# Cirrus Near IR

The “cirrus” near-infrared band at 1.37 μm will detect very thin cirrus clouds during the
day. This band is centered in a strong water vapor absorption spectral region. It does 
not routinely sense the lower troposphere, where there is substantial water vapor, and
thus provides excellent daytime sensitivity to high, very thin cirrus under most circum-
stances, especially in warm, moist atmospheres. Correction for the presence of contrail
and thin cirrus, which are possible with this band, is important when estimating many
surface parameters. Hence, this band can be used to distinguish between low and high
clouds or other bright objects and high clouds.

### Appearance

Color scale from blue to red.

### Intended usage

Cirrus, contrail and thin clouds detection, smoke plumes, ash plumes.

### Limitations

It can detect also ash and smoke (e.g. from forest fires or volcanoes) that might be mistaken for cirrus at the first glance.

### References

Schmit et al., 2005