From Dirk (ESA) Kiruna, northern Sweden, 9 December

Preparing for limb sounding

Last Sunday, I made my way up to Kiruna in northern Sweden to follow the ESSENCE campaign.

The aim is to carry out measurements of the atmosphere from a high-altitude research aircraft called Geophysica to support the development of a candidate ESA Earth Explorer mission called PREMIER which promises to provide vital clues on how atmospheric chemistry and climate are linked.

Geophysica is one of the very few aircraft that can fly up to 21 km above the surface of Earth, which is twice the height of a commercial plane.

A new ‘limb’ sounder is onboard. This type of instrument looks horizontally through the atmosphere so that information on temperature, trace gases and water vapour at different altitudes can be gathered.

This unique instrument, called GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere), is the first to use 2D detector arrays to image the atmosphere with very high resolution.

The instrument was developed by Karlsruhe Institute of Technology and Research Centre Juelich in Germany, involving scientists from a number of different disciplines.

Our plan is to make four flights in total. The first two flights are dedicated to the basic testing of the instrument. The other two flights will hopefully give new insights into climate-relevant trace gases such as water vapour, ozone and carbon dioxide.

Computer troubles

GLORIA installed on Geophysica

The idea was to fly on Tuesday, but during testing on Sunday and Monday the main computer crashed when the engines of the aircraft were started.

It took a long time for the crew to fix this problem, but eventually the problem was fixed. In principle, it would have been possible to fly today, but some of the team had worked through the night so it was to have a day’s rest day and start afresh and on Friday.

So we keep our fingers crossed for the first flight tomorrow.

The nice thing is that we will have a satellite-phone connection to the instrument, so we will hear if the instrument works properly during the actual flight.