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Book Chapter
Talley, LD.  1996.  Antarctic Intermediate Water in the South Atlantic. The South Atlantic : present and past circulation. ( Wefer G, Berger WH, Siedler G, Webb D, Eds.).:219-238., Berlin ; New York: Springer Abstract
Cronin, MF, Bond N, Booth J, Ichikawa H, Joyce TM, Kelly K, Kubota M, Qiu B, Reason C, Rouault M, Sabine C, Saino T, Small J, Suga T, Talley LD, Thompson LA, Weller RA.  2010.  Monitoring Ocean - Atmosphere Interactions in Western Boundary Current Extensions. Proceedings of OceanObs’09: Sustained Ocean Observations and Information for Society. 2( Hall J, Harrison DE, Stammer D, Eds.).   doi:10.5270/OceanObs09.cwp.20   Abstract
Bindoff, NL, Willebrand J, Artale V, Cazenave A, Gregory J, Gulev S, Hanawa K, Le Quere C, Levitus S, Nojiri Y, Shum CK, Talley LD, Unnikrishnan A.  2007.  Observations: Oceanic Climate Change and Sea Level. Climate change 2007 : the physical science basis : contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. ( Solomon S, Qin D, Manning M, Chen Z, Marquis M, Avery KB, Tignor M, Miller H, Eds.).:387-432., Cambridge ; New York: Cambridge University Press Abstract
Talley, LD.  1999.  Some aspects of ocean heat transport by the shallow, intermediate and deep overturning circulations. Mechanisms of global climate change at millennial time scales. ( Clark PU, Webb RS, Keigwin LD, Eds.).:1-22., Washington, DC: American Geophysical Union Abstract
Journal Article
Alley, RB, Marotzke J, Nordhaus WD, Overpeck JT, Peteet DM, Pielke RA, Pierrehumbert RT, Rhines PB, Stocker TF, Talley LD, Wallace JM.  2003.  Abrupt climate change. Science. 299:2005-2010.   10.1126/science.1081056   AbstractWebsite

Large, abrupt, and widespread climate changes with major impacts have occurred repeatedly in the past, when the Earth system was forced across thresholds. Although abrupt climate changes can occur for many reasons, it is conceivable that human forcing of climate change is increasing the probability of large, abrupt events. Were such an event to recur, the economic and ecological impacts could be large and potentially serious. Unpredictability exhibited near climate thresholds in simple models shows that some uncertainty will always be associated with projections. In light of these uncertainties, policy-makers should consider expanding research into abrupt climate change, improving monitoring systems, and taking actions designed to enhance the adaptability and resilience of ecosystems and economies.

Gordon, AL, Ma SB, Olson DB, Hacker P, Ffield A, Talley LD, Wilson D, Baringer M.  1997.  Advection and diffusion of Indonesian throughflow water within the Indian Ocean South Equatorial Current. Geophysical Research Letters. 24:2573-2576.   10.1029/97gl01061   AbstractWebsite

Warm, low salinity Pacific water weaves through the Indonesian Seas into the eastern boundary of the Indian Ocean. The Indonesian Throughflow Water (ITW) adds freshwater into the Indian Ocean as it spreads by the advection and diffusion within the Indian Ocean's South Equatorial Current (SEC). The low salinity throughflow trace, centered along 12 degrees S, stretches across the Indian Ocean, separating the monsoon dominated regime of the northern Indian Ocean from the more typical subtropical stratification to the south. ITW is well represented within the SEC thermocline, extending with concentrations above 80% of initial characteristics from the sea surface to 300-m within the eastern half of the Indian Ocean, with 60% concentration reaching well into the western Indian Ocean. The ITW transport within the SEC varies from 4 to 12 x 10(6) m(3)sec(-1), partly in response to variations of the injection rate at the eastern boundary and to the likelihood of a zonally elongated recirculation cell between the Equatorial Counter Current and the SEC within the Indian Ocean. Lateral mixing disperses the ITW plume meridionally with an effective isopycnal mixing coefficient of 1.1 to 1.6 x 10(4) m(2)sec(-1).

