Special note on May 9, 2013 reading

In Measurement Notes by Rob Monroe

May 10 Comment:
NOAA has reported 400.03 for May 9, 2013, while Scripps has reported 399.73. The difference partly reflects different reporting periods. NOAA uses UTC, whereas Scripps uses local time in Hawaii to define the 24-hr reporting period. If Scripps were to use same reporting period as NOAA, we would report 400.08 for May 9.