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Full-Text Articles in Life Sciences
Remote Sensing Observations Of Winter Phytoplankton Blooms Southwest Of The Luzon Strait In The South China Sea, Dan-Ling Tang, I-Hsun Ni, Dana R. Kester, Frank E. Muller-Karger
Remote Sensing Observations Of Winter Phytoplankton Blooms Southwest Of The Luzon Strait In The South China Sea, Dan-Ling Tang, I-Hsun Ni, Dana R. Kester, Frank E. Muller-Karger
Marine Science Faculty Publications
The Luzon Strait is a channel between the Philippine Sea and the South China Sea. This area is traditionally classified as an oligotrophic zone with low primary productivity. Even so, high concentrations of pigment were detected 100 km southwest of the Strait through analysis of historical Coastal Zone Color Scanner (CZCS) data that the Nimbus-7 satellite collected during the winters of 1979 to 1986. These blooms were observed in December 1979, February 1983, February 1985, and January 1986, when sea surface temperatures measured with the National Oceanic and Atmospheric Administration's (NOAAs) Advanced Very High Resolution Radiometer (AVHRR) were 23 to …
Tropical Pacific Near-Surface Currents Estimated From Altimeter, Wind, And Drifter Data, Gary S. E. Lagerloef, Gary T. Mitchum, Roger B. Lukas, Pearn P. Niiler
Tropical Pacific Near-Surface Currents Estimated From Altimeter, Wind, And Drifter Data, Gary S. E. Lagerloef, Gary T. Mitchum, Roger B. Lukas, Pearn P. Niiler
Marine Science Faculty Publications
Tropical surface currents are estimated from satellite-derived surface topography and wind stress using a physically based statistical model calibrated by 15 m drogue drifters. The model, assumes a surface layer dominated by steady geostrophic and Ekman dynamics. Geostrophy varies smoothly from a beta plane formulation at the equator to an f plane formulation in midlatitude, with the transition occurring at similar to 2 degrees-3 degrees latitude. The transition is treated with a Gaussian weight function having a meridional decay scale that is found to be approximately the Rossby radius (similar to 2.2 degrees latitude). The two-parameter Ekman model represents drifter …
West Florida Continental Shelf Response To Upwelling Favorable Wind Forcing 2. Dynamics, Zhenjiang Li, Robert H. Weisberg
West Florida Continental Shelf Response To Upwelling Favorable Wind Forcing 2. Dynamics, Zhenjiang Li, Robert H. Weisberg
Marine Science Faculty Publications
Dynamics analyses are presented for the west Florida continental shelf response to upwelling favorable, alongshore or offshore winds using a three-dimensional, time-dependent, primitive equation model. These analyses complement the kinematics analyses of Li and Weisberg [1999]. Results are provided on four topics: (1) the response evolutions to quasi steady states, (2) the across-shelf distributions of the vertically integrated alongshore and across-shelf momentum balances, (3) the three-dimensional structures of the terms composing the momentum balance closures, and (4) the model sensitivity to vertical friction parameterization. The response evolution starts with a local wind-driven acceleration, and it transitions over the inner shelf …
Validation Of Coral Temperature Calibrations, Thomas J. Crowley, Terrence M. Quinn, William T. Hyde
Validation Of Coral Temperature Calibrations, Thomas J. Crowley, Terrence M. Quinn, William T. Hyde
Marine Science Faculty Publications
Geochemical analyses of coral skeletons are increasingly used to estimate past sea surface temperatures (SSTs). In this paper we suggest that the standard method of calibrating geochemical time series against a (usually short) local time series requires modification. In order to draw large‐scale inferences about climate from coral proxy data it is also necessary to (1) calibrate against larger fields such as the local gridded data sets and (2) validate results against an independent data set (e.g., early 20th century). This approach has been applied in a pilot study to a coral record from New Caledonia. Despite a high δ18O …
West Florida Shelf Response To Upwelling Favorable Wind Forcing: Kinematics, Zhenjiang Li, Robert H. Weisberg
West Florida Shelf Response To Upwelling Favorable Wind Forcing: Kinematics, Zhenjiang Li, Robert H. Weisberg
Marine Science Faculty Publications
The barotropic responses of the west Florida continental shelf to idealized upwelling favorable alongshore and offshore wind stresses are studied using the three-dimensional, time-dependent, primitive equation Princeton Ocean Model (POM). When forced with uniform winds, the shelf circulation evolves quickly to a quasi steady state. A southeastward alongshore wind lowers sea level along the coast and drives a southeastward coastal jet with a relatively weak northwestward return flow farther offshore. A southwestward offshore wind lowers sea level along the west Florida coast and raises sea level along the Panhandle coast. Two independent circulation gyres are set up in association with …
