National Oceanic and
Atmospheric Administration (NOAA),
Earth System Research Laboratory (ESRL)
This program measures the pH, conductivity, anions and cations of local precipitation.
Rain is collected continuously in a precipitation collector. When a sensor on the collector detects rain, the cover opens and rain collects in a bucket. Every week the bucket is changed and the sample is taken to the MLO office in Hilo where the precipitation is analyzed in a chemistry laboratory. A ph Meter is used to measure pH, a conductivity bridge is used to measure conductivity, and an ion chromatograph is used to measure anions and cations.
This research follows up previous rain studies at Mauna Loa, extending the length of precipitation chemistry programs here.
This data follows established trends in that the values remain close to carbonic acid values for this island.
Again, this program follows the trends of old acid rain programs such as the NADP (National Atmospheric Deposition Program)
The NADP began this program. See also the EPA Mercury Precipitation program at Mauna Loa.