Pressure

Question 1

Define the word Isobars:

Answer 1

Lines on a synoptic charts which join places of equal pressure at MSL.

Question 2

Depression or low:

This region can be classified as -

The type of movement(clockwise or anti-clockwise) -

The type of flow(outwards/inwards/upwards) -

Answer 2

a region of relatively low pressure

clockwise rotation in the southern hemisphere

Inwards and upwards flow towards the centre.

Question 3

Anti-cyclone or high:

The type of movement(clockwise or anti-clockwise) -

The type of flow(inwards/outwards/downwards/upwards) -

Answer 3

Anti-clockwise flow in the southern hemisphere

Outwards and downwards flow from the centre

Question 4

Explain what a “col area” is:

Answer 4

A neutral region between two highs and two lows. It is an area of stagnation

Question 5

Define the word isallobars:

Answer 5

Line joining places of equal pressure tendencies(pressure decrease or increase)

Question 6

What is the difference between pressure tendency and pressure characteristic?

Answer 6

Tendency is the rise or fall of pressure and characteristic is the rate of change of pressure.

Question 7

Weather associated with a depression or low:

1. Cloud -
2. Precipitation -
3. Visibility -
4. Temperature -
5. Winds -

Answer 7

1. Extensive and may extend from altitude to the tropopause
2. May be continuous/intermittent rain or showers and intensity can range depending or the type of depression.
3. Poor in precipitation otherwise good due to ascending air.
4. Depends on the type of depression
5. Winds are usually strong - the deeper the depression and the closer the isobars, the stronger the wind.

Question 8

Weather associated with a anti-cyclone or high:

SUMMER (and cold anticyclones in winter):

1. Cloud -
2. Precipitation -
3. Visibility -
4. Temperature -
5. Winds -

WINTER (warm anticyclones):

1. Cloud -
2. Precipitation -
3. Visibility -
4. Temperature -
5. Winds -

Answer 8

1. None except on the edge of the anticyclone.
2. None.
3. Generally moderate with haze
4. Dependent on type.
5. Light.
6. Extensive stratus with a low base and limited vertical extent.
7. Possibly drizzle.
8. Generally moderate to poor with mist and fog likely.
9. Relatively warm.
10. Light.