At the start of the water vapor animation, near 0000 UTC, thick clouds cover southern California (and the sounding from San Diego shows saturated conditions); dry layers in the sounding appear by 1200 UTC. The 7.4 µm weighting function shows that information is detected by the satellite from lower down in the atmosphere; energy detected at 6.5 µm comes from higher in the atmosphere. This difference arises because of the better absorptive qualities of water vapor gas for 6.5 µm radiation vs. 7.4 µm radiation. By 1200 UTC, sufficient drying has occurred that the 7.4 µm Sounder Channel is detecting radiation that emanates from sea level. Note also at 1200 UTC that each individual moist layer influences the weighting function — but there is insufficient moisture at 1200 UTC in those moist layers that they are opaque to energy at either 6.5 µm or 7.4 µm.
The path of the eclipse shadow (courtesy of EarthSky.org) is shown below.True-color GOES-16 Red/Green/Blue (RGB) images are shown below (courtesy of Kaba Bah, CIMSS). Note: the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing on-orbit testing.
The corresponding daylight Meteosat-10 High Resolution Visible (0.8 µm) images (below) revealed better detail of the various cloud structures associated with the storm.True-color Red/Green/Blue (RGB) images from Terra/Aqua MODIS and Suomi NPP VIIRS visualized using RealEarth are shown below. EUMETSAT posted a natural-color RGB animation here.
The improved spatial resolution of the GOES-16 data (2-km at satellite sub-point, vs 4-km for GOES-13) also aided in the detection and characterization of the small and short-lived fires.
Fire detection points from the NOAA Hazard Mapping System for 20 February are shown below.Note: GOES-16 data shown on this page are preliminary, non-operational data and are undergoing on-orbit testing.