Hiroki Iwata

Hiroki Iwata
Assistant Professor, Shinshu University
affiliations: IARC/IJIS
email: hiwata attsymbol for nospam shinshu-u [dot] ac [dot] jp
phone: 907-474-7337



  • improve the synthesis study
  • develop new model using IJIS system
  • continue the field observation with Masahito Ueyama

Professional Interests

  • Turbulence in the atmospheric boundary layer
  • Energy and mass exchange between land and the atmosphere


  • Faculty of Environmental Science and Technology, Okayama University
  • Okayama University Graduate School of Natural Science and Technology
  • Graduate School of Life and Environmental Sciences, University of Tsukuba

Selected Publications

Kobayashi, H., Yunus, A. P., Nagai, S., Sugiura, K., Kim, Y., Van Dam, B., Nagano, H., Zona, D., Harazono, Y., Bret-Harte, M. S., Ichii, K., Ikawa, H., Iwata, H., Oechel, W. C., Ueyama, M., Suzuki, R.: Latitudinal gradient of spruce forest understory and tundra phenology in Alaska as observed from satellite and ground-based data, Remote Sensing of Environment, in press, in press, 2016

Iwata, H., Harazono, Y., Ueyama, M., Sakabe, A., Nagano, H., Kosugi, Y., Takahashi, K., Kim, Y.: Methane exchange in a poorly-drained black spruce forest over permafrost observed using the eddy covariance technique, Agricultural and Forest Meteorology, 214-215, 157-168, 2015

Starkenburg, D., Fochesatto, G. J., Cristobal, J., Prakash, A., Gens, R., Alfieri, J., Nagano, H., Harazono, Y., Iwata, H., and Kane, D. L.: Temperature regimes and turbulent heat fluxes across a heterogeneous canopy in an Alaskan boreal forest, Journal of Geophysical Research: Atmospheres, 120, 1348-1360, 2015

Harazono, Y., Iwata, H., Sakabe, A., Ueyama, M., Takahashi, K., Nagano, H., Nakai, T., and Kosugi, Y.: Effects of water vapor dilution on trace gas flux, and practical correction methods, Journal of Agricultural Meteorology, 71, 65-76, 2015

Ueyama, M., Ichi, K., Iwata, H., Euskirchen, E. S., Zona, D., Rocha, A. V., Harazono, Y., Iwama, C., Nakai, T., and Oechel, W. C.: Change in surface energy balance in Alaska due to fire and spring warming, based on upscaling eddy covariance measurements, Journal of Geophysical Research - Biogeosciences, 119, 1947-1969, 2014

Nakai, T., Iwata, H., Harazono, Y., and Ueyama, M.: An inter-comparison between Gill and Campbell sonic anemometers, Agricultural and Forest Meteorology, 195-196, 123-131, 2014

Cable, J. M., Ogle, K., Bolton, W. R., Bentley, L. P., Romanovsky, V., Iwata, H., Harazono, Y., and Welker, J.: Permafrost thaw affects boreal deciduous plant transpiration through increased soil water, deeper thaw, and warmer soils, Ecohydrology, 7, 982-997, 2014

Iwata, H., Kosugi, Y., Ono, K., Mano, M., Sakabe, A., Miyata, A. and Takahashi, K.: Cross-validation of open-path and closed-path eddy-covariance techniques for observing methane fluxes, Boundary-Layer Meteorology, 151, 95-118, 2014

Ueyama, M., Iwata, H., and Harazono, Y.: Autumn warming reduces the CO2 sink of a black spruce forest in interior Alaska based on a nine-year eddy covariance measurement, Global Change Biology, 20, 1161-1173, 2014

Ueyama, M., Ichii, K., Iwata, H., Euskirchen, E. S., Zona, D., Rocha, A. V., Harazono, Y., Iwama, C., Nakai, T., and Oechel, W. C.: Upscaling terrestrial carbon dioxide fluxes in Alaska with satellite remote sensing and support vector regression, Journal of Geophysical Research: Biogeosciences, 118, 1266-1281, 2013

Ueyama, M., Iwata, H., Harazono, Y., Euskirchen, E. S., Oechel, W. C., and Zona, D.: Growing season and spatial variations of carbon fluxes of Arctic and boreal ecosystems in Alaska, Ecological Applications, 23, 1798-1816, 2013

Iwata, H., Ueyama, M., Iwama, C., and Harazono, Y.: A variation in the fraction of absorbed photosynthetically active radiation and a comparison with MODIS data in burned black spruce forests of interior Alaska, Polar Science, 7, 113-124, 2013

Iwata, H., Harazono, Y., and Ueyama, M.: Sensitivity and offset changes of a fast-response open-path infrared gas analyzer during long-term observations in an Arctic environment, Journal of Agricultural Meteorology, 68, 175-181, 2012

Saito, K., Yamaguchi, S., Iwata, H., Harazono, Y., Kosugi, K., Lehning, M. and Shulski, M.: Climatic physical snowpack properties for large-scale modeling examined by observations and a physical model, Polar Science, 6, 79-95, 2012

Mizoguchi, Y., Ohtani, Y., Takanashi, S., Iwata, H., Yasuda, Y., and Nakai, Y.: Seasonal and interannual variation in net ecosystem production of an evergreen needleleaf forest, Journal of Forest Research, 17, 283-295, 2012.

Iwata, H., Harazono, Y., and Ueyama, M.: The role of permafrost in water exchange of a black spruce forest in Interior Alaska, Agricultural and Forest Meteorology 161, 107-115, 2012.

Marthews, T. R., Malhi, Y., and Iwata, H.: Calculating downward longwave radiation under clear and cloudy conditions over a tropical lowland forest site: an evaluation of model schemes for hourly data, Theoretical and Applied Climatology 107, 461-477, 2012.

Iwata, H., Harazono, Y., Ueyama, M., Tsuyuzaki, S., Kondo, M., and Uchida, M.: Quick recovery of carbon dioxide exchanges in a burned black spruce forest in Interior Alaska, SOLA 7, 105-108, 2011.

Nakai, T., Iwata, H., and Harazono, Y.: Importance of mixing ratio for a long-term CO2 flux measurement with a closed-path system, Tellus 63B, 302-308, 2011.

Mizoguchi, Y., Ohtani, Y., Nakai, Y., Iwata, H., Takanashi, S., Yasuda, Y., Nakano, T., Yasuda, T., Watanabe, T.: Climatic characteristics of the Fujiyoshida forest meteorology research site. Mount Fuji Research, 5, 1-6, 2011.

Iwata, H., Harazono, Y., and Ueyama, M.: Influence of source/sink distributions on flux-gradient relationships in the roughness sublayer over an open forest canopy under unstable conditions, Boundary-Layer Meteorology 136, 391-405, 2010.

Iwata, H., Asanuma, J., Ohtani, Y., Mizoguchi, Y., and Yasuda, Y.: Vertical length scale of transporting eddies for sensible heat in the unstable roughness sublayer over a forest canopy, Journal of Agricultural Meteorology 65, 1-9, 2009.

Iwata, H., Malhi, Y., and von Randow, C.: Gap-filling measurements of carbon dioxide storage in tropical rainforest canopy air space, Agricultural and Forest Meteorology 132, 305-314, 2005.