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Wildfire smoke EPA monitor flag

2007-04-29 wildfire smoke episode affecting Jacksonville, FL

April 29, 2007

Daily PM2.5 peaked at 39.4 µg/m³ near Jacksonville 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 ≈ 1.4 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 2.5 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 basis for “Wildfire smoke”

Qualified frozen causal evidence supports wildfire smoke as the broad root cause.

EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.

U.S. EPA Air Quality System and the submitting air monitoring agency · Apr 29, 2007 official

AQS PM2.5 qualifier RT — Wildfire-U. S.

EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 2 PM2.5 samples in the candidate CBSA on 2007-04-29, 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.

Georgia Department of Natural Resources, Environmental Protection Division · Nov 1, 2008 hypothesis

2007 Georgia Ambient Air Surveillance Report

The report's Brunswick April 29 case study says trajectories and satellite information indicated that smoke from Waycross-area fires could have contributed to elevated PM2.5 at Brunswick. It does not assess Jacksonville or establish the cause of this candidate.

See every retained source and limitation ↓

Evidence path

From source to city

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.

Open the evidence ledger ↓
  1. 1

    Source or mechanism

    Wildfire smoke

    EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 2 PM2.5 samples in the candidate CBSA on 2007-04-29, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official…

    View supporting source ↗
    Documented
  2. 2

    Air-mass movement

    Transport into the affected region is documented

    The report's Brunswick April 29 case study says trajectories and satellite information indicated that smoke from Waycross-area fires could have contributed to elevated PM2.5 at Brunswick. It does not assess Jacksonville or establish the cause of…

    View transport source ↗
    Documented
  3. 3

    Local response

    39.4 µg/m³ near Jacksonville

    EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 1.8 cigarette-equivalents at the outdoor daily rate.

    Inspect the pollutant and weather signals ↓
    Documented

Event autopsy

What the instruments saw

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.

Observed context · not attribution

Jacksonville, FL

Monitor comparison window 2007-04-26 to 2007-05-02 · PM2.5 target: Mandarin

5 pollutant signals
Fine-particle pulse 39.2 µg/m³

131% above nearby days

Carbon monoxide 0.542 ppm

63% higher than surrounding days

Pollution fingerprint

Metro-wide median of reporting monitors
PM2.5 39.2 µg/m³

131% higher than surrounding days

Before7.40 µg/m³ Event39.2 µg/m³ After31.8 µg/m³
2 monitors · 24 HOUR
Carbon monoxide 0.542 ppm

63% higher than surrounding days

Before0.258 ppm Event0.542 ppm After0.408 ppm
3 monitors · 1 HOUR
Nitrogen dioxide 6.46 ppb

27% lower than surrounding days

Before8.75 ppb Event6.46 ppb After10.7 ppb
1 monitor · 1 HOUR
Sulfur dioxide 3.08 ppb

131% higher than surrounding days

Before0.917 ppb Event3.08 ppb After1.67 ppb
5 monitors · 1 HOUR
Ozone 0.046 ppm

About the same as surrounding days

Before0.048 ppm Event0.046 ppm After0.052 ppm
3 monitors · 8-HR RUN AVG BEGIN HOUR

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.

Measured daily PM2.5 at EPA monitors, as cigarette-equivalents
EPA monitors sit in metro areas, so the colour clusters there. Land between and beyond them is unmeasured, not clean: this map shows where IAQng has readings, not the extent of the smoke.

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

Camera views near

Browse the camera map →

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.

Affected metros

MetroPeak PM2.5Cigarettes, whole eventPeak dayAll-time standing
Jacksonville, FL 39.4 µg/m³ 1.8 Apr 29, 2007 #20 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

What supports this account

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.

EPA AQS monitor qualifier 1

  • AQS PM2.5 qualifier RT — Wildfire-U. S.

    U.S. EPA Air Quality System and the submitting air monitoring agency · Apr 29, 2007 official government

    EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 2 PM2.5 samples in the candidate CBSA on 2007-04-29, 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.

Agency and publisher pages 1

  • 2007 Georgia Ambient Air Surveillance Report

    Georgia Department of Natural Resources, Environmental Protection Division · Nov 1, 2008 hypothesis government

    The report's Brunswick April 29 case study says trajectories and satellite information indicated that smoke from Waycross-area fires could have contributed to elevated PM2.5 at Brunswick. It does not assess Jacksonville or establish the cause of this candidate.

What remains uncertain

Status and provenance

EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.

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.