Talley, LD, Tishchenko P, Luchin V, Nedashkovskiy A, Sagalaev S, Kang DJ, Warner M, Min DH.  2004.  Atlas of Japan (East) Sea hydrographic properties in summer, 1999. Progress in Oceanography. 61:277-348.   10.1016/j.pocean.2004.06.011   AbstractWebsite

Hydrographic properties from CTD and discrete bottle sample profiles covering the Japan (East) Sea in summer, 1999, are presented in vertical sections, maps at standard depths, maps on isopycnal surfaces, and as property-property distributions. This data set covers most of the Sea with the exception of the western boundary region and northern Tatar Strait, and includes nutrients, pH, alkalinity, and chlorofluorocarbons, as well as the usual temperature, salinity, and oxygen observations. (C) 2004 Elsevier Ltd. All rights reserved.

Gray, AR, Johnson KS, Bushinsky SM, Riser SC, Russell JL, Talley LD, Wanninkhof R, Williams NL, Sarmiento JL.  2018.  Autonomous biogeochemical floats detect significant carbon dioxide outgassing in the high-latitude Southern Ocean. Geophysical Research Letters. 45:9049-9057.   10.1029/2018gl078013   AbstractWebsite

Although the Southern Ocean is thought to account for a significant portion of the contemporary oceanic uptake of carbon dioxide (CO2), flux estimates in this region are based on sparse observations that are strongly biased toward summer. Here we present new estimates of Southern Ocean air-sea CO2 fluxes calculated with measurements from biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling project during 2014-2017. Compared to ship-based CO2 flux estimates, the float-based fluxes find significantly stronger outgassing in the zone around Antarctica where carbon-rich deep waters upwell to the surface ocean. Although interannual variability contributes, this difference principally stems from the lack of autumn and winter ship-based observations in this high-latitude region. These results suggest that our current understanding of the distribution of oceanic CO2 sources and sinks may need revision and underscore the need for sustained year-round biogeochemical observations in the Southern Ocean. Plain Language Summary The Southern Ocean absorbs a great deal of carbon dioxide from the atmosphere and helps to shape the climate of Earth. However, we do not have many observations from this part of the world, especially in winter, because it is remote and inhospitable. Here we present new observations from robotic drifting buoys that take measurements of temperature, salinity, and other water properties year-round. We use these data to estimate the amount of carbon dioxide being absorbed by the Southern Ocean. In the open water region close to Antarctica, the new estimates are remarkably different from the previous estimates, which were based on data collected from ships. We discuss some possible reasons that the float-based estimate is different and how this changes our understanding of how the ocean absorbs carbon dioxide.

Johnson, KS, Plant JN, Coletti LJ, Jannasch HW, Sakamoto CM, Riser SC, Swift DD, Williams NL, Boss E, Haentjens N, Talley LD, Sarmiento JL.  2017.  Biogeochemical sensor performance in the SOCCOM profiling float array. Journal of Geophysical Research-Oceans. 122:6416-6436.   10.1002/2017jc012838   AbstractWebsite

The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) program has begun deploying a large array of biogeochemical sensors on profiling floats in the Southern Ocean. As of February 2016, 86 floats have been deployed. Here the focus is on 56 floats with quality-controlled and adjusted data that have been in the water at least 6 months. The floats carry oxygen, nitrate, pH, chlorophyll fluorescence, and optical backscatter sensors. The raw data generated by these sensors can suffer from inaccurate initial calibrations and from sensor drift over time. Procedures to correct the data are defined. The initial accuracy of the adjusted concentrations is assessed by comparing the corrected data to laboratory measurements made on samples collected by a hydrographic cast with a rosette sampler at the float deployment station. The long-term accuracy of the corrected data is compared to the GLODAPv2 data set whenever a float made a profile within 20 km of a GLODAPv2 station. Based on these assessments, the fleet average oxygen data are accurate to 1 +/- 1%, nitrate to within 0.5 +/- 0.5 mu mol kg(-1), and pH to 0.005 +/- 0.007, where the error limit is 1 standard deviation of the fleet data. The bio-optical measurements of chlorophyll fluorescence and optical backscatter are used to estimate chlorophyll a and particulate organic carbon concentration. The particulate organic carbon concentrations inferred from optical backscatter appear accurate to with 35 mg C m(-3) or 20%, whichever is larger. Factors affecting the accuracy of the estimated chlorophyll a concentrations are evaluated.

