Postdoctoral Advisors: Drs. Ronald Zaneveld and Timothy Cowles (Oregon State Univ.)
Students Advised: Jessica Dombroski (M.S., Univ. Rhode Island, 2004)

• Leads an oceanographic research and R&D team, specializing in environmental optics
• Designs optical sensors for oceanographic research applications and supervises development from design to realization as commercial product
• Contributes to the advancement of the ocean optics community through workshops, federal review panels, optics courses, and conferences.

PUBLICATIONS
Please note that the links to the .pdf files are provided for personal use and not intended for distribution.

Twardowski M., and Jonasz M. 2006. Topic 1: VSF at the small angles for natural dispersions and power-law slopes; Topic 2: Power law in spectral scattering by natural dispersions: Derivation; Topic 3: Power law in spectral scattering by natural dispersions: Finite range of the particle diameter. Top. Part. Disp. Sci. (on-line at www.tpdsci.com).

Dombroski, J., and M.S. Twardowski. 2007. Identification of fluorophoric components of dissolved organic matter in Narragansett Bay , Rhode Island using excitation-emission matrices and Parallel Factor Analysis (PARAFAC). Science of the Total Environment , in review.

Glenn, S., C. Jones, M. Twardowski , L. Bowers, J. Kerfoot, J. Kohut, D. Webb, and O. Schofield. 2007. Riders in the storm: studying resuspension processes in the mid-Atlantic Bight with Slocum gliders. Limnol. Oceanogr., in press.

Huot, Y., M. Babin, F. Bruyant, C. Grob, M. S. Twardowski , and H. Claustre. 2007. Does chlorophyll a provide the best index of phytoplankton biomass for primary productivity studies? Biogeosciences , 4:853-868. www.biogeosciences.net/4/853/2007/ .

Huot, Y., A. Morel, M. Twardowski , D. Stramski, and R. Reynolds. 2007. Particle optical backscattering along a chlorophyll gradient in the upper layer of the eastern South Pacific. Biogeosciences. http://www.biogeosciences-discuss.net/4/4571/2007/bgd-4-4571-2007.pdf.

Stramski, D., R. Reynolds, M. Babin, H. Claustre, S. Kaczmarek, M. Lewis, R. Rottgers, A. Sciandra, M. Stramska, and M. Twardowski. 2007. Relationships between the particulate organic carbon concentration and optical properties of surface waters in the South Pacific and Atlantic Oceans . Biogeosciences. http://www.biogeosciences.net/5/171/2008/ .

Twardowski , M.S., H. Claustre, S.A. Freeman, D. Stramski, and Y. Huot. 2007. Optical backscattering properties of the “clearest” natural waters. Biogeosciences , 4, 1041–1058, www.biogeosciences.net/4/1041/2007/ .

Sullivan, J.M., M.S. Twardowski, J.R.V. Zaneveld, C. Moore, A. Barnard, P. Donaghay, and B. Rhoades. 2007The hyperspectral temperature and salinity dependencies of absorption by water and heavy water in the 400–750 nm spectral range. Appl. Opt., 45:5294–5309.

Sullivan, J.M., M.S. Twardowski, Donaghay, P.L., and Freeman, S.A. 2005. Using Scattering Characteristics to Discriminate Particle Types in US Coastal Waters, Appl. Opt., 44:1667-1680.

Trees, C.C., P.W. Bissett, H,. Dierssen, D.D.R. Kohler, M.A. Moline, J.L. Mueller, R.E. Pieper, M.S. Twardowski, and J.R.V. Zaneveld. 2005. Monitoring water transparency and diver visibility in ports and harbors using aircraft hyperspectral remote sensing. Prodeedings from SPIE Port and Harbor Security Conference, Vol. 5780, February, Orlando, FL.

Twardowski, M.S., J.R.V. Zaneveld, C.M. Moore, J. Mueller, C. Trees, O. Schofield, S. Freeman, T. Helble, and G. Hong. 2005. Diver visibility measured with a compact scattering-attenuation meter (SAM) compatible with AUVs and other small deployment platforms. Prodeedings from SPIE Port and Harbor Security Conference, Vol. 5780, February, Orlando, FL.

Twardowski, M.S., M. Lewis, A. Barnard, J.R.V. Zaneveld. 2005. In-water instrumentation and platforms for ocean color remote sensing applications. In:Remote Sensing of Coastal Aquatic Waters, R. Miller and C. Del-Castillo [Eds.], Springer-Kluwer Publishing, pp. 69-100.

Zaneveld, J.R.V., M.S. Twardowski, M. Lewis, and A. Barnard. 2005. Radiative transfer and remote sensing. In: Remote Sensing of Coastal Aquatic Waters, R. Miller and C. Del-Castillo [Eds.], Springer-Kluwer Publishing, pp. 1-20.

Boss, E., W. S. Pegau, M. Lee, M. S. Twardowski, E. Shybanov, G. Korotaev, and F. Baratange. 2004. The particulate backscattering ratio at LEO 15 and its use to study particles composition and distribution. J. Geophys. Res., 109, C01014, doi:10.1029/2002JC001514.

Moore, C., J. Da Cuhna, B. Rhoades, M.S. Twardowski, J.R.V. Zaneveld, J. Dombroski. 2004. A new in-situ measurement and analysis system for excitation-emission fluorescence in natural waters. Proceedings of Ocean Optics XVII, October 25-29, Freemantle, Australia.

