Validation of AMSR-E Soil Moisture Estimation in Mongolia and A Renewal Plan of Ground-based Monitoring Instruments Ichirow Kaihotsu (Hiroshima University) 1. Current status of ground-based monitoring 2. Latest validation results 3. Replacing old ground-based monitoring instruments 4. New technology to monitor soil moisture in the surface thin soil layer Telluride July 13-16, 2007

Working stations in the MAVEX (Mongol AMSR/AMSR-E/ALOS Validation Experiment) study area as of April., 2008 ( :AWS （ Automatic Weather Station), : ASSH （ Automatic Station for Soil Hydrology), SA : Study area of AMPEX/MAVEX, UB: Ulaanbaatar ) DRS MGS(Mandalgobi AWS site) UB Mongolia SA Russia China AWS ASSH

Comparison of the AMSR-E standard product (Ver. 6.0) with NAMHEM in the Mongolian plateau every ten days ｆ rom 2002 to km 450 km NAMHEM validation area of the Mongolian plateau

A time series of AMSR-E soil moisture estimations (Vers.5 and 6) and the daily ground-based soil moisture at 3 cm depth in the Sanzai site in 2006

Relationship between AMSR-E estimation （ Ver. 6.0) and ground-based soil moisture at 3 cm depth in the Sanzai site (VWC:Volumetric Water Content (%)

Replacing ground-based monitoring instruments Design/actual life problem of ground-based monitoring instruments in the study area in the Mongolian plateau Ongoing AWS and ASSH are nine and eight years old, as of this July, respectively. So, we started to replace little by little the old instruments from ↓ We will complete replacing all old instruments in the study area in the Mongolian plateau by this September at latest.

Laboratory test of new instruments to replace (Hiroshima University in early spring, 2008)

Sample of probe error test results of new soil moisture TDR probes (TRIME IT probes) to replace

A time series of AMSR-E estimation, ground-based soil moisture (daily mean area averaged soil moisture) and area averaged precipitation (P area ) in the study area

New technology to measure soil moisture in the surface thin soil layer Prototype of Coil Probe (CP) (by Drs. Nissen and Moldrup: From MEXT project of microprobe development for in-situ soil moisture measurement in cooperation with University of Arlborg, Denmark since 2001) ２ rod type TDR probe (2R TDR probe)

Installation condition of CP and 2R TDR probes CP 2R probe WaCS at Sanzai site

Comparison of CP soil moisture with 2R TDR soil moisture in the Sanzai site

Relationship between soil moistures (SM) by coil probes (CP 1 and 2) and by 2Rmon1 ( ２ rod type TDR probe)

A cross section of installation condition of 2 rod type TDR (TRIME IT TDR) and CP probes for in-situ error test 3 cm d. Measurement effective area of 2 rod typed TDR probe Soil surface New 2 rod type TDR probes (old TRIME IT TDR probes) Old 2 rod type TDR probes (old TRIME IT TDR probes) 10 cm d. CP probes at MGS 1 cm d. About 7.5 cm

▮ Well working of AWS and ASSH except AWS at DRS as of this April ▮ Better validation results using the new standard product (Ver. 6.0) of AMSR-E soil moisture estimation in the Mongolian plateau ▮ Underestimation of AMSR-E observation under the highly wetted soil condition in Sanzai site ▮ No actual probe error of new 2 rod type TDR probes to replace ▮ New challengeable technology to monitor soil moisture in the surface thin soil layer Summary