Takashi SEKIYA

Profile

Takashi SEKIYA

Research Institute for Global Change
Earth Surface System Research Center
Environmental Geochemical Cycle Research Group
Research Scientist

Address

Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
Yokohama Institute for Earth Sciences (YES)
3173-25, Showa-machi, Kanazawa-ku, Yokohama, Kanagawa
Tel: +81-(0)45-778-5719
Fax: +81-(0)45-778-5706


Research Interests

  • Data assimilation for atmospheric chemistry and aerosols
  • Short- and long-term changes in short-lived atmospheric constituents
  • Developments and applications of global chemical transport model

Curriculum Vitae

Education experience

Apr. 2011-Mar. 2014 Ph.D., Nagoya University, Department of Earth and Environmental Sciences, Graduate School of Environmental Studies
Apr. 2009-Mar. 2011 M.Sc., Nagoya University, Department of Earth and Environmental Sciences, Graduate School of Environmental Studies
Apr. 2005-Mar. 2009 B.Sc., Nagoya University, Department of Science

Research experience

Aug. 2019- Scientist, ESS, RIGC, JAMSTEC
Apr. 2019-Jul. 2019 Post-doc researcher, IACE, RIGC, JAMSTEC
Apr. 2016-Mar. 2019 Post-doc researcher, Project Team for HPC Advanced Predictions utilizing Big Data, JAMSTEC
Apr. 2014-Mar. 2016 Post-doc Researcher, Nagoya University