Williams, NL, Juranek LW, Feely RA, Johnson KS, Sarmiento JL, Talley LD, Dickson AG, Gray AR, Wanninkhof R, Russell JL, Riser SC, Takeshita Y.  2017.  Calculating surface ocean pCO(2) from biogeochemical Argo floats equipped with pH: An uncertainty analysis. Global Biogeochemical Cycles. 31:591-604.   10.1002/2016gb005541   AbstractWebsite

More than 74 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10 day intervals have been deployed throughout the Southern Ocean. Calculating the surface ocean partial pressure of carbon dioxide (pCO(2sw)) from float pH has uncertainty contributions from the pH sensor, the alkalinity estimate, and carbonate system equilibrium constants, resulting in a relative standard uncertainty in pCO(2sw) of 2.7% (or 11 mu atm at pCO(2sw) of 400 mu atm). The calculated pCO(2sw) from several floats spanning a range of oceanographic regimes are compared to existing climatologies. In some locations, such as the subantarctic zone, the float data closely match the climatologies, but in the polar Antarctic zone significantly higher pCO(2sw) are calculated in the wintertime implying a greater air-sea CO2 efflux estimate. Our results based on four representative floats suggest that despite their uncertainty relative to direct measurements, the float data can be used to improve estimates for air-sea carbon flux, as well as to increase knowledge of spatial, seasonal, and interannual variability in this flux. Plain Language Summary The Southern Ocean is a key player in the global flow of carbon, yet it is hard to reach, and there are relatively few measurements there, especially in winter. Measuring the amount of carbon dioxide gas in seawater is key to advancing our understanding of the Southern Ocean. More than 74 robotic floats that use sensors to measure seawater properties have been deployed throughout the Southern Ocean, and each has a lifetime of around 5 years. It is currently not possible to directly measure carbon dioxide gas from these floats; however, it is possible to estimate carbon dioxide from things that the float can measure, like pH, a measure of ocean acidity. Here surface ocean carbon dioxide is estimated from several floats and compared to two ship-based estimates. In some locations, the floats closely match the existing estimates, but in other locations the floats see significantly higher surface ocean carbon dioxide in the wintertime, reinforcing the idea that the Southern Ocean's role in the global carbon cycle needs a closer look. Our results show that despite not measuring carbon dioxide directly, these floats will help scientists learn a lot about the Southern Ocean's part in the global flow of carbon.

Talley, LD, Feely RA, Sloyan BM, Wanninkhof R, Baringer MO, Bullister JL, Carlson CA, Doney SC, Fine RA, Firing E, Gruber N, Hansell DA, Ishii M, Johnson GC, Katsumata K, Key RM, Kramp M, Langdon C, Macdonald AM, Mathis JT, McDonagh EL, Mecking S, Millero FJ, Mordy CW, Nakano T, Sabine CL, Smethie WM, Swift JH, Tanhua T, Thurnherr AM, Warner MJ, Zhang J-Z.  2016.  Changes in Ocean Heat, Carbon Content, and Ventilation: A Review of the First Decade of GO-SHIP Global Repeat Hydrography. Annual Review of Marine Science. 8:185-215.   10.1146/annurev-marine-052915-100829   AbstractWebsite

Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19% of this excess in the abyssal ocean beneath 2,000 m, dominated by Southern Ocean warming. The ocean also has taken up about 27% of anthropogenic carbon, resulting in acidification of the upper ocean. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcingand ventilation. The most recent decade of global hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (∼20%) and deep-ocean oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the ocean's overturning circulation.

