Pressure Systems Flashcards
What instrument is used for measuring atmospheric pressure?
The Barometer is used for measuring atmospheric pressure.
What determines how strong the wind is between pressure gradient?
The pressure difference between the two gradients and how close the are together. The closer they are and bigger the difference is, the stronger the wind.
What is a pressure gradient?
The change in air pressure per over a horizontal distance.
What is the difference between geostrophic wind and gradient wind?
Geographic blows parallel to the isobars. Gradient is the result of the friction slowing down the geographic wind causing it to cross the isobars at an angle.
How do low pressure system rotate in both the north/south hemisphere?
- North: Anti-Clockwise
- South: Clockwise
Where do depressions usually occur?
In mid latitudes 30-60 as cold polar winds meet warmer air.
How do depressions rotate in the northern/southern hemisphere?
- Northern: Anti-Clockwise
- Southern: Clockwise
What are some features of a warm front?
- Has warm air behind it and cool air ahead of it
- Cirrus Clouds
What are the features of a cold front?
- Has cool air behind it and warm air ahead of it
- Large Cumulus or Cumulonimbus Clouds
What happens when a cold front catches up with a warm front?
When a cold front reaches a warm front, it raises the warm front and causes an Occluded Front.
What causes a depression to dissipate?
Once most of the warm air has been forced upwards by the cold air, the temperature difference between them reduces as the warm air cools. This causes the air to stabilize.
What is a cold/warm front?
A cold front is a boundary between the trailing cold sector and the warm sector.
A warm front is the boundary between the warm sector and the leading cold sector.
What is the difference between a cold/warm occlusion?
A cold occlusion: The air behind the warm sector is colder than the air in front of it.
A warm occlusion: the air behind the warm sector is warmer than the air ahead of it.
What is the average global atmospheric pressure?
1013 mb
Which unit of measurement is equivalent to millibars (mb)?
Hectopascals (hPa)
