![Page 1: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/1.jpg)
INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION
Ben MaathuisDepartment of Water
ResourcesITC-Enschede
The Netherlands
From Cloud Top Temperature to Rainfall; Blending MSG and TRMM
![Page 2: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/2.jpg)
From temperature to rainfall (1)
Use TRMM to calibrate Meteosat Cloud Top Temperature (10.8 micron band) and transform a time series of MSG images into Precipitation.
![Page 3: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/3.jpg)
View TRMM data using Orbit Viewer and select area, export data to lat/long/rainfall intensity table
From temperature to rainfall (2)
Available from http://tsdis.gsfc.nasa.gov
![Page 4: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/4.jpg)
Import time series of MSG data using the MSG Data Retriever, converted to TOA Temperature
From temperature to rainfall (3)
Some Key-features: Based on open source
GDAL drivers; Fully controlled geometry &
radiometry, conversions to diff. data formats: DN, radiances, reflectance, temperature;
Diff. user defined output formats and resolutions (interpolation);
Easy date/time range selection and series construction.
![Page 5: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/5.jpg)
Import of tabular TRMM observations, linking the point map and corresponding MSG image using ILWIS
Large number of TRMM rainfall observations
From temperature to rainfall (4)
![Page 6: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/6.jpg)
Low correlation due to spatial and temporal offsets when aligning geostationary IR and LEO PMW datasets on a per-pixel basis;
Improvement of correlation by averaging procedure.
From temperature to rainfall (5)
After: “Validation of an operational global precipitation analysis at short time scales”. By: F. Joseph Turk, et al Marine Meteorology Division, Naval Research Laboratory, Monterey, California 93943
![Page 7: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/7.jpg)
TRMM rainfall pixels are averaged based on MSG–IR temperature class intervals (in classes of 0.5 or 1 degree K) to obtain for a temperature range (e.g. from 180 to 260 Kelvin) for each temperature class the average corresponding rainfall intensity
From temperature to rainfall (6)
![Page 8: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/8.jpg)
Develop an improved relationship between averaged rainfall intensity and temperature
From temperature to rainfall (7)
![Page 9: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/9.jpg)
Transform temperature time series to rainfall by single statement
From temperature to rainfall (8)
rain08sept:=maplistapplic(t_200509080000_ir_108.mpl, "iff((##)<260,4.3505278e-005*(exp(2550.0127/(##))),0)")
Can also be displayed as animation
![Page 10: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/10.jpg)
Rainfall per time step Accumulated 24 hour rainfall
From temperature to rainfall (9)
![Page 11: INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Ben Maathuis Department of Water Resources ITC-Enschede The Netherlands From](https://reader030.vdocuments.mx/reader030/viewer/2022032722/56649cda5503460f949a3c84/html5/thumbnails/11.jpg)
TRMM observations can be used for MSG-IR calibration after an averaging procedure but needs better cloud mask and type determination;
For validation synoptic station data has to be used (at appropriate temporal resolution -> tipping bucket);
Low cost ground receiving station and free software sources make such a near real-time system suitable for e.g. National Hydrological Services and Basin Authorities;
Especially suitable for short duration rainfall events, e.g. for flash floods.
Conclusion