Tuesday, 4 May 2010

The Dalhousie LIDAR

On the 14th and 15th April the first full science team meeting was held in Edinburgh. The two days consisted of discussions of logistics and presentations from participants, but also provided a brilliant opportunity to meet some of the people we will be spending a month with in the summer. Having been on a few research campaigns before I thought I knew quite a lot of people from the UK atmospheric science community, but on receiving the list of attendees I realised that there were rather a lot of unfamiliar names. You might think this would make the meeting less fun, but it turned out that I knew very little about the science that most of these guys did and so I found myself really interested in the presentations being given.

An example of one of these interesting presenters is Tom Duck from Dalhousie University in Canada. Tom operates an instrument called a Raman Lidar. Lidar is actually another acronym standing for Light Detection And Ranging. It is similar to Radar (Radio Detection And Ranging) which is often used to track aircraft or ships. In this case laser light is used to detect particles in the atmosphere, also known as aerosols, by measuring the laser radiation scattered by these particles. Above is a picture (taken from Tom’s presentation) of the laser beam from the lidar coming from what Tom calls his ‘penthouse laboratory’. It is apparently a popular site around Halifax and I’m not surprised, it looks like something from a comic book or sci-fi movie.
And the plots of data from this instrument are just as cool; above is an example of a plot from Tom’s lidar data when biomass burning plumes were overhead. The warm colours indicate the greatest backscatter showing the presence of a thick layer of aerosol at a height of between 3.5 and 5.5 km. It will be interesting to see what the data shows during our campaign in July, hopefully some similar events will be observed! More details about Tom's work can be found on the Dalhousie University Atmospheric-Optics Laboratory webpages.

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