Near-Real-Time Monitoring of Cold Air Aloft for Aviation Safety in the United States and Canada

Monitoring temperature at cruising altitudes is important for aircrafts flying over the United States and Canada during winter months. Cold air aloft can be hazardous as jet fuel begins to gel at -65 C, which can cause engine malfunctions and increase risk of aircraft loss. Flight planners and dispatchers therefore desire to avoid these regions of cold air aloft, but the scant number of upper air observations (especially at the higher latitudes where both cold air and great circle airways are common) makes it difficult to identify regions to be avoided.

Near-real time observations from polar-orbiting satellite sounders are one way to address this issue. Temperature observations from five pressure levels near cruising altitudes are retrieved from the NOAA-Unique Combined Atmospheric Processing System (NUCAPS) thermodynamic profiles. NUCAPS uses brightness temperature observations from the Cross-track InfraRed Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) onboard the NASA Suomi-NPP (SNPP) and the NOAA-20 satellites. These observations are displayed in RealEarth, a web-based display program developed by the Space Science and Engineering Center (SSEC) at the University of Wisconsin-Madison, and update in near-real time. This presentation demonstrates the utility of such a product by examining a case day during the 2019 polar vortex over North America; validation of the product will be demonstrated against contemporaneous AMDAR observations.