WRF Configuration for Prediction of Aircraft-Induced Cirrus Formation

Northrop Grumman Corporation (NGC), in partnership with NASA’s Jet Propulsion Laboratory (JPL), is developing modeling capabilities for the prediction of Aircraft-Induced Cirrus (AIC) cloud generation by commercial aviation operators. This work is in support of the United States Department of Energy’s (DOE) Advanced Research Projects Agency – Energy (ARPA-E) Predictive Real-time Emissions Technologies Reducing Aircraft Induced Lines in the Sky (PRE-TRAILS) program. Leveraging NGC knowledge and flight test data on contrail prediction and formation, NGC is developing the Contrail Avoidance System (CAS) to prevent the formation of AIC by enabling aircraft to identify and avoid Ice Super Saturated Regions (ISSRs) in real time. The two key components of this work are development of a new instrument, JPL’s Y-band Temperature and Humidity Profiler (YTHP), and prediction of contrail formation and evolution to AIC using a fusion of NGC’s existing Contrail Prediction Model and the Weather Research and Forecasting (WRF) numerical weather prediction model.

YTHP is an aircraft-mounted submillimeter-wave spectroradiometer that will retrieve vertical profiles of atmospheric temperature and moisture in front of an aircraft. As part of the PRE-TRAILS program, we plan 12 flight test missions in which the YTHP sensor and our operational contrail-avoidance tools will be characterized and validated. Ground observers will track the onset and evolution of persistent contrails using photometrically calibrated cameras.

We will use WRF as a cloud-resolving regional model for the spatial domain covering the flight testing of YTHP. Our long-term modeling goals are to develop a method to insert recently created contrails into the WRF simulation to predict the evolution of contrails to persistent cirrus, and to show how assimilation of YTHP profiles improves that prediction capability. These efforts support the project goal of integrating the YTHP sensor onto aircraft, allowing flight crews to proactively respond to ISSR in the flight path minutes prior to the formation of contrails that would otherwise become AIC.

We will present results of our initial modeling work, which is aimed at assessing WRF performance for simulating ISSRs that cause persistent contrails/AIC. Our studies will include comparison of WRF ISSR representation to contrail formation flight test data previously gathered by NGC.  We will also present comparisons of WRF ISSR results with areas of AIC visible in satellite images.