![GOES-17 Low-level Water Vapor (7.3 µm) images, plus topography [click to play animation | MP4]](https://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2019/01/190118_goes17_waterVapor_Brooks_Range_AK_anim.gif)
GOES-17 Low-level Water Vapor (7.3 µm) images, plus topography [click to play animation | MP4]
* GOES-17 images shown here are preliminary and non-operational *
A comparison of GOES-17 Low-level Water Vapor (7.3 µm) images with topography (above) revealed that radiation being emitted by the higher elevations of the Brooks Range in northern Alaska was able to be sensed by the 7.3 µm detectors — in spite of the very large satellite viewing angle (or zenith angle) around 75 degrees.
The GOES-17 ABI Water Vapor band weighting functions calculated using 12 UTC rawinsonde data from Fairbanks (below) showed that the presence of cold, dry air within the middle to upper troposphere had shifted the peak pressure of the 7.3 µm band downward to 753.63 hPa (corresponding to an altitude of 7053 feet) — which was at or below the elevation of much of the higher terrain of the Brooks Range. There was very little absorption of upwelling surface radiation by the small amount of water vapor that was present within the middle/upper troposphere, allowing the thermal signature of the terrain to be observed on the Water Vapor imagery.
![GOES-17 Water Vapor weighting functions calculated using 12 UTC rawinsonde data from Fairbanks [click to enlarge]](https://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2019/01/190118_12utc_pafa_g17_wv_wf.png)
GOES-17 Water Vapor weighting functions calculated using 12 UTC rawinsonde data from Fairbanks [click to enlarge]
from CIMSS Satellite Blog http://cimss.ssec.wisc.edu/goes/blog/archives/31422
No comments:
Post a Comment