Wind 1 Flashcards
What is wind?
The horizontal motion of the air over the surface of the earth
What units are used to measure wind
Knots
Kilometres per hour
Meters or second
Wind direction?
Related to true north except when taking readings from an anemometer. That is in relation to magnetic
What does an anemometer do?
Measures wind speed at ground level and the direction is displayed in a vane
What is gusts
When the wind increases in strength for a short period of time
What is a lull?
When wind decreases in strength for a short period of time
If wind speed increases for minutes it’s called a
Squall
What are squalls associated with?
Cumulonimbus clouds
What wind speeds are needed to be a gale?
A mean value of 34 kts or gusting to 43kts it greater
A change in wind direction clockwise the wind is said to?
Veer
A change in wind direction anti-clockwise is said to
Back
Wind moves from….
Relatively high pressure to low pressure
What are isobars?
Continuous lines joining places of equal pressure
If there is rapid change in pressure isobars will be?
Closer together
What is the pressure gradient?
It is a force perpendicular to the isobars proportional to the gradient and produces a transient wind.
