The High-Altitude MMIC Sounding Radiometer (HAMSR) on the Global Hawk for TC Reconnaissance: Observations during the SHOUT Campaign

The paper presents results from HAMSR during the 2016 NOAA SHOUT campaign. HAMSR is a 25 channel cross-track scanning microwave sounder with channels near the 60 and 118 GHz oxygen lines and the 183 GHz water vapor line. In 2015 and 2016, it participated in the NOAA SHOUT campaign on the NASA Global Hawk Unmanned Aerial Vehicle (UAV). The objective of the SHOUT campaign is to demonstrate the forecast improvement of significant weather events enabled by the long-duration and far-reaching capability of the Global Hawk aircraft instrumented with in situ and remote sensing instruments. In addition to HAMSR, the plane carried the HiWRAP radar to measure precipitation and winds and dropsondes to provide in situ vertical profiles of temperature, wind and humidity.

During the 2016 tropical cyclone campaign, several storms ranging in strength from tropical storms to Category 4 were observed over the period of several hours. The most significant storm observed was Hurricane Matthew. The Global Hawk made three consecutive flights over the storm as it transitioned from a tropical to extra-tropical cyclone. During the second flight, Matthew had sustained Category 4 status but was weakening. The HAMSR observations show the evolution of the warm core structure over 10 hours as it was weakening.

In this paper we will highlight the observations of the TC structure and evolution derived from the HAMSR thermodynamic measurements for the 7 flights over 4 named storms. We will show an inter-comparison of the HAMSR vertical temperature and moisture profiles with the co-incidence dropsonde measurements and will discuss the down-scaled product that was developed for data assimilation. Finally, we will discuss the real-time data products that are available during the flight in the context of real-time diagnosis of storm intensity, center position and environmental conditions.