NASA Langley Research Center Support for ACCESS and ACCESS2 Field Campaign

Persistent contrails require a relative humidity with respect to ice (RHI) that exceeds 100%. We know that contrails are sometimes observed in areas where estimates of the RHI are less than 100%. The existence of contrails in those locations highlights the "dry-bias" in the humidity fields of the models. Because the input data do not perfectly characterize the meteorological conditions, the diagnoses of persistent contrail conditions are only estimates and will not detect all of the areas where persistent contrails will form and may also add areas of formation that do not exist. All estimates of persistent contrail formation conditions are based on a modified Appleman curve using three different engine propulsion efficiencies. Favorable contrail conditions, for a range of pressure levels between 125 and 400 mb, are represented as concentric circles - color coded with reducing diameter for each level. These results are displayed for engine efficiencies of 0.2, 0.3, and 0.4.

Rapid Refresh (RAP) Model: Latest short-term contrail prediction

Click to view an image loop of the most recent predictions