Faculty & Scientists

Dr. Parker's research interest is marine microbial biogeochemistry, addressing questions related to: 1) characterizing underlying controls on phytoplankton and bacterial processes in aquatic systems. 2) quantifying microbial food web dynamics 3) understanding microbial responses to coastal nutrient pollution. He primarily works in urbanized estuaries (Delaware Bay and San Francisco Bay Estuary) where coastal pollution, including large-scale nutrient fertilization, has had major impacts on the microbial community. In addition to estuarine work, he has also conducted research in the Gulf of the Farallones National Marine Sanctuary, the Equatorial Pacific Ocean, the Chukchi Sea (Arctic Ocean) and in Antarctica.

With several published papers and more than one hundred research cruises to survey the San Francisco Estuary, Dr. Parker works regularly with state science and natural resource agencies to evaluate estuarine management strategies.

Glibert, P.M., R. C. Dugdale, F Wilkerson, A. E. Parker, J. Alexander, E. Antell, S. Blaser, A. Johnson, J. Lee, T. Lee, S. Murasko, S. Strong. 2014.  Major – but rare – spring blooms in 2014 in San Francisco Bay Delta, California, a result of the long-term drought, increased residence time, and altered nutrient loads and forms.  Journal of Experimental Marine Biology and Ecology.  460: 8-18.

Buck, C., F. P. Wilkerson, A.E. Parker, R.C. Dugdale 2014. The influence of coastal nutrients on phytoplankton productivity in a shallow low inflow estuary, Drakes Estero, California (USA). Estuaries and Coasts. DOI 10.1007/s12237-013-9737-6

Parker, A.E.,W.J.  Kimmerer, U. Lidstrom, U. 2012. Re-evaluating the generality of empirical models for light-limited primary production in the San Francisco Estuary. Estuaries and Coasts.  35(4):930-942.

Kimmerer, W.J., A.E. Parker, U.  Lidstrom 2012. Short-Term and Interannual Variability in Primary Productivity in the low-salinity zone of the San Francisco Estuary. Estuaries and Coasts. 35(4): 913-929.

Parker, A.E., F.P. Wilkerson, R.C. Dugdale. 2012. Elevated ammonium concentrations from wastewater discharge depress primary productivity in the Sacramento River and the northern San Francisco Estuary. Marine Pollution Bulletin. 64(3):574-586

Lefebvre, S.C., Benner, I., Drake, M.K., Rossignol, P.E., Okimura, K.M., Komada, T., Stillman, J.H., Parker, A.E. Carpenter, E.J. 2012. Nitrogen source and pCO₂ synergistically affect carbon allocation, growth and morphology of the coccolithophoreEmiliania huxleyi.  Global Change Biology. 18(2):493-503.

Parker, A.E., Wilkerson, F., Dugdale R.C., Hogue, V., Marchi, A. 2011.  Understanding spatial patterns in nitrogen uptake and phytoplankton in the equatorial Pacific upwelling zone (110ºW – 140ºW) during 2004 and 2005. Deep Sea Research II. 58 (3-4): 417-433.

Brzezinski, M.A., Baines, S., Chai, F., Balch, W.M., Dugdale, R.C., Krause, J.W., Landry, M.R., Marchi, A., Measures, C.I., Nelson, D.M., Parker, A.E., Selph, K.E., Strutton, P., Taylor, A.G., Twining, B.S., Beucher, C. 2011. Co-limitation of diatoms by iron and silicic acid in the equatorial Pacific. Deep Sea Research II.  58 (3-4): 493-512.

Sharp, J.H., Yoshiyama, K., Parker, A.E., Schwartz, M. C., Curless, S. E., Beauregard, A.Y., Ossolinski, J., Davis, A.R.  2009. The chemistry of the Delaware Estuary: seasonal and spatial trends and correlations. Estuaries and Coasts 32(6): 1023-1043

Kirchman, D.L., Hill, V, Cottrell, M.T., Gradinger, R., Malmstrom R.R., Parker, A.E. 2008 Primary production and the processing of organic carbon by heterotrophic bacteria in the western Arctic Ocean. Deep Sea Research II, 56(17): 1237-1248.

Cottrell, M. T., R. R. Malmstrom, Hill, V. Parker, A.E. Kirchman, D.L. 2006. The metabolic balance between autotrophy and heterotrophy in the western Arctic Ocean.Deep Sea Research Part I 53(11): 1831-1844.

Parker, A. E. 2005. Differential supply of autochthonous organic carbon and nitrogen to the microbial loop of the Delaware Estuary.Estuaries 28(6): 856-867.

