Category: Physical Oceanography

Gliders Patrol Ocean Waters with a Goal of Improved Prediction of Hurricane Intensity

Scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory are in the Caribbean to launch two underwater gliders from a vessel off Puerto Rico to collect temperature and other weather data to improve hurricane forecasting.One of the gliders will collect observations in the Caribbean Sea, and another in the North Atlantic Ocean. They are positioned to operate over the next six months (June-November) collecting data in areas where hurricanes are common and areas where there is a lack of environmental data.

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Wind forced variability of the Antarctic Circumpolar Current south of Africa between 1993 and 2010

Researchers from PhOD and from the University of Cape Town used temperature data from the AX25 repeat XBT transect (from South Africa to Antarctica) in combination with other hydrographic and satellite observations to report a mechanism by which local winds alter the structure of the Antarctic Circumpolar Current flow south of Africa.

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Impact of canonical and Modoki El Niño on tropical Atlantic SST

Results from research performed by Dillon Amaya, an undergraduate Hollings Scholar from Texas A&M University, were published recently in Journal of Geophysical Research. Dillon’s work was carried out in the Physical Oceanography Division of AOML during the summer of 2013 and focused on understanding the impacts of different types of El Niño events (“canonical” and “Modoki”) on sea surface temperatures in the tropical Atlantic. The main result from the research is that Modoki El Niño;s fail to produce significant warming in the tropical North Atlantic, in contrast to the well known warming following canonical events.

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Oceanographic conditions in the Gulf of Mexico in July 2010, during the Deepwater Horizon oil spill

Results from collaborative research conducted by AOML and NOAA’s Southeast Fisheries Science Center (SEFSC) in response to the 2010 Deepwater Horizon oil spill, were recently published in Continental Shelf Research (December, 2013). PhOD oceanographers R. Smith, E. Johns, G. Goni, J. Trinanes, and R. Lumpkin, in collaboration with other researchers at AOML (M. Wood, C. Kelble, and S. Cummings) and SEFSC (J. Lamkin and S. Privoznik) report on the surface and subsurface connectivity across the eastern Gulf of Mexico (GOM) during July 2010.

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Mean Meridional Currents in the Central and Eastern Equatorial Atlantic

In an article recently published in Climate Dynamics (Perez et al., 2013) , scientists in PhOD (R. Perez, R. Lumpkin, C. Schmid) described for the first time the mean vertical and cross-equatorial structure of the upper-ocean meridional currents in the Atlantic cold tongue region, using in situ observations including drifters, Argo, shipboard/lowered ADCP, and moored ADCP. This study involves collaborations with scientists from the University of Miami, Scripps Institution of Oceanography, and several international institutions and makes use of data from several major tropical Atlantic field programs including NOAA’s PIRATA Northeast Extension.

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AOML Tests New Deep Water Data Pod System  “ABIISS” 

The AOML technology test of a system to autonomously retrieve data from subsurface moored instruments has had a major success. The Adaptable Bottom Instrument Information Shuttle System (ABIISS) is in the midst of its first 4000+ meter test, and on November 6th, 2015 the first data pod surfaced and successfully transmitted its daily data record from the ocean bottom pressure-equipped inverted echo […]

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Inter-hemispheric Influence of the Northern Summer Monsoons on the Southern Subtropical Anticyclone

In a recent article accepted for publication in the Journal of Climate, scientists in PhOD, S.-K. Lee (CIMAS) and C. Wang collaborated with R. Mechoso and D. Neelin, both at UCLA, to explore why the southern subtropical anticyclones are notably stronger in the austral winter than in summer, which is in contrast with the Northern Hemisphere (NH) in which subtropical anticyclones are more intense in summer according to the monsoon heating paradigm. They performed model experiments to show that during the boreal summer enhanced tropical convection activity in the NH plays important roles in strengthening the southern subtropical anticyclones.

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Triggering of El Nino through trade-wind induced charging of the equatorial Pacific

In a recent study by scientists at Boston University, PHOD, and NCAR, a new mechanism was uncovered for initiating ENSO events wherein SLP-generated North Pacific trade winds induce subsurface heat content changes that serve as precursors to El Ninos. This trade-wind charging mechanism of the equatorial Pacific is fundamentally different from any previously diagnosed, and studies examining the surface and subsurface ocean dynamics associated with this mechanism are underway.

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Relationship between the Off-equatorial Current System and the Tropical Atlantic Variability

Scientists at PHOD developed a synthetic method, which combines high-density expendable bathythermograph (XBT) temperature data along the AX08 XBT transect (which runs between Cape Town and NYC) with altimetric sea level anomalies, to estimate the variability of the off-equatorial currents, such as the North Equatorial Countercurrent and the North Equatorial Undercurrent, on seasonal to interannual timescales. Understanding how the ocean dynamics is liked to anomalies of temperature and wind-stress in the tropical Atlantic is critical to understand the climate and weather variability in the adjacent continental areas.

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