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Michael Twardowski
Michael Twardowski
Email | Website
Research Professor in the Harbor Branch Oceanographic Institute of Florida Atlantic University
Recent PACE-related Publications | See All ►
Modeling Atmosphere-Ocean Radiative Transfer: A PACE Mission Perspective (2019)
An Overview of Approaches and Challenges for Retrieving Marine Inherent Optical Properties from Ocean Color Remote Sensing (2018)
Chapter 3: Sustainable Monitoring of Algal Blooms (2016)
Simulation of the Scattering Properties of a Chain-forming Triangular Prism Oceanic Diatom (2016)

Science Meeting Presentations (10)

Atmospheric Correction for Retrieval of Ocean Spectra from Space (ACROSS)
Chowdhary, J., Cairns, B., Zhai, P., Xu, F., Frouin, R., Stamnes, S., Cetinic, I., Liu, L., Twardowski, M., Hu, Y., Mischenko, M., Ottaviani, M., Remer, L., Boss, E., Lee, Z., Zhang, X., Dierssen, H., and Ibrahim, A. (16-Jan-18). Topics: 1) RT benchmark results, 2) ACROSS-II hydrosol model, 3) plankton particle scattering, 4) ocean surface polarization studies, and 5) PACE RT chapter. Click here to view this presentation with audio.
Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the Volume Scattering Function
Twardowski, M. and Tonizzo, A. (16-Jan-18). Click here to view this presentation with audio.
Improving IOP Measurement Uncertainties for PACE Ocean Color Remote Sensing Applications
Sullivan, J., Twardowski, M., Moore, T., McKee, D., Röttgers, R., and Stockley, N. (16-Jan-18). Click here to view this presentation with audio.
Assessing the Impact of a Variable Seawater Depolarization Ratio on IOP Retrievals
Moore, T., Sullivan, J., and Twardowski, M. (16-Jan-18)
Absorption Closure Cruise for PACE
Twardowski, M. (17-Jan-17)
Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the Volume Scattering Function
Twardowski, M., Sullivan, J., Tonizzo, A., Stockley, N., Freeman, S., and Slivkoff, M. (17-Jan-17). Click here to view this presentation with audio.
Improving IOP Measurement Uncertainties for PACE Ocean Color Remote Sensing Applications
Sullivan, J., Twardowski, M., Moore, T., McKee, D., Röttgers, R., and Stockley, N. (17-Jan-17). Click here to view this presentation with audio.
Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the Volume Scattering Function
Twardowski, M., Sullivan, J., Tonizzo, A., Stockley, N., Freeman, S., and Slivkoff, M. (21-Jan-16)
Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the VSF
Twardowski, M. and Sullivan, J. (14-Jan-15)
Improving IOP Measurement Uncertainties for PACE Ocean Color Remote Sensing Applications
Sullivan, J., Twardoswski, M. and Moore, T. (14-Jan-15)

ROSES Proposal

Improving Retrieval of IOPs from Ocean Color Remote Sensing Through Explicit Consideration of the Volume Scattering Function
Radiative transfer (RT) approximations form the basis of semi-analytical (SA) inversion algorithms formulated to derive IOPs and subsequently biogeochemical parameters from ocean color remote sensing. Leading SA inversion algorithms, however, have not been rigorously assessed with respect to particulate volume scattering function (VSF) variability in the ocean, as, up until very recently, the comprehensive VSF data sets required for such an assessment have not been available. It is generally recognized by the community that there is likely no larger source of uncertainty in current SA algorithms to derive IOPs than the uncertainty associated with variability in VSF shapes, as the other important parameters in the inversions have been rigorously assessed (Loisel et al. 2001; Morel et al. 2002; Gordon 2002). Through field work since 2005 supported by NASA and other sources, we now have extensive in situ IOP data sets from 18 locations that contain fully resolved VSFs in a wide range of Case I and Case II waters throughout the world (Sullivan and Twardowski 2009; Czerski et al. 2011; You et al. 2011; Twardowski et al. 2012; Gilerson et al. 2013; Randolph et al., in press). Included in these data sets are NASA ocean color validation experiments with concurrently collected IOP (including VSF) and radiometric measurements, where the technological assets employed, scope of the measurements, and attention