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Full-Text Articles in Life Sciences

Interannual Volume Variability In The Tropical Pacific, Christina L. Holland, Gary T. Mitchum Nov 2003

Interannual Volume Variability In The Tropical Pacific, Christina L. Holland, Gary T. Mitchum

Marine Science Faculty Publications

The question of whether or not the volume of the tropical Pacific changes over the course of an El Niño event has potentially important consequences for our understanding of the dynamical mechanisms responsible for El Niño‐Southern Oscillation (ENSO) events. In this study, we examine the volume variability of the tropical Pacific, defined as the areal integral of the sea surface height variability, using TOPEX/Poseidon altimetric sea surface heights and the output of a numerical model. We find that volume gradually builds up in the tropical Pacific prior to a typical ENSO event and rapidly decreases during the event due to …


Large Scale Ocean Circulation From The Grace Ggm01 Geoid, B. D. Tapley, D. Chambers, S. Bettadpur, J. C. Ries Nov 2003

Large Scale Ocean Circulation From The Grace Ggm01 Geoid, B. D. Tapley, D. Chambers, S. Bettadpur, J. C. Ries

Marine Science Faculty Publications

The GRACE Gravity Model 01 (GGM01), computed from 111 days of GRACE K-band ranging (KBR) data, is differenced from a global mean sea surface (MSS) computed from a decade of satellite altimetry to determine a mean dynamic ocean topography (DOT). As a test of the GGM01 gravity model, large-scale zonal and meridional surface geostrophic currents are computed from the topography and are compared with those derived from a mean hydrographic surface. Reduction in residual RMS between the two by 30–60% (and increased correlation) indicates that the GGM01 geoid represents a dramatic improvement over older geoid models, which were developed from …


Ocean Observer Study: A Proposed National Asset To Augment The Future U. S. Operational Satellite System, John D. Cunningham, Don P. Chambers, Curtiss O. Davis, Andrew Gerber, Rosalind Hetz, James P. Mcguire, William Pichel Oct 2003

Ocean Observer Study: A Proposed National Asset To Augment The Future U. S. Operational Satellite System, John D. Cunningham, Don P. Chambers, Curtiss O. Davis, Andrew Gerber, Rosalind Hetz, James P. Mcguire, William Pichel

Marine Science Faculty Publications

The next generation of U.S. polar orbiting environmental satellites, are now under development. These satellites, jointly developed by the Department of Defense (DoD), the Department of Commerce (DOC), and the National Aeronautics and Space Administration (NASA), will be known as the National Polar-orbiting Operational Environmental Satellite System (NPOESS). It is expected that the first of these satellites will be launched in 2010. NPOESS has been designed to meet the operational needs of the U.S. civilian meteorological, environmental, climatic, and space environmental remote sensing programs, and the Global Military Space and Geophysical Environmental remote sensing programs. This system, however, did not …


New Evidence For Enhanced Ocean Primary Production Triggered By Tropical Cyclone, I. Lin, W. Timothy Liu, Chun-Chieh Wu, George T. F. Wong, Chuanmin Hu, Zhiqiang Chen, Wen-Der Liang, Yih Yang, Kon-Kee Liu Jul 2003

New Evidence For Enhanced Ocean Primary Production Triggered By Tropical Cyclone, I. Lin, W. Timothy Liu, Chun-Chieh Wu, George T. F. Wong, Chuanmin Hu, Zhiqiang Chen, Wen-Der Liang, Yih Yang, Kon-Kee Liu

Marine Science Faculty Publications

New evidence based on recent satellite data is presented to provide a rare opportunity in quantifying the long-speculated contribution of tropical cyclones to enhance ocean primary production. In July 2000, moderate cyclone Kai-Tak passed over the South China Sea (SCS). During its short 3-day stay, Kai-Tak triggered an average 30-fold increase in surface chlorophyll-a concentration. The estimated carbon fixation resulting from this event alone is 0.8 Mt, or 2–4% of SCS's annual new production. Given an average of 14 cyclones passing over the SCS annually, we suggest the long-neglected contribution of tropical cyclones to SCS's annual new production may be …


