Wednesday 27 August 2008

Every morning we get the following report from the aerosol lab prepared by Doug Orsini (U Leipzig), describing their observations for the previous day and the current meteorological conditions

===========================

Current conditions from the bridge:

Heading: 87.21

Wind True: 82 deg. Wind Speed: 3.1 m/s

Temp. : -3.1 C



There is a planned ship engine test today at 14:30. (This means shut down your atmospheric sampling or you'll sample black ship exhaust)



Tuesday Aug 26, between 12:00 and 16:00 we measured a rather fluctuating but semi-continuous period of nucleation (= formation if tiny new particles). This was the day that the ship sat to the Northwest of a band of sunshine. We are now dominated by a high pressure system, and winds should slowly rotate from the North as it moves through.



Current trajectories (= where the air is coming from and where it has been for the previous days as it affects its chemical and physical properties) show an air history that has been at least 3 days over the pack ice. Air is drier (90% relative humidity), stable (= it is has been thoroughly mixed top to bottom), and coming around the pole from the east.



Helicopter Flights:



Staffan:

"Yesterday at noon, an event (= particle formation) of diameters 3-10nm was detected, confined from ground to 100 meters height (in the air) below the (atmospheric) inversion. We flew at 18:00 out Southeast to the sunny stripe and there was a similar event. At 23:30, that event had faded and cold air moved in under the cloud layer from the east. "



Gas Results:

A perfect sampling mission at 23:30 showed that in the (atmospheric) inversion, elevated levels of DMS were detected,-a factor of 10 higher than the very low levels at the surface. That was also detected at the cloud edge, out in the sun.