Ishii Masao

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  • Article
    Correction to “Using altimetry to help explain patchy changes in hydrographic carbon measurements”
    (American Geophysical Union, 2009-12-09) Rodgers, Keith B. ; Key, Robert M. ; Gnanadesikan, Anand ; Sarmiento, Jorge L. ; Aumont, Olivier ; Bopp, Laurent ; Doney, Scott C. ; Dunne, John P. ; Glover, David M. ; Ishida, Akio ; Ishii, Masao ; Jacobson, Andrew R. ; Monaco, Claire Lo ; Maier-Reimer, Ernst ; Mercier, Herlé ; Metzl, Nicolas ; Perez, Fiz F. ; Rios, Aida F. ; Wanninkhof, Rik ; Wetzel, Patrick ; Winn, Christopher D. ; Yamanaka, Yasuhiro
  • Article
    Air-sea CO2 flux in the Pacific Ocean for the period 1990–2009
    (Copernicus Publications on behalf of the European Geosciences Union, 2014-02-06) Ishii, Masao ; Feely, Richard A. ; Rodgers, Keith B. ; Park, Geun-Ha ; Wanninkhof, Rik ; Sasano, D. ; Sugimoto, H. ; Cosca, Catherine E. ; Nakaoka, Shin-ichiro ; Telszewski, Maciej ; Nojiri, Yukihiro ; Mikaloff Fletcher, Sara E. ; Niwa, Y. ; Patra, Prabir K. ; Valsala, V. ; Nakano, Hideyuki ; Lima, Ivan D. ; Doney, Scott C. ; Buitenhuis, Erik T. ; Aumont, Olivier ; Dunne, John P. ; Lenton, Andrew ; Takahashi, Taro
    Air–sea CO2 fluxes over the Pacific Ocean are known to be characterized by coherent large-scale structures that reflect not only ocean subduction and upwelling patterns, but also the combined effects of wind-driven gas exchange and biology. On the largest scales, a large net CO2 influx into the extratropics is associated with a robust seasonal cycle, and a large net CO2 efflux from the tropics is associated with substantial interannual variability. In this work, we have synthesized estimates of the net air–sea CO2 flux from a variety of products, drawing upon a variety of approaches in three sub-basins of the Pacific Ocean, i.e., the North Pacific extratropics (18–66° N), the tropical Pacific (18° S–18° N), and the South Pacific extratropics (44.5–18° S). These approaches include those based on the measurements of CO2 partial pressure in surface seawater (pCO2sw), inversions of ocean-interior CO2 data, forward ocean biogeochemistry models embedded in the ocean general circulation models (OBGCMs), a model with assimilation of pCO2sw data, and inversions of atmospheric CO2 measurements. Long-term means, interannual variations and mean seasonal variations of the regionally integrated fluxes were compared in each of the sub-basins over the last two decades, spanning the period from 1990 through 2009. A simple average of the long-term mean fluxes obtained with surface water pCO2 diagnostics and those obtained with ocean-interior CO2 inversions are −0.47 ± 0.13 Pg C yr−1 in the North Pacific extratropics, +0.44 ± 0.14 Pg C yr−1 in the tropical Pacific, and −0.37 ± 0.08 Pg C yr−1 in the South Pacific extratropics, where positive fluxes are into the atmosphere. This suggests that approximately half of the CO2 taken up over the North and South Pacific extratropics is released back to the atmosphere from the tropical Pacific. These estimates of the regional fluxes are also supported by the estimates from OBGCMs after adding the riverine CO2 flux, i.e., −0.49 ± 0.02 Pg C yr−1 in the North Pacific extratropics, +0.41 ± 0.05 Pg C yr−1 in the tropical Pacific, and −0.39 ± 0.11 Pg C yr−1 in the South Pacific extratropics. The estimates from the atmospheric CO2 inversions show large variations amongst different inversion systems, but their median fluxes are consistent with the estimates from climatological pCO2sw data and pCO2sw diagnostics. In the South Pacific extratropics, where CO2 variations in the surface and ocean interior are severely undersampled, the difference in the air–sea CO2 flux estimates between the diagnostic models and ocean-interior CO2 inversions is larger (0.18 Pg C yr−1). The range of estimates from forward OBGCMs is also large (−0.19 to −0.72 Pg C yr−1). Regarding interannual variability of air–sea CO2 fluxes, positive and negative anomalies are evident in the tropical Pacific during the cold and warm events of the El Niño–Southern Oscillation in the estimates from pCO2sw diagnostic models and from OBGCMs. They are consistent in phase with the Southern Oscillation Index, but the peak-to-peak amplitudes tend to be higher in OBGCMs (0.40 ± 0.09 Pg C yr−1) than in the diagnostic models (0.27 ± 0.07 Pg C yr−1).
