07 Local Winds

TRUE or FALSE?

Sea breezes generally blow during the day and land breezes blow at night.

• TRUE

• FALSE

What surface wind is most likely to be experienced given that the geostrophic wind above the Canterbury Plains at midday in mid-Summer is 150°M/15kts and the ambient surface temperature is 25°C,?

• Westerly / 5kts

• Northerly / 5kts

• Southerly / 5kts

• Easterly /5kts

Where is the highest air temperature likely to be found in the following conditions?

A 20 to 25 knot wind is striking high rising mountainous terrain that lies at right angles to the prevailing wind

• on the windward side of the mountain range at the base of the mountains

• on the windward side of the mountain range at the top of the mountains

• on the lee side of the mountain range at or close to the level of the mountain crests

• on the lee side of the mountain range at or close to the level of the base of mountains

Select the set of words and phrases that when inserted into the gaps within the following text produces a TRUE statement.

sea breeze starts by (i)............ when the land is (ii).......... leading to a relatively (iii) .......... pressure over the land, and this causes (iv).........on the surface.

• (i) day (ii) warming (iii) low (iv) an inflow of air towards the land

• (i) night (ii) cooling (iii) low (iv) an outflow of air towards

• (i) day (ii) warming (iii) high (iv) an outflow of air towards the sea

• (i) night (ii) warming (iii) high (iv) an inflow of air towards the land

What wind is … “a down slope wind caused by the cooling of the air in contact with the terrain at altitude” ?

• Adiabatic

• Anabatic

• Karibiotic

• Katabatic

Which of the following listed texts IS NOT one of the 4 pre-requisites for the formation of mountain waves?

• A mountain range of substantial height dimension

• Ambient surface level temperatures that differ by a minimum of 15 degrees between the windward and leeward sides of the range

• The windward, low-level wind speed must be at least 15 knots and it has to increase with speed with an increase height

• Wind that blows onto the mountain at more or less right angles to the orientation of the range

Which of the following listed texts IS NOT one of the 3 pre-requisites for the occurrence of a Fohn wind?

• A mountain range that has a substantial height dimension

• A mountain range that is oriented more or less right angles to the wind flow

• Approaching wind that has a high moisture content within it

• Surface/sea-level temperatures that differ by a minimum of 15 degrees Celsius between the windward and leeward sides of the range

Given the statement that the wavelength of a mountain wave depends primarily on the prevailing wind strength, does a strong wind strength produce a shorter or longer wavelength wave than a weaker strength wind?

• Longer

• Shorter

What cloud type, often found above and slightly downwind of the mountain range crest height is most commonly associated with mountain waves?

• Altostratus

• Towering Cumulus

• Cumulonimbus (Cb)

• lenticular

• lunonauticular

TRUE or FALSE?

Lenticular clouds tend to have high concentrations of supercooled water droplets and therefore pose serious icing problems to aircraft that may fly through them

• TRUE

• FALSE