Marshall, J, Andersson A, Bates N, Dewar W, Doney S, Edson J, Ferrari R, Forget G, Fratantoni D, Gregg M, Joyce T, Kelly K, Lozier S, Lumpkin R, Maze G, Palter J, Samelson R, Silverthorne K, Skyllingstad E, Straneo F, Talley L, Thomas L, Toole J, Weller R, Climode G.  2009.  The CLIMODE FIELD CAMPAIGN Observing the Cycle of Convection and Restratification over the Gulf Stream. Bulletin of the American Meteorological Society. 90:1337-1350.   10.1175/2009bams2706.1   AbstractWebsite
Gladyshev, S, Talley L, Kantakov G, Khen G, Wakatsuchi M.  2003.  Distribution, formation, and seasonal variability of Okhotsk Sea Mode Water. Journal of Geophysical Research-Oceans. 108   10.1029/2001jc000877   AbstractWebsite

Russian historical data and recently completed conductivity-temperature-depth surveys are used to examine the formation and spread in the deep Ohkotsk Sea of dense shelf water (DSW) produced in the Okhotsk Sea polynyas. Isopycnal analysis indicates that all of the main polynyas contribute to the ventilation at sigma(theta) < 26.80, including the Okhotsk Sea Mode Water (OSMW), which has densities σ(θ) = 26.7-27.0. At densities greater than 26.9 σ(θ) the northwest polynya is the only contributor to OSMW. (Although Shelikhov Bay polynyas produce the densest water with σ(θ) > 27.1, vigorous tidal mixing leads to outflow of water with a density of only about 26.7 sigma(theta)). In the western Okhotsk Sea the East Sakhalin Current rapidly transports modified dense shelf water along the eastern Sakhalin slope to the Kuril Basin, where it is subject to further mixing because of the large anticyclonic eddies and tides. Most of the dense water flows off the shelves in spring. Their average flux does not exceed 0.2 Sv in summer and fall. The shelf water transport and water exchange with the North Pacific cause large seasonal variations of temperature at densities of 26.7-27.0 sigma(theta) (depths of 150-500 m) in the Kuril Basin, where the average temperature minimum occurs in April-May, and the average temperature maximum occurs in September, with a range of 0.2degrees-0.7degreesC. The average seasonal variations of salinity are quite small and do not exceed 0.05 psu. The Soya Water mixed by winter convection, penetrating to depths greater than 200 m, in the southern Kuril Basin also produces freezing water with density greater than 26.7 sigma(theta). Using a simple isopycnal box model and seasonal observations, the OSMW production rate is seen to increase in summer up to 2.2 +/- 1.7 Sv, mainly because of increased North Pacific inflow, and drops in winter to 0.2 +/- 0.1 Sv. A compensating decrease in temperature in the Kuril Basin implies a DSW volume transport of 1.4 +/- 1.1 Sv from February through May. The residence time of the OSMW in the Kuril Basin is 2 +/- 1.7 years.

Williams, NL, Juranek LW, Johnson KS, Feely RA, Riser SC, Talley LD, Russell JL, Sarmiento JL, Wanninkhof R.  2016.  Empirical algorithms to estimate water column pH in the Southern Ocean. Geophysical Research Letters. 43:3415-3422.   10.1002/2016gl068539   AbstractWebsite

Empirical algorithms are developed using high-quality GO-SHIP hydrographic measurements of commonly measured parameters (temperature, salinity, pressure, nitrate, and oxygen) that estimate pH in the Pacific sector of the Southern Ocean. The coefficients of determination, R-2, are 0.98 for pH from nitrate (pH(N)) and 0.97 for pH from oxygen (pH(Ox)) with RMS errors of 0.010 and 0.008, respectively. These algorithms are applied to Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) biogeochemical profiling floats, which include novel sensors (pH, nitrate, oxygen, fluorescence, and backscatter). These algorithms are used to estimate pH on floats with no pH sensors and to validate and adjust pH sensor data from floats with pH sensors. The adjusted float data provide, for the first time, seasonal cycles in surface pH on weekly resolution that range from 0.05 to 0.08 on weekly resolution for the Pacific sector of the Southern Ocean.

