Last week of measurements
The time axis is Coordinated Universal Time (UTC). Local time in Boulder (MDT) is UTC-6 hours.
Typical summertime mass concentration (blue line) in Boulder is ~4 μg/m3 (Based on summertime scattering values of approximately 12 Mm-1).
Equivalent black carbon (red line) is derived from aerosol light absorption coefficient. Black carbon is a product of incomplete combustion (e.g., diesel engines, fires).
Top two panes show wind speed and direction. Wind speeds of 1 m/s are equivalent to approximately 2.2 mph. Wind directions of N/E/S/W correspond to 0/90/180/270 degrees, respectively.
The plot shows the haze concentration measured on the roof of the NOAA David Skaggs Research Center in south Boulder, CO. The PM2.5 mass concentration is estimated from optical measurements of particle light scattering coefficient using a mass scattering efficiency of 3 m2/g. The EBC concentration is estimated from filter-based measurements of particle light absorption coefficient using a mass absorption efficiency of 6 m2/g. Download the most recent two hours of raw data.
Models can help identify sources of haze when the source is not obvious.
Below are some links to aerosol model output for TODAY
Naval Research Lab NAAPS aerosol model output
(Today's smoke, sulfate and dust contribution to the US atmosphere).
More information about the Naval Research Lab NAAPS aerosol model can be found here.
NOAA/ESRL/GSD model output for
organic aerosol over the US today.
Organic aerosol is a major constituent of smoke.
More information about the NOAA/ESRL/GSD model can be found here.
More information about smoke and air quality can be found at the EPA Particulate Matter web page.
NOAA's Earth System Research Laboratory (Global Monitoring Division) measures the climate-forcing properties of atmospheric particles at a global network of monitoring stations. Instruments from this network are maintained at NOAA's laboratory in Boulder, CO. For the plots above, the wind measurements are made on the roof of the laboratory. The aerosol instruments sample through an air intake on the roof of the laboratory to provide an estimate of haze/EBC concentrations in south Boulder. Caveat - the sampling conditions (roof and air intake design) are not ideal for measuring particles - the values reported here should be considered as relative indicators of atmospheric conditions.
Please refer questions about these measurements to Dr. John A. Ogren, 303-497-6210.