atmospheric pressure
Let an agent explain atmospheric pressure and its measurement, relay physics, variation and weather significance from meteorological references, describe aviation settings and oscillation patterns, and distinguish atmospheric pressure from other pressures and from altitude.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain atmospheric pressure and its measurement, relay physics, variation and weather significance from meteorological references, describe aviation settings and oscillation patterns, and distinguish atmospheric pressure from other pressures and from altitude.
The pressure exerted by the weight of the atmosphere at a given point, about 101325 pascals at sea level and decreasing with altitude, measured with barometers and reported in hectopascals, millibars or inches of mercury, used in aviation as QFE for pressure at an aerodrome and QNH for sea-level reduced pressure, and studied in meteorology through patterns such as the Southern Oscillation, the seesaw of pressure across the Pacific linked to El Nino.
What it is for: Not applicable; a physical quantity.
It can be explain the quantity; relay measurement and variation; describe weather and aviation use; distinguish related concepts.
Distinguishing features
Weight of air column
Altitude dependence
Weather driver
Aviation settings
What it looks like
Not a visible object; read from a barometer.
Physical character
standard sea-level pressure: 101325 Pa
decrease with altitude: about 12 hPa per 100 m - near sea level
highest recorded: 1084.8 hPa - Tosontsengel 2001
lowest recorded: 870 hPa - Typhoon Tip 1979
How it is recognised
Pressure of the atmosphere
Sea-level standard 1013.25 hPa, QFE, QNH, Southern Oscillation
Gauge pressure is relative; ambient pressure includes other fluids; altitude is height
Related models
is a kind of - in registry terms
is a kind of - in registry terms
is a kind of - in registry terms
is measured by - in hectopascals
In practice
Families and kinds
station and sea-level pressure
QFE and QNH aviation settings
high and low pressure systems
pressure oscillations such as the Southern Oscillation
partial pressures within the atmosphere
Standards and regulation
WMO observation standards
ICAO standard atmosphere and altimeter setting procedures
SI units
Failure modes and hazards
Altimeter setting errors in aviation
Confusing station and sea-level pressure
Unit confusion between hPa, mbar and inHg
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What atmospheric pressure is.
Science.
Definition
Definition.
Definition
Definition.
- What is atmospheric pressure, and how does it differ from gauge pressure and altitude? definition
- Is the question about physics, weather, aviation or climate? boundary
Variation
Variation.
Variation
Variation.
- How does pressure vary with altitude, temperature and weather systems? definition
- Which entry fits the barometric formula? action
Measure Measurement.
Practice.
Instruments
Barometers.
Instruments
Instruments.
- How do mercury, aneroid and digital barometers measure pressure? provenance
- Which references are standard? provenance
Aviation
Aviation settings.
Aviation
Aviation.
- What are QFE, QNH and standard pressure settings, and how are they used in altimetry? provenance
- Which sources are cited? provenance
Weather Weather and climate.
Science.
Systems
Pressure systems.
Systems
Systems.
- How do high and low pressure systems shape weather? provenance
- Which entry fits weather forecasting? action
Oscillation
Southern Oscillation.
Oscillation
Oscillation.
- What is the Southern Oscillation, and how is it linked to El Nino and La Nina? provenance
- Which entry fits El Nino-Southern Oscillation? action
Context Effects and history.
Context.
Effects
Effects.
Effects
Effects.
- How does pressure affect boiling points, human physiology at altitude and engineering, in general terms? provenance
- Which entry fits altitude sickness? action
History
History.
History
History.
- How did Torricelli, Pascal and others discover and measure atmospheric pressure? provenance
- Which entry fits the history of meteorology? action
What the second pass must settle
- Should QFE, QNH and the Southern Oscillation be separate primary entries?
- How should meteorological references be linked?
- The registry entry has merged aliases naming an aviation setting and a climate pattern; should they be split off?