Wildfire smoke Agency determination
Named source Great Dismal Swamp wildfire
Daily PM2.5 peaked at 52.9 µg/m³ near Virginia Beach across 1 covered metro home to 1.8 million people.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 2.0 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 3.7 million cigarettes. An awareness illustration of outdoor exposure at 22 µg/m³ per cigarette (Berkeley Earth), counting only the event's ranked days; not a medical dose.
Why we think this happened
The Virginia DEQ alert and supporting frozen records attribute the August 19 Hampton Roads fine-particle episode to smoke from the Great Dismal Swamp wildfire.
Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.
U.S. EPA Air Quality System and the submitting air monitoring agency · Aug 19, 2011 official
EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 3 PM2.5 samples in the candidate CBSA on 2011-08-19, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
Virginia Department of Environmental Quality / National Weather Service Wakefield · Aug 18, 2011 official
The archived Virginia DEQ alert, issued August 18 and effective through August 19, attributed a Code Orange fine-particle alert in the Hampton Roads region to smoke from the Great Dismal Swamp wildfire.
National Weather Service via Iowa Environmental Mesonet archive · Aug 19, 2011 corroborates
An archived NWS Air Quality Alert for Virginia Beach-Norfolk-Newport News, VA-NC, issued 2011-08-19T21:13Z, explicitly identifies wildfire smoke. IEM is the archive, not the official system of record.
Evidence path
A cause is more convincing when the record connects three things: something happened, the air mass moved toward the region, and local instruments responded. Here is how much of that chain is documented for this event.
Source or mechanism
EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 3 PM2.5 samples in the candidate CBSA on 2011-08-19, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official…
View supporting source ↗Air-mass movement
The retained record does not yet show how air traveled from the proposed source to these metros. A trajectory replay or dated plume analysis belongs here.
Local response
EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 2.4 cigarette-equivalents at the outdoor daily rate.
Inspect the pollutant and weather signals ↓Event autopsy
Before, during, and after the episode: nearby pollutant monitors and surface-weather stations show what changed. This context tests the “Wildfire smoke” explanation; it does not assign the cause by itself.
Virginia Beach-Norfolk-Newport News, VA-NC
Monitor comparison window 2011-08-16 to 2011-08-22 · PM2.5 target: NASA Langley Research Center
297% above nearby days
No adjacent-day comparison
297% higher than surrounding days
No adjacent-day comparison
122% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Source: U.S. EPA AirData daily observations and, where available, nearby ASOS/AWOS surface observations. Values are descriptive medians over the retained monitor set; missing measurements remain missing. Transport and source evidence remain separate layers because this instrument pattern does not assign a cause by itself.
Episode peak
-- cigarettes
The smoke map's scale, replayed over this event: the surface interpolates between covered metros' daily records, framed to the affected region. Hover for a reading, click a metro to pin it to the card. Days a monitor did not report draw nothing.
Views from the selected metro
Select a metro on the map to see nearby cameras. Where an operator archive reaches the event, drag the divider to compare two moments, adjust either date and time, or play the available event-day frames. Camera imagery is visual context, not an air-quality measurement or proof of smoke.
No useful public camera views are currently available within 80 km of this metro.
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Virginia Beach-Norfolk-Newport News, VA-NC | 52.9 µg/m³ | 2.4 | Aug 19, 2011 | #11 of its top days |
"Cigarettes, whole event" totals a metro's ranked event days at 22 µg/m³ per cigarette: what a person outdoors there breathed across the event, as the illustration. "All-time standing" is where this episode's days sit in each metro's ranked record (worst-area measure, since 1999). Full local context is on each metro's Air Records page.
Public evidence library
Each card states what a source supports—and what it does not. Official records, research, reporting, community observations, and transparent inferences remain visibly different kinds of evidence.
AQS PM2.5 qualifier RT — Wildfire-U. S.
EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 3 PM2.5 samples in the candidate CBSA on 2011-08-19, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
An archived NWS Air Quality Alert for Virginia Beach-Norfolk-Newport News, VA-NC, issued 2011-08-19T21:13Z, explicitly identifies wildfire smoke. IEM is the archive, not the official system of record.
The archived Virginia DEQ alert, issued August 18 and effective through August 19, attributed a Code Orange fine-particle alert in the Hampton Roads region to smoke from the Great Dismal Swamp wildfire.
Cited authorities: Virginia Department of Environmental Quality
Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.
This episode was grouped from the monitor record by the catalog pipeline and given its cause from the evidence listed above. It has not been individually reviewed and signed off, so its boundaries, cause, and name may change as evidence accumulates. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula. If it is wrong, tell us.