This week, we continue testing on our mini-SENSE network which is nearing its deployment test phase. Above is a plot of the past three days of data from sensor packages, many of which are on the roof of our building here at the University of Maryland.  Once all of the bugs have been worked out with data collection and transmission, the packages will be distributed to volunteer beta testers to discover unknown complications within the system.
     
Some interesting things to note from this plot are:

1. The synoptic scale weather pattern causing the fast drop in pressure from 1025mb to 995mb over a period of less than 36 hours. Those of us in the area know that a low pressure system has brought rain to us over the past 24 hours or so.
2. The distinct diurnal (daily) cycle of CO2 concentration occurring in College Park. At night, concentrations are higher and lower during the day. This is due to the height of the atmospheric boundary layer, the lowest section of the atmosphere. It generally ranges in height from a few hundred to just over a thousand meters, and a shallow boundary layer can allow for more pollutants to accumulate near the surface. At night, the layer is short, and the sun causes it to grow during the day, causing this distinct cycle of concentration of CO2 and other here near the ground. The boundary layer, which acts like a lid on the air, is also responsible for smog days in cities such as Los Angeles during the summer.