PF's+Researchable+Cosmic+Ray+Question

What effect does barometric pressure in an area have on the number of muons detected? Are there more muons detected when there is higher barometric pressure or vice versa? Is the relationship between barometric pressure and muon detection direct or inverse?

In order to answer this question, I chose 3 different detectors from roughly the same area in or around Chicago. The detector ID's are 5098, 52, and 57, and are located at the Adler Planetarium, the University of Illinois at Chicago, and PatsLabFermiLab respectively. First, I checked the [|Cosmic Ray e-lab] to make sure that these detectors all had data from the same days. Then, I used [|wunderground.com] to get barometric pressure readings. Using the weather graphs, I found the days during the week that had the highest barometric pressure reading and the point that had the lowest. Then, I ran flux studies for those days. By comparing the weather graphs and flux study graphs, I was able to draw some conclusions about the effect of barometric pressure on muon detection.

=Adler Planetarium Data=



By looking at the barometric pressure graph above, I determined that the highest pressure during the week occurred around the middle of the day on Sunday May 13, 2007. The lowest pressure occurred sometime during the afternoon on Tuesday May 15, 2007. I ran flux studies on the data collected by detector 5098 for both of these days. These are those graphs:



As you can see in the graph of Sunday May 13, 2007 (TOP), at around noon, the time when the barometric pressure was the highest of the week, there is a pretty dramatic decrease in the number of muons detected. Looking at the graph of Tuesday May 15, 2007 (BOTTOM), the day with the lowest barometric pressure of the week, although there is a slight decrease in the number of muons detected, there is a much higher average number of muons detected compared to the 13th. The top graph shows a decrease in the number of muons detected during the time of a high barometric pressure reading, and the bottom graph shows an increase in the number of muons detected during the time of a low barometric pressure reading.

=University of Illinois at Chicago Data=



Again, near midday on Sunday May 13, 2007, the highest barometric pressure reading occurred. Also, the lowest barometric pressure reading occurred sometime during the afternoon on Tuesday May 15, 2007.



 Carefully comparing the graphs of Sunday May 13, 2007 (TOP), and Tuesday May 15, 2007 (BOTTOM), shows that there is a very slight increase in the number of muons detected from Sunday to Tuesday. On Sunday, the day with the highest pressure reading, the range of the number of muons detected is approximately 2,500-4,500. On Tuesday, the day with the lowest pressure reading, it ranges from approximately 2,750-5,000. Although it is slight, the top graph shows an increase in the number of muons detected during the time of a low barometric pressure reading, and the bottom graph shows a decrease in the number of muons detected during the time of a high barometric pressure reading.  **PatsLab Fermilab Data

**

Again this graph shows the high barometric pressure that occurred on Sunday May 13th and the low barometric pressure that occurred on Tuesday May 15th.






Again if you look closely at the two graphs, you can see that as the barometric pressure was higher on Sunday the 13th, the muon count is between approx. 15 and 22, while on Tuesday 15th when the barometric pressure was lowest, the muon count was between approx. 17 and 25. Once again the difference is very slight, but once again the data suggests that as the barometric decreases, the muon count increases and vice versa.