Observation Network of

Hydrological Cycle Program at IORGC/JAMSTEC

Tetsuo Ohata

Institute of Observational Research for Global Change

Japan Agency for Marine-Earth Science and Technology

Asian Water Cycle Symposium, Nov., 2005. Tokyo

Scientific objectivesTo reveal and understand hydro-

meteorological processes in the eastern part of Eurasian and west pacific region (including the western Pacific warm pool, the maritime continent, and the cold region of Eurasia), which regulate climate formation including the Asian monsoon system and its variability, through large-scale intensive process studies and long-term measurements.

To contribute to the climate modeling and prediction, by improving the physical model and model parametarization of hydro-meteorological processes.

P

S

C

PERMAFROST

SNOWCOVER

R

C

REGIONALWATER CYCLE

Affected bySTRUCTUREENERGY

CONDITIONS

E

IORGC primarily initiated in 1999, and reformed in 2004.

Regional Water/energy cycle

Monsoon System

Global warming

Strategy(1) Stress on observations on long-term changes, large

scale observation campaign, since these are essential for Global Change studies, but difficult for small research group or organizations.

(2) To supplement ground based observation data in addition to the hydro-meteorological network which are maintained operationally.

(3) To establish and take part in the international program such as WCRP(GEWEX, CliC, CEOP) , inter-governmental programs (GEOSS, IAEA) and others.

(4) Data-open policy, and research cooperation at national and inter-national levels.

Hydro-meteorological observation network of IORGC

Main long-term observation systems

(1) Super-stations for atmospheric and hydrospheric measurements.

(2) Super-stations including drainage measurements for hydrological studies.

(3) Widely distributed network for water vapor amount by GPS measurements.

(4) Water sampling network system for stable isotope analysis for precipitation, river water, snow cover. (Massspectrometer analysis system at lab)

Super-station(1)Tiksi

Main objectives: Water and energy exchange at tundra region at drainage scale

ACOS

AWS

Soil Moisture

Discharge

Snow Survey

Snow Drift

Snow Dam

Tiksi Measurements

(1) Initiated in 1997 by Univ. groups and succeeded in 2000 by IORGC.

(2) CEOP reference site.

Super-station(2)Yakutsk

Main objectives: Water and energy exchange at taiga forested region

Pine Forest

Larch Forest

Larch Forest FloorSoil MoistureTree tally

Water Sampling

Grassland

Pond

Larch Forest

Larch Forest Floor

Evapotranspiration

Aircraft Observation

Yakutsk Observation

(1)The whole obs. system operated in 2000 campaign. Afterwards, half is remained to monitor different climate years.

(2) CEOP reference site

(3) Cooperating with Dutch scientist on CO2 studies.

Still operating

0

100

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300

0.0 0.5 1.0 1.5 2.0

Evaporation(mm)

Prec

ipita

tion

(mm

)

Interannual variation of summer evaporation (1998-2003)

Negative relation to precipitation

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150

200

1985

1986

1987

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2001

年

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期平

均フ

ラッ

クス

(W/m

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Rn

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lE

lEp

0.36

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0.4

0.42

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10 15 20 25 30 35

開葉日 (５月の日付)

E/E

p

Some results from tundra and taiga

Tundra: Variable summer evapotranspiration Taiga: stable eavpotranspiration

Based on improved land-surface model from present data

Start of leaf blooming date and season E/Ep

2003

2002

Super-station (3)Northern Mongolia

Main objective: Land surface processes and runoff generation and variation mechanism at southern end of boreal forest region.

(1) Measurement started 2002.

(2) Drainage study is target.

E-4 Forest system and ground thermal hydro- condition.(Ishikawa et al., SUB)

Questions: ・

●Large difference in temperature condition at N and S facing slope, but not soil moisture.

●Frozen ground and forest exists at N facing slope.

Super-station (4)Kotobatan

Main objectives: Seasonal to intra-seasonal variation of moisture transport and precip.

00LT15LT 18LT 21LT

03LT 06LT 09LT 12LT

海大陸の巨大日変化

　雲・降水

GPS observationMain objective: Obtain total water vapor amount for shorter time scale (diurnal variation) and at area where radio-sondeobservations are not made.

Some results using GPS derived water vapor data

From regional model

Comparison of model output and GPS obs.

Tibetan Plateau

Limited radio-sonde obs.

Water sampling for stable isotope analysisMain objectives: Understand the global and regional water cycle through the behavior of the stable isotope of water in various conditions

H2O

Physical water amount

(Precip, vapor, river, soil moist)

+

Isotopic Composition of water

Better understanding of water cycle

Super-station (5) Western tropical Pacific observation around Palau

PALAU (Pacific Area Long-term Atmospheric observation for Understanding of climate change) project began in Nov. 2000

AWS・GPS 　 ★：PeleliuWindprofiler・Radar ☆：AimeliikSonde obs. by NOAA ◎：Koror

Guam

Palau

10°N

Eq.

140°E130°E

1 3 4 ﾟ30'E

7ﾟN

8ﾟN

Koror

Peleliu Is.Philippine

Indonesia

☆　Aimeliik

Warm Water Pool

Main Objective

To elucidate the global climate change, focusing on the ENSO (El Nino Southern Oscillation) event around the Western Tropical Pacific

To understand the mechanism of cloud-precipitation processes and air-sea interactions over the warm water pool, focusing on seasonal and intra-seasonal variations

Contact: Ryuichi SHIROOKA

IORGC/JAMSTEC

shiro@jamstec.go.jp

Windprofiler（Wind speed,Wind direction)

Micro-wave radiometer（Water vapor, temperature )

Ceilometer（Cloud base height )

Disdrometer（Drop size distribution)

AWS (Automatic Weather Station)RASS

(Radio Acoustic Sounding System)

Micro-rain radar ↓

G-II Aircraft (dropsonde)

Peleliu Doppler radar

Aimeliik Doppler radar

R/V Mirai

Peleliu AWS site

Aimeliik observatory

Other network and observations in the past and under preparation

(1) Radar profiler network in the Indonesia maritime continent. (funded)

(2) Prepatory observation for the establishment of the hydro-meteorological network in Philippine Island.

(3) Cooperative work on radar network at Yangtze River with China. (Main obs, systems are Chinese) 2000-

(4) Super-station at Tynda, southern Siberia.(2000-2002)

Data distribution and policy of Water Cycle Program of IORGC/JAMSTEC

(1) Data are supplied to foreign Institutes which we have agreements, domestic Institute which we have cooperative works and certain individual researchers.

(2) A part of the data are supplied to GAME-AAN, CEOP, IAEA and from there, data are accessible.

(3) A part of the data have been distributed in the form of CD-ROM in relation to the participation to GAME Project.

<Future>・The non-opened period will be specified (probably 2 years) , and after that all obtained data will be available at web site of IORGC, excluding some special data. This will be settled during the 2005 fiscal year.・Quality check of these data will be made periodically.

Concluding remarks

Present IORGC/JAMSTEC observation network will be contributing to GEOSS in many aspects.

We also expect to contribute in the data matters and others.

Northern and mountainous region of Asia is also important from the standpoint of establishing well-balanced global observation system for future in GEOSS.