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PM2.5 aerosol mass concentration from Purple Air UNR Physics Roof

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PM2.5 aerosol mass concentration from Purple Air UNR Physics Rm 113

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PM2.5 aerosol mass concentration 2 miles west of UNR Physics

PM2.5 aerosol mass concentration obtained from aerosol light scattering
at 532 nm divided by a mass scattering efficiency factor of 3.8 m²/gram.
Data is from the photoacoustic instruments operated by Pat Arnott from
the 4th floor of Physics, UNR.
Archived data.

Press the PM2.5 Graph button to update if needed.
Time on the x axis is given as Local Standard Time (LST) since 2020.
When it is daylight savings time (spring, summer, and fall), add an hour
to get to local daylight time (LDT).

Black carbon (BC) mass concentration obtained from aerosol light
absorption at 532 nm divided by a mass absorption efficiency factor
of 8.8 m²/gram. Data is from the photoacoustic instruments operated
by Pat Arnott from the 4th floor of Physics, UNR.
Archived data.

Press the BC Graph button to update if needed.
Time on the x axis is given as Local Standard Time (LST) since 2020.
When it is daylight savings time (spring, summer, and fall), add an hour
to get to local daylight time (LDT).

Extinction=scattering + absorption.
SSA=scattering/extinction, bright aerosol when close to 1.
SSA small, for example 0.3, aerosol is dark, like diesel soot.
Data is from the 532 nm photoacoustic instruments
Archived data.

Press the SSA Graph button to update if needed.
Time on the x axis is given as Local Standard Time (LST) since 2020.
When it is daylight savings time (spring, summer, and fall), add an hour
to get to local daylight time (LDT).

The rationale for using these optical measurements to estimate PM2.5 and BC mass concentration is discussed in our paper.
The EPA PM2.5 standard is discussed here.
Salt Lake City has PM2.5 issues and has a good discussion (by the Atmospheric Science program at the University of Utah.)
There currently is no separate standard for BC.

Highlighted Days

PM2.5 aerosol mass concentration during the Mosquito fire by Forest Hill, 62 miles from Reno. This is a new record for Reno. See this link for a Reno NWS office video of how fast smoke can enter Reno (video from September 11th 2022). It likely rained some on the fire before this smoke arrived, perhaps enhancing smoldering rather than flaming stage of combustion.

Black carbon aerosol mass concentration, single scattering albedo and extinction coefficient at 532 nm during the Mosquito fire by Forest Hill, 62 miles from Reno. This is a new record for Reno. See this link for a video of the smoke approaching Reno, from the NWS office in Reno. September 12th 2022.

September 12th photo from the roof of the Physics building before the smoke arrived. The crane is about 0.27 miles away.

September 12th photo from the roof of the Physics building at the peak of the smoke. The crane is about 0.27 miles away.

PM2.5 mass concentration during the Loyalton CA fire, and many other fires in Northern CA due to lightning strikes. This is a new record for Reno/UNR for regional smoke events. Raw data.

BC mass concentration during the Loyalton CA fire, and many other fires in Northern CA due to lightning strikes. Note that the amount of black carbon produced by the smoke is much less than the total PM2.5. The health rating for BC is currently unknown so the same rating as for total PM2.5 was used.

Photograph at UNR by Jeremy Benik on 19 August 2020.

Photograph at UNR by Jeremy Benik at the same place on a clean winter day.

Here is the PM2.5 from the King Fire on the day of maximum concentration in Reno. This day had higher PM2.5 concentration than any during the Rim fire of 2013 or during July 2008 when fires from Northern CA were intense. We have published a study of the 2008 fire season as noted here. Here is the raw data.

BC mass concentration during the King Fire. Note that the amount of black carbon produced by the smoke is much less than the total PM2.5. The health rating for BC is currently unknown so the same rating as for total PM2.5 was used.