to accuracy make these data sets special and unique. Not only are they some of the few nominally complete data sets from an RT closure perspective that we are aware of (as they include full VSFs and full radiance distributions), but the data quality is the highest possible that can be achieved at this time. With such measurements in hand, we have an exciting opportunity to evaluate the effects of varying VSF shape on retrieval uncertainties for the leading SA inversions, and to assess performance for a variety of specific environmental conditions. There is also the opportunity to reevaluate RT approximations such as a Zaneveld (1995) model that explicitly includes VSF shape information, as these models have generally been avoided due to the historical lack of representative VSF data. The specific goals of this work are to 1) assess the full range of variability in VSF shapes in the ocean using an extensive data base of custom VSF measurements collected by our lab, 2) evaluate uncertainties in leading SA inversion approaches associated with this natural VSF variability through RT modeling, and 3) to resuscitate, rework, and evaluate uncertainties in native, analytical RT approximations developed by Zaneveld (1995) and Jerlov (1976) that have received little attention to date specifically because of the fact that they included explicit VSF formulations that could not be practically applied in the past. Our approach will first involve computing remote sensing reflectances from our extensive data sets using the Hydrolight RT solution. Reflectances will then be validated using concurrently measured radiometry data to assess convolved errors in the measurements (separate from uncertainties related to inversion approximations), and to ensure the data sets are sound from a theoretical standpoint. The SA inversion algorithms will then be applied, with the retrieved absorption and backscattering compared to the original measurements to quantify uncertainties. Our overall goal is to quantify and minimize errors in inversion results when applied to a representative range of observed VSFs in the ocean, leading to recommendations in SA algorithm applications for the future PACE mission.

Publications (61)

Chowdhary, J., Zhai, P-W., Boss, E., Dierssen, H., Frouin, R., Ibrahim, A., Lee, Z., Remer, L.A., Twardowski, M., Xu, F., Zhang, X., Ottaviani, M. Espinosa, W.R., and Ramon, D. (2019). Modeling Atmosphere-Ocean Radiative Transfer: A PACE Mission Perspective, Front. Earth Sci., 7 (100), 1-53, doi: 10.3389/feart.2019.00100.
Werdell, P.J., McKinna, L.I.W., Boss, E., Ackleson, S.G., Craig, S.E., Gregg, W.W., Lee, Z., Maritorena, S., Roesler, C.S., Rousseaux, C.S., Stramski, D., Sullivan, J.M., Twardowski, M., Tzortziou, M., and Zhang, X. (2018). An Overview of Approaches and Challenges for Retrieving Marine Inherent Optical Properties from Ocean Color Remote Sensing, Prog. Oceanogr., 160, 186-212, doi:10.1016/j.pocean.2018.01.001.
Zamankhan, H, Westrick, J., Anscombe, F.R. Stumpf, R., Wynne, T.T., Sullivan, J., Twardowski, M., Moore, T., and Choi, H. (2016). Chapter 3: Sustainable Monitoring of Algal Blooms, In: Sustainable Water Management and Technologies (D.H. Chen, ed.), Taylor and Francis Group, Boca Raton, FL.
Sun, B., Kattawar, G.W., Yang, P., Twardowski, M.S., and Sullivan, J.M. (2016). Simulation of the Scattering Properties of a Chain-forming Triangular Prism Oceanic Diatom, J. Quant. Spectrosc. Ra., 178, 390-399, doi: 10.1016/j.jqsrt.2016.02.035.
Valente, A., Sathyendranath, S., Brotas, V., Groom, S., Grant, M., Taberner, M., Antoine, D., Arnone, R., Balch, W. M., Barker, K., Barlow, R., Bélanger, S., Berthon, J.-F., Beşiktepe, Ş., Brando, V., Canuti, E., Chavez, F., Claustre, H., Crout, R., Frouin, R., García-Soto, C., Gibb, S.W., Gould, R., Hooker, S., Kahru, M., Klein, H., Kratzer, S., Loisel, H., McKee, D., Mitchell, B.G., Moisan, T., Muller-Karger, F., O'Dowd, L., Ondrusek, M., Poulton, A.J., Repecaud, M., Smyth, T., Sosik, H.M., Twardowski, M., Voss, K., Werdell, J., Wernand, M., and Zibordi, G. (2016). A Compilation of Global Bio-optical In Situ Data for Ocean-colour Satellite Applications, Earth Syst. Sci. Data, 8(1), 235-252, doi: 10.5194/essd-8-235-2016.
