What does this program measure?
Total Downwelling solar and thermal infrared radiation (or irradiance) is measured in units of Watts per square meter. Aaerosol optical depth is also measured.
How does this program work?
We primarily use commercial thermopile broadband radiometers to measure the irradiance and aerosol optical depth, a measure of the total dust and particle load of the atmosphere, is measured with a sunphotometer.
Solar and infrared radiation are fundamental ingredients in maintaining the current climate, and also play a major role in anticipated changes in that climate. Aerosol optical depth helps quantify the role of aerosol in radiatively forced climate change.
Are there any trends in the data?
Read a MLO Solar Irradiance publication (.pdf format)
How does this program fit into the big picture?
What is it's role in global climate change?
Solar and thermal infrared (IR) radiation are vehicles for climate change but at the same time are affected by that change. Our radiation measurements can be used to investigate both the causes of and the response to climate change.
Comments and References
Dutton, E. G., J. J. DeLuisi, and A. P. Austring, 1985. Interpretation of Mauna Loa
Atmospheric Transmission Relative to Aerosols, Using Photometric Precipitable Water Amounts. J. Atmos. Chem., 3, 53-68.
Dutton, E.G., 1992. A Coherence Between the QBO and the Amplitude of the Mauna Loa Atmospheric Transmission Annual Cycle. International J. Climatology 12, 383-396.
Dutton, E.G. and J.R. Christy, 1992. Solar Radiative Forcing at Selected Locations and Evidence for Global Lower Tropospheric Cooling Following the Eruptions of El Chichón and Pinatubo. Geophys. Res. Lett. 19, 2313-2316.
Dutton, E.G., P. Reddy, S. Ryan, and J.J. DeLuisi, 1994. Features and effects of optical depth observed at Mauna Loa, Hawaii: 1982-1992. J. Geophys. Res. 99, 8295-8306.
Dutton, E.G. and B.A. Bodhaine, 2001: Solar irradiance anomalies caused by clear-sky transmission variations above Mauna Loa 1957-1999. J. Clim., 14, 3255-3262.