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Ricardo M. Letelier

Ricardo Letelier photo

Discipline: Ocean Ecology and Biogeochemistry
Office: Burt 140
Phone: 541-737-3890
Fax: 541-737-2064
Email: letelier@coas.oregonstate.edu

Research Interests

Scales of response of marine pelagic microorganisms, populations, and communities to environmental perturbations; the role of these responses on biogeochemical cycles, primary productivity, nitrogen fixation, photosynthesis, chlorophyll passive (solar-induced) fluorescence; and the physical and chemical factors controlling these processes.

Current Research

Scales of variability of phytoplankton productivity in the coastal environments; the interpretation of phytoplankton passive fluorescence as measured from space; seasonal, and long-term changes in pelagic community structure in the North Pacific subtropical gyre with emphasis in phytoplankton production.


BS, Universidad de Concepcion, Chile (Marine Biology), 1988
PhD, University of Hawaii at Manoa (Oceanography), 1994


1992 Karl, D.M., R.M. Letelier, D.V. Hebel, D.F. Bird, and C.V. Winn. Trichodesmium blooms and new nitrogen in the North Pacific gyre, In: E.J. Carpenter et al. (eds.), Marine Pelagic Cyanobacteria: Trichodesmium and Other Diazotrophs, pp. 219-237, Kluwer Academic Publishers, Netherlands.

1993 Letelier, R.M, R.R. Bidigare, D.V. Hebel, M. Ondrusek, C.D. Winn, and D.M. Karl. Temporal variability of phytoplankton community structure based in pigment analysis. Limmnol. Oceanogr. 38:1420-1437.

1995 Karl, D.M., R.M. Letelier, D. Hebel, L. Tupas, J. Dore, J. Christian, and C. Winn. Ecosystem changes in the North Pacific subtropical gyre attributed to the 1991-1992 El Niño. Nature 373:230-234.

1995 Winn, C.D., L. Campbell, J.R. Christian, R.M. Letelier, D.V. Hebel, J.E. Dore, L. Fujieki, and D.M. Karl. Seasonal variability in the phytoplankton community of the North Pacific Subtropical Gyre. Global Biogeochem. Cycles 9:605-620.

1996 Letelier, R.M. and M.R. Abbott. An analysis of chlorophyll fluorescence algorithms for the Moderate Resolution Imaging Spectrometer (MODIS). Rem. Sens. Environ. 58: 215-223.

1996 Letelier, R.M, D.M. Karl. The role of Trichodesmium spp. in the productivity of the subtropical North Pacific Ocean.. Mar. Ecol. Prog. Ser. 133:263-273.

1996 Letelier, R.M., J.E. Dore, C.D. Winn, and D.M. Karl. Seasonal and interannual variations in autotrophic carbon assimilation at Station ALOHA . Deep-Sea Res. 43:467-490.

1996 Karl, D.M., J.R. Christian, J.E. Dore, and R.M. Letelier. Microbial oceanography in the region west of the Antarctic Peninsula: Microbial Dynamics, Nitrogen Cycle and Carbon Flux. In: R.R. Ross et al. (eds.), Foundations for Ecological Research West of the Antarctic Peninsula , pp. 303-332, American Geophysical Union, Antarctic Research Series 70.

1996 Karl, D.M., J.R. Christian, J.E. Dore, D.V. Hebel, R.M. Letelier, L.M. Tupas, and C.D. Winn. Seasonal and interannual variability in primary production and particle flux at station ALOHA. Deep-Sea Res. 43:539-568.

1997 Letelier, R.M., M.R. Abbott, and D.M. Karl. Chlorophyll natural fluorescence response to upwelling events in the Southern Ocean. Geophysical Research Letters 24(4): 409-412.

1997 Karl, D.M., R.M. Letelier, L. Tupas, J. Dore, J. Christian, and D. Hebel. The role of nitrogen fixation in biogeochemical cycling in the subtropical North Pacific Ocean. Nature 387: 533-538.

1997 Abbott, M.R. and R.M. letelier. Going with the Flow - The use of Optical Drifters to Study Phytoplankton Dynamics. In: Mati Kahru and C. W. Brown (eds.), Monitoring Algal Blooms: New Techniques for Detecting Large-Scale Environmental Change, pp. 143-168, Landes Bioscience, USA.