Twardowski, M., Sullivan, J. and Dalgleish, F. (2016). Studying Undisturbed Particle Fields in the Ocean Novel Instrument Suite for More Representative Particle Measurements, Sea Technol, 57(2), 15-19.
Gu, Y., Carrizo, C., Gilerson, A.A., Parrish C. Brady, P.D., Cummings, M.E., Twardowski, M.S., Sullivan, J.M., Ibrahim, A.I., and Kattawar, G.W. (2016). Polarimetric Imaging and Retrieval of Target Polarization Characteristics in Underwater Environment, Appl. Opt., 55(3), 626-637, doi: 10.1364/AO.55.000626.
Jay, D.A., Talke, S.A., Hudson, A., and Twardowski, M. (2015). Estuary Turbidity Maxima Revisited: Instrumental Approaches, Remote Sensing, Modeling Studies, and New Directions, In: Fluvial-Tidal Sedimentology, Developments in Sedimentology, 68 (P. Ashworth et al., eds.), 49-109, ISBN: 9780444635297.
Brady, P., Gilerson, A., Kattawar, G., Sullivan, J., Twardowski, M., Dierssen, H., Gao, M., Travis, K., Etheredge, R.I., Tonizzo, A., Ibrahim, A., Carrizo, C., Gu, Y., Russell, B., Mislinski, K., Zhao, S., Tonizzo, A., and Cummings, M. (2015). Open-Ocean Fish Reveal an Omnidirectional Solution to Camouflage in Polarized Environments, Science, 350(6263), 965-969, doi: 10.1126/science.aad5284.
Twardowski, M.S., Townsend, D.W., Sullivan, J.M., Koch, C., Pettigrew, N.R., O'Donnell, J., Stymiest, C., Salisbury, J., Moore, T., Young-Morse, R., Stockley, N.D., and Morrison, J.R. (2015). Developing the First Operational Nutrient Observatory for Ecosystem, Climate, and Hazard Monitoring for NERACOOS, Mar. Tech. Soc. J., 49(3), 72-80, doi: 10.4031/MTSJ.49.3.11.
Mouw, C.B., Greb, S., Aurin, D., DiGiacomo, P., Lee, Z., Twardowski, M., Binding, C. Hu, C., Ma, R., Moore, T., Moses, W., and Craig, S.E. (2015). Aquatic Color Radiometry Remote Sensing of Coastal and Inland Waters: Challenges and Recommendations for Future Satellite Missions, Remote Sens. Environ., 160, 15-30, doi: 10.1016/j.rse.2015.02.001.
Churnside, J.H., Sullivan, J.M., and Twardowski, M.S. (2014). Lidar Extinction-to-backscatter Ratio of the Ocean, Opt. Express, 22(15), 18698-18706, doi: 10.1364/OE.22.018698.
Wei, J., M.R. Lewis, M.R., Van Dommelen, R., Zappa, C.J., and Twardowski, M.S. (2014). Wave-Induced Light Field Fluctuations in Measured Irradiance Depth Profiles: A Wavelet Analysis, J. Geophys. Res. Oceans, 119(2), 1344-1364, doi: 10.1002/2013JC009572.
Randolph, K., Dierssen, H.M., Twardowski, M., Cifuentes-Lorenzen, A., and Zappa, C.J. (2014). Optical Measurements of Small Deeply-penetrating Bubble Populations Generated by Breaking Waves in the Southern Ocean, J. Geophys. Res. Oceans, 119, doi:10.1002/2013JC009227.
Moore, T. Twardowski, M., and Koch, C. (2014). Developing Predictive Models for Cyanobacterial Blooms in Western Lake Erie, Lakeline, 34(1), 26-28.