Simulation Of Carbon-Nitrogen Cycling During Spring Upwelling In The Cariaco Basin, John J. Walsh, Dwight A. Dieterle, Frank E. Muller-Karger, Richard Bohrer, W. Paul Bissett, Ramon J. Varela, Ruben Aparicio, Rafael Diaz, Robert Thunell, Gordon T. Taylor, Mary I. Scranton, Kent A. Fanning, Edward T. Peltzer
Simulation Of Carbon-Nitrogen Cycling During Spring Upwelling In The Cariaco Basin, John J. Walsh, Dwight A. Dieterle, Frank E. Muller-Karger, Richard Bohrer, W. Paul Bissett, Ramon J. Varela, Ruben Aparicio, Rafael Diaz, Robert Thunell, Gordon T. Taylor, Mary I. Scranton, Kent A. Fanning, Edward T. Peltzer
Marine Science Faculty Publications
Coupled biological-physical models of carbon-nitrogen cycling by phytoplankton, zooplankton, and bacteria assess the impacts of nitrogen fixation and upwelled nitrate during new production within the shelf environs of the Cariaco Basin. During spring upwelling in response to a mean wind forcing of 8 m s(-1), the physical model matches remote-sensing and hydrographic estimates of surface temperature. Within the three-dimensional flow field, the steady solutions of the biological model of a simple food web of diatoms, adult calanoid copepods, and ammonifying/nitrifying bacteria approximate within similar to 9% the mean spring observations of settling fluxes caught by a sediment trap at similar …
Particle Trajectories In An Indian Ocean Model And Sensitivity To Seasonal Forcing, Meredith A. Haines, Rana A. Fine, Mark E. Luther, Zaihua Ji
Particle Trajectories In An Indian Ocean Model And Sensitivity To Seasonal Forcing, Meredith A. Haines, Rana A. Fine, Mark E. Luther, Zaihua Ji
Marine Science Faculty Publications
Trajectory experiments in a thermocline layer of an Indian Ocean model are used to investigate the role of different meridional transport mechanisms and quantify spreading pathways and rates under different forcing. Particles are introduced along two boundaries: the south Indian Ocean at 30 degrees S and the Indonesian Throughflow. Particles are advected horizontally within the layer by archived model velocity fields (1/3 degrees X 1/3 degrees resolution) for a period of 50 years. The velocity fields are the result of forcing the model by monthly mean climatology (case A). The distribution of particles within the Tropics suggests efficient ater mass …
Western Pacific Interannual Variability Associated With The El Niño‐Southern Oscillation, Chunzai Wang, Robert H. Weisberg, Jyotika I. Virmani
Western Pacific Interannual Variability Associated With The El Niño‐Southern Oscillation, Chunzai Wang, Robert H. Weisberg, Jyotika I. Virmani
Marine Science Faculty Publications
Observations of sea surface temperature (SST), sea level pressure (SLP), surface wind, and outgoing longwave radiation (OLR) show that the El Niño‐Southern Oscillation (ENSO) displays western Pacific anomaly patterns in addition to eastern Pacific anomaly patterns. During the warm phase of ENSO, warm SST and low SLP anomalies in the equatorial eastern Pacific and low OLR anomalies in the equatorial central Pacific are accompanied by cold SST and high SLP anomalies in the off‐equatorial western Pacific and high OLR anomalies in the off‐equatorial far western Pacific. Also, while the zonal wind anomalies over the equatorial central Pacific are westerly, those …
Semianalytic Moderate-Resolution Imaging Spectrometer Algorithms For Chlorophyll A And Absorption With Bio-Optical Domains Based On Nitrate-Depletion Temperatures, Kendall L. Carder, F. R. Chen, Z. P. Lee, S. K. Hawes, D. Kamykowski
Semianalytic Moderate-Resolution Imaging Spectrometer Algorithms For Chlorophyll A And Absorption With Bio-Optical Domains Based On Nitrate-Depletion Temperatures, Kendall L. Carder, F. R. Chen, Z. P. Lee, S. K. Hawes, D. Kamykowski
Marine Science Faculty Publications
This paper describes algorithms for retrieval of chlorophyll a concentration and phytoplankton and gelbstoff absorption coefficients for the Moderate-Resolution Imaging Spectrometer (MODIS) or sensors with similar spectral channels. The algorithms are based on a semianalytical, bio-optical model of remote sensing reflectance, Rrs([lambda]). The Rrs([lambda]) model has two free variables, the absorption coefficient due to phytoplankton at 675 nn, a[Phi](675), and the absorption coefficient due to gelbstoff at 400 nm, ag(400). The Rrs model has several parameters that are fixed or can be specified based on the region and season of the …