Ogle, SE, Tamsitt V, Josey SA, Gille ST, Cerovecki I, Talley LD, Weller RA.  2018.  Episodic Southern Ocean heat loss and its mixed layer impacts revealed by the farthest south multiyear surface flux mooring. Geophysical Research Letters. 45:5002-5010.   10.1029/2017gl076909   AbstractWebsite

The Ocean Observatories Initiative air-sea flux mooring deployed at 54.08 degrees S, 89.67 degrees W, in the southeast Pacific sector of the Southern Ocean, is the farthest south long-term open ocean flux mooring ever deployed. Mooring observations (February 2015 to August 2017) provide the first in situ quantification of annual net air-sea heat exchange from one of the prime Subantarctic Mode Water formation regions. Episodic turbulent heat loss events (reaching a daily mean net flux of -294W/m(2)) generally occur when northeastward winds bring relatively cold, dry air to the mooring location, leading to large air-sea temperature and humidity differences. Wintertime heat loss events promote deep mixed layer formation that lead to Subantarctic Mode Water formation. However, these processes have strong interannual variability; a higher frequency of 2 sigma and 3 sigma turbulent heat loss events in winter 2015 led to deep mixed layers (>300m), which were nonexistent in winter 2016.

Talley, LD, White WB.  1987.  Estimates of Time and Space Scales at 300-Meters in the Midlatitude North Pacific from the Transpac-Xbt Program. Journal of Physical Oceanography. 17:2168-2188.   10.1175/1520-0485(1987)017<2168:eotass>;2   AbstractWebsite

Estimates of length and time scales of temperature variability at 300 meters in the midlatitude North Pacific are made. Data are XBT traces collected from 1976 to 1984 in the TRANSPAC Volunteer Observing Ship program. Temperatures at 300 meters are grouped in two-mouth bins and gridded using the Surface II mapping program.Temperature variance about the time mean is largest in the Kuroshio Extension and nearly constant in the eastern North Pacific. A cooling trend occurred in the eastern North Pacific over the eight years of the dataset. In the western Pacific, the annual cycle is most intense 1°–2° north of the Kuroshio Extension, with an indication of meridional propagation away from the region of most intense variability. Propagation of annual waves in the eastern Pacific was predominantly northwestward.Wavenumber and frequency spectra are computed from normalized temperatures with the mean and bimonthly average removed in order to eliminate the dominant annual cycle. Based on the overall temperature variance, the North Pacific was divided into western and eastern regions. Zonal wavenumber and frequency spectra and two-dimensional ω/k spectra were computed for a number of latitudes in the eastern and western regions. Two-dimensional k/l spectra were also computed for the western and eastern regions. The spectra indicate westward propagation throughout the midlatitude North Pacific with additional eastward propagation in the Kuroshio Extension region, shorter length and time scales in the Kuroshio Extension compared with other regions, and slight dominance of southwestward propagation in bath the eastern and western North Pacific.Tests to determine the effective spatial resolution of the dataset indicate that local average-station spacing is a good measure of local Nyquist wavelength. However, because of the nearly random sampling in a spatially limited region, an unresolved wave is aliased more or less in a band stretching towards low wavenumber rather than folded in coherent, predictable locations in the spectrum. With the choice of a two-month time bin, spectra are about equally aliased in space and time, with Nyquist wavelength and period close to the beginning of energy rolloff reported in other surveys, which have better spatial resolution but less degrees of freedom.

Whalen, CB, MacKinnon JA, Talley LD, Waterhouse AF.  2015.  Estimating the mean diapycnal mixing using a finescale strain parameterization. Journal of Physical Oceanography. 45:1174-1188.   10.1175/jpo-d-14-0167.1   AbstractWebsite

Finescale methods are currently being applied to estimate the mean turbulent dissipation rate and diffusivity on regional and global scales. This study evaluates finescale estimates derived from isopycnal strain by comparing them with average microstructure profiles from six diverse environments including the equator, above ridges, near seamounts, and in strong currents. The finescale strain estimates are derived from at least 10 nearby Argo profiles (generally <60 km distant) with no temporal restrictions, including measurements separated by seasons or decades. The absence of temporal limits is reasonable in these cases, since the authors find the dissipation rate is steady over seasonal time scales at the latitudes being considered (0 degrees-30 degrees and 40 degrees-50 degrees). In contrast, a seasonal cycle of a factor of 2-5 in the upper 1000m is found under storm tracks (30 degrees-40 degrees) in both hemispheres. Agreement between the mean dissipation rate calculated using Argo profiles and mean from microstructure profiles is within a factor of 2-3 for 96% of the comparisons. This is both congruous with the physical scaling underlying the finescale parameterization and indicates that the method is effective for estimating the regional mean dissipation rates in the open ocean.