Gilerson, A.A., Stepinski, J., Ibrahim, A.I., You, Y., Sullivan, J.M., Twardowski, M.S., Dierssen, H.M., Russell, B., Cummings, M.E., Brady, P., Ahmed, S.A., and Kattawar, G.W. (2013). Benthic Effects on the Polarization of Light in Shallow Waters, Appl. Opt., 52(36), 8685-8705, doi: 10.1364/AO.52.008685.
Chang, G., Jones, C., and Twardowski, M. (2013). Prediction of Optical Variability in Dynamic Nearshore Environments, Method. Oceanogr., 7, 63-78, doi: 10.1016/j.mio.2013.12.002.
Talapatra, S., Hong, J., McFarland, M., Nayak, A.R., Zhang, C., Katz, J., Sullivan, J., Twardowski, M., Rines, J., and Donaghay, P. (2013). Characterization of Biophysical Interactions in the Water Column Using In Situ Digital Holography, Mar. Ecol. Prog. Ser., 473, 29-51, doi: 10.3354/meps10049.
Sullivan, J.M., Twardowski, M.S., Zaneveld, J.R.V., and Moore, C.C. (2012). Measuring Optical Backscattering in Water, In Light Scattering Reviews 7 (A.A. Kokhanovsky, ed.), 189-224, doi: 10.1007/978-3-642-21907-8_6.
Dickey, T.D., Banner, M.L., Bhandari, P., Boyd, T., Carvalho, L., Chang, G., Chao, Y., Czerski, H., Darecki, M., Dong, C., Farmer, D., Freeman, S., Gemmrich, J., Gernez, P., Hall-Patch, N., Holt, B., Jiang, S., Jones, C., Kattawar, G., LeBel, D., Lenain, L., Lewis, M., Liu, Y., Logan, L., Manov, D., Melville, W.K., Moline, M.A., Morison, R., Nencioli, F., Pegau, W.S., Reineman, B., Robbins, I., Röttgers, R., Schultz, H., Shen, L., Shinki, M., Slivkoff, M., Sokólski, M., Spada, F., Statom, N., Stramski, D., Sutherland, P., Twardowski, M., Vagle, S., Van Dommelen, R., Voss, K., Washburn, L., Wei, J., Wijesekera, H., Wurl, O., Yang, D., Yildiz, S., You, Y., Yue, D.K.P., Zaneveld, R., and Zappa, C.J. (2012). Recent Advances in the Study of Optical Variability in the Near-Surface and Upper Ocean, J. Geophys. Res. Oceans, 117(C7), C00H20, doi: 10.1029/2012JC007964.
Gleason, A.C.R., Voss, K.J., Gordon, H.R., Twardowski, M., Sullivan, J., Trees, C., Weidemann, A., Berthon, J.-F., Clark, D., and Lee, Z.-P. (2012). Detailed Validation of the Bidirectional Effect in Various Case I and Case II Waters, Opt. Express, 20(7), 7630-7645, doi: 10.1364/OE.20.007630.
Groundwater, H., Twardowski, M., Dierssen, H., Sciandre, A., and Freeman, S. (2012). Determining Oceanic Particle Size Distributions and Particle Composition: A New SEM-EDS Protocol with Validation and Comparison to Other Methods, J. Atmos. Ocean Tech., 29, 433-449, doi: 10.1175/JTECH-D-11-00026.1.
Twardowski, M., Zhang, X., Vagle, S., Sullivan, J., Freeman, S., Czerski, H., You, Y., Bi, L., and Kattawar, G. (2012). The Optical Volume Scattering Function in a Surf Zone Inverted to Derive Sediment and Bubble Particle Subpopulations, J. Geophys. Res., 117(C7), C00H17, doi: 10.1029/2011JC007347.
You, Y., Tonizzo, A., Gilerson, A.A., Cummings, M.E., Brady, P., Sullivan, J.M., Twardowski, M.S., Dierssen, H.M., Ahmed, S.A., and Kattawar, G.W. (2011). Measurements and Simulations of Polarization States of Underwater Light in Clear Oceanic Waters, Appl. Opt., 50(24), 4873-4893, doi: 10.1364/AO.50.004873.
Chang, G. and Twardowski, M. (2011). Effects of Physical Forcing and Particle Characteristics on Underwater Imaging Performance, J. Geophys. Res. Oceans, 116(C7), C00H03, doi:10.1029/2011JC007098.
