Atmospheric science

HAPs also provide a means by which remote sensing instruments can be deployed to detect atmospheric composition, aerosols, clouds and dynamics. HAPs are now seen as increasingly essential trials facilities to test new technologies and small space instruments for atmospheric science.

In situ atmospheric composition

The upper troposphere and lower stratosphere, between 10 and 25 km, are a critical part of the atmospheric system, and the chemistry and physics that occur in these regions is central to controlling radiative forcing, climate and stratospheric ozone depletion. Studying in detail the exchanges between troposphere and stratosphere is a very active area of current research in atmospheric science.

Measuring the detailed composition of this region is challenging and historically was limited to high altitude aircraft such as the ER-2 or free floating balloons. Autonomous large payload HAPs are transforming this field of science allowing research and new measurements in previously untested regions of the atmosphere, notably over the remote Pacific, South Atlantic and polar regions.

Remote sensing

Remote sensing methods provide a detailed view of the vertical composition of the atmosphere and give insight into the distribution of clouds, water vapour and chemicals from surface upwards. Remote sensing is an essential complementary data source that is used to improve the accuracy of weather and climate models.

HAPs provide an ideal facility for the deployment of remote sensing instruments, giving observational envelopes that are similar to low Earth orbit satellites but at a drastically reduced cost and with more flexibility. They are beginning to provide an essential pathway for new instrument development and for the proof of principle testing of new technologies earmarked for future satellite missions.