  • Article
    Sea–air CO2 fluxes in the Southern Ocean for the period 1990–2009
    (Copernicus Publications on behalf of the European Geosciences Union, 2013-06-19) Lenton, Andrew ; Tilbrook, Bronte ; Law, R. M. ; Bakker, Dorothee C. E. ; Doney, Scott C. ; Gruber, Nicolas ; Ishii, Masao ; Hoppema, Mario ; Lovenduski, Nicole S. ; Matear, Richard J. ; McNeil, B. I. ; Metzl, Nicolas ; Mikaloff Fletcher, Sara E. ; Monteiro, Pedro M. S. ; Rodenbeck, C. ; Sweeney, Colm ; Takahashi, Taro
    The Southern Ocean (44–75° S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea–air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Southern Ocean sea–air CO2 fluxes between 1990–2009. Using all models and inversions (26), the integrated median annual sea–air CO2 flux of −0.42 ± 0.07 Pg C yr−1 for the 44–75° S region, is consistent with the −0.27 ± 0.13 Pg C yr−1 calculated using surface observations. The circumpolar region south of 58° S has a small net annual flux (model and inversion median: −0.04 ± 0.07 Pg C yr−1 and observations: +0.04 ± 0.02 Pg C yr−1), with most of the net annual flux located in the 44 to 58° S circumpolar band (model and inversion median: −0.36 ± 0.09 Pg C yr−1 and observations: −0.35 ± 0.09 Pg C yr−1). Seasonally, in the 44–58° S region, the median of 5 ocean biogeochemical models captures the observed sea–air CO2 flux seasonal cycle, while the median of 11 atmospheric inversions shows little seasonal change in the net flux. South of 58° S, neither atmospheric inversions nor ocean biogeochemical models reproduce the phase and amplitude of the observed seasonal sea–air CO2 flux, particularly in the Austral Winter. Importantly, no individual atmospheric inversion or ocean biogeochemical model is capable of reproducing both the observed annual mean uptake and the observed seasonal cycle. This raises concerns about projecting future changes in Southern Ocean CO2 fluxes. The median interannual variability from atmospheric inversions and ocean biogeochemical models is substantial in the Southern Ocean; up to 25% of the annual mean flux, with 25% of this interannual variability attributed to the region south of 58° S. Resolving long-term trends is difficult due to the large interannual variability and short time frame (1990–2009) of this study; this is particularly evident from the large spread in trends from inversions and ocean biogeochemical models. Nevertheless, in the period 1990–2009 ocean biogeochemical models do show increasing oceanic uptake consistent with the expected increase of −0.05 Pg C yr−1 decade−1. In contrast, atmospheric inversions suggest little change in the strength of the CO2 sink broadly consistent with the results of Le Quéré et al. (2007).
  • Article
    Using altimetry to help explain patchy changes in hydrographic carbon measurements
    (American Geophysical Union, 2009-09-18) Rodgers, Keith B. ; Key, Robert M. ; Gnanadesikan, Anand ; Sarmiento, Jorge L. ; Aumont, Olivier ; Bopp, Laurent ; Doney, Scott C. ; Dunne, John P. ; Glover, David M. ; Ishida, Akio ; Ishii, Masao ; Jacobson, Andrew R. ; Monaco, Claire Lo ; Maier-Reimer, Ernst ; Mercier, Herlé ; Metzl, Nicolas ; Perez, Fiz F. ; Rios, Aida F. ; Wanninkhof, Rik ; Wetzel, Patrick ; Winn, Christopher D. ; Yamanaka, Yasuhiro
    Here we use observations and ocean models to identify mechanisms driving large seasonal to interannual variations in dissolved inorganic carbon (DIC) and dissolved oxygen (O2) in the upper ocean. We begin with observations linking variations in upper ocean DIC and O2 inventories with changes in the physical state of the ocean. Models are subsequently used to address the extent to which the relationships derived from short-timescale (6 months to 2 years) repeat measurements are representative of variations over larger spatial and temporal scales. The main new result is that convergence and divergence (column stretching) attributed to baroclinic Rossby waves can make a first-order contribution to DIC and O2 variability in the upper ocean. This results in a close correspondence between natural variations in DIC and O2 column inventory variations and sea surface height (SSH) variations over much of the ocean. Oceanic Rossby wave activity is an intrinsic part of the natural variability in the climate system and is elevated even in the absence of significant interannual variability in climate mode indices. The close correspondence between SSH and both DIC and O2 column inventories for many regions suggests that SSH changes (inferred from satellite altimetry) may prove useful in reducing uncertainty in separating natural and anthropogenic DIC signals (using measurements from Climate Variability and Predictability's CO2/Repeat Hydrography program).
