Thursday, 16 January 2014

Meetings, Seminars and Coffee Breaks

  The first week is nearly coming to an end and so far so good. Getting settled in at my desk and making it feel homely with my old name tag from the door in Birmingham, a selection of mugs, a pint glass for my orange squash and my second sun to help on those dark overcast winter days. Slowly remembering names of people I meet (takes me a while) and have met many who I working in my subject area which will hopefully lead to many a useful conversation on the ins and outs of the Met Office Unified Model (UM), but not all the time I hope.  

   Unfortunately the Meteorology Department is very spread out these days due to rapid growth over the last decade meaning it has out grown the Met Building (I remember them building the last extension) with my office not in it :( This however has aided my new year fitness regime no end as I have to scuttle across campus to various buildings in double quick time. Couple this with the 113 steps up to the 5th floor of the Lyle building and I will be back in shape in no time!    

   It may be week one but I have already come to the conclusion that a PhD is clearly just a series of meetings, seminars and coffee breaks. Just need to make sure I fit some work in between them!!!!

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Urban Met Group Seminar

Comparisons of observations in central London with the UM 
Sian Lane (Uni of Reading)

   They must have known I was joining the department as this gave me a brief introduction to the UM model that I will be working with! Sian has been comparing observations from a number of urban heat island (UHI) events in London with model output from the UM (single tile JULES urban surface scheme).

   As people may know (or not) London and Britain as a whole are not renowned for our scorching temperatures and clear skies (even in summer a bit of fair weather cumulus likes to make an appearance), so the number of 'classic' UHI events is few and far between in the dataset she was using. To account for this she looked at the UHI intensity using average temperatures from a number of MetOffice synoptic stations inside the M25 for urban and stations outside it for rural observations, making clear that many of the so called urban stations were located in grassed areas (e.g. airports and parks) so were not necessarily giving the true urban temperature. Selecting UHI intensity events in the upper quartile led to her having about 90 days of data. Quite surprisingly the days with the largest magnitude UHI intensity were distributed fairly evenly across the year, not with the majority in the summer as would be expected.

   The comparison focused mainly on turbulent fluxes of heat and moisture (comparison was also made for urban air temperatures with a difference between observed and modeled of ~ 1 K - plotted results not shown) determined using Eddy Covariance (EC) techniques from two flux tower sites in central London. One on the top of BT Tower (within the Mixing Layer) and a second site located on top of the offices of Westminster City Council on Marylebone Road (within the Surface Layer). Results for all days for turbulent sensible heat flux (H) compared with UM output showed the model captured the diurnal variation in the H fluxes but under estimated the magnitude. Unfortunately there seemed to be a problem with the modeled latent heat flux which fluctuated barely above zero, Sian noted that she will need to investigate this further as one would expect higher modeled latent heat fluxes even in central London which is highly urban.

   As this was a Urban Met Group seminar they are designed to be less formal and more interactive than departmental seminars so lots of discussion was made of the results and suggestions were made for possible further analysis, statistical techniques and possible reasons for the differences in model output and observed fluxes that will hopefully aid Sian as she moves forward with her research.

This style of seminar is of great use to all concerned as it gives a relaxed setting to discuss results, techniques and the finer points of urban met theory. I intended to make the most of such opportunities throughout my PhD.    

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