G-Rad is involved in
observational and theoretical research of
the Earth's surface and atmospheric radiation budgets. The group specializes
in the investigation of climatically significant variations in long-term
radiation and meteorological
made at diverse globally-remote sites
and continental US sites (SURFRAD).
In addition, we make observations of spectral solar radiation for the purpose of
remote sensing of certain atmospheric constituents and determination of variations
in the UV irradiance.
Our research interests include the extent and cause of observed radiation and
climate variations, and in collaborating with other research groups making satellite
observations and climate model calculations.
A relatively new program in the group is the absolute
measurement of spectral solar UV for the investigation of the interaction of ozone
and solar radiation.
The G-Rad group makes continuous measurements of surface radiation quantities at
several field sites around the world and across the continental US.
The individual sites have varying characteristics and attributes and, therefore, are
involved in different projects and applications.
The NOAA Solar calculator allows users to pinpoint their desired location on a Google map interface.
Accurate latitude and longitude coordinates are then combined with the user’s desired date and time
values to generate estimates for sunrise, sunset, solar noon and the position of the sun in the sky.
The data collected from the observing network are used by the G-Rad group and its collaborators
in a wide variety of research projects. Many of those projects are primarily related to the role
of radiation and aerosols in climate variability and forcing.
Both broadband and spectrally select radiation measurements are made.
Upwelling and downwelling broadband solar and thermal irradiances are measured as well
as relative spectral direct solar measurements for purposes of determining aerosol optical
depth and precipitable water.
Raw data from the observing networks are centrally collected and processed in our Boulder office.
The field data have preliminary calibrations applied and initial data editing is preformed.
The availability of the data varies as the processing completed for different sites and instruments.
G-Rad maintains basic independent but traceable calibration facilities for broadband solar,
broadband IR, and spectral solar primarily in the UV