* What time period does each AVHRR image cover?
* Why are there large areas without wind vectors in the AVHRR wind plots?
Other:* Are the wind data available?
* What recent changes have there been?
What time period does each AVHRR image cover?
Each image is a composite over a 24 hour period beginning at 0Z.Why are there large areas without wind vectors in the AVHRR wind plots?
The major drawback of using the AVHRR for wind retrieval is that there is no water vapor channel. Therefore, all wind vectors are derived by tracking clouds. With MODIS we can track both clouds and water vapor features, covering both clear and cloudy areas. We have found that with MODIS, more wind vectors are obtained from water vapor tracking than from cloud tracking.Are the wind data available?
Yes. MODIS wind data access and format is described here as a web page or here as a PDF file For AVHRR wind data, please ask.Are the data archived?
No, neither the data nor the plots are archived.What recent changes have there been?
See the revision history for a complete list of changes.