Summary

The Global Environmental Science Group has 2 CCS staff, Dr. H. L. Tanaka, Dr. H. Kusaka. They are officially affiliated in the Graduate School in Life and Environmental Science, working at CCS. In addition to these CCS staff, we have campus affiliated staff of Dr. F. Kimura, Dr. T. Hashimoto in the Graduate School in Life and Environmental Science, and cooperative affiliated staff of Dr. A. Kitoh in Meteorological Research Center.

In Global Environmental Science Group, the cloud resolving general circulation model NICAM started to run under PACS-CS and T2K-Tsukuba PC clusters. This model ran only in the Earth Simulator before, which now runs in CCS. Using NICAM we started to analyze dynamical processes associated with Arctic Oscillation, Arctic cyclone, blocking high, and tropical cyclone. In November 2007, an international symposium on the Arctic research called ISAR-1was held in Tokyo. In addition, meso-scale phenomena such as heavy rain, heat island, and urban climate were analyzed with WRF model imported from NCAR in the USA. Using WRF containing an original urban canopy model, the effect of metropolitan was investigated.

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Achievements

Tanaka

  1. Theoretical and analytical study of the Arctic Oscillation and blocking phenomenon and their prediction.
  2. Implementation of NICAM at PACS-CS and T2K-Tsukuba and time integration with 224 km (gl=5) to 7 km (gl=10) resolution models.
  3. Experiments of ensemble Kalman filters of LETKF using a barotropic S-model developed at the University of Tsukuba and the NICAM.
  4. Analysis of 3D normal mode energetic of the general circulation. The revisit of Rossby wave saturation theory which produces an energy spectrum of E=mc2.
  5. Organization of the First International Symposium on the Arctic Research (ISAR-1) in Tokyo. There are 190 participants including 59 scientists from foreign countries.

Kusaka

We have conducted the regional/urban-scale climate simulation using the WRF model. Moreover, we have developed a new urban canopy model. We will predict the regional/urban-scale future climate by this approach. Furthermore, we will investigate the relationship between local heavy rainfall and urban heat island.

  1. Regional climate simulation over the Japanese islands has been numerically conducted for 20-years period using the WRF model, and the results are verified against the observations.
  2. Numerical simulation of local heavy rainfalls over the Tokyo metropolitan area in summer has been done using the WRF model, and the results are validated
  3. The record high temperature observed at Kumagaya, Japan is investigated to find the combined causes of urban heat island and dynamical downdraft which lasted many days.
  4. We have developed a new urban canopy model for simulating temperature distribution in a city.

Future plan

Tanaka

  1. Analysis of the Arctic cyclone in relation to the recent drastic reduction of the Arctic sea ice, using the cloud resolving model NICAM.
  2. Four dimensional data assimilation for NICAM by means of the ensemble Kalman filter LETKF.
  3. 3D spectral analysis of the atmosphere using very high resolution model experiments with NICAM.
  4. Analysis of the relationship between the Arctic Oscillation and global warming using the IPCC climate model data and the barotropic S-model developed at the University of Tsukuba.
  5. Further examination of the singular eigenmode theory for the Arctic Oscillation using the barotropic S-model.

Kusaka

  1. Numerical climate prediction in a near future will be performed for the Japanese islands, using the WRF model with 20-km resolution. Additionally, the future climate simulation for the Tokyo metropolitan area will be conducted by the WRF model with 4-km resolution.
  2. The impact of the urban heat island on the local heavy rainfall will be investigated by the high-resolution WRF model.
  3. Investigation of the mechanism of the record high temperature observed at Tajimi in Gifu prefecture.
  4. The 40 thermometers will be set in Tsukuba city and the heat island phenomenon of the city will be revealed.
Papers in 2008

Tanaka

  1. Watarai, Y. and H.L. Tanaka 2008: Characteristics of the JRA-25 dataset from the viewpoint of global energetics. International Conf. on Reanalysis. February 2008, Tokyo Japan.
  2. Byun, H.R., H. L. Tanaka, H. Michalopoulou, R.P. Pandey and D. Azzaya 2008: A study on ice control for the production of 5th-generation water resources and the arrest of global warming. Asia-Pacific J. Atmos. Sci., 44, 137-146.
  3. Matsueda, M. and H. L. Tanaka, 2008: Can MCGE Outperform the ECMWF Ensemble? SOLA, 4, 77-80.
  4. Tanaka, H.L., 2008: The First International Symposium on the Arctic Research: Drastic Change under the Global Warming, Preface. Proc. First International Symposium on the Arctic Research, Nov. 4-6, 2008, Miraikan, Tokyo, Japan. 1-2.
  5. Tanaka, H.L., and M. Ohhashi, 2008: Mechanism of the Decadal-Scale Variation of the Arctic Oscillation Index. Proc. First International Symposium on the Arctic Research, Nov. 4-6, 2008, Miraikan, Tokyo, Japan. 20-23.
  6. Kondo, K. and H. L. Tanaka 2009: Comparison of the extended Kalman filter and the ensemble Kalman filter using the barotropic general circulation model. J. Meteor. Soc. Japan, 87, Accepted.

Kusaka

  1. Kusaka, H., (2008) Recent progress on urban climate study in Japan: Geograph. Rev. Japan, 81, 361-374.
  2. Ohashi, Y., T. Kawabe, Y. Shigeta, Y. Hirano, H. Kusaka, H. Fudeyashu, and K. Fukao (2008) Thermal Environments in Commercial and Residential Spaces in Okayama City, Japan, Using the Wet-Bulb Globe Temperature Index. Evaluation of Urban. Theoretical and Applied Climatology, 95, 279-289.
  3. Suga, M., R. Oda, H. Kusaka, and M. Kanda (2009) Impacts of anthropogenic energy and urban canopy model on urban atmosphere, Annual Journal of Hydraulic Engineering, JSCE, 53. In press.
Center for Computational Sciences, University of Tsukuba