Publications

  • 23) Sekiya, T., Miyazaki, K., Eskes, H., Bowman, K., Sudo, K., Kanaya, Y., and Takigawa, M., The worldwide COVID-19 lockdown impacts on global secondary inorganic aerosols and radiative budget, Sci. Adv., 9, eadh2688, doi:10.1126/sciadv.adh2688, 2023
  • 22) Bisht, J. S. H., Patra, P. K., Takigawa, M., Sekiya, T., Kanaya, Y., Saitoh, N., and Miyazaki, K.: Estimation of CH4 emission based on an advanced 4D-LETKF assimilation system, Geosci. Model Dev., 16, 1823–1838, https://doi.org/10.5194/gmd-16-1823-2023, 2023.
  • 21) Takashima, H., Kanaya, Y., Kato, S., Friedrich, M. M., Van Roozendael, M., Taketani, F., Miyakawa, T., Komazaki, Y., Cuevas, C. A., Saiz-Lopez, A., and Sekiya, T., Full latitudinal marine atmospheric measurements of iodine monoxide, Atmos. Chem. Phys., 22, 4005–4018, https://doi.org/10.5194/acp-22-4005-2022, 2022.
  • 20) Sekiya, T., Miyazaki, K., Eskes, H., Sudo, K., Takigawa, M., and Kanaya, Y., A comparison of the impact of TROPOMI and OMI tropospheric NO2 on global chemical data assimilation, Atmos. Meas. Tech., 15, 1703–1728, https://doi.org/10.5194/amt-15-1703-2022, 2022.
  • 19) Miyazaki, K., Bowman, K., Sekiya, T., Takigawa, M., Neu, J. L., Sudo, K., Osterman, G., and Eskes, H., Global tropospheric ozone responses to reduced NOx emissions linked to the COVID-19 worldwide lockdowns, Sci. Adv., 7, 24, abf7460, https://doi.org/10.1126/sciadv.abf7460, 2021.
  • 18) Sekiya, T., Miyazaki, K., Ogochi, K., Sudo, K., Takigawa, M., Eskes, H., and Boersma, K. F., Impacts of horizontal resolution on global data assimilation of satellite measurements for tropospheric chemistry analysis, J. Adv. Model. Earth Syst., 13, e2020MS002180. https://doi.org/10.1029/2020MS002180, 2021
  • 17) Zhang, Y., West, J. J., Emmons, L. K., Flemming, J., Jonson, J. E., Lund, M. T., Sekiya, T., Sudo, K., Gaudel, A., Chang, K.-L., Nédélec, P., Thouret, V., Contributions of World Regions to the Global Tropospheric Ozone Burden Change from 1980 to 2010, Geophys. Res. Lett., 48, e2020GL089184. https://doi.org/10.1029/2020GL089184, 2021
  • 16) Miyazaki, K., Bowman, K., Sekiya, T., Jiang, Z., Chen, X., Eskes, H., Ru, M., Zhang, Y., Shindell, D., Air quality response in China linked to the 2019 novel coronavirus (COVID-19) lockdown, Geophys. Res. Lett., 47, e2020GL089252. https://doi.org/10.1029/2020GL089252, 2020
  • 15) Miyazaki, K., Bowman, K., Sekiya, T., Eskes, H., Boersma, F., Worden, H., Livesey, N., Payne, V. H., Sudo, K., Kanaya, Y., Takigawa, M., and Ogochi, K.: Updated tropospheric chemistry reanalysis and emission estimates, TCR-2, for 2005–2018, Earth Syst. Sci. Data, 12, 2223–2259, https://doi.org/10.5194/essd-12-2223-2020, 2020.
  • 14) Huijnen, V., Miyazaki, K., Flemming, J., Inness, A., Sekiya, T., and Schultz, M. G., An intercomparison of tropospheric ozone reanalysis products from CAMS, CAMS interim, TCR-1, and TCR-2, Geosci. Model Dev., 13, 1513–1544, https://doi.org/10.5194/gmd-13-1513-2020, 2020.
  • 13) Sekiya, T., Kanaya, Y., Sudo, K., Taketani, F., Iwamoto, Y., Aita, M. N., Yamamoto, A., Kawamoto, K., Global bromine- and iodine-mediated tropospheric ozone loss estimated using the CHASER chemical transport model, SOLA, 2020-037, https://doi.org/10.2151/sola.2020-037, 2020
  • 12) Kanaya, Y., Miyazaki, K., Taketani, F., Miyakawa, T., Takashima, H., Komazaki, Y., Pan, X., Kato, S., Sudo, K., Sekiya, T., Inoue, J., Sato, K., and Oshima, K., Ozone and carbon monoxide observations over open oceans on R/V Mirai from 67° S to 75° N during 2012 to 2017: testing global chemical reanalysis in terms of Arctic processes, low ozone levels at low latitudes, and pollution transport, Atmos. Chem. Phys., 19, 7233–7254, https://doi.org/10.5194/acp-19-7233-2019, 2019.
