Monday, 11 October 2010

My First Research Flight

Sorry it's been so long, thesis writing and submission took over for a while. So I think it's time for an update...

On 7th of September I had my first flight on the UK BAe 146 Atmospheric Research Aircraft. This was my first opportunity to see the LIF instrument from L'Aquila (see post from Friday 11th June) in action since its installation on the aircraft. Piero and Eleonora (from University of L'Aquila in Italy) were already at the airport hotel and had been taking part in flights for the previous couple of weeks. It was decided when I arrived on the evening of the 6th that Eleonora and I would do the flight and so Piero would do the instrument warm up...for which we were very grateful. The flight was scheduled for take off at 04:30 and so pre-flight warm up began around midnight. Eleonora and I arrived at the aircraft around 02:30 for a final calibration and the security check and pre-flight briefing. A nice civilised hour for my first experience of science flying!

The plan for this flight was to watch the change in atmospheric composition as the sun rose and photochemistry began to breakdown species such as nitrate radicals and N2O5 and nitrogen oxide begins to be formed from photolysis of nitrogen dioxide. We took off from East Midlands Airport at 04:30 as planned and immediately ascended to 20,000 ft for our transit to the area of interest. Once we reached the designated point, just off the east coast near Middlesborough, we descended to 6000 ft and did a run up the coast to Aberdeen for the lidar to find the aerosol layers that indicate the presence of polluted air from the east coast. We then descended into the layers identified and did repeated runs through sunrise to see the transformation as photochemistry begins to occur. The LIF performed well with no obvious problems so fingers crossed the data will look good.

My second flight was two days later and at a more reasonable hour. This time we were aiming to find a suitably large ship and fly in and out of the associated pollutant plume. This gave the opportunity for some low level flying over the ship and I tried to get some pictures to show how close we were (see below).

This was the best picture I got as we flew over the ship whose plume we were attempting to sample.

I expected low level flying to be very turbulent but was a little disappointed that I didn't feel queasy at all and in fact the whole flight was surprisingly smooth (all credit to the brilliant pilots!). Again the LIF instrument operated with no apparent problems and we seemed to see large peaks as we transitioned through the ship's plume. So the changes made to the instrument to make it suitable for aircraft measurements do not appear to have significantly hampered the performance which is great news for the BORTAS campaign. Access to the lasers for changes in the alignment of the mirrors that direct the beams into the measurement cells is now only allowed when on the ground and whilst wearing laser goggles. Below is a picture taken between the two flights, it shows Piero and Eleonora trying to get the best sensitivity by making tiny changes to the alignment of the mirrors.

Having removed one panel Eleonora now has access to the mirrors inside the enclosure. Goggles must be worn by everyone on the aircraft since when the second panel is removed the green laser light can be clearly seen and could potentially damage eyes.