Addressing the Cold Air Aloft Aviation Challenge with Satellite Sounding Observations

Abstract

At high latitudes in winter, the atmosphere at flight levels used by passenger and cargo aircraft can reach temperatures cold enough to restrict the flow of jet fuel from the fuel tanks to the engine, due either to water freezing in the fuel or the fuel itself freezing. Currently, aviation forecasters rely on a combination of aircraft reports, pilot reports, a sparse network of radiosondes, and global model fieldsfor identifying and characterizing Cold Air Aloft (CAA) events. More atmospheric data are needed to improve forecasts of CAA placement and timing, and satellite observations can help fill the gap. In particular, products derived from the NOAA-Unique Combined Atmospheric Processing System (NUCAPS) can be utilized by National Weather Service (NWS) forecasters to assist in the production of aviation hazard products. NUCAPS combines measurements from infrared and microwave sounding instruments on polar-orbiting satellites to retrieve atmospheric profiles of temperature and moisture in the high latitudes. NWS forecasters have real-time access to NUCAPS soundings via the Advanced Weather Interactive Processing System-II (AWIPS-II). The Joint Polar Satellite System Sounding Applications Initiative created Gridded NUCAPS in order to view soundings as isobaric surfaces or vertical cross sections in AWIPS-II. The Cooperative Institute for Research in the Atmosphere (CIRA) developed a web-based product for displaying satellite-derived CAA information. This paper describes how the AWIPS-II and CIRA displays of satellite sounding observations augment aviation forecasting activities in Alaska using two specific CAA cases from the 2016–2017 and 2017–2018 winter seasons.

Validation and Utility of Satellite Retrievals of Atmospheric Profiles in Detecting and Monitoring Significant Weather Events

“…More than augmenting radiosondes, forecasters can visualize the high-density Gridded NUCAPS product to show horizontal spatial gradients of stability parameters, enabling situational awareness in 3D (Weaver et al 2019;Esmaili et al 2020;Berndt et al, 2020). Gridded…”

“…NUCAPS meets the forecasters' latency requirements for fast decision-making (Smith et al, 2019). However, in practice, it is equally essential for researchers to actively engage with NWS forecasters to ensure NUCAPS is an effective tool for pre-convective forecasting on 1-2 hour timescales (Esmaili et al 2020) (SHARPpy)", to increase data access (Blumberg et al, 2017) and for Cold Air Aloft monitoring for aviation weather (Weaver et al, 2019). These partnerships have also led to researchers using NUCAPS to study the thermodynamic structure of the Saharan air layer (Kuciauskas et al, 2020) and tropical cyclones (Barnet et al, 2019) the severe windstorm in the international border area of southern Texas.…”

Adapting Satellite Soundings for Operational Forecasting within the Hazardous Weather Testbed

“…Gridded NUCAPS [3,25] displays horizontal "slices" through a swath of NUCAPS soundings at specific pressure levels, which includes humidity and temperature as well as additional derived fields, such as lapse rate and stability indices for severe weather potential ( Figure 2d). The horizontal display enables quick visualization of hotspots or areas of interest with convective potential.…”

Observation of the Tropical Cyclone Diurnal Cycle Using Hyperspectral Infrared Satellite Sounding Retrievals

“…NUCAPS produces vertical profiles of temperature and moisture, trace gases, and cloud properties globally using a combination of both infrared and microwave sounding instrumentation (Gambacorta 2013). This algorithm is capable of retrieving atmospheric profiles over nearly 80% of the globe under clear to partly cloudy (non-precipitating) conditions (Nalli et al 2013(Nalli et al , 2018Susskind et al 2003) (Weaver et al 2019); observing the pre-convective environment (Iturbide-Sanchez et al 2018;Esmaili et al 2020); and diagnosing extratropical transition (Berndt and Folmer 2018).…”