  • Article
    OceanGliders: A component of the integrated GOOS
    (Frontiers Media, 2019-10-02) Testor, Pierre ; de Young, Brad ; Rudnick, Daniel L. ; Glenn, Scott ; Hayes, Daniel J. ; Lee, Craig M. ; Pattiaratchi, Charitha ; Hill, Katherine Louise ; Heslop, Emma ; Turpin, Victor ; Alenius, Pekka ; Barrera, Carlos ; Barth, John A. ; Beaird, Nicholas ; Bécu, Guislain ; Bosse, Anthony ; Bourrin, François ; Brearley, J. Alexander ; Chao, Yi ; Chen, Sue ; Chiggiato, Jacopo ; Coppola, Laurent ; Crout, Richard ; Cummings, James A. ; Curry, Beth ; Curry, Ruth G. ; Davis, Richard F. ; Desai, Kruti ; DiMarco, Steven F. ; Edwards, Catherine ; Fielding, Sophie ; Fer, Ilker ; Frajka-Williams, Eleanor ; Gildor, Hezi ; Goni, Gustavo J. ; Gutierrez, Dimitri ; Haugan, Peter M. ; Hebert, David ; Heiderich, Joleen ; Henson, Stephanie A. ; Heywood, Karen J. ; Hogan, Patrick ; Houpert, Loïc ; Huh, Sik ; Inall, Mark E. ; Ishii, Masao ; Ito, Shin-ichi ; Itoh, Sachihiko ; Jan, Sen ; Kaiser, Jan ; Karstensen, Johannes ; Kirkpatrick, Barbara ; Klymak, Jody M. ; Kohut, Josh ; Krahmann, Gerd ; Krug, Marjolaine ; McClatchie, Sam ; Marin, Frédéric ; Mauri, Elena ; Mehra, Avichal ; Meredith, Michael P. ; Meunier, Thomas ; Miles, Travis ; Morell, Julio M. ; Mortier, Laurent ; Nicholson, Sarah ; O'Callaghan, Joanne ; O'Conchubhair, Diarmuid ; Oke, Peter ; Pallás-Sanz, Enric ; Palmer, Matthew D. ; Park, Jong Jin ; Perivoliotis, Leonidas ; Poulain, Pierre Marie ; Perry, Ruth ; Queste, Bastien ; Rainville, Luc ; Rehm, Eric ; Roughan, Moninya ; Rome, Nicholas ; Ross, Tetjana ; Ruiz, Simon ; Saba, Grace ; Schaeffer, Amandine ; Schönau, Martha ; Schroeder, Katrin ; Shimizu, Yugo ; Sloyan, Bernadette M. ; Smeed, David A. ; Snowden, Derrick ; Song, Yumi ; Swart, Sebastiaan ; Tenreiro, Miguel ; Thompson, Andrew ; Tintore, Joaquin ; Todd, Robert E. ; Toro, Cesar ; Venables, Hugh J. ; Wagawa, Taku ; Waterman, Stephanie N. ; Watlington, Roy A. ; Wilson, Doug
    The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the world: (1) to observe the long-term physical, biogeochemical, and biological ocean processes and phenomena that are relevant for societal applications; and, (2) to contribute to the GOOS through real-time and delayed mode data dissemination. The OceanGliders program is distributed across national and regional observing systems and significantly contributes to integrated, multi-scale and multi-platform sampling strategies. OceanGliders shares best practices, requirements, and scientific knowledge needed for glider operations, data collection and analysis. It also monitors global glider activity and supports the dissemination of glider data through regional and global databases, in real-time and delayed modes, facilitating data access to the wider community. OceanGliders currently supports national, regional and global initiatives to maintain and expand the capabilities and application of gliders to meet key global challenges such as improved measurement of ocean boundary currents, water transformation and storm forecast.