Local Winds

Question 1

Sea breeze

Answer 1

Air over land is easily warmed —> cause reduction in pressure lapse rate eg pressure falls more slowly
Air over sea is colder —> pressure decreases more quickly

Transfer of air 1000ft above ground level outwards from land to sea = pressure increase over sea and pressure decrease over land

Air then flows back from sea to land due to PGF

Question 2

Sea breeze deflection in northern hemisphere

Answer 2

Sea breeze initially blows at 90 degrees to the coastline.

as the PGF gradually increases the speed increases

As the Coriolis effect increases, (CF proportional to wind speed)the wind will veer in the N Hemisphere

In the S Hemisphere the wind will back

Question 3

Land breeze

Answer 3

Air over sea is warm = reduction in pressure lapse rate eg pressure falls more slowly
Leading to higher pressure compared to pressure of cold land

Hence transfer of air from sea towards land - > surface pressure over sea decreases and increases over land

Air then moves back from land —> sea

Question 4

Anabatic wind ‘valley breeze’

Answer 4

Wind which blows upwards in a mountainous area
Due to daytime heating of hillside slopes causing air to heat up and rise

‘Ana’ meaning rising

Question 5

Katabatic wind ‘mountain breeze’

Answer 5

Develops during night with radiative cooling of hillside slopes causing air to cool and descend

‘Kata’ meaning descend

Question 6

The bora

Answer 6

Katabatic wind

affecting the Adriatic Sea

Strongest in winter

Winds can exceed 100kts

Question 7

The mistral

Answer 7

Valley wind

Blows from the north along the Rhone valley; often due to high pressure in the Bay of Biscay causing a northerly flow to affect central/southern France

Alps and Massif Central create a natural venturi which accelerates the air

Strongest in winter, a very cold wind with speeds up to 70kts

Question 8

Föehn winds

Answer 8

STABLE AIR MASS REQUIRED

Cloud forms on the windward (upwind) side of mountain

Precipitation on the windward slope removes moisture from the airmass, causing the DP temp to be reduced = clouds are produced

Warm dry descending wind on the downwind side of a mountain

Eg chinook

Question 10

Pampero

Answer 10

burst/advance of cold polar air from the south

Blows across the pampas of South America as a S/SW wind