pressure

Question 1

define surface pressure in meteorology

Answer 1

the weight of air above a unit area

Question 2

equation for calculating pressure

Answer 2

p=m x g/A

Question 3

when the pressure exerted by the mercury column is equal to the atmospheric pressure, what is the height of the column

Answer 3

29.92in

Question 4

why do we use mercury column height as a measure of atmospheric pressure

Answer 4

mercury’s density doesn’t change significantly with height

Question 5

what is the instrument used to measure atmospheric pressure

Answer 5

barometer

Question 6

true or false

pressure is usually between 950 - 1050hPa

Answer 6

True

Question 7

why does pressure decrease in an exponential fashion

Answer 7

because air density decreases with height

Question 8

true or false

horizontal pressure gradient is greater than vertical pressure gradient.

Answer 8

False

• vertical pressure gradient is much greater (eg. 800hPa decrease in 15 km, while for hog, u might only get 12 hPa decrease in 200km)
• therefore pressure doesn’t vary much with countries

Question 9

what is the formula for calculating R

Answer 9

1000 x R*/Mr

Question 10

what is the R for moist air

Answer 10

Rd (1 +0.61q)

Question 11

pressure decreases by 50% for every _____km increase in altitude

Answer 11

5.5

Question 12

pressure decreases by a factor of ____ for every 16 km

Answer 12

10

Question 13

the ________ of a layer fives a dirt measure of its average temperature

Answer 13

thickness

Question 14

the thinner the layer (delta z), the _______ the average temp and the ______ the atmosphere

Answer 14

colder
denser
-as colder air is denser, its more compacted hence thinner

Question 15

how are the thickness lines presented on the plotted chart?

Answer 15

dashed line

Question 16

what causes the isobaric layers to be thicker?

Answer 16

increase in temp, air becomes less dense and expands, hence thicker

Question 17

true or false
the greater the distance between two height level on the plotted chart (isobaric layer), the thicker the layer and the higher the temperautre

Answer 17

true

Question 18

how can thickness contours help to identify fronts

Answer 18

cold front brings cold air, therefore packed thickness lines could mean a cold front.

Question 19

what does thickness lower than 522 dam indicate?

Answer 19

likely to snow if there is precipitation

Question 20

what does thickness lower than 528 dam indicate?

Answer 20

snow above 300m

Question 21

what does thickness greater than 564 dam indicate?

Answer 21

probable heatwaves

Question 22

1 hPa = ____ Pa

Answer 22

100