote Sensing, IEEE Geosci. Remote S., 37(3), 1575-1585, doi: 10.1109/36.763268.
Moisan, T.A. and Mitchell, B.G. (1999). Photophysiological Acclimation of Phaeocystis Antarctica Karsten Under Light Limitation, Limnol. Oceanogr., 44(2), 247-258, doi: 10.4319/lo.1999.44.2.0247.
Kahru, M. and Mitchell, B.G. (1999). Empirical Chlorophyll Algorithm and Preliminary SeaWiFS Validation for the California Current, Intl. J. Remote Sens., 20(N17), 3423-3429, doi: 10.1080/014311699211453.
O'Reilly, J.E., Maritorena, S., Mitchell, B.G., Siegel, D.A., Carder, K.L., Garver, S.A., Kahru, M., and McClain, C. (1998). Ocean Color Chlorophyll Algorithms For SeaWiFS, J. Geophys. Res. Oceans, 103(C11), 24937-24953, doi: 10.1029/98JC02160.
Kahru, M. and Mitchell, B.G. (1998). Spectral Reflectance and Absorption of a Massive Red Tide Off Southern California, J. Geophys. Res. Oceans, 103(C10), 21601-21609, doi: 10.1029/98JC01945.
Mitchell, B.G. and Kahru, M. (1998). Algorithms for SeaWiFS Standard Products Developed with the CALCOFI Bio-Optical Data Set, Calif. Coop. Oceanic Fish. Invest. Rep., 39, 133-147.
Sosik, H.M. and Mitchell, B.G. (1995). Light Absorption by Phytoplankton, Photosynthetic Pigments, and Detritus in the California Current System, Deep-Sea Res., 42(10), 1717-1748, doi: 10.1016/0967-0637(95)00081-G.
Garver, S.A., Siegal, D.A., and Mitchell, B.G. (1994). Variability in Near Surface Particulate Absorption Spectra: What Can a Satellite Ocean Color Imager See?, Limnol. Oceanogr., 39(6), 1349-1367, doi: 10.4319/lo.1994.39.6.1349.
McClain, C.R., Esaias, W.E., Barnes, W., Guenther, B., Endres, D., Hooker, S., Mitchell, G. and Barnes, R. (1992). SeaWiFS Calibration and Validation Plan, NASA Tech. Memo., 104566(3), 1-41.
Mitchell, B.G. (1992). Predictive Bio-Optical Relationships for Polar Oceans and Marginal Ice Zones, J. Mar. Syst., 3(1-2), 91-105, doi: 10.1016/0924-7963(92)90032-4.
Stramski, D., Booth, C.R., and Mitchell, B.G. (1992). Estimation of Downward Irradiance Attenuation from a Single Moored Instrument, Deep-Sea Res., 39(3-4), 567-584, doi: 10.1016/0198-0149(92)90089-C.
Mitchell, B.G., Brody, E.A., Yeh, E.-N., McClain, C., Comiso, J.C., and Maynard, N.G. (1991). Meridional Zonation of the Barents Sea Ecosystem Inferred from Satellite Remote Sensing and In Situ Bio-Optical Observations, Polar Res. 10(1),147-162 doi: 10.1111/j.1751-8369.1991.tb00641.x.
Mitchell, B.G., Brody, E.A., Holm-Hansen, O., McClain, C.R., and Bishop, J. (1991). Light Limitation of Phytoplankton Biomass and Macro-Nutrient Utilization in the Southern Ocean, Limnol. Oceanogr., 36(8), 1662-1677, doi: 10.4319/lo.1991.36.8.1662.
Carder, K.L., Hawes, S.K., Baker, K.S., Smith, R.C., Steward, R.G., and Mitchell, B.G. (1991). Reflectance Model for Quantifying Chlorophyll-A in the Presence of B. G. Mitchell Productivity Degradation Products, J. Geophys. Res. Oceans, 96(C11), 20599-20611, doi: 10.1029/91JC02117.
Mitchell, B.G. and Holm-Hansen, O. (1991). Bio-Optical Properties of Antarctic Peninsula Waters: Differentiation from Temperate Ocean Models, Deep-Sea Res., 38(8-9), 1009-1028, doi: 10.1016/0198-0149(91)90094-V.
Siegel, D.A., Dickey, T.D., Washburn, L., Hamilton, M.K., and Mitchell, B.G. (1989). Optical Determination of Particulate Abundance and Production Variations In the Oligotrophic Ocean, Deep-Sea Res., 36(2), 211-222, doi: 10.1016/0198-0149(89)90134-9.
Mitchell, B.G. and Kiefer, D.A. (1988). Chlorophyll a Specific Absorption and Fluorescence Excitation Spectra for Light-Limited Phytoplankton, Deep-Sea Res., 35(5), 639-663, doi: 10.1016/0198-0149(88)90024-6.
Mitchell, B.G. and Kiefer, D.A. (1988). Variability in Pigment Specific Particulate Fluorescence and Absorption Spectra in the Northeastern Pacific Ocean, Deep-Sea Res., 35(5), 665-689, doi: 10.1016/0198-0149(88)90025-8.
Iturriaga, R., Mitchell, B.G., and Kiefer, D.A. (1988). Microphotometric Analysis of Individual Particle Absorption Spectra, Limnol. Oceanogr., 33(1), 128-135, doi: 10.4319/lo.1988.33.1.0128.
Kiefer, D.A. and Mitchell, B.G. (1983). A Simple, Steady State Description of Phytoplankton Growth Based On Absorption Cross Section and Quantum Efficiency, Limnol. Oceanogr., 28(4), 770-776, doi: 10.4319/lo.1983.28.4.0770.