Abstracts for the 6th International GAME Conf.

3-5 December 2004

Kyoto Japan

A climatological divide between wetness dominant and warmth dominant regimes of the vegetation in Siberia

Rikie SUZUKI (1), Jianqing XU (1), Ken MOTOYA (1)

The wetness and the warmth are principal factor that dominates global vegetation distribution. This paper employs the Normalized Difference Vegetation Index (NDVI), Warmth Index (WAI), and Wetness Index (WEI), and focuses on an essential climate-vegetation relationship. The predominancy between the two factors for the vegetation over Siberia was investigated. The NDVI value was acquired from 'Twenty-year global 4-minute AVHRR NDVI dataset' produced by CEReS, Chiba University. WEI is defined as the fraction of the precipitation to the potential evaporation. WAI was represented by cumulative monthly mean temperature of the portion exceeded 5C throughout the year. Meteorological data for the WEI and WAI calculation were obtained from the ISLSCP II dataset. All analyses were conducted for 1 x 1 degree grid cell at global scale, and on annual value basis averaged from 1986 to 1995. The relationship among NDVI, WEI, and WAI was examined in a so-called 'vegetation-climate diagram' which has an orthogonal coordinate system with WEI-abscissa and WAI-ordinate. Major two regimes were found in the vegetation-climate diagram, wetness dominant and warmth dominant regimes for NDVI. The geographical divide between the two regimes is located in the zone around 60N in Siberia. The author's previous studies delineated that this zone is covered by high NDVI and the maximum monthly temperature is around 18C. According to these results, it was clearly revealed that this 18C zone corresponds to the optimum climatic zone for vegetation, and the vegetation to the south of this zone is constrained by aridity with higher temperature and small amount of precipitation, while that to the north of this zone is constrained by lower temperature.

Submittal Information

Name : Date :
    Dr. Rikie Suzuki
    28-Jul-04-18:06:37
Organization : Theme :
    Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology
    Theme 8
Address : Presentation :
    3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, Japan
    Poster or oral
Country : Abstract ID :
    Japan
    T8DRS28Jul04180637
Phone : Fax :
    +81-45-778-5541
    +81-45-778-5706
E-mail :
    rikie@jamstec.go.jp