Response Of The West Florida Shelf Circulation To Climatological Wind Stress Forcing, Huijun Yang, Robert H. Weisberg
Response Of The West Florida Shelf Circulation To Climatological Wind Stress Forcing, Huijun Yang, Robert H. Weisberg
Marine Science Faculty Publications
The response of the west Florida: continental shelf circulation to monthly mean climatological wind forcing is investigated by using the three-dimensional, primitive equation Princeton Ocean Model. Two basic seasonal patterns of circulation and sea surface elevation occur under a barotropic setting: A winter pattern from October to March and a summer pattern from April to September. An interesting finding in winter is an anticyclonic gyre over the northeastern (Florida Big Bend) region that merges with a northwestward flow from the south. The Big Bend Gyre is caused by a convergence of two separate flows: A nearshore along-shelf southeastward flow and …
Non‐Redfield Carbon And Nitrogen Cycling In The Arctic: Effects Of Ecosystem Structure And Dynamics, Kendra L. Daly, Douglas W. R. Wallace, Walker O. Smith Jr., Annelie Skoog, Rubén Lara, Michel Gosselin, Eva Falck, Patrick L. Yager
Non‐Redfield Carbon And Nitrogen Cycling In The Arctic: Effects Of Ecosystem Structure And Dynamics, Kendra L. Daly, Douglas W. R. Wallace, Walker O. Smith Jr., Annelie Skoog, Rubén Lara, Michel Gosselin, Eva Falck, Patrick L. Yager
Marine Science Faculty Publications
The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so‐called Redfield ratio (C:N = 6.6 by atoms) [Redfield et al., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and …
Orbitally-Tuned Sr Isotope Chemostratigraphy For The Late Middle To Late Miocene, E. E. Martin, N. J. Shackleton, J. C. Zachos, Benjamin P. Flower
Orbitally-Tuned Sr Isotope Chemostratigraphy For The Late Middle To Late Miocene, E. E. Martin, N. J. Shackleton, J. C. Zachos, Benjamin P. Flower
Marine Science Faculty Publications
We present a Sr chemostratigraphic reference section for the late middle to late Miocene (14-5 Ma) from Ocean Drilling Program site 926 on the Ceara Rise. This site combines a precise, orbitally tuned timescale with a high sedimentation rate (15 m/m.y.), continuous deposition, and excellent biostratigraphic control. The Sr isotope curve is based on measurements of cleaned, planktonic foraminifera at 100-200 kyr sample intervals and it illustrates periods of rapid change in Sr-87/Sr-86 alternating with periods of little change. Chemostratigraphically-defined ages for these intervals can be determined within +/-0.8 m.y. and +/-1.6 m.y, respectively. There is excellent correlation with the …
Anomalous Warming In The Indian Ocean Coincident With El Niño, D. P. Chambers, B. D. Tapley, R. H. Stewart
Anomalous Warming In The Indian Ocean Coincident With El Niño, D. P. Chambers, B. D. Tapley, R. H. Stewart
Marine Science Faculty Publications
The TOPEX/POSEIDON altimeter has provided further evidence that interannual warming occurs in the Indian Ocean with a frequency similar to that of El Niño in the Pacific and has yielded important clues to the dynamics driving the warming. The signal is especially strong during the 1997 El Niño. The altimeter observes long waves which move westward from the southeastern Indian Ocean at about the same time as westwardly wind anomalies appear in the east-central portion of the basin. The sea level peaks in the southwestern Indian Ocean and causes a sea level variation signal that is a near mirror image …
Variations In Global Mean Sea Level Associated With The 1997–1998 Enso Event: Implications For Measuring Long Term Sea Level Change, R. S. Nerem, D. P. Chambers, E. W. Leuliette, Gary T. Mitchum, B. S. Giese
Variations In Global Mean Sea Level Associated With The 1997–1998 Enso Event: Implications For Measuring Long Term Sea Level Change, R. S. Nerem, D. P. Chambers, E. W. Leuliette, Gary T. Mitchum, B. S. Giese
Marine Science Faculty Publications
The TOPEX/POSEIDON satellite has observed variations in global mean sea level with a precision of 4 mm at 10-day intervals since late 1992. During the 1997–1998 ENSO event, a 20 mm rise, and subsequent fall, of mean sea level was observed. These changes are well correlated with global mean sea surface temperature anomalies, which exhibit a similar response for every major ENSO event since 1981, suggesting the observed mean sea level change is mostly caused by thermal expansion. An Empirical Orthogonal Function analysis of the altimeter-derived sea level maps also suggests a connection with ENSO. We observed the same signal …