Sharp, J. H., A. Y. Beauregard, Burdige, D., Cauwet, G., Curless, S. E.,Lauck, R., Nagel, K., Ogawa, H., Parker, A. E., Primm, O. 2004. A direct instrument comparison for measurement of total dissolved nitrogen in seawater. Marine Chemistry 84(3-4): 181-193. 

Marine Biology 
Marine Ecology
Oceanographic Instruments and Analysis
Marine Microbial Ecology

Alejandro Cifuentes-Lorenzen studies boundary layer physics. His research is focused on further elucidating the role of waves in the transfer of momentum and kinetic energy across the air-sea interface and is principally focused on wave-driven turbulence. An objective of this work is to better understand wave-induced perturbations at the boundary (above and below the sea surface) and, because these small-scale processes have an enormous impact on regional and global transport but cannot be numerically resolved, he seeks to characterize them and to contribute to the development of parameterizations that can improve general circulation and atmospheric modeling efforts. 

Current Projects:

What: Further elucidate the transfer of energy from the atmosphere to the sea, a process mediated by waves, including addressing the subsurface turbulent kinetic energy (TKE) dissipation rate under breaking conditions and the wave dependent TKE dissipation rate profile, a direct consequence of the energy exchange between wind and waves. We will also investigate the importance of Langmuir circulation relative to Eulerian shear production and the injection of TKE from wave breaking. 

Who: A multi-institution, NSF supported project, in collaboration with scientists from the University of Connecticut, Lamont Doherty Earth Observatory at Columbia, University of Rhode Island and Woods Hole Oceanographic Institution.

Where: Dr. Cifuentes-Lorenzen led a comprehensive field campaign out of the Martha's Vineyard Coastal Observatory (Fall 2019), designed to track the evolution of the turbulent kinetic energy budget on both sides of the air-sea interface, capturing wave-driven dynamics and wave-driven turbulence at the boundary layer. 

Randolph, K and Cifuentes-Lorenzen, A. (submitted): The case for measuring whitecaps using ocean color and initial linkages to subsurface physics. Special Topics in Air-Sea Interaction, Springer.

Cifuentes-Lorenzen, A., Edson, J., Zappa, C.J., (2018): Air-Sea Interaction in the Southern Ocean; Exploring the Height of the Wave Boundary Layer at the Air-Sea Interface. Boundary-Layer Meteorol. https://doi.org/10.1007/s10546-018-0376-0

Cifuentes-Lorenzen, A., J.B. Edson, and C.J. Zappa (2013) A Multisensor Comparison of Ocean Wave Frequency Spectra from a Research Vessel during the Southern Ocean Gas Exchange Experiment. Journal of Atmospheric and Oceanic Technology, 30 (12): 2907–25.

Randolph, K., H.M. Dierssen, A. Cifuentes-Lorenzen, W.M. Balch, E.C. Monahan, C.J. Zappa, D.T. Drapeau, and B. Bowler (2017) Novel Methods for Optically Measuring Whitecaps under Natural Wave-Breaking Conditions in the Southern Ocean. J. Atmos. Oceanic Technol., 34, 533–554, https://doi.org/10.1175/JTECH-D-16-0086.1

Randolph, K., H.M. Dierssen, M. Twardowski, A. Cifuentes-Lorenzen, and C.J. Zappa (2014). Optical measurements of bubble size distributions at 6-9 m depths generated by large scale breaking waves in the Southern Ocean. J. Geophys. Res. Ocean, 119, 757-776.

Lund, B., C.J. Zappa, H.C. Graber, and A. Cifuentes-Lorenzen (2017) Shipboard Wave Measurements in the Southern Ocean. J. Atmos. Oceanic Technol., 34, 2113–2126, https://doi.org/10.1175/JTECH-D-16-0212.1

Brumer, S.E., C.J. Zappa, B.W. Blomquist , C.W. Fairall, A. Cifuentes-Lorenzen, J.B. Edson, I.M. Brooks, and B.J. Huebert. (2017) Wave-related Reynolds number parameterizations of CO₂ and DMS transfer velocities. Geophys. Res. Letters, 44. doi: 10.1002/2017GL074979

Brumer, S.E., Christopher J. Zappa, Ian M. Brooks, Hitoshi Tamura, Scott M. Brown, Byron W. Blomquist, Christopher W. Fairall, and Alejandro Cifuentes-Lorenzen. (2017) Whitecap Coverage Dependence on Wind and Wave Statistics as Observed during SO GasEx and HiWinGS. Journal of Physical Oceanography 47:9, 2211-2235.