  • 11) Miyazaki, K., Sekiya, T., Fu, D., Bowman, K. W., Kulawik, S. S., Sudo, K., Walker, T., Kanaya, Y., Takigawa, M., Ogochi, K., Eskes, H., Boersma, K. F., Thompson, A. M., Gaubert, B., Barre, J., Emmons, L. K., Balance of emission and dynamical controls on ozone during the Korea-United States Air Quality campaign from multiconstituent satellite data assimilation. J. Geophys. Res., 124, 387– 413. https://doi.org/10.1029/2018JD028912, 2019
  • 10) Dong, X., Fu, J. S., Zhu, Q., Sun, J., Tan, J., Keating, T., Sekiya, T., Sudo, K., Emmons, L., Tilmes, S., Jonson, J. E., Schulz, M., Bian, H., Chin, M., Davila, Y., Henze, D., Takemura, T., Benedictow, A. M. K., and Huang, K., Long-range transport impacts on surface aerosol concentrations and the contributions to haze events in China: an HTAP2 multi-model study, Atmos. Chem. Phys., 18, 15581–15600, https://doi.org/10.5194/acp-18-15581-2018, 2018.
  • 9) Liang, C.-K., West, J. J., Silva, R. A., Bian, H., Chin, M., Davila, Y., Dentener, F. J., Emmons, L., Flemming, J., Folberth, G., Henze, D., Im, U., Jonson, J. E., Keating, T. J., Kucsera, T., Lenzen, A., Lin, M., Lund, M. T., Pan, X., Park, R. J., Pierce, R. B., Sekiya, T., Sudo, K., and Takemura, T., HTAP2 multi-model estimates of premature human mortality due to intercontinental transport of air pollution and emission sectors, Atmos. Chem. Phys., 18, 10497–10520, https://doi.org/10.5194/acp-18-10497-2018, 2018.
  • 8) Taketani, F., Aita, M.N., Yamaji, K., Sekiya, T., Ikeda, K., Sasaoka, K., Hashioka, T., Honda, M.C., Matsumoto., K., and Kanaya, Y., Seasonal Response of North Western Pacific Marine Ecosystems to Deposition of Atmospheric Inorganic Nitrogen Compounds from East Asia. Sci Rep 8, 9324, https://doi.org/10.1038/s41598-018-27523-w, 2018
  • 7) Galmarini, S., Kioutsioukis, I., Solazzo, E., Alyuz, U., Balzarini, A., Bellasio, R., Benedictow, A. M. K., Bianconi, R., Bieser, J., Brandt, J., Christensen, J. H., Colette, A., Curci, G., Davila, Y., Dong, X., Flemming, J., Francis, X., Fraser, A., Fu, J., Henze, D. K., Hogrefe, C., Im, U., Garcia Vivanco, M., Jiménez-Guerrero, P., Jonson, J. E., Kitwiroon, N., Manders, A., Mathur, R., Palacios-Peña, L., Pirovano, G., Pozzoli, L., Prank, M., Schultz, M., Sokhi, R. S., Sudo, K., Tuccella, P., Takemura, T., Sekiya, T., and Unal, A., Two-scale multi-model ensemble: is a hybrid ensemble of opportunity telling us more?, Atmos. Chem. Phys., 18, 8727–8744, https://doi.org/10.5194/acp-18-8727-2018, 2018.
  • 6) Sekiya, T., Miyazaki, K., Ogochi, K., Sudo, K., and Takigawa, M., Global high-resolution simulations of tropospheric nitrogen dioxide using CHASER V4.0, Geosci. Model Dev., 11, 959–988, https://doi.org/10.5194/gmd-11-959-2018, 2018.
  • 5) Patra, P.K., Crisp, D., Kaiser, J.W., Debra Wunch, Saeki, T., Ichii, K., Sekiya, T., Wennberg, P.O., Feist, D.G., Pollard, D.F., Griffith, D.W.T., Velazco, V.A., De Maziere, M., Sha, M.K., Roehl, C., Chatterjee, A., Ishijima, K., The Orbiting Carbon Observatory (OCO-2) tracks 2–3 peta-gram increase in carbon release to the atmosphere during the 2014–2016 El Niño, Sci Rep 7, 13567, https://doi.org/10.1038/s41598-017-13459-0, 2017.
  • 4) Kashimura, H., Abe, M., Watanabe, S., Sekiya, T., Ji, D., Moore, J. C., Cole, J. N. S., and Kravitz, B., Shortwave radiative forcing, rapid adjustment, and feedback to the surface by sulfate geoengineering: analysis of the Geoengineering Model Intercomparison Project G4 scenario, Atmos. Chem. Phys., 17, 3339–3356, https://doi.org/10.5194/acp-17-3339-2017, 2017.
  • 3) Sekiya, T., Sudo, K., and Nagai, T., Evolution of stratospheric sulfate aerosol from the 1991 Pinatubo eruption: Roles of aerosol microphysical processes, J. Geophys. Res. Atmos., 121, 2911– 2938, doi:10.1002/2015JD024313, 2016.
  • 2) Sekiya, T., and Sudo, K., Roles of transport and chemistry processes in global ozone change on interannual and multidecadal time scales”, J. Geophys. Res. Atmos., 119, 4903– 4921, doi:10.1002/2013JD020838, 2014.
  • 1) Sekiya, T., and Sudo, K., Role of meteorological variability in global tropospheric ozone during 1970–2008, J. Geophys. Res., 117, D18303, doi:10.1029/2012JD018054, 2012.