Joyce, TM, Warren BA, Talley LD.  1986.  The Geothermal Heating of the Abyssal Sub-Arctic Pacific-Ocean. Deep-Sea Research Part a-Oceanographic Research Papers. 33:1003-1015.   10.1016/0198-0149(86)90026-9   AbstractWebsite

Recent deep CTD-O2 measurements in the abyssal North Pacific along 175°W, 152°W, and 47°N indicate large-scale changes in the O-S characteristics in the deepest kilometer of the water column. Geothermal heat flux from the abyssal sediments can be invoked as the agent for causing large-scale modification of abyssal temperatures (but not salinities) in the subarctic Pacific Ocean. East-west and north-south thermal age differences of about 100 years are inferred using a spatially uniform geothermal heat flux of 5 x 10-2 WrmW m-2.

Waterhouse, AF, MacKinnon JA, Nash JD, Alford MH, Kunze E, Simmons HL, Polzin KL, St Laurent LC, Sun OM, Pinkel R, Talley LD, Whalen CB, Huussen TN, Carter GS, Fer I, Waterman S, Garabato ACN, Sanford TB, Lee CM.  2014.  Global patterns of diapycnal mixing from measurements of the turbulent dissipation rate. Journal of Physical Oceanography. 44:1854-1872.   10.1175/jpo-d-13-0104.1   AbstractWebsite

The authors present inferences of diapycnal diffusivity from a compilation of over 5200 microstructure profiles. As microstructure observations are sparse, these are supplemented with indirect measurements of mixing obtained from(i) Thorpe-scale overturns from moored profilers, a finescale parameterization applied to (ii) shipboard observations of upper-ocean shear, (iii) strain as measured by profiling floats, and (iv) shear and strain from full-depth lowered acoustic Doppler current profilers (LADCP) and CTD profiles. Vertical profiles of the turbulent dissipation rate are bottom enhanced over rough topography and abrupt, isolated ridges. The geography of depth-integrated dissipation rate shows spatial variability related to internal wave generation, suggesting one direct energy pathway to turbulence. The global-averaged diapycnal diffusivity below 1000-m depth is O(10(-4))m(2) s(-1) and above 1000-m depth is O(10(-5))m(2) s(-1). The compiled microstructure observations sample a wide range of internal wave power inputs and topographic roughness, providing a dataset with which to estimate a representative global-averaged dissipation rate and diffusivity. However, there is strong regional variability in the ratio between local internal wave generation and local dissipation. In some regions, the depth-integrated dissipation rate is comparable to the estimated power input into the local internal wave field. In a few cases, more internal wave power is dissipated than locally generated, suggesting remote internal wave sources. However, at most locations the total power lost through turbulent dissipation is less than the input into the local internal wave field. This suggests dissipation elsewhere, such as continental margins.

Bourassa, MA, Gille ST, Bitz C, Carlson D, Cerovecki I, Clayson CA, Cronin MF, Drennan WM, Fairall CW, Hoffman RN, Magnusdottir G, Pinker RT, Renfrew IA, Serreze M, Speer K, Talley LD, Wick GA.  2013.  High-latitude ocean and sea ice surface fluxes: Challenges for climate research. Bulletin of the American Meteorological Society. 94:403-423.   10.1175/bams-d-11-00244.1   AbstractWebsite