Phytoplankton Response To Intrusions Of Slope Water On The West Florida Shelf: Models And Observations, John J. Walsh, Robert H. Weisberg, Dwight A. Dieterle, Ruoying He, Brian P. Darrow, Jason K. Jolliff, Kristen M. Lester, Gabriel A. Vargo, Gary J. Kirkpatrick, Kent A. Fanning, Tracy T. Sutton, Ann E. Jochens, Douglas C. Biggs, Bisman Nababan, Chuanmin Hu, Frank E. Muller-Karger Jun 2003

Phytoplankton Response To Intrusions Of Slope Water On The West Florida Shelf: Models And Observations, John J. Walsh, Robert H. Weisberg, Dwight A. Dieterle, Ruoying He, Brian P. Darrow, Jason K. Jolliff, Kristen M. Lester, Gabriel A. Vargo, Gary J. Kirkpatrick, Kent A. Fanning, Tracy T. Sutton, Ann E. Jochens, Douglas C. Biggs, Bisman Nababan, Chuanmin Hu, Frank E. Muller-Karger

Marine Science Faculty Publications

Previous hypotheses had suggested that upwelled intrusions of nutrient‐rich Gulf of Mexico slope water onto the West Florida Shelf (WFS) led to formation of red tides of Karenia brevis. However, coupled biophysical models of (1) wind‐ and buoyancy‐driven circulation, (2) three phytoplankton groups (diatoms, K. brevis, and microflagellates), (3) these slope water supplies of nitrate and silicate, and (4) selective grazing stress by copepods and protozoans found that diatoms won in one 1998 case of no light limitation by colored dissolved organic matter (CDOM). The diatoms lost to K. brevis during another CDOM case of the models. In …


Local And Deep-Ocean Forcing Contributions To Anomalous Water Properties On The West Florida Shelf, Robert H. Weisberg, Ruoying He Jun 2003

Local And Deep-Ocean Forcing Contributions To Anomalous Water Properties On The West Florida Shelf, Robert H. Weisberg, Ruoying He

Marine Science Faculty Publications

Material property distributions on continental shelves result from the mixing and modifications of estuarine and deep-ocean source waters. How this occurs depends on the momentum and buoyancy that are input either locally on the shelf or from the deep-ocean at the shelf break. We address this question of local versus deep-ocean forcing for the West Florida Shelf (WFS) using in situ data and a numerical circulation model. The spring and summer seasons of 1998 and 1999 show distinctively different water properties on the shelf and at the shelf break. We account for these differences by a combination of local forcing, …


Millennial- To Century-Scale Variability In Gulf Of Mexico Holocene Climate Records, R. Z. Poore, H. J. Dowsett, S. Verardo, Terrence M. Quinn Jun 2003

Millennial- To Century-Scale Variability In Gulf Of Mexico Holocene Climate Records, R. Z. Poore, H. J. Dowsett, S. Verardo, Terrence M. Quinn

Marine Science Faculty Publications

Proxy records from two piston cores in the Gulf of Mexico (GOM) provide a detailed (50–100 year resolution) record of climate variability over the last 14,000 years. Long‐term (millennial‐scale) trends and changes are related to the transition from glacial to interglacial conditions and movement of the average position of the Intertropical Convergence Zone (ITCZ) related to orbital forcing. The δ18O of the surface‐dwelling planktic foraminifer Globigerinoides ruber show negative excursions between 14 and 10.2 ka (radiocarbon years) that reflect influx of meltwater into the western GOM during melting of the Laurentide Ice Sheet. The relative abundance of the …


Chlorophyll Dispersal By Eddy-Eddy Interactions In The Gulf Of Mexico, M. Toner, A. D. Kirwan, A. C. Poje, L. H. Kantha, Frank E. Muller-Karger, C. K. R. T. Jones Apr 2003

Chlorophyll Dispersal By Eddy-Eddy Interactions In The Gulf Of Mexico, M. Toner, A. D. Kirwan, A. C. Poje, L. H. Kantha, Frank E. Muller-Karger, C. K. R. T. Jones

