Analysis of the Earth and Environment Lecture 6: Meteorology

Question 1

Define Meteorology

Answer 1

the study of phenomena of the
atmosphere – includes the dynamics, physics, and
chemistry of the atmosphere.

Question 2

Define Weather

Answer 2

The state of the atmosphere; mainly with
respect to its effects upon human activities. Short term
variability of the atmosphere

(time scales of minutes to
months).

Question 3

Define Climate

Answer 3

Long term statistical description of the
atmospheric conditions, averaged over a specified
period of time - usually decades.

Question 4

List all the variables in meteorology

Answer 4

Temperature
* Wind speed
* Wind direction
* Clouds
* Precipitation?
* Visibility
* Fog, haze
* Humidity

Question 5

What units are used for temperature in Meterology

Answer 5

Temperature: Kelvin (K) (SI unit) necessary for
many calculations.
Kelvin = Celcius + 273.15

Degrees Celcius (C) : (non-SI) usually used to
quote temperature in general use – more readily
understood and values in convenient range
0 K = -273.15 C

Question 6

What is the conversion of celsius to farenheit

Answer 6

𝑇(𝑐𝑒𝑙𝑐𝑖𝑢𝑠) =
5
9
(𝑇 𝐹𝑎ℎ𝑟𝑒𝑛ℎ𝑒𝑖𝑡 − 32)

0 degrees celsius = 32 farenheit

Question 7

What units are used for measuring pressure in meteorology

Answer 7

Pressure: SI unit of pressure is the Pascal (Pa) and atmospheric pressure is quoted in:
hectoPascal (hPa) = hundred Pascals.
1 hPa = 100 Pa

• Pressure is frequently quoted in millibars (mb) (non SI unit)
  1 mb = 1 hPa

Question 8

What unit is used to measure wind speed in Meteorology

Answer 8

Multiple units used to measure wind speed:

Meter per second (ms-1 or m/s)(SI unit) – all
scientific use, and frequent common use

• Knots (kt) = nautical miles per hour
  1 kt = 0.514 m/s

Question 9

Define relative humidity

Answer 9

Water vapour content of the air as a percentage of the maximum possible, saturation or
equilibrium vapour content at that temperature.

It is a ratio but
often expressed as a percentage (%).

Question 10

Define dew point

Answer 10

The temperature to which a
parcel of air must be cooled
to become saturated with
water vapor and can no
longer hold water in gaseous
form

Question 11

Define dew point depression

Answer 11

The difference between the
temperature of a parcel of
air, and its dew point
temperature.

Question 12

Define mixing ratio

Answer 12

Ratio of the mass of water
vapour to mass of dry air.

Question 13

Define Absolute Humidity/Vapour Density

Answer 13

The mass of water vapour
per unit volume of moist
air

Question 14

Define specific humidity

Answer 14

The ratio of the mass of
water vapour to the mass
of moist air.