Seminar

Abstract

The Global Hawk Pacific Mission (GloPac) was the first demonstration of the Global Hawk (GH) unmanned aircraft system (UAS) for Earth science. The two principal GloPac objectives were routine operation to obtain science-quality data over remote atmospheric regions and the exploration of trace gases, aerosols, and the dynamics in remote regions of the upper troposphere and lower stratosphere. A payload of 11 sampling instruments was integrated onto the Global Hawk in March 2010. Three subsequent science flights ranged in duration from 14 to 28 hrs, reached cruise altitudes up to 65,000 ft, spanned latitudes from 12°N to 85°N in the remote Pacific and Arctic, and covered distances of 4600 to 9700 nmi.

The payload in situ instruments provided a number of gas measurements, including ozone, water vapor, and long-lived gases such as nitrous oxide and methane. Aerosols measurements included sizes in the range of 40 - 1000 nm diameter. Precise winds and temperatures were recorded along with the vertical temperature profile near the aircraft. A lidar system observed aerosols and clouds between the aircraft and the ground, while a spectrometer detected nitrogen dioxide and ozone column abundances below the aircraft.

Highlights of the Global Hawk flights include sampling a large fragment of the Arctic polar vortex in the Gulf of Alaska, sampling aerosol dust plumes from Asia extending from the surface to 10-km altitude over the Pacific, and extensive flight legs along the ground track of the A-train satellites coinciding with satellite overpass times.

The success of the GloPac provided a wealth of information and experience for future science and operation teams. The follow-on GRIP mission has successfully sampled tropical storms in the Pacific and Atlantic Oceans.