NOAA logo National Oceanic and Atmospheric Administration (NOAA),
Earth System Research Laboratory (ESRL)

What does this program measure?

The ESRL GMD Meteorology program measures ambient and dewpoint temperatures, relative humidity, precipitation (in inches), and wind speed and direction.

How does this program work?

The dewpoint hygrothermometer measures ambient and dewpoint temperatures, from which relative humidity is calculated. Precipitation is continuously measured (in inches) with a tipping bucket.

A Mauna Loa PC based system utilizes RS-485 serial communications to collect data from the instruments. The data is recorded as one minute averages, except for precipitation. Precipitation is measured as a daily total accummulation.

Measurement Instruments Frequency
Air Temperature Aspirated thermistor, 2m, 9m, 37mm heights continuous
Air Temperature Max/Min thermometers, 2-m height daily
Temperature gradient Aspirated thermistor, 2m, 9m, 37m heights continuous
Dew point temperature Dew point hygrometer, 2m height continuous
Relative Humidity TSL 2m height continuous
Pressure Capacitance Transducer continuous
Pressure Mercurial barometer 5/week
Wind (speed and direction) 10m, and 38m heights continuous

Why is this research important?

In order to monitor the trends in meteorological parameters, and to assist in the interpretation of other parameters such as aerosols.

Are there any trends in the data?

Day rose and night rose (below) show the wind direction at the observatory. Note that the night rose shows only the southerly component which is the desired downslope conditions.

Day Rose
Night Rose

MLO press and MLO temps (below) is the running record since 1977. There is a slightly increasing trend in the ambient temperature since 1977.

MLO Pressure
MLO Temperatures

How does this program fit into the big picture?

What is it's role in global climate change?

It allows us to see how changes in other atmospheric variables affect the meteorology of the station.

Comments and References

Lead Investigator(s):

Thomas Mefford

MLO Contact(s):

Matthew Martinsen
Paul Fukumura
808-933-6965 (x223)

Web Site(s)

Date Started


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