5

Satellite Images

GOES-R

Properties of Water Vapor Satellite Images

How does cloud altitude and upper tropospheric humidity alter the appearance of water vapor imagery?

The image to the left is an example of a water vapor image made from radiometers flown on several geostationary satellites. A part of this image has been extracted and appears as a square below the larger satellite image. This portion of the image contains a cloud and some clear sky areas. You can change the appearance of this extracted image by changing the cloud altitude (and its associated ambient air temperature) or the humidity of the upper troposphere (approximately 200 to 600 mb). You do this by moving the sliding scales (scroll bars) accompanying the picture on the right and the bottom.

Vertical Slider : Changes the cloud altitude and air temperature using the vertical slider. The numbers on the left side of figure shows the altitude and the numbers on the right side of figure shows corresponding temperature, assuming standard atmospheric conditions.

Horizontal Slider: Modify the amount of water vapor in the upper troposphere using the horizontal slider to bottom of the figure.

You must use an up-to-date browser to view this

Questions to consider:

  • What happens to the image when you lower the cloud?
  • What happens to the image when you decrease the ground temperature?
  • Adjust the cloud altitude and ground temperature so that the cloud is no longer visible in the image. Can you think of a situation when this might occur?
  • Adjust the cloud and altitude and ground temperature so that the cloud appears darker than the ground. Can you think of a time of year and geographic region when this meteorological situation might occur?