Bhandari, P., Voss, K., Logan, L., and Twardowski, M. (2011). The Variation of the Polarized Downwelling Radiance Distribution With Depth in the Coastal and Clear Ocean, J. Geophys. Res. Oceans, 116(C7), C00H10, doi:10.1029/2011JC007320.
Czerski, H., Twardowski, M., Zhang, X., and Vagle, S. (2011). Resolving Size Distributions of Bubbles with Radii Less than 30 um with Optical and Acoustical Methods, J. Geophys. Res., 116(C7), C00H11, doi: 10.1029/2011JC007177.
Lee, Z.P., Lance, V.P., Shang, S., Vaillancourt, R., Freeman, S., Lubac, B., Hargreaves, B.R., Del Castillo, C., Miller, R., Twardowski, M., and Wei, G. (2011). An Assessment of Optical Properties and Primary Production Derived from Remote Sensing in the Southern Ocean (SO GasEx), J. Geophys. Res. Oceans, 116(C4), C00F03, doi: 10.1029/2010JC006747.
Zhang, X., Twardowski, M., and Lewis, M. (2011). Retrieving Composition and Sizes of Oceanic Particle Subpopulations from the Volume Scattering Function, Appl. Opt., 50(9), 1240-1259, doi: 10.1364/AO.50.001240.
Voss, K.J., McLean, S., Lewis, M., Johnson, C., Flora, F., Feinholz, M., Yarbrough, M., Trees, C., Twardowski, M., and Clark, D. (2010). An Example Crossover Experiment for Testing New Vicarious Calibration Techniques for Satellite Ocean Color Radiometry, J. Atmos. Ocean Tech., 27, 1747-1759, doi: 10.1175/2010JTECHO737.1.
Aurin, D. A., Dierssen, H.M., Twardowski, M.S., and Roesler, C.S. (2010). Optical Complexity in Long Island Sound and Implications for Coastal Ocean Color Remote Sensing, J. Geophys. Res., 115, C07011, doi: 10.1029/2009JC005837.
Chang, G., Twardowski, M.S., You, Y., Moline, M., Zhai, P., Freeman, S., Slivkoff, M., Nencioli, F., and Kattawar, G. (2010). Platform Effects of Optical Variability On the Prediction of Underwater Visibility, Appl. Opt., 49(15), 2784-2796, doi: 10.1364/AO.49.002784.
Nencioli, F., Chang, G., Twardowski, M., and Dickey, T.D. (2010). Optical Characterization of an Eddy-Induced Diatom Bloom West of the Island of Hawaii, Biogeosciences, 7, 151-162, doi: 10.5194/bg-7-151-2010.
Sullivan, J.M. and Twardowski, M.S. (2009). Angular Shape of the Volume Scattering Function in the Backwards Direction, Appl. Opt., 48(35), 6811-6819, doi: 10.1364/AO.48.006811.
Zhang, X., Hu, L., Twardowski, M.S., and Sullivan, J.M. (2009). Scattering by Solutions of Major Sea Salts, Opt. Express, 17(22), 19580-19585, doi: 10.1364/OE.17.019580.
Gordon, H.R., Lewis, M.R., McLean, S.D., Twardowski, M.S., Freeman, S.A., Voss, K.J., and Boynton, G.C. (2009). Spectra of Particulate Backscattering in Natural Waters, Opt. Express, 17(18), 16192-16208, doi: 10.1364/OE.17.016192.
Zhou, J., Tonizzo, A., Gilerson, A., Twardowski, M., Gray, D., Weidemann, A., Arnone, R., Gross, B., Moshary, F., and Ahmed, S. 2009. Polarization Characteristics of Coastal Waters and Their Impact On In-Water Visibility. (2009). Polarization Characteristics of Coastal Waters and Their Impact on In-Water Visibility, Proc. SPIE, 73170H, doi: 10.1117/12.820738.
Tonizzo, A., Zhou, J., Gilerson, A., Twardowski, M., Gray, D., Arnone, R., Gross, B., Moshary, F., and Ahmed, S. (2009). Polarization Measurements in Coastal Waters: Hyperspectral and Multiangular Analysis, Opt. Express, 17(7), 5666-5683, doi: 10.1364/OE.17.005666.
