Friday 15 July 2011

First Science Flight Out of Halifax

So the flight today was not particularly successful. With the exception of a few bumps in the CO concentration, the odd fluctuation in the amount of peroxyacetyl nitrate (PAN), a little acetonitrile and a trace of black carbon there really wasn't a lot of evidence of the plume we were hoping to see. Part of the problem was that we couldn't get permission to fly as low as we wanted to so we had to stay above 13,000 ft. Out the window we saw lots of trees, some hills and a white water river sparking comments from the pilots comparing Nova Scotia to the original Scotland. Probably the most exciting bit was some slight turbulence as we flew through the top of the cloud. There were some indications that there was uplift through the cloud from the boundary layer below; the PTR-MS saw some isoprene, a compound most commonly emitted by vegitation, and MVK, a product of the breakdown of isoprene. It looked like the level of PAN also went down then which would support this suggestion since PAN is a reservoir compound for nitrogen oxides which degrades at the higher temperatures found lower in the atmosphere.

Despite the lack of scientific excitement Axel Wellpot, the flight manager, was still very busy as can be seen by the number of windows he has open on his three screens! He has to keep a record of changes in flight level, control a number of core instruments, print predictions of pollution for the mission scientist and weather for the
pilots, he produces beautiful Google Earth plots for data visualisation and does numerous other things I don't even know about.




The scientists were showing less dedication to the cause as evidenced by the pictures below, but then there wasn't much else to do except watch your instrument flatline for 4hrs. Maybe in post processing we can see something of more use in the finer detail of the measurements but none of the massive elevations in concentration we were hoping for.



There are still a couple of instrument issues; the GC-MS pump continues to leak so the GC-MS now has to share the pump that is used to fill the whole air sampling (WAS) bottles, the NOx analyser has flow rate problems at high altitude (above about 20000 ft) and it looks as though the instrument that measures CO2
and methane was sucking a small amount of air in from the cabin. Stephane Bauguitte, the core chemistry operator, thinks that is now fixed but ideally he would put in a new, dedicated inlet for that instrument to ensure that sufficient flow is maintained and so it will not suck in any cabin air. Watch this space to find out if we can fix any of these problems or if we will just have to find a way to work around them.


Steph and Seb try and fix the problem with the CO2 instrument while Piero talks to Axel.

In other news we saw a rather interesting looking aircraft outside the hanger we are working at yesterday. Looks to me like the propellers are on backwards but the engineers, after a little joking around, assured me that it makes no difference and that it is just the way the Japanese decided to build that particular model.


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