Edson, J.B., C.W. Fairall, L. Bariteau, C.J. Zappa, A. Cifuentes-Lorenzen, W.R. McGillis, S. Pezoa, J.E. Hare, and D. Helmig (2011). Direct Covariance Measurement of CO₂ Gas Transfer Velocity during the 2008 Southern Ocean Gas Exchange Experiment: Wind Speed Dependency. Journal of Geophysical Research, Vol 116, 24 pp.

Oceans I
Oceans II
Oceans and Climate
Physical Oceanography

Dr. Murphy has a diverse research background, including experience working in deep sea hydrothermal vent systems with the ROV JASON and oxidation-reduction chemistry in permeable sediments at a near shore cabled observatory on Oahu. She has worked in salt marshes around the San Francisco Estuary and Hawaiian Fishponds on Oahu, examining the impact of photosynthetic organisms on nutrient cycling near the sediment-water interface.

Murphy, Jennifer L. and Christopher I. Measures. 2014. Ocean Acidification: The Role of CO2. Oceanography 27(1):238-246.

Marine Biology and Marine Biology Lab
Marine Ecology Lab
Chemical Oceanography

Dr. Randolph has been developing methods to measure whitecaps and bubble plumes using measurements of in and above water optical properties and coupling the optics with meteorological and wave field parameters to investigate the mechanisms underlying the distribution and evolution and of naturally occurring, wind-wave induced bubbles populations. She is further developing and implementing these approaches to link light scattering and ocean color during wave breaking to turbulent kinetic energy dissipation rates in an effort to characterize light scattering during wave breaking and to further elucidate wave-driven turbulence at the air-sea interface. She has developed, coordinated, and conducted field campaigns using a wide range of in and above water oceanographic instrumentation from a variety of platforms.

Kate is leading a NASA funded effort to quantify the effects of breaking waves, and bubble plumes on hyperspectral reflectance and to relate ocean color to turbulent kinetic energy dissipation rates using above surface radiometry and in situ optics from the Air-Sea Interaction Tower at Martha's Vineyard Coastal Observatory, Woods Hole Oceanographic Institute. 

Randolph, K., H.M. Dierssen, A. Cifuentes-Lorenzen, W.M. Balch, E.C. Monahan, C.J. Zappa, D.T. Drapeau, and B. Bowler. (2017). Novel methods for optically measuring whitecaps under natural wave breaking conditions. J. Atmos. Oceanic Tech., 34, 533-554.

Randolph, K., H.M. Dierssen, M. Twardowski, A. Cifuentes-Lorenzen, and C.J. Zappa. (2013). Optical measurements of small, deeply penetrating bubble populations generated by breaking waves in the Southern Ocean. Journal of Geophysical Research Oceans, 119, 757-776.

Hedley, J., B. Russell. K. Randolph, M.A. Perez-Castro, R.M. Vasquez-Elizondo, S. Enriquez, and H.M. Dierssen. (2017). Remote sensing of seagrass leaf area index and species: the capability of a model inversion method assessed by sensitivity analysis and hyperspectral data of Florida Bay. Frontiers in Marine Science, 4, 362.

Hedley, J., B. Russell, K. Randolph, and H.M. Dierssen. (2016). A physics based method for the remote sensing of seagrasses, Remote sensing of Environment, 174, 134-147.

Dierssen, H. and K. Randolph. (2013). Remote Sensing of Ocean Color, in Earth System Monitoring, edited by J. Orcutt, pp. 439-472, Springer New York.

Randolph, K., J. Wilson, L.P. Tedesco, L. Li, D.L. Pascual and E. Soyeux. (2008). Hyperspectral remote sensing of cyanobacteria in turbid productive water using optically active pigments, chlorophyll a and phycocyanin, Remote Sensing of Environment, 112, 4009-4019.

Stephens, B. et al. (2018). The O₂/N₂ Ratio and CO₂ Airborne Southern Ocean Study, Bull. Amer. Meteor. Soc., 99, 381–402, https://doi.org/10.1175/BAMS-D-16-0206.1.

Cifuentes-Lorenzen and K. Randolph. (2020). The Case for Measuring Whitecaps Using Ocean Color and Initial Linkages to Subsurface Physics. In: Vlahos P., Monahan E. (eds) Recent Advances in the Study of Oceanic Whitecaps (pp. 175-195). Springer, Cham.

Introduction  to Ocean Remote Sensing