1. European Geosciences Union General Assembly 2015
Vienna | Austria | 12 – 17 April 2015
Long term global scale root zone soil moisture monitoring at ECMWF using a surface-only land data assimilation system
C. Albergel(1), P. de Rosnay(1), C. Massari(2), L. Brocca(2), J. Munoz-Sabater(1), G. Balsamo(1), E. Dutra(1), T. Kral(1), L. Isaksen(1) and S. Boussetta(1)
(1)European Centre for Medium Weather Forecast (ECMWF), Reading, UK
(2)Research Institute for Geo-Hydrological Protection, CNR , Italy
28/05/2018

2. HSAF Project at ECMWF
ECMWF H-SAF activities : developing surface and root zone SM based on satellite derived surface SM data assimilation (scatterometer data)
Remote Sensing : shallow near surface layer
Main variable of interest : root-zone soil moisture
Complementarity between model and
observations
Assimilation algorithms :
Combines observations and model trajectory
Propagates information from surface observations into deeper layers
28/05/2018

3. SM-DAS-2 (H14), operational since 07/2012
Based on physical soil freezing processes representation, expressed into liquid soil moisture index (daily product, 25km)
ASCAT operational SSM, screen level variables (T2M, RH2M)
0-7cm, 7-28cm, cm ( cm)
SM-DAS-3 (H27)
Re-analysis of SM-DAS-2 (16km)
Provide long time series of the liquid root zone soil moisture index (covering )
ASCAT & ERS reprocessed SSM, screen level variables (T2M, RH2M)
0-7cm
7-28cm
28/05/2018

4. SM-DAS-2 (H14), operational since 07/2012
Based on physical soil freezing processes representation, expressed into liquid soil moisture index (daily product, 25km)
ASCAT operational SSM, screen level variables (T2M, RH2M)
0-7cm, 7-28cm, cm ( cm)
SM-DAS-3 (H27)
Re-analysis of SM-DAS-2 (16km)
Provide long time series of the liquid root zone soil moisture index (covering )
ASCAT & ERS reprocessed SSM, screen level variables (T2M, RH2M)
0-7cm
7-28cm
28/05/2018

5. SM-DAS-3 (H27) :
Surface-only Land Data Assimilation System : ASCAT reprocessed data and screen level variables (T2M, RH2M)
28/05/2018

6. SM-DAS-3 (H27) :
Surface-only Land Data Assimilation System : ASCAT reprocessed data and screen level variables (T2M, RH2M) R
R Anomaly time series
USCRN
USCRN R
R Anomaly time series
SCAN
SCAN
Better quality
More data available
28/05/2018

7. SM-DAS-3 (H27) : evaluation
H27 vs. in situ measurements (France, USA)
Winter
Spring
Summer
Autumn
Obs.
H27
Monthly
anomalies
SCAN (USA)
SMOSMANIA (Fr.)
USCRN (USA)
Obs. H27
28/05/2018

8. SM-DAS-3 (H27) : evaluation
H27 used for initializing simple event based rainfall-runoff model
“Simplified Continuous Rainfall Runoff” model
(SCRRM, Massari et al. 2014, HESS)
Chiani Catchment 460 km2 (sub catchment of the Tiber River)
19 flood events, mean Nash-Sutcliffe=0.59, median Nash-Sutcliffe=0.69
Results provided by C. Massari, L. Brocca, Research Institute for Geo-Hydrological Protection, CNR , Italy
28/05/2018

9. SM-DAS-3 (H27) : evaluation
Estimating rainfall from soil moisture (Italy)
talk from Brocca et al / EGU
Better results compared to a control experiment (i.e. no data assimilation)
1 layer of soil [0-7]
5 days accumulated rainfall
1-3 layers of soil [0-100cm]
5 days accumulated rainfall
Brocca, L., et al. (2013). A new method for rainfall estimation through soil moisture observations. Geophysical Research Letters, 40(5), , doi: /grl
Results provided by C. Massari, L. Brocca, Research Institute for Geo-Hydrological Protection, CNR , Italy
28/05/2018

10. SM-DAS-3 (H27) : evaluation
Surface / atmosphere interaction
1-day forecast initialised everyday (00:00UTC) June-Aug using a control (Tctrl) and H27 (TH27) [uncoupled system]
Sensitivity(T2M) = TH27 - Tctrl
Blue : more water, cooling
Yellow-red : less water, heating
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11. Monthly mean soil moisture increments
SM-DAS-3 (H27) : evaluation
Surface / atmosphere interaction
1-day forecast initialised everyday (00:00UTC) June-Aug using a control (Tctrl) and H27 (TH27) [uncoupled system]
Sensitivity(T2M) = TH27 - Tctrl
Blue : more water, cooling
Yellow-red : less water, heating
Monthly mean soil moisture increments
(0-100cm) for July and June 2008
28/05/2018

12. SM-DAS-3 (H27) : evaluation
Surface / atmosphere interaction
1-day forecast initialised everyday (00:00UTC) June-Aug using a control (Tctrl) and H27 (TH27) [uncoupled system]
Sensitivity(T2M) = TH27 - Tctrl
Impact(T2M) = |TH27 – Tan*|-|Tctrl- Tan |
*Tan ECMWF IFS
Blue : more water, cooling
Yellow-red : less water, heating
Blue : reduces errors
Yellow-red : increases errors
28/05/2018

13. Water holding capacity = f(soil texture)
SM-DAS-3 (H27) : Perspectives
Key aspect of DA : prescription of background and observations errors
H14 (H27 preliminary version) : fixed in time and space
(0.01 m3m-3 model, 0.05 m3m-3 ASCAT)
Background error : % of the water holding capacity (varies in space)
[e.g. 5%, 3%, 1% for soil layers 1-3]
Observation error (ASCAT) : ASCAT noise (varies in time and space)
Water holding capacity = f(soil texture)
ASCAT monthly mean Noise (march 2010)
28/05/2018

14. SM-DAS-3 (H27) : Perspectives
Key aspect of DA : prescription of background and observations errors
H14 (H27 preliminary version) : fixed in time and space
(0.01 m3m-3 model, 0.05 m3m-3 ASCAT)
Background error : % of the water holding capacity (varies in space)
[e.g. 5%, 3%, 1% for soil layers 1-3]
Observation error (ASCAT) : ASCAT noise (varies in time and space)
Layer 1 (0-7cm)
Layer 2 (7-28cm)
Layer 3 (28-100cm)
28/05/2018

15. SM-DAS-3 (H27) : Perspectives
Develop & evaluate H27 over
In situ measurements when/where available
Hydrological model
T2m / RH2m forecast
Optimise background and model errors
Assess H27 added value compared to a control model experiment
Impact of the different observations type (satellite derived SSM, screen level variables)
28/05/2018

16. http://hsaf.meteoam.it (/soil-moisture.php)
European Geosciences Union General Assembly 2015
Vienna | Austria | 12 – 17 April 2015
Long term global scale root zone soil moisture monitoring at ECMWF using a surface-only land data assimilation system
Thank you for your attention!
Contact :
(/soil-moisture.php)
28/05/2018