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 […]
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.
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.
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.
Using over 30 years of observations from drogued, satellite-tracked surface drifting buoys, Lumpkin and Johnson (2013) developed a methodology to map seasonally-varying surface currents at 1/2 degree resolution. Results from this study can be used to better understand how the ocean transports properties like heat, salt, and passive tracers, and serves as a reference to study changes in ocean currents over time. One key result from this study is the global distribution of mean, seasonal and eddy kinetic energy, which totals 4.6x1017J in the upper 30 m of the ocean and reveals the presence of three large eddy “deserts”, one in the Atlantic Ocean and the other two in the Pacific.
Using over 30 years of observations from satellite-tracked surface drifting buoys, NOAA oceanographers derived a global climatology of seasonally-varying ocean surface currents at one-half degree resolution. This data set can be used to better understand how the ocean transports properties like heat, salt, and passive tracers, and as a reference to study changes in ocean […]
The record-breaking U.S. tornado outbreaks in the spring of 2011 prompt the need to identify long-term climate signals that could potentially provide seasonal predictability for U.S. tornado outbreaks. A new research led by scientists in the Physical Oceanography Division of NOAA-AOML used both observations and model experiments to show that a positive phase Trans-Niño may be one such climate signal.
A news article that appeared on August 27 shows the ocean conditions in the Gulf of America during hurricanes Katrina (August 2005) and Isaac (August 2012). The ocean conditions are depicted by the upper ocean heat content derived from satellite altimetry using a methodology developed at NOAA/AOML. The upper ocean heat content had larger values during Katrina mainly due to an anticyclonic warm ring and an extended Loop Current. These conditions, not found during the passage of Hurricane Isaac, partly contributed to the intensification of Katrina.
A new study led by researchers from University of Miami, NOAA-AOML, IFM-GEOMAR, and NCAR explores why the Atlantic Ocean has warmed substantially more than any other ocean basin since the 1950s. The research article published in the Geophysical Research letters evidences that the observed large warming of the Atlantic Ocean since the 1950s is largely induced by an increase in the inter-ocean heat transport from the Indian Ocean via the Agulhas leakage. The study points to an important role played by the Atlantic meridional overturning circulation (AMOC) in the South Atlantic in enhancing the secular warming of the Atlantic Ocean.
A joint workshop hosted by NOAA and the National Aeronautics and Space Administration (NASA) for bluefin tuna research was held at the University of Miami on December 6-7th. Researchers with AOML’s Physical Oceanography Division (PhOD) presented the results of their collaborative efforts with NOAA’s Southeast Fisheries Science Center (SEFSC), which have focused on the link between the ocean and stock assessment species of relevant commercial importance.
