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 in BTS ASSH

Data log., Battery ST sensors

TDR probes

Aerovane

Thermometer・Hygrometer

Infrared thermometer

Net radiometer

Raingauge

TDR probes・ST sensors in the soil

Three cup wind anemometer

Data logger・Barometer

AWS

ASSH

0123

45

6

7

8

A B C D E F G H I

Comparison of the AMSR-E standard product (Ver. 6.0) with NAMHEM in the Mongolian plateau

every ten days ｆ rom 2002 to 2006

WA EA

1200 km450

km

NAMHEM validation area of the Mongolian plateau

04/21/03 05/31/03 07/10/03 08/19/03 09/28/03

0

10

20

30

VW

C (

%)

2003AM SR -E (Ver. 5 .0)

AM SR -E (Ver. 6 .0)

N AM H EM (0-10 cm d.)

04/15/04 05/25/04 07/04/04 08/13/04 09/22/04

0

10

20

30

VW

C (

%)

2004AM SR -E (Ver. 5 .0)

AM SR -E (Ver. 6 .0)

N AM H EM (0-10 cm d.)

06/15/02 07/25/02 09/03/02 10/13/02

0

10

20

30

VW

C (

%)

2002AM SR -E (Ver. 5 .0)

AM SR -E (Ver. 6 .0)

N AM H EM (0-10cm d.)

03/26/06 05/05/06 06/14/06 07/24/06 09/02/06 10/12/06

0

10

20

30

VW

C (

%)

2006AM SR -E (Ver. 5 .0)

AM SR -E (Ver. 6 .0)

N AM H EM (0-10 cm d.)

04 /10/05 05/20/05 06/29/05 08/08/05 09/17/05

0

10

20

30

VW

C (

%)

2005AM SR -E (Ver. 5 .0)

AM SR -E (Ver. 6 .0)

N AM H EM (0-10 cm d.)

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

4/3/06 5/23/06 7/12/06 8/31/06 10/20/06D ate (M /D /Y )

0

20

40

60

VW

C (

%)

Sanza i s ite (Apr-O ct,2006)AM SR -E (Ver.5.0)G round-based (by 2R probe at 3cm d.)C P1SM (3 cm depth SM )Precip ita tion: PAM SR -E (ver. 6 .0)

120

80

40

0

P (

mm

)

Relationship between AMSR-E estimation （ Ver. 6.0) and ground-based soil moisture at 3 cm depth in the San

zai site (VWC:Volumetric Water Content (%)

0 20 40 60In-situ V W C (% )

0

20

40

60

AM

SR

-E(V

er.6

) V

WC

(%

)

Sanzai site (Apr-Oct,2006)R -squared = 0.145919A veraged abso lute error =31.53

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 2006. ↓

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

0 10 20 30 40 50Vo lu m e tric W a te r C o n te n t (% )

0

10

20

30

40

50

Me

asu

red

VW

C (

%)

IT14702(ASSH 819-1) Y = 0.9936 * X + 0.0172 R -squared = 0.994

0 10 20 30 40 50V o lu m e tric W a te r C o n te n t (% )

0

10

20

30

40

50

Me

asu

red

VW

C (

%)

IT14701(ASSH 814-1) Y = 1.0106 * X + 0.2303 R -squared = 0.988

0 10 20 30 40 50Vo lu m e tric W a te r C o n te n t (% )

0

10

20

30

40

50

Me

asu

red

VW

C (

%)

IT14700(ASSH 814-2) Y = 1.0178 * X - 0.1180 R -squared = 0.994

0 10 20 30 40 50V o lu m e tric W a te r C o n te n t (% )

0

10

20

30

40

50

Me

asu

red

VW

C (

%)

IT14708(ASSH 818-1) Y = 1.0020 * X + 0.1653 R -squared = 0.994

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

0

10

20

30

40

SM

(%

by

v.)

3 0

2 0

1 0

0

Par

ea (

mm

/d)

14/3 3 /5 22/6 11 /8 30/9

2004

0

10

20

30

SM

(%

by

v.)

4 0

3 0

2 0

1 0

0

Pa

rea (

mm

/d)

29/3 8 /5 17/6 27/7 5 /9 15/10

2005

0

10

20

30

SM

(%

by

v.)

3 0

2 0

1 0

0

Pa

rea

(mm

/d)

27/3 3 /5 12 /6 22/7 31/8 10/10

2006

G round-based A M S R -E

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

4/3/06 5/23/06 7/12/06 8/31/06 10/20/06D ate (M /D /Y )

0

20

40

60

VW

C (

%)

Sanza i s ite (Apr-O ct,2006)AM SR -E (Ver.5.0)G round-based (by 2R probe at 3cm d.)C P1SM (3 cm depth SM )Precip ita tion: PAM SR -E (ver. 6 .0)

120

80

40

0

P (

mm

)

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

0 20 40 602R m on1 SM (% in vo lum e)

0

20

40

60

80

CP

1 S

M(%

in v

olum

e)

0 20 40 602R m on1 S M(% in vo lum e)

0

20

40

60

80

CP

2 S

M(%

in v

olum

e)

3cm (Left) 3cm (R ight)

1:1 1:1

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