Spectrum Bay News 9 · May 21, 2022 hypothesis
First round of Saharan dust moves in
The report says the season's first Saharan dust plume moved into Florida on May 21-22.
Dust Possible
2022-05-21 Cape Coral-Fort Myers, FL dust episode
Daily PM2.5 peaked at 21 µg/m³ near Cape Coral across 1 covered metro home to 860,959 people.
Why we think this happened
The basis for “Dust”
Transported Saharan dust was documented over Florida on the exact date, but the surface impact at Fort Myers was not established.
Possible This is a transparent hypothesis supported by limited evidence or an explicit inference, not a definitive attribution.
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.
- 1Open question
Source or mechanism
Source not directly documented
The catalog has a grouping hypothesis, but no retained source directly establishes the proposed cause.
- 2Documented
Air-mass movement
Transport into the affected region is documented
The report says the season's first Saharan dust plume moved into Florida on May 21-22.
View transport source ↗ - 3Documented
Local response
21 µg/m³ near Cape Coral
EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 1.0 cigarette-equivalents at the outdoor daily rate.
Inspect the pollutant and weather signals ↓
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 “Dust” explanation; it does not assign the cause by itself.
Cape Coral-Fort Myers, FL
Monitor comparison window 2022-05-18 to 2022-05-24 · PM2.5 target: Winkler Pump Station
213% above nearby days
198% higher than surrounding days
Pollution fingerprint
Metro-wide median of reporting monitors PM2.5 20.6 µg/m³
213% higher than surrounding days
Before6.59 µg/m³ Event20.6 µg/m³ After6.32 µg/m³
PM10 61 µg/m³
198% higher than surrounding days
Before16 µg/m³ Event61 µg/m³ After20.5 µg/m³
Ozone 0.018 ppm
15% lower than surrounding days
Before0.026 ppm Event0.018 ppm After0.021 ppm
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.
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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
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Cape Coral-Fort Myers, FL | 21 µg/m³ | 1.0 | May 21, 2022 | #24 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.
First round of Saharan dust moves in
Spectrum Bay News 9
The report says the season's first Saharan dust plume moved into Florida on May 21-22.
What it supports
This source supports a possible mechanism or occurrence; it does not establish the cause by itself.
Limit
The report says much of the plume was elevated and does not attribute Cape Coral-Fort Myers surface PM2.5 to it.
What remains uncertain
- Aloft transport evidence is not proof of surface exposure; confidence is capped at possible.
Status and provenance
Possible This is a transparent hypothesis supported by limited evidence or an explicit inference, not a definitive attribution.
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.