Figure 9. Atmospheric pressure time series from National Oceanic and Atmospheric Administration station DPIA1 and USGS measurements from an Onset Hobo U20 pressure sensor at site 965 on Dauphin Island, Alabama, in 2013. Although the study covered from July 22 through November 20, 2013, this graph only shows August 1 through October 1, 2013, to highlight the difference between the two sensors. dbar, decibars.