Glenn, S., Jones, C., Twardowski, M., Bowers, L., Kerfoot, J., Kohut, J., Webb, D., and Schofield, O. (2008). Glider Observations of Sediment Resuspension in a Middle Atlantic Bight Fall Transition Storm, Limnol. Oceanogr., 53(5, Part II), 2180-2196, doi: 10.4319/lo.2008.53.5_part_2.2180.
Huot, Y., Morel, A., Twardowski, M., Stramski, D., and Reynolds, R. (2008). Particle Optical Backscattering Along a Chlorophyll Gradient in the Upper Layer of the Eastern South Pacific, Biogeosciences, 5, 495-507, doi: 10.5194/bg-5-495-2008.
Stramski, D., Reynolds, R.A., Babin, M., Kaczmarek, S., Lewis, M.R., Röttgers, R., Sciandra, A., Stramska, M., Twardowski, M.S., Franz, B.A., and Claustre, H. (2008). Relationships Between the Surface Concentration of Particulate Organic Carbon and Optical Properties in the Eastern South Pacific and Eastern Atlantic Oceans, Biogeosciences, 5, 171-201, doi:10.5194/bg-5-171-2008.
Twardowski, M.S., Claustre, H., Freeman, S.A., Stramski, D., and Huot, Y. (2007). Optical Backscattering Properties of the "Clearest" Natural Waters, Biogeosciences, 4, 1041-1058, doi: 10.5194/bg-4-1041-2007.
Huot, Y., Babin, M., Bruyant, F., Grob, C., Twardowski, M.S., and Claustre, H. (2007). Relationship Between Photosynthetic Parameters and Different Proxies of Phytoplankton Biomass in the Subtropical Ocean, Biogeosciences, 4, 853-868, doi: 10.5194/bg-4-853-2007.
Sullivan, J.M., Twardowski, M.S., Zaneveld, J.R., Moore, C., Barnard, A., Donaghay, P.L., and Rhoades, B. (2006). Hyperspectral Temperature and Salt Dependencies of Absorption by Water and Heavy Water in the 400-750 nm Spectral Range, Appl. Opt., 45(21), 5294-5309, doi: 10.1364/AO.45.005294.
Sullivan, J.M., Twardowski, M.S., Donaghay, P.L., and Freeman, S. (2005). Using Optical Scattering to Discriminate Particle Types in Coastal Waters, Appl. Opt., 44(9), 1667-1680, doi: 10.1364/AO.44.001667.
Twardowski, M.S., Lewis, M., Barnard, A., and Zaneveld, J.R.V. (2005). In-Water Instrumentation and Platforms for Ocean Color Remote Sensing Applications, In: Remote Sensing of Coastal Aquatic Waters (R. Miller, C. Del Castillo, and B. Mckee, eds.), 69-100, doi: 10.1007/978-1-4020-3100-7_4.
Zaneveld, J.R.V., Twardowski, M.S., Lewis, M., and Barnard, A. (2005). Radiative Transfer And Remote Sensing, In: Remote Sensing of Coastal Aquatic Waters (R. Miller, C. Del Castillo, and B. Mckee, eds.), 1-20, doi: 10.1007/978-1-4020-3100-7_4.
Twardowski, M.S., Boss, E., Sullivan, J.M., and Donaghay, P.L. (2004). Modeling Spectral Absorption by Chromophoric Dissolved Organic Matter (CDOM), Mar. Chem., 89(1-4), 69-88, doi: 10.1016/j.marchem.2004.02.008.
Boss, E., Pegau, W.S., Lee, M., Twardowski, M.S., Shybanov, E., Korotaev, G., and Baratange, F. (2004). The Particulate Backscattering Ratio at LEO 15 and its Use to Study Particles Composition and Distribution, J. Geophys. Res., 109(C1), C01014, doi: 10.1029/2002JC001514.