Polar regions have great sensitivity to climate forcing; however, understanding of the physical processes coupling the atmosphere and ocean in these regions is relatively poor. Improving our knowledge of high-latitute surface fluxes will require close collaboration among meteorologists, oceanographers, ice physicists, and climatologists, and between observationalists and modelers, as well as new combinations of in situ measurements and satellite remote sensing. This article describes the deficiencies in our current state of knowledge about air-sea surface fluxes in high latitutes, the sensitivity of various high-latitude processes to changes in surface fluxes, and the scientific requirements for surface fluxes at high latitutdes. We inventory the reasons, both logistical and physical, why existing flux products do not meet these requirements. Capturing an annual cycle in fluxes requires that instruments function through long periods of cold polar darkness, often far from support services, in situations subject to icing and extreme wave conditions. Furthermore, frequent cloud cover at high latitudes restricts the avilability of surface and atmospheric data from visible and infrared (IR) wavelength satellite sensors. Recommendations are made for improving high-latitude fluxes, including 1) acquiring more in situ observations, 2) developing improved satellite-flux-observing capabilities, 3) making observations and flux products more accessible, and 4) encouraging flux intercomparisons.

Park, GH, Lee K, Tishchenko P, Min DH, Warner MJ, Talley LD, Kang DJ, Kim KR.  2006.  Large accumulation of anthropogenic CO(2) in the East (Japan) Sea and its significant impact on carbonate chemistry. Global Biogeochemical Cycles. 20   10.1029/2005gb002676   AbstractWebsite

[ 1] This paper reports on a basin-wide inventory of anthropogenic CO(2) in the East ( Japan) Sea determined from high-quality alkalinity, chlorofluorocarbon, and nutrient data collected during a summertime survey in 1999 and total dissolved inorganic carbon data calculated from pH and alkalinity measurements. The data set comprises measurements from 203 hydrographic stations and covers most of the East Sea with the exception of the northwestern boundary region. Anthropogenic CO(2) concentrations are estimated by separating this value from total dissolved inorganic carbon using a tracer-based ( chlorofluorocarbon) separation technique. Wintertime surface CFC-12 data collected in regions of deep water formation off Vladivostok, Russia, improve the accuracy of estimates of anthropogenic CO(2) concentrations by providing improved air-sea CO(2) disequilibrium values for intermediate and deep waters. Our calculation yields a total anthropogenic CO(2) inventory in the East Sea of 0.40 +/- 0.06 petagrams of carbon as of 1999. Anthropogenic CO(2) has already reached the bottom of the East Sea, largely owing to the effective transport of anthropogenic CO(2) from the surface to the ocean interior via deep water formation in the waters off Vladivostok. The highest specific column inventory ( vertically integrated inventory per square meter) of anthropogenic CO(2) of 80 mol C m(-2) is found in the Japan Basin ( 40 degrees N - 44 degrees N). Comparison of this inventory with those for other major basins of the same latitude band reveal that the East Sea values are much higher than the inventory for the Pacific Ocean (20 - 30 mol C m(-2)) and are similar to the inventory for the North Atlantic (66 - 72 mol C m(-2)). The substantial accumulation of anthropogenic CO(2) in the East Sea during the industrial era has caused the aragonite and calcite saturation horizons to move upward by 80 - 220 m and 500 - 700 m, respectively. These upward movements are approximately 5 times greater than those found in the North Pacific. Both the large accumulation of anthropogenic CO(2) and its significant impact on carbonate chemistry in the East Sea suggest that this sea is an important site for monitoring the future impact of the oceanic invasion of anthropogenic CO(2).

Whalen, CB, MacKinnon JA, Talley LD.  2018.  Large-scale impacts of the mesoscale environment on mixing from wind-driven internal waves. Nature Geoscience. 11:842-+.   10.1038/s41561-018-0213-6   AbstractWebsite

Oceanic mesoscale structures such as eddies and fronts can alter the propagation, breaking and subsequent turbulent mixing of wind-generated internal waves. However, it has been difficult to ascertain whether these processes affect the global-scale patterns, timing and magnitude of turbulent mixing, thereby powering the global oceanic overturning circulation and driving the transport of heat and dissolved gases. Here we present global evidence demonstrating that mesoscale features can significantly enhance turbulent mixing due to wind-generated internal waves. Using internal wave-driven mixing estimates calculated from Argo profiling floats between 30 degrees and 45 degrees N, we find that both the amplitude of the seasonal cycle of turbulent mixing and the response to increases in the wind energy flux are larger to a depth of at least 2,000 m in the presence of a strong and temporally uniform field of mesoscale eddy kinetic energy. Mixing is especially strong within energetic anticyclonic mesoscale features compared to cyclonic features, indicating that local modification of wind-driven internal waves is probably one mechanism contributing to the elevated mixing observed in energetic mesoscale environments.

