1 / 15

R. Tsheko , M. Tapela, N.J. Batisani Botswana College of Agriculture Crop and Rangeland Monitoring

R. Tsheko , M. Tapela, N.J. Batisani Botswana College of Agriculture Crop and Rangeland Monitoring Agriculture Service. Agenda SADC THEMA Services. Course Content Rainfall Products. Rainfall products. What are RFEs?. Rainfall products.

huyen
Download Presentation

R. Tsheko , M. Tapela, N.J. Batisani Botswana College of Agriculture Crop and Rangeland Monitoring

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. R. Tsheko, M. Tapela, N.J. Batisani Botswana College of Agriculture Crop and Rangeland Monitoring Agriculture Service

  2. Agenda SADC THEMA Services Course Content • Rainfall Products

  3. Rainfall products • What are RFEs?

  4. Rainfall products • Most of the developing world and huge water bodies like the ocean do not have adequate rainfall gauge networks and weather radars coverage Global telecommunication stations

  5. Rainfall products • Meteorological satellites are then only source of precipitation information to fill in the gaps. • Characterization of rainfall variation in time and space is very important for crop monitoring for food security in the SADC region • Satellite rainfall estimates could be fed into crop yield models

  6. Rainfall products • remote sensing systems unlike rain gauges, do not directly measure rainfall but rather rely indirectly measure the precipitation based on cloud reflectance, cloud-top temperature, and on the presence of frozen precipitation to estimation rainfall intensity

  7. Rainfall products • There are several different types of satellite rainfall estimation algorithms developed and these may use, only infrared (IR) data; passive microwave (PM) data; combination of IR and PM; assimilate available real-time gauge data and precipitation data onboard the Tropical Rainfall Measuring Mission (TRMM) satellite

  8. Rainfall products • The GOES Precipitation Index (GPI) is based on the thermal infrared information of the clouds (temperature of clouds-top is below 235 K and is assigned a rain rate of 3 mmhr-1 ). • MeteoSat data used to composite a CCD image at -38oC, a rainfall estimate is generated from the CCD using the GOES Precipitation Index (GPI) where GPI = CCD x 3

  9. Rainfall products • Microwave sensors are used to estimate rainfall based on the emmissivity of the cloud (ice particles and large rainfall drops reduces emmissivity hence reduces cloud brightness temperature) • The Tropical Applications of Meteorology using SATellite (TAMSAT) group at Reading produced daily CCD (Cold Cloud Duration) maps from raw Meteosat thermal infra-red (IR) images using a -38oC threshold temperature.

  10. Rainfall products • The Tropical Applications of Meteorology using SATellite (TAMSAT) group at Reading produced daily CCD (Cold Cloud Duration) maps from raw Meteosat thermal infra-red (IR) images using a -38oC threshold temperature. CCD – cold cloud duration Created from Thermal &IR images (Met Sats)

  11. Rainfall products • The NOAA Climate Prediction Center (CPC) used the Rainfall Estimation (RFE 1.0) algorithm from 1995 to 2000 • In 2001, the Rainfall Estimation Algorithm Version 2 (RFE 2.0) replaced REF 1.0 on operation status. • The REF 2.0 significantly reduced bias and random error hence increases the accuracy of the rainfall estimates.

  12. Rainfall products • REF 2.0 ingests four (4) different data sets namely; • 1) Daily Global Telecommunications Station (GTS) rainfall gauge data for up to 1000 stations • 2) AM SU microwave precipitation estimates • 3) Special Sensor Microwave/Imager (SSM/I) satellite rainfall estimates and • 4) GPI cloud-top IR temperature estimates.

  13. Rainfall products

  14. Rainfall Products

  15. The END Thank You.

More Related