legends · 4 min read ·
Mast Three, Ten-Minute Averages
A weather mast's spare anemometer records not wind but the people standing at the foot of the mast.
**Carrowmoor Met Station · Mast 3 · 10-minute averages · Logger: CM3-B**
*Sensors: wind speed (anemometer A), wind direction (vane), temperature, pressure, anemometer B (secondary, unlabelled).*
- **Time · Wind speed (m/s) · Direction · Temp (°C) · Pressure (hPa) · Anemometer B**
- 14:00 · 4.2 · 246 · 9.1 · 1011 · 0.0
- 14:10 · 4.5 · 248 · 9.0 · 1011 · 0.0
- 14:20 · 4.1 · 245 · 9.0 · 1010 · 0.0
- 14:30 · 3.9 · 251 · 8.9 · 1010 · 0.0
*Anemometer B has no calibration record. It was installed on the mast in 1987 and has not been reported as a fault.*
· · ·
**Engineer's note (M. Forde, 3 Nov)**
Anemometer B logged a speed of 0.0 for the whole week. Mast 3 is in a sheltered position, but the vane is working and A shows real wind. B is either stuck or not connected to anything.
I went up to check. B's cup wheel is not turning, but the bearing is warm. The housing has a fresh set of scratches, shallow, in a line, like something has been counting the rotations by hand.
· · ·
**Data log, 4 Nov (anomaly flagged)**
- **Time · Wind speed (m/s) · Direction · Temp (°C) · Pressure (hPa) · Anemometer B**
- 02:00 · 0.8 · 271 · 4.3 · 1013 · 0.0
- 02:10 · 0.6 · 270 · 4.2 · 1013 · 0.0
- 02:20 · 0.7 · 272 · 4.2 · 1013 · 0.0
- 02:30 · 0.7 · 271 · 4.1 · 1013 · 0.0
*Logger note: Anemometer B shows no value. Direction vane reports 271 for the full period, which is the bearing of the station's door. Wind speed A is recorded at 0.7 m/s, and the station's own door has not opened since 17:00.*
· · ·
**Data log, 5 Nov (anomaly flagged)**
Anemometer B: 0.0 at all intervals. Pressure falling steadily at the mast, 1 hPa per hour, while the barometer in the hut stays flat.
Logger has recorded a second temperature reading, unlabelled, at the top of the mast, 3.8 degrees lower than the sensor below it. The values match the room temperature of the lower hut, measured at the ground, a metre from the logger.
· · ·
**Engineer's letter (M. Forde to Dr. S. Hallam, 6 Nov)**
Dear Sophie,
I've been up Mast 3 four times this week and I want to put something on record, because the logger won't flag it and I think you should see it.
Anemometer B has started turning. Not in the wind. It turns when I stand under the mast, with my back to the hut, and it stops when I turn round to face it. Each rotation is counted on the logger as a single gust. I counted two thousand gusts in an hour. The logger shows a mean wind speed of 0.0 for the same hour. The vane is pointing at the door.
I think it's counting people, not weather. I think it's been counting since 1987, and the count has been wrong the whole time, because nobody thought to ask who was standing at the foot of the mast.
· · ·
**Data log, 9 Nov (manual entry, M. Forde)**
Mast 3 shows no fault. Pressure, temperature, wind speed A: nominal. Vane: nominal.
Anemometer B: 0.0. Count of rotations observed from the ground in ten minutes, by hand: 312.
*Manual note: Please do not replace the cup wheel. I've been asked not to.*
· · ·
**Station closure notice (Carrowmoor, 12 Nov)**
Mast 3 has been decommissioned. The logger has been removed for analysis. Recorded values for the final week are archived.
*Archive note: the final ten-minute average for Anemometer B, logged at 23:58 on 11 November, reads 312.0. The unit is in a sealed box, labelled "do not switch on." The box is warm.*
· · ·
**Final log entry, Carrowmoor Met Station (dated 14 Nov, on a page of the archive copy)**
- **Time · Wind speed (m/s) · Direction · Temp (°C) · Pressure (hPa) · Anemometer B**
- 00:00 · 0.0 · 180 · 3.0 · 1009 · 0.0
*Note in pencil, beneath the table: Calm. The mast is standing. The cups are still turning, very slowly, for the people who came in out of the weather and never got to the door. Please log the calm. It's the only record we have of them staying.*