McManus, M.M., Alldredge, A.L., Barnard, A., Boss, E., Case, J., Cowles, T.J., Donaghay, P.L., Eisner, L.B., Gifford, D.J., Greenlaw, C.F., Herren, C., Holliday, D.V., Johnson, D., Macintyre, S., McGehee, D., Osborn, T.R., Perry, M.J., Pieper, R., Rines, J.E.B., Smith, D.C., Sullivan, J.M., Talbot, M.K., Twardowski, M.S., Weidemann, A., and Zaneveld, J.R. (2003). Characteristics, Distribution and Persistence of Thin Layers Over a 48 Hour Period, Mar. Ecol. Prog. Ser., 261, 1-19, doi: 10.3354/meps261001.
Eisner, L., Twardowski, M.S., Cowles, T.J., and Perry, M.J. (2003). Resolving Phytoplankton Photoprotective:Photosynthetic Carotenoid Ratios on Fine Scales Using In Situ Spectral Absorption Measurements, Limnol. Oceanogr., 48(2), 632-646, doi: 10.4319/lo.2003.48.2.0632.
Miller, R., Twardowski, M.S., Moore, C., and Casagrande, C. (2003). The Dolphin: Technology to Support Remote Sensing Bio-Optical Algorithm Development and Applications, Backscatter, 14(2), 8-12.
Twardowski, M.S. and Donaghay, P.L. (2002). Photobleaching of Aquatic Dissolved Materials: Absorption Removal, Spectral Alteration, and Their Interrelationship, J. Geophys. Res. Oceans, 107(C8), 6.1-6.12, doi: 10.1029/1999JC000281.
Rines, J.E.B., Donaghay, P.L., Dekshenieks, M., Sullivan, J.M., and Twardowski, M.S. (2002). Thin Layers and Camouflage: Hidden Pseudo-Nitzschia Spp. (Bacillariophyceae) Populations in a Fjord in the San Juan Islands, Washington, U.S.A., Mar. Ecol. Prog. Ser., 225, 123-137 doi: 10.3354/meps225123.
Dekshenieks, M.M., Donaghay, P.L., Sullivan, J.M., Rines, J.E.B., Osborn, T.R., and Twardowski, M.S. (2001). Temporal and Spatial Occurrence of Thin Phytoplankton Layers in Relation to Physical Processes, Mar. Ecol. Prog. Ser., 223, 61-71, doi: 10.3354/meps223061.
Boss, E., Twardowski, M.S., and Herring, S. (2001). Shape of the Particulate Beam Attenuation Spectrum and its Inversion to Obtain the Shape of the Particulate Size Distribution, Appl. Opt., 40(27), 4885-4893, doi: 10.1364/AO.40.004885.
Twardowski, M.S., Boss, E., Macdonald, J.B., Pegau, W.S., Barnard, A.H., and Zaneveld, J.R.V. (2001). A Model for Estimating Bulk Refractive Index from the Optical Backscattering Ratio and the Implications For Understanding Particle Composition in Case I and Case II Waters, J. Geophys. Res. Oceans, 106(C7), 14129-14142, doi: 10.1029/2000JC000404.
Boss, E., Pegau, W.S. Gardner, W.D., Zaneveld, J.R.V., Barnard, A.H., Twardowski, M.S., G.C. Chang, G.C., and Dickey. T.D. (2001). Spectral Particulate Attenuation in the Bottom Boundary Layer of a Continental Shelf, J. Geophys. Res. Oceans, 106(C5), 9509-9516, doi: 10.1029/2000JC900077.
Twardowski, M.S. and Donaghay, P.L. (2001). Separating In Situ And Terrigenous Sources of Absorption By Dissolved Material in Coastal Waters, J. Geophys. Res. Oceans, 106(C2), 2545-2560, doi: 10.1029/1999JC000039.
Twardowski, M.S. and Barnard, A. (2001). Observing the Ocean: Sensing Technology and Observation Platforms, Maritimes, 43(4).
Twardowski, M.S., Sullivan, J.M., Donaghay, P.L., and Zaneveld, R.V. (1999). Microscale Quantification of the Absorption by Dissolved and Particulate Material in Coastal Waters with an ac-9, J. Atmos. Ocean. Tech., 16, 691-707, doi: 10.1175/1520-0426(1999)016<0691:MQOTAB>2.0.CO;2.