This was a project undertaken with Dr. Greg Bothun at the University of Oregon and in collaboration with Portland State Aerospace, when I was a 3rd and 4th year undergraduate in Physics.

Background

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Thin cirrus clouds have a net climate warming effect, but are not well captured in general circulation models of the atmosphere. This is mainly because they are difficult to detect, making estimates of their global coverage challenging.

Cirrus clouds can be detected from orbit (looking nadir at the planet) using the 1.38 μm H2O absorption line, but this method is imperfect because of the likelihood of also detecting surface ice (polar caps, glaciers, snow, etc).

Methods

This project focused on employing commonly used astronomical photometry flux ratios as a method of detecting cirrus clouds, either from the ground looking up (at the zenith) or from orbiting cubesats, eliminating the potential degeneracy with ground ice and removing the need to rely on specific absorption lines in spectra. Using photometry and characterizing the flux ratio (basically an astronomical color), large areas of coverage could be analyzed simultaneously. The method also had the advantage of being fairly cheap to implement, using simple COTS (commercial off the shelf) cameras and equipment.

Results

Results were originally presented at the 2016 NASA Oregon Space Grant Symposium. See the associated poster: Flux Ratio Detection of Global Thin Cirrus Clouds