The lower troposphere over the coast of northern Chile, Peru, and southern Ecuador is believed to be characterized by inversions throughout much of the year, causing the area’s aridity. However, scarcity of radiosonde data makes it difficult to detect and characterize these inversions, motivating a search for a way to do so through remote sensing. I therefore am testing for Antofagasta, Chile (23.43°S, 70.44°W) variations on a technique that has shown some success in describing inversion depth and strength over Antarctica. This method is based on the difference between the brightness temperatures of the 7.35 µm water vapor and 11 µm thermal infrared bands (bands 28 and 31) as sensed by the MODIS Aqua platform, and it had relatively high success in predicting the strength and depth of strong inversions over Antarctica.
I have already found that, while the 7.35 µm band temperatures did not accurately represent the brightness temperatures of the atmosphere at the top of the Chilean inversions, the brightness temperature differences between bands 28 and 31 did reflect the seasonal cycle in inversion strength and duplicate some major events in changes of inversion strength. These results, combined with clear paths available to better their accuracy, suggest that it should be possible to develop consistent remotely-sensed descriptions of strong inversions along the South American coast. I am currently using more accurate weighting functions and a broader dataset to further this work.