Marine Science Faculty Publications

A Lagrangian analysis of the transport and dispersal of plumes observed in satellite‐derived ocean color images was conducted using a data‐assimilating model of the Gulf of Mexico. The interaction between pervasive cyclonic and anticyclonic eddies in the Gulf generated advective paths that connect remote shelf regions. These paths aligned remarkably well with the plume events recorded with the chlorophyll‐a ocean color product from SeaWiFS. Two such events were studied. In one event material was transported in a thin strip between the northern wall of the Loop Current and an adjacent cyclone, connecting the eastern Campheche shelf (off the Yucatan Peninsula) …


A Loop Current Intrusion Case Study On The West Florida Shelf, Ruoying He, Robert H. Weisberg Feb 2003

A Loop Current Intrusion Case Study On The West Florida Shelf, Ruoying He, Robert H. Weisberg

Marine Science Faculty Publications

The Gulf of Mexico Loop Current intruded upon the West Florida continental shelf in June 2000. In situ currents and hydrography along with satellite temperature and altimetry measurements are used to describe this event and its effects on the shelf. A strong southward current is observed to flow along the shelf slope seaward of the intruded water boundary. This current transported cold, nutrient-rich water from the north, thereby producing anomalous hydrographic features near the shelf break (80-m isobath). An array of moored velocity profilers reveals that the currents landward of the intruded water are independent of the Loop Current and …


El Niño Tropical Pacific Ocean Surface Current And Temperature Evolution In 2002 And Outlook For Early 2003, Gary S. Lagerloef, Roger Lukas, Fabrice Bonjean, John T. Gunn, Gary T. Mitchum, Mark Bourassa, Antonio J. Busalacchi Jan 2003

El Niño Tropical Pacific Ocean Surface Current And Temperature Evolution In 2002 And Outlook For Early 2003, Gary S. Lagerloef, Roger Lukas, Fabrice Bonjean, John T. Gunn, Gary T. Mitchum, Mark Bourassa, Antonio J. Busalacchi

Marine Science Faculty Publications

[1] The timing and magnitude of the 2002–2003 El Niño/Southern Oscillation (ENSO) warm episode has been monitored for the first time with near real time satellite-derived surface current (SC) fields in addition to the operational temperature, wind and sea level satellite and in situ measurements previously used. The record of the past decade shows that dominant SC anomalies generally lead ENSO sea surface temperature (SST) anomalies by 2.5–3 months, and that a rapid SC anomaly reversal has coincided with the peak SST of warm events. During September to December 2002, SST anomalies increased and spread eastward in conjunction with strong, …


New Topex Sea State Bias Models And Their Effect On Global Mean Sea Level, D. P. Chambers, S. A. Hayes, J. C. Ries, T. J. Urban Jan 2003

New Topex Sea State Bias Models And Their Effect On Global Mean Sea Level, D. P. Chambers, S. A. Hayes, J. C. Ries, T. J. Urban

Marine Science Faculty Publications

[1] During the calibration of the Jason-1 altimeter, it was discovered that the Jason-TOPEX sea surface height (SSH) residuals contained a trend correlated with significant wave height (SWH), indicating an error in the sea state bias (SSB) model for one or both of the altimeters. After updating the SSB model for Jason the trend remained, which pointed to an error in the TOPEX model. Since two different TOPEX altimeters (TOPEX_A and TOPEX_B) have operated during the mission, we estimated new SSB models using data from each one. The estimated SSB model for TOPEX_B is significantly different than the model provided …


Submarine Strombolian Eruptions On The Gorda Mid‐Ocean Ridge, David A. Clague, Alicé S. Davis, Jacqueline E. Dixon Jan 2003

Submarine Strombolian Eruptions On The Gorda Mid‐Ocean Ridge, David A. Clague, Alicé S. Davis, Jacqueline E. Dixon

Marine Science Faculty Publications

Compositionally variable limu o Pele occurs in widely distributed sediments collected during ROV Tiburon dives along the Gorda Ridge axis. The fragments formed deeper than the critical depth of seawater and are unlikely to be formed by supercritical expansion of seawater upon heating in contact with hot lava. Discharge of C02 through erupting lava is the most likely way to make such bub­bles at >298 bars pressure. The distribution and composition of limu o Pele frag­ments indicate that low-energy strombolian activity is a common, although minor, component of eruptions along mid-ocean ridges. Combined dissolved and exsolved volatile contents of N-MORB …