← Air events

Wildfire smoke Corroborated

2021-03-08 Tulsa wildfire-smoke episode

March 8, 2021 to March 9, 2021 · Origin: Tulsa, OK

Daily PM2.5 peaked at 79.6 µg/m³ near Tulsa across 1 covered metro home to 1.1 million people. 1 metro recorded their worst day on record.

Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 4.4 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 4.6 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”

Supplied qualified evidence supports wildfire-smoke as the root cause. The grouping includes only events linked by explicit shared episode evidence; otherwise this remains a single-event episode.

Corroborated Independent reporting agrees on the cause, with no agency determination, monitor flag, or published assessment behind it.

News On 6 · Mar 9, 2021 corroborates

Northeastern Oklahoma Air Quality Affected By Smoke From Fires

The opened report attributes Tulsa and Okmulgee counties' unhealthy March 8 air to smoke from fires, citing the Oklahoma Department of Environmental Quality and its health advisory. It corroborates fire smoke but does not distinguish wildfire from prescribed burning or quantify smoke-attributable PM2.5.

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

    The opened report attributes Tulsa and Okmulgee counties' unhealthy March 8 air to smoke from fires, citing the Oklahoma Department of Environmental Quality and its health advisory. It corroborates fire smoke but does not distinguish wildfire from…

    View supporting source ↗
    Documented
  2. 2

    Air-mass movement

    The transport path has not been reconstructed

    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.

    Research gap
  3. 3

    Local response

    79.6 µg/m³ near Tulsa

    EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 3.6 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

Tulsa, OK

Monitor comparison window 2021-03-05 to 2021-03-12 · PM2.5 target: Glenpool

6 pollutant signals
Fine-particle pulse 46.2 µg/m³

166% above nearby days

Air movement 8.67 kt

70% higher than surrounding days

PM10 46.3 µg/m³

83% higher than surrounding days

Pollution fingerprint

Metro-wide median of reporting monitors
PM2.5 46.2 µg/m³

166% higher than surrounding days

Before20.7 µg/m³ Event46.2 µg/m³ After10.1 µg/m³
2 monitors · 1 HOUR
PM10 46.3 µg/m³

83% higher than surrounding days

Before23.5 µg/m³ Event46.3 µg/m³ After14 µg/m³
2 monitors · 24-HR BLK AVG
Carbon monoxide 0.304 ppm

11% higher than surrounding days

Before0.310 ppm Event0.304 ppm After0.168 ppm
1 monitor · 1 HOUR
Nitrogen dioxide 5.89 ppb

9% lower than surrounding days

Before10.6 ppb Event5.89 ppb After4.10 ppb
1 monitor · 1 HOUR
Sulfur dioxide 0.083 ppb

Adjacent observations available

Before0 ppb Event0.083 ppb After0 ppb
3 monitors · 1 HOUR
Ozone 0.050 ppm

33% higher than surrounding days

Before0.035 ppm Event0.050 ppm After0.017 ppm
6 monitors · 8-HR RUN AVG BEGIN HOUR

Atmospheric conditions

Nearby EPA weather observations
Humidity 47.6 %

23% lower than surrounding days

Temperature 59.9 °F

8% higher than surrounding days

Wind 8.67 kt

70% higher than 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.

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.

Affected metros

MetroPeak PM2.5Cigarettes, whole eventPeak dayAll-time standing
Tulsa, OK 79.6 µg/m³ 5.3 Mar 8, 2021 Worst day on record

"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.

News discovery (GDELT) 1

  • Northeastern Oklahoma Air Quality Affected By Smoke From Fires

    News On 6 · Cal Day · Mar 9, 2021 corroborates

    The opened report attributes Tulsa and Okmulgee counties' unhealthy March 8 air to smoke from fires, citing the Oklahoma Department of Environmental Quality and its health advisory. It corroborates fire smoke but does not distinguish wildfire from prescribed burning or quantify smoke-attributable PM2.5.

internet-archive-wayback-cdx 2

gdelt-doc-api 1

What remains uncertain

Status and provenance

Corroborated Independent reporting agrees on the cause, with no agency determination, monitor flag, or published assessment behind it.

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.