1998 Abbott, M.R. and R.M. Letelier. Decorrelation scales of chlorophyll as observed from bio-optical drifters in the California Current. Deep-Sea Res., 45: 1639-1668.

1998 Karl, D.M, D. Hebel, K. Bjorkman, and R.M. Letelier. The role of dissolved organic matter exudation in the productivity of the oligotrophic North Pacific Ocean. Limnology and Oceanography, 43(6): 1270-1286.

1998 Letelier, R.M. and D.M. Karl. Trichodesmium spp. physiology and nutrient fluxes in the North Pacific subtropical gyre. Aquatic Microbial Ecology 15(3): 265-276.

1998 Essaias, W. et al. An overview of MODIS capabilities for ocean science observations. IEEE Transactions of Geoscience and Remote Sensing 36(4):1250-1265.

2000 Letelier, R.M, D.M. Karl, M.R Abbott, P. Flament, M. Freilich, R. Lukas, and T. Strub, Role of late winter mesoscale events in the biogeochemical variability of the upper water column of the North Pacific Subtropical Gyre, Journal of Goephysical Research, 105: 28,723-28,740. Correction in Journal of Goephysical Research, 106: 7181-7182.

2000 Abbott, M.R., J.G. Richman, R.M. Letelier, and J.S. Bartlett. The spring bloom in the Antarctic Polar Frontal Zone as Observed from a Mesoscale Array of Bio-optical Sensors, Deep-Sea Res. II, 47: 3285-3314.

2001 Karl, D.M, R.R. Bidigare and R.M. Letelier, Long-term changes in plankton community structure and productivity in the subtropical North Pacific Ocean: The domain shift hypothesis, Deep-Sea Res. II, 48: 1449-1470.

2001 Landry, M.R., S.L. Brown, K.E. Selph, M.R. Abbott, R.M. Letelier, S. Christensen, R.R. Bidigare, and K. Casciotti, Initiation of the spring phytoplankton increase in the Antarctic Polar Front Zone at 170°W. Journal of Geophysical Research, 106: 13,903-13,915.

2001 Laney, S.R., R.M. Letelier, R.A. Desiderio, M.R. Abbott, D.A. Kiefer, and C.R. Booth. Measuring the natural fluorescence of phytoplankton cultures. J. Atmos. Ocean. Tech., 18: 1924-1934.

2001 Nahorniak, J.S., M.R. Abbott, R.M. Letelier, and W.S. Pegau. Analysis of a method to estimate chlorophyll-a concentration from irradiance measurements at varying depths. J. Atmos. Ocean. Tech.,. 18: 2063-2073.

2001 Fennel, K., Y.H. Spitz, R.M. Letelier, and M.R. Abbott. A deterministic model for N2-fixation at the HOT site in the subtropical North Pacific. Deep-Sea Res.II, 49: 149-174.

2001 Laney, S.R., R.M. Letelier, R.A. Desiderio, M.R. Abbott, D.A. Kiefer, and C.R. Booth. Measuring the natural fluorescence of phytoplankton cultures. J. Atmos. Ocean. Tech., 1: 1924-1934.

2001 Mengelt, C., M. Abbott, R.M. Letelier, J.A. Barth, C. Measures, and S. Vink, Phytoplankton pigment distribution in relation to the physics across the Antarctic Polar Front, 170°W, Deep-Sea Res.II, 48: 4081-4100.

2001 Karl, D.M., K.M. Björkman, J.E. Dore, L. Fujieki, D.V. Hebel, T. Houlihan, R.M. Letelier, and L.M. Tupas. Ecological Nitrogen-to-Phosphorus Stoichiometry at Station ALOHA. Deep-Sea Res. II, 48: 1529-1566.

2002 Karl, D.M., R. Bidigare, and R.M. Letelier. Sustained Seasonal and Interannual Variability of Phytoplankton Processes in the North Pacific Subtropical Gyre. In: P.J. Le B. Williams, D.N. Thomas, and C. Reynolds (eds.), Phytoplankton Productivity: Carbon Assimilation in Marine and Freshwater Ecosystems, p. 222-264, Blackwell Science Ltd., Oxford, U.K.

