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Carter, BR, Feely RA, Wanninkhof R, Kouketsu S, Sonnerup RE, Pardo PC, Sabine CL, Johnson GC, Sloyan BM, Murata A, Mecking S, Tilbrook B, Speer K, Talley LD, Millero FJ, Wijffels SE, Macdonald AM, Gruber N, Bullister JL.  2019.  Pacific anthropogenic carbon between 1991 and 2017. Global Biogeochemical Cycles. 33:597-617.   10.1029/2018gb006154   AbstractWebsite

We estimate anthropogenic carbon (C-anth) accumulation rates in the Pacific Ocean between 1991 and 2017 from 14 hydrographic sections that have been occupied two to four times over the past few decades, with most sections having been recently measured as part of the Global Ocean Ship-based Hydrographic Investigations Program. The rate of change of C-anth is estimated using a new method that combines the extended multiple linear regression method with improvements to address the challenges of analyzing multiple occupations of sections spaced irregularly in time. The C-anth accumulation rate over the top 1,500 m of the Pacific increased from 8.8 (+/- 1.1, 1 sigma) Pg of carbon per decade between 1995 and 2005 to 11.7 (+/- 1.1) PgC per decade between 2005 and 2015. For the entire Pacific, about half of this decadal increase in the accumulation rate is attributable to the increase in atmospheric CO2, while in the South Pacific subtropical gyre this fraction is closer to one fifth. This suggests a substantial enhancement of the accumulation of C-anth in the South Pacific by circulation variability and implies that a meaningful portion of the reinvigoration of the global CO2 sink that occurred between similar to 2000 and similar to 2010 could be driven by enhanced ocean C-anth uptake and advection into this gyre. Our assessment suggests that the accuracy of C-anth accumulation rate reconstructions along survey lines is limited by the accuracy of the full suite of hydrographic data and that a continuation of repeated surveys is a critical component of future carbon cycle monitoring.

Tsuchiya, M, Talley LD.  1998.  A Pacific hydrographic section at 88 degrees W: Water-property distribution. Journal of Geophysical Research-Oceans. 103:12899-12918.   10.1029/97jc03415   AbstractWebsite

Full-depth conductivity-temperature-depth (CTD)/hydrographic measurements with high horizontal and vertical resolution were made in February-April 1993 along a line lying at a nominal longitude of 88 degrees W and extending from southern Chile (54 degrees S) to Guatemala (14 degrees N). It crossed five major deep basins (Southeast Pacific, Chile, Peru, Panama, and Guatemala basins) east of the East Pacific Rise. Vertical sections of potential temperature, salinity, potential density, oxygen, silica, phosphate, nitrate, and nitrite are presented to illustrate the structure of the entire water column. Some features of interest found in the sections are described, and an attempt is made to interpret them in terms of the isopycnal property distributions associated with the large-scale ocean circulation. These features include: various near-surface waters observed in the tropical and subtropical regions and the fronts that mark the boundaries of these waters; the possible importance of salt fingering to the downward salt transfer from the high-salinity subtropical water; a shallow thermostad (pycnostad) developed at 16 degrees-18.5 degrees C in the subtropical water; low-salinity surface water in the subantarctic zone west of southern Chile; large domains of extremely low oxygen in the subpycnocline layer on both sides of the equator and a secondary nitrite maximum associated with a nitrate minimum in these low-oxygen domains; high-salinity, low-oxygen, high-nutrient subpycnocline water that is carried poleward along the eastern boundary by the Peru-Chile Undercurrent; the Subantarctic Mode and Antarctic Intermediate waters; middepth isopycnal property extrema observed at the crest of the Sala y Gomez Ridge; influences of the North Pacific and the North Atlantic upon deep waters along the section; and the characteristics and sources of the bottom waters in the five deep basins along the section.

Briggs, EM, Martz TR, Talley LD, Mazloff MR, Johnson KS.  2018.  Physical and biological drivers of biogeochemical tracers within the seasonal sea ice zone of the Southern Ocean from profiling floats. Journal of Geophysical Research-Oceans. 123:746-758.   10.1002/2017jc012846   AbstractWebsite

Here we present initial findings from nine profiling floats equipped with pH, O-2, , and other biogeochemical sensors that were deployed in the seasonal ice zone (SIZ) of the Southern Ocean in 2014 and 2015 through the Southern Ocean Carbon and Climate Observations and Modelling (SOCCOM) project. A large springtime phytoplankton bloom was observed that coincided with sea ice melt for all nine floats. We argue this bloom results from a shoaling of the mixed layer depth, increased vertical stability, and enhanced nutrient and light availability as the sea ice melts. This interpretation is supported by the absence of a springtime bloom when one of the floats left the SIZ in the second year of observations. During the sea ice covered period, net heterotrophic conditions were observed. The rate of uptake of O-2 and release of dissolved inorganic carbon (derived from pH and estimated total alkalinity) and is reminiscent of biological respiration and is nearly Redfieldian for the nine floats. A simple model of mixed layer physics was developed to separate the physical and biological components of the signal in pH and O-2 over one annual cycle for a float in the Ross Sea SIZ. The resulting annual net community production suggests that seasonal respiration during the ice covered period of the year nearly balances the production in the euphotic layer of up to 5 molCm(-2) during the ice free period leading to a net of near zero carbon exported to depth for this one float.

