Geostrophic wind

Geostrophic wind is horizontal airflow in which the pressure-gradient force balances the Coriolis effect, producing motion approximately parallel to isobars. It is an idealized limit approached above the friction-dominated atmospheric boundary layer.

Pressure-gradient force: A force per unit mass that accelerates air from higher toward lower pressure. It drives the flow that the Coriolis effect redirects into geostrophic balance.
Isobar: A line on a map joining points with equal atmospheric pressure. Geostrophic wind runs approximately along these lines rather than directly across them.
Wind barbs: Symbols on weather maps that represent wind direction and speed. Observed wind barbs can be compared with the direction and speed implied by isobars.
Ageostrophic wind: The part of actual wind that differs from the geostrophic wind. It measures the component not explained by the pressure–Coriolis balance.
Buys–Ballot's law: A rule relating wind direction to the position of low pressure in a rotating atmosphere. It gives a practical directional consequence of geostrophic flow in each hemisphere.
Coriolis effect: The apparent deflection of moving objects in a rotating reference frame, including Earth’s atmosphere. Its acceleration balances the pressure-gradient force in geostrophic flow.
Pressure: Force exerted per unit area by a fluid or gas. Horizontal pressure differences supply the driving force for geostrophic wind.
Isobaric chart: A weather map showing atmospheric height or other fields on a constant-pressure surface. It provides the mapped pressure or height gradients used to estimate geostrophic flow.
Gradient-wind balance: A balance among pressure-gradient, Coriolis, and centrifugal accelerations in curved flow. The extra centrifugal term matters around curved highs and lows.
Cyclogenesis: The development or intensification of a cyclone. Ageostrophic motions around developing systems help change pressure patterns and geostrophic flow.

Linked from 15 pages