2002 Karl, D.M., A. Michaels, B. Bergman, D.G. Capone, E. Carpenter, R. Letelier, F. Lipschultz., H. Pearl, D. Sigma, and L. Stal. Nitrogen fixation in the world's oceans. Biogeochemistry, 57/58: 47-98.

2003 Hogue, F.E., P.E. Lyon, R.N. Swift, J.K. Yungel, M.R. Abbott, R.M. Letelier, W.E. Esaias. Validation of Terra-MODIS Phytoplankton Chlorophyll Fluorescence Line Height. I. Initial Airborne Lidar Results. Appl. Optics, 42(15): 2761-2771.

2004 Wetz, M.S. , P.A. Wheeler, and R.M. Letelier. Light induced growth of winter phytoplankton collected from the benthic boundary layer off Oregon, USA. , Mar. Ecol. Prog. Ser. 208: 95-104.

2004 Sakamoto C, et al., Influence of Rossby waves on nutrient dynamics and plankton community structure in the North Pacific subtropical gyre. J. Geophys. Res.109: C05032.

2004 Letelier, R.M., D.M. Karl, M.R. Abbott, and R.R. Bidigare. Light driven seasonal patterns of chlorophyll and nitrate in the lower euphotic zone of the North Pacific Subtropical Gyre. Limnol. Oceanogr. 49: 508-519.

2005 Corno, G., R.M. Letelier, M.R. Abbott, and D.M. Karl. Assessing primary production variability in the North Pacific subtropical gyre: A comparison of Fast Repetition Rate fluorometry and 14C measurements. J. Phycol. 42: 51-60.

2005 Laney, S.R., R.M. Letelier, and M.R. Abbott. Parameterizing the natural fluorescence kinetics of Thalassiosira weissflogii. Limnol. Oceanogr. 50(5): 1499-1510.

2006 Behrenfeld, M.J., R.T. O’Malley, D.A. Siegel, C.R. McClain, J.L. Sarmiento, G.C. Feldman, A.J. Milligan, P.G. Falkowski, R.M. Letelier, E.S.Boss. Climate-driven trends in contemporary ocean productivity. Nature, 444: 752-755.

2006 White, A.E., Y.H. Spitz, and R.M. Letelier, Modeling carbohydrate ballasting by Trichodesmium spp. at Station ALOHA. Mar. Ecol. Prog. Ser,. 323: 35-45.

2006 Church, M.J., H.W. Ducklow, R.M. Letelier, and D.M. Karl. Temporal dynamics in heterotrophic picoplankton productivity in the subtropical North Pacific Ocean. Aquat. Microb. Ecol, 45: 41-53.

2006 White, A.E., Y. Spitz, D.M. Karl, and R.M. Letelier. Ecological implications of flexible elemental stoichiometry in Trichodesmium spp. Limnol. Oceanogr. 51(4): 1777-1790.

2007 Bane, J.M., Y.H. Spitz, R.M. Letelier, and W.T. Peterson. Jet stream intraseasonal oscillations drive dominant ecosystem variations in Oregon’s summertime coastal upwelling system. Proc. Nat. Acad. Sci. 104: 13,262-13,267.

2007 Corno, G., D.M. Karl, M.A. Abbott, M.J. Church, R. Lukas, and R.M. Letelier. Impact of climate forcing on ecosystem processes in the North Pacific subtropical gyre. J. Geophys. Res., 112, C04021, doi:10.1029/2006JC003730.

2007 Huyer, A., M. Kosro, R. Letelier, R.L. Smith, and P.A. Wheeler. The Newport Line off Oregon: Studies in the North East Pacific. Progress in Oceanography, doi: 10.1016/j.pocean.2007.08.003.

2007 White, A. E., F.G. Prahl, R.M. Letelier, and B.N. Popp. Summer surface waters in the Gulf of California: prime habitat for biological N2 fixation. Global Biogeochemical Cycles, 21, GB2017, doi:10.1029/2006GBC002779.

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