Talley, LD.  1996.  Physical oceanography. Encylopedia of Earth Sciences. :745-749., New York: MacMillan Publishing Abstract
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Talley, LD, Fryer G, Lumpkin R.  1998.  Physical oceanography of the tropical Pacific. Geography of the Pacific Islands. ( Rapaport M, Ed.).:19-32., Honolulu: Bess Press Abstract
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Talley, LD, Nagata Y.  1995.  PICES Working Group I: Review of the Okhotsk Sea and Oyashio Region. PICES Scientific Report. 2:227.: North Pacific Marine Science Organization (PICES) Abstract
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Talley, LD.  1988.  Potential Vorticity Distribution in the North Pacific. Journal of Physical Oceanography. 18:89-106.   10.1175/1520-0485(1988)018<0089:pvditn>2.0.co;2   AbstractWebsite

Vertical sections and maps of potential vorticity ρ−1f∂ρ/∂z for the North Pacific are presented. On shallow isopycnals, high potential vorticity is found in the tropics, subpolar gyre, and along the eastern boundary of the subtropical gyre, all associated with Ekman upwelling. Low potential vorticity is found in the western subtropical gyre (subtropical mode water), in a separate patch near the sea surface in the eastern subtropical gyre and extending around the gyre, and near sea-surface outcrops in the subpolar gyre; the last is analogous to the subpolar mode water of the North Atlantic and Southern Ocean.Meridional gradients of potential vorticity are high between the subtropical and subpolar gyres at densities which outcrop only in the subpolar gyre; lateral gradients of potential vorticity are low in large regions of the subtropical gyre on these isopycnals. On slightly denser isopycnals which do not outcrop in the North Pacific, there are large regions of low potential vorticity gradients which cross the subtropical-subpolar gyre boundary. These regions decrease in area with depth and vanish between 2500 and 3000 meters. Regions of low lateral gradients of potential vorticity are surrounded by and overlie regions where the meridional gradient of potential vorticity is approximately β. In the abyssal waters, below 3500 meters, meridional potential vorticity gradients again decrease, perhaps associated with slow geothermal heating. The depth and shape of the region wheel potential vorticity is relatively uniform or possesses closed contours is noted and related to theories of wind-driven circulation.

Talley, LD, Baringer MO.  1997.  Preliminary results from WOCE hydrographic sections at 80 degrees E and 32 degrees S in the central Indian Ocean. Geophysical Research Letters. 24:2789-2792.   10.1029/97gl02657   AbstractWebsite

The hydrographic properties and circulation along sections at 80 degrees E and 32 degrees S in March, 1995, in the Indian Ocean are described very briefly. A halocline was well-developed in the tropics. A westward coastal jet of fresh Bay of Bengal water was present at the sea surface at Sri Lanka with eastward flow of saline Arabian Sea water below. The Equatorial Undercurrent was well developed as were the deep equatorial jets. The Indonesian throughflow jet presented a large dynamic signature at 10 to 14 degrees S coinciding with a strong front in all properties to great depth. Its mid-depth salinity minimum is separated from that of the Antarctic Intermediate Water. The Subantarctic Mode Water of the southeastern Indian Ocean imparts its high oxygen ventilation signature to the whole of the transects, including the tropical portion. The deepest water in the Central Indian Basin is pooled in the center of the basin, and its principal source appears to be the sill at 11 degrees S through the Ninetyeast Ridge. Northward deep water transports across the 32 degrees S section were similar to those observed in 1987 but the deep water was lower in oxygen and fresher than in 1987. Upper ocean waters at 32 degrees S were more saline and warmer in 1995.

Delman, AS, McClean JL, Sprintall J, Talley LD, Bryan FO.  2018.  Process-specific contributions to anomalous Java mixed layer cooling during positive IOD events. Journal of Geophysical Research-Oceans. 123:4153-4176.   10.1029/2017jc013749   AbstractWebsite

Negative sea surface temperature (SST) anomalies associated with positive Indian Ocean Dipole (pIOD) events first appear in the seasonal upwelling zone along the southern coast of Java during May-July. The evolution of anomalous SSTs in this coastal region is analyzed by computing a temperature budget using output from a strongly eddy-active ocean general circulation model. The seasonal cooling south of Java in May-July is driven by a reduction in incoming shortwave radiation and by vertical mixing, consistent with earlier studies in the region; however, the model budget also shows an advective contribution that drives anomalous cooling at the onset of pIOD events. To identify which process(es) are responsible for the anomalous advective cooling during pIOD events, a novel process index regression method is used to estimate the contributions of wind stress, equatorial Kelvin waves, mesoscale eddies, and Lombok Strait flow to anomalous cooling south of Java. Using this method, wind stress forcing along the west coast of Sumatra is found to make the most substantial contribution to anomalous cooling south of Java, with lesser contributions from equatorially sourced Kelvin waves and local wind stress. Mesoscale eddies redistribute heat from the Lombok Strait outflow, and have an anomalous warming effect on the eastern side of the upwelling region. The process-specific temperature budget south of Java highlights the importance of wind stress forcing west of Sumatra relative to equatorial and local forcing, and explains most of the mixed layer temperature anomaly evolution associated with advection during pIOD events. Plain Language Summary Climate variations from year to year in much of the Indian Ocean region are controlled by a phenomenon called the Indian Ocean Dipole, which is similar to El Nino but centered on the Indian Ocean basin. The positive phase of the Indian Ocean Dipole, or pIOD, typically brings drought conditions to Indonesia and unusually heavy rainfall to east Africa. These pIOD events are caused in part by unusually strong cooling in sea surface temperatures south of the Indonesian island of Java, but the series of events that causes this strong cooling has not been well understood previously. This paper uses the results obtained from a high-resolution ocean model, together with a new method for analyzing these results, to study exactly how much sea surface cooling (or warming) is caused by specific processes in the Java region. The study finds that changes in wind patterns adjacent to the Indonesian island of Sumatra can explain nearly all of the unusual cooling that develops south of Java in years when these pIOD events happen. The analysis method introduced in this paper may be adapted to study how processes in the ocean or atmosphere cause changes in the Earth's climate system.