Russell, JL, Kamenkovich I, Bitz C, Ferrari R, Gille ST, Goodman PJ, Hallberg R, Johnson K, Khazmutdinova K, Marinov I, Mazloff M, Riser S, Sarmiento JL, Speer K, Talley LD, Wanninkhof R.  2018.  Metrics for the evaluation of the Southern Ocean in coupled climate models and earth system models. Journal of Geophysical Research-Oceans. 123:3120-3143.   10.1002/2017jc013461   AbstractWebsite

The Southern Ocean is central to the global climate and the global carbon cycle, and to the climate's response to increasing levels of atmospheric greenhouse gases, as it ventilates a large fraction of the global ocean volume. Global coupled climate models and earth system models, however, vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic trend. Due to the region's complex water-mass structure and dynamics, Southern Ocean carbon and heat uptake depend on a combination of winds, eddies, mixing, buoyancy fluxes, and topography. Observationally based metrics are critical for discerning processes and mechanisms, and for validating and comparing climate and earth system models. New observations and understanding have allowed for progress in the creation of observationally based data/model metrics for the Southern Ocean. Metrics presented here provide a means to assess multiple simulations relative to the best available observations and observational products. Climate models that perform better according to these metrics also better simulate the uptake of heat and carbon by the Southern Ocean. This report is not strictly an intercomparison, but rather a distillation of key metrics that can reliably quantify the "accuracy" of a simulation against observed, or at least observable, quantities. One overall goal is to recommend standardization of observationally based benchmarks that the modeling community should aspire to meet in order to reduce uncertainties in climate projections, and especially uncertainties related to oceanic heat and carbon uptake. Plain Language Summary Observationally based metrics are essential for the standardized evaluation of climate and earth system models, and for reducing the uncertainty associated with future projections by those models.

Centurioni, LR, Hormann V, Talley LD, Arzeno I, Beal L, Caruso M, Conry P, Echols R, Fernando HJS, Giddings SN, Gordon A, Graber H, Harcourt RR, Jayne SR, Jensen TG, Lee CM, Lermusiaux PFJ, L'Hegaret P, Lucas AJ, Mahadevan A, McClean JL, Pawlak G, Rainville L, Riser SC, Seo H, Shcherbina AY, Skyllingstad E, Sprintall J, Subrahmanyam B, Terrill E, Todd RE, Trott C, Ulloa HN, Wang H.  2017.  Northern Arabian Sea Circulation Autonomous Research (NASCar): A research initiative based on autonomous sensors. Oceanography. 30:74-87.   10.5670/oceanog.2017.224   AbstractWebsite

The Arabian Sea circulation is forced by strong monsoonal winds and is characterized by vigorous seasonally reversing currents, extreme differences in sea surface salinity, localized substantial upwelling, and widespread submesoscale thermohaline structures. Its complicated sea surface temperature patterns are important for the onset and evolution of the Asian monsoon. This article describes a program that aims to elucidate the role of upper-ocean processes and atmospheric feedbacks in setting the sea surface temperature properties of the region. The wide range of spatial and temporal scales and the difficulty of accessing much of the region with ships due to piracy motivated a novel approach based on state-of-the-art autonomous ocean sensors and platforms. The extensive data set that is being collected, combined with numerical models and remote sensing data, confirms the role of planetary waves in the reversal of the Somali Current system. These data also document the fast response of the upper equatorial ocean to monsoon winds through changes in temperature and salinity and the connectivity of the surface currents across the northern Indian Ocean. New observations of thermohaline interleaving structures and mixing in setting the surface temperature properties of the northern Arabian Sea are also discussed.

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.