Presentació realitzada per Yoann Malbeteau (CESBIO) a la jornada "Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques" (03/06/2016)

1. Validating satellite-derived land surface
temperature over mountainous area with in
situ measurements
Imlil Valley (High Atlas) - Morocco
Yoann Malbéteau
CESBIO / Toulouse
yoann.malbeteau@cesbio.cnes.fr
http://rec.isardsat.com
Merlin O., Gascoin S., Gastellu J.P., Mattar, C. Olivera L., Khabba S., Jarlan L.

2. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques 1 of 15
Temperature of Earth's lands during the daytime
April 2016 marks 12th consecutive month of record warmth for globe (NOAA)
Climatic scale
Land & Ocean temperature Percentiles Jan-April 2016
NOAA’s National centers for Environmental Information
Data Source: GHCN-M version 3.3.0 & ERSST version 4.0.0
Record
Warmest
Much
Warmer than
average
Warmer than
average
Near
average
Much
Cooler than
average
Cooler than
average
Record
Coldest
Over land: +2.33°C
Over land and ocean: +1.11°C
above the 20th century average

3. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques 2 of 15
Land surface temperature for agriculture….
Evapotranspiration estimation / Soil moisture downscaling
amongst of others…
Regional and parcel scale
ASTER temperature (90 m)
ET (mm/day)
0 108642
Olivera-Guerra L. et al. (2014)

4. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques 2 of 15
Land surface temperature for agriculture….
Evapotranspiration estimation / Soil moisture downscaling
amongst of others…
Regional and parcel scale
SMOS Product
Soil moisture
Disaggregated
82 000 km2
ASTER temperature (90 m)
MODIS land surface temperature (1 km)
ET (mm/day)
0 108642
Olivera-Guerra L. et al. (2014)
Malbeteau Y. et al. (2016)
6050 km2

5. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
What’s land surface temperature ?
LST
(Land Surface
Temperature)
NDVI
Soil
Moisture
Albedo
texture
ET
Meteo
Topo
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6. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
What’s land surface temperature ?
LST
(Land Surface
Temperature)
NDVI
Soil
Moisture
Albedo
texture
ET
Meteo
Topo
3 of 15
LST landsat at 100m resolution
05 Septembre 2014
Lake
Mountains
Clouds
55
40
30
25
50
45
35
T °C

7. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
What’s land surface temperature over mountains?
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Illumination
Elevation

8. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Land surface temperature over mountains
5 of 15
Aremd station
Northing
Easting
Elevation
1400
0
W.m-2
Net Radiation at 8m (from DART model)
at 11h21, the 05th of September
6 km

9. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Land surface temperature over mountains
6 of 15
45
30
20
15
40
35
25
T °CSun-exposed
slope
Shadowed
slope
Vegetation
River
Land surface temperature observed by ASTER satellite
6 km

10. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Scheme placement …
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Temperature sensors/loggers
Different illumination and elevation
Spacing: ~100m
(ASTER/landsat resolution)
6 months
45
30
20
15
40
35
25
T °C

11. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
How can we validate surface temperature ?
8 of 15
Temperature sensors/loggers
ibutton sensor
135 ibuttons
Set up over
45 points
Locations of the 45 ibutton plates, each of them containing 3
ibutton sensors.
Red cross indicate plates not used for the study.

12. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Results: sample of in situ surface temperature
9 of 15
Date (mm/dd/2014)
Surfacetemperature(°C)
Sun exposed shadow exposed

13. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Results: sample of in situ surface temperature
Date (mm/dd/2014)
Surfacetemperature(°C)
Sun exposed shadow exposed
14°C
5°C
9 of 15

14. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Results: sample of in situ surface temperature
Date (mm/dd/2014)
Surfacetemperature(°C)
lag time
9 of 15
Sun exposed shadow exposed

15. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Results: sample of in situ surface temperature
Date (mm/dd/2014)
Surfacetemperature(°C)
Cloudy day
9 of 15

16. Energy balance
Transpiration
Evaporation
land surface
temperature
𝑻 𝑬𝑩 = 𝒇𝒗 𝑻𝒗 𝑬𝑩 + 𝟏 − 𝒇𝒗 𝑻𝒔 𝑬𝑩
Based on double source
(vegetation/soil) energy
balance model
𝑻𝒔 𝑬𝑩 = 𝒇𝒔𝒔 𝑻𝒔, 𝒅𝒓𝒚 𝑬𝑩 + 𝟏 − 𝒇𝒔𝒔 𝑻𝒔, 𝒘𝒆𝒕 𝑬𝑩
𝑻𝒗 𝑬𝑩 = 𝒇𝒔𝒗 𝑻𝒗, 𝒅𝒓𝒚 𝑬𝑩 + 𝟏 − 𝒇𝒔𝒗 𝑻𝒗, 𝒘𝒆𝒕 𝑬𝑩
Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Modeling topographic effect over mountains
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17. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Modeling topographic effect over mountains
ASTER LST simulated LST
45
30
20
15
40
35
25
T °C
90 m resolution 8 m resolution
Representativeness
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6 km6 km

18. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Useful for model and observed data validation
14th April 2014 30th April 2014 05th September 2014
Simulated LST
ASTER LST
R (correlation) 14th April 30th April 05th September
Simulated LST 0.75 0.68 0.64
Observed LST 0.64 0.68 0.67
Scatterplots of ASTER and simulated LST at 90m
resolution versus ibutton measurements
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19. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Useful for model and observed data validation
14th April 2014 30th April 2014 05th September 2014
Simulated LST
ASTER LST
R (correlation) 14th April 30th April 05th September
Simulated LST 0.75 0.68 0.64
Observed LST 0.64 0.68 0.67
B (bias) 14th April 30th April 05th September
Simulated LST 1.48 2.74 -0.43
Observed LST 3.04 3.38 0.78
Scatterplots of ASTER and simulated LST at 90m
resolution versus ibutton measurements
12 of 15

20. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Additional slide….
for future application over mountains
45
30
20
15
40
35
25
T °C
Before correction After correction
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21. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
14 of 15

22. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
intercomparison between remotely sensed data
14 of 15

23. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
intercomparison between remotely sensed data
Terrain accessibility … “When science goes messy”
14 of 15

24. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
intercomparison between remotely sensed data
Terrain accessibility … “When science goes messy”
14 of 15

25. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
intercomparison between remotely sensed data
Terrain accessibility … “When science goes messy”
14 of 15

26. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
intercomparison between remotely sensed data
Terrain accessibility … “When science goes messy”
14 of 15

27. Validació de dades teletransportades en camp; Aplicacions agrícoles i hidrogeològiques
Conclusion
Challenges:
Representativeness of in situ measurement for remote sensing data validation
solution ? very dense in situ measurement  aggregation
few in situ measurement  disaggregation (downscaling)
in situ measurement representative at the scale resolution
intercomparison between remotely sensed data
Terrain accessibility
But it is great …
14 of 15

28. Validating satellite-derived land surface
temperature over mountainous area with in situ
measurements