MAX-DOAS measurements in Athens
A MAXDOAS instrument was installed at the at NOA premises on Penteli hill to the northeast of Athens in October 2012. The site offers a unique view over Athens and its surroundings. The instrument performs measurements in zenith direction as well as vertical scans in multiple solar azimuth directions. This BREDOM site is operated in co-operation with the Atmospheric Physics and Chemistry Group (APCG), Institute for Environmental Research and Sustainable Development at the National Observatory of Athens, Greece.
Athens (instrument position: 38.05°N, 23.86°E) is a city with a population of about 4 millions. Frequent pollution episodes from local sources (traffic, harbor, industry) as well as episodes of high aerosol load from fires and desert dust in combination with high photochemical activity make this a complex and interesting measurement site.
The instrument in Athens consists of a grating spectrometer, covering the spectral range of about 330 - 500 nm. The spectrometer is equipped with cooled CCD detector and is temperature stabilized to minimize spectral drift. The set-up is equipped with a MAXDOAS telescope which can be pointed any nearly any point. The measurement program includes zenith-sky observations and scans from below the horizon to 30° elevation in different azimuth directions. An example for possible viewing directions and their characteristics is given in the figure. More on the instrument and measurement principle can be found on our MAXDOAS page.
An example of the NO2 measurements in the 2° elevation for a clear day is given below.Viewing directions are labeled as in the map above. In the morning, the boundary layer develops and NO2 remains low until the top of the boundary layer reaches the altitude of the measurements. From this point on, NO2 increases strongly over the city while only a short and much lower peak is observed in the directions of the ocean and the airport. During the day, NO2 moves from the coast inlands and largest values are observed in the afternoon in direction "W" and 'B'. The large horizontal gradients in tropospheric NO2 observed at this station are evident.
If you have any requests, please contact Folkard Wittrock.
If you are interested in more information or would like to have access to our data, please contact Folkard Wittrock.