Jet Stream Flashcards
Width of jet stream =
Length=
(Minimums)
200NM
2000NM
Low pressure around equator because
Hot air rising more. (Bc of positioning to sun, the tilt). As hot air rising, low pressure is left at the bottom
Higher pressure in colder areas as
Hot air rises, but bc it’s dense it doesn’t leave a void of low pressure. Air comes back down after rising, compresses, causes high pressure.
Troughs represent
Pressure decrease, like a trench downwards.
Orographic Low/depressions
Mountains, ALPS eg. Air moves around mountains, meaning area behind mountains have low pressure.
High pressure systems
Air moves down, gets warmer
Small scale heat
Ground heat moves up to tropopause
Large scale heat
Earths tilt, heating dependant on that
Ride of high pressure
Extension of high pressure regions. Protrude outwards into other pressure regions
Anticyclones =
High pressure.
In N Hemisphere, spin clockwise
Cyclones in northern hemisphere
LOW pressure
Wind spins anti clockwise
Buy ballots law
Back to wind in northern hemisphere. Low pressure to the left.
Blocking anticyclones
50⚫️N and 70⚫️N
Block depression (low pressure) movement
COL
Saddle shaped ridge. Between two highs or two lows
In day, around 2/3pm sea breeze…
Comes across from sea to land. Highest amount of air has risen from land. Greatest temperatures. Leaves greatest low pressure at bottom. For high pressure cold sea breeze to fill
At night time. Sea has high specific heat capacity. So hot air only rises significantly at night, causing low pressure. This means that breeze come from
Land over sea. Pressure is now higher over land, as the land has cooled.
Anabatic wind
DAYTIME
Hot air rises up the sides of the mountains.
Katabatic wind
NIGHT TIME.
cold, heavy air, flows down into valley, gets lower, and gets colder, gets denser.
The Bora (katabatic)
Cold air found around coastlines east of Adriatic sea. Cold air comes down from alps and from east Croatia.
Jet streams tend to flow
From west to east
The mistral
Airflow between two mountains. Like Venturi. Area decreases, speed increases.
Happens around southern France area. Goes into the Mediterranean.
Fohn wind
Air approaches mountain. Rises, cools. Use DALR 3⚫️ per 1000ft. Humidity increases, eventually reaches 100% saturation. Then use SALR 1.8⚫️ per 1000ft. In which case clouds are formed. Will then precipitate, as can’t hold any more water. Then eventually moves back to DALR as it heats back up again when coming down other side of mountain.
African winds (local winds) going into Mediterranean
Sirocco
(north west)
Ghibli
(central Northern Africa)
Khamsin
(towards Egypt area, going into Mediterranean)
Global surface winds
Refer to picture in gallery (of globe with many arrows on. And roaring something bottom right of page.
Hadley cells above and below ITCZ.
Ferrell cell after Hadley
Polar cells after Ferrell
ITCZ
Inter tropical convergence Zone