Schofield, O., J. Kohut, J. Kerfoot, L. Creed, C. Mugdal, S. Glenn, M. Twardowski, C. Jones, and D. Webb. 2004. Dawn in the age of ocean robots: what can they see? Proceedings of Ocean Optics XVII, October 25-29, Freemantle, Australia.

Sullivan, J.M., M.S. Twardowski, J.R.V. Zaneveld, C. Moore, B. Rhoades, and R. Miller. 2004. The hyperspectral temperature and salinity dependent absorption coefficients of pure water.  Proceedings of Ocean Optics XVII, October 25-29, Freemantle, Australia.

Twardowski, M.S., and J.R.V. Zaneveld. 2004. Progress toward a Generalized Optical-Biogeochemical Inversion (GOBI) for natural waters. Proceedings of Ocean Optics XVII, October 25-29, Freemantle, Australia.

Twardowski, M.S., E. Boss, J.M. Sullivan, and P.L. Donaghay. 2004. Modeling spectral absorption by chromophoric dissolved organic matter (CDOM). Mar. Chem., 89: 69-88, doi:10.1016/j.marchem.2004.02.008.

Zaneveld, J.R.V., C. Moore, A.H. Barnard, M.S. Twardowski, and G.C. Chang. 2004. Correction and analysis of spectral absorption data taken with the WET Labs AC-S. Proceedings of Ocean Optics XVII, October 25-29, Freemantle, Australia.

Eisner, L., M.S. Twardowski, T.J. Cowles, and M.J. Perry. 2003. Resolving phytoplankton photoprotective:photosynthetic carotenoid ratios on fine scales using in situ spectral absorption measurements. Limnol. Oceanogr., 48:632-646.

Dekshenieks, M.M., AL Alldredge, A Barnard, E Boss, J Case, TJ Cowles, PL Donaghay, LB Eisner, DJ Gifford, CF Greenlaw, C Herren, DV Holliday, D Johnson, S MacIntyre, D McGehee, TR Osborn, MJ Perry, R Pieper, JEB Rines, DC Smith, JM Sullivan, MK Talbot, MS Twardowski, A Weidemann and JR Zaneveld. 2003. Characteristics, Distribution and Persistence of Thin Layers Over a 48 Hour Period. Mar. Ecol. Prog. Ser., 261:1-19.

Miller, R., M.S. Twardowski, C. Moore, and C. Casagrande. 2003. The Dolphin: Technology to Support Remote Sensing Bio-optical Algorithm Development and Applications. Backscatter 14(2):8-12.

Rines, J.E.B., P.L. Donaghay, M. Dekshenieks, J.M. Sullivan, and M.S. Twardowski. 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.

Twardowski, M.S., and P.L. Donaghay. 2002. Photobleaching of aquatic dissolved materials: absorption removal, spectral alteration, and their interrelationship. J. Geophys. Res, 107(C8):6.1-6.12.

Twardowski, M.S., J.R.V. Zaneveld, and C. Moore. 2002.  A novel technique for determining beam attenuation compatible with a small sensor form factor and compact deployment platforms. Proceedings from Ocean Optics XVI, November 18-22, Santa Fe.

Zaneveld, J.R.V., M.S. Twardowski, K.S. Shifrin, W.S. Pegau, E. Boss, and I. Zolotov. 2002.  Inversion of light scattering measurements to obtain biogeochemical parameters. Proceedings from Ocean Optics XVI, November 18-22, Santa Fe.

Boss, E., W.S. Pegau, W.D. Gardner, J.R.V. Zaneveld, A.H. Barnard, M.S. Twardowski, G.C. Chang, and T.D. Dickey. 2001. Spectral particulate attenuation in the bottom boundary layer of a continental shelf. J. Geophys. Res., 106(C5):9509-9516.

Boss, E., M.S. Twardowski, and S. Herring. 2001. Shape of the particulate beam attenuation spectrum and its inversion to obtain the shape of the particulate size distribution. Appl. Opt., 40:4885-4893.

Dekshenieks, M.M., P.L. Donaghay, J.M. Sullivan, J.E.B. Rines, T.R. Osborn, and M.S. Twardowski. 2001. Temporal and spatial occurrence of thin phytoplankton layers in relation to physical processes. Mar. Ecol. Prog. Ser., 223:61-71.

Twardowski, M.S. and A. Barnard. 2001. Observing the ocean: sensing technology and observation platforms. Maritimes, 43(4).

Twardowski, M.S., and P.L. Donaghay. 2001. Separating in situ and terrigenous sources of absorption by dissolved material in coastal waters. J. Geophys. Res., 106(C2):2545-2560.

Twardowski, M.S., E. Boss, J.B. Macdonald, W.S. Pegau, A.H. Barnard, and J.R.V. Zaneveld. 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., 106(C7):14,129-14,142.

Moore, C., M.S. Twardowski, and J.R.V. Zaneveld. 2000. The ECO VSF—A multi-angle scattering sensor for determination of the volume scattering function in the backward direction. Proceedings from Ocean Optics XV, October 16-20, Monaco.

Twardowski, M.S. 2000. Ocean research in the ocean state. The Rhode Island Trooper,12(1):107-109.

Twardowski, M.S., J.M. Sullivan, P.L. Donaghay, and J.R.V. Zaneveld. 1999. Microscale quantification of the absorption by dissolved and particulate material in coastal waters with an ac-9. J. Atmos. Ocean. Technol. 16(12):691-707.