Ambient Radioactivity 2005 Graphs
The time is plotted in EST. In summer, add one hour to x-axis for DST. (Click on the first link below for an enlargement of the plot.)
(Unusually strong diurnal peak pattern in September 2005: The house was completely ventilated to outside air between Sept 4 and the evening Sept 10. The diurnal peak pattern seen on the early mornings of the 7th through 11th (the 11th being a close-house air-conditioned day) therefore appear unrelated to ventilation issues. Whether or not the very large peak on the early morning of the 11th is due to closing the house is unknown, but was the only event that seemed to occur near the same time. However, around noon on Sept 16, the AC thermostat was set at a higher temperature (around 80F) and the diurnal peak pattern decreased, so the degree to which the peak intensity is related to household ventilation remains ambiguous. Interestingly, during this period the ground was more dry than usual due to a local drought, and deep "mud" cracks were visible in the soil of the back yard.)
