GOES Low-Level Water Vapor Imagery:
This imagery is created using the 7.3 µm channel on the GOES-East satellite.
This infrared low-level water vapor band is sensitive to both temperature and
water vapor in the atmosphere and has a weighting function that peaks at ~620 hPa.
Weighting functions describe the layer of the atmosphere from which the radiation
measured by a particular satellite channel was emitted. The weighting function
for the 7.3 µm channel is fairly broad and typically detects temperature and
water vapor in a layer from ~300-925 hPa.
This imagery is useful for tracking low to mid-level water vapor features such
as the Saharan Air Layer and mid-latitude dry air intrusions and can also be used
for estimating low- to mid-level atmospheric motion vectors (AMVs).
• Due to the low altitude of the weighting function of the 7.3 µm
channel, upper-level atmospheric features (e.g., tropical cyclone outflow layers
and cold lows) may not be readily detectable using this imagery.
For more SAL information, please visit the
SAL Background Information