P. 1 - The weather Flashcards
What is the difference between climate and weather?
Climate is the avarage state of the atmosphere over a longer period of time (30 decades often) in a certain place and weather is the current state of the atmosphere over a shorter amount of time (hours, days etc.)
What is the definition of the keyword weather?
The current state of the atmosphere
Wat are the 4 most important parameters when it comes to weather
- Temperature
- Cloud coverage
- Wind
- Precipitation
Where does the weather phenomena take place?
Mostly in the trophosphere (lowest layer of the atmosphere)
What is the definition of the keyword temperature?
The objective measurement of hot or cold
How do you measure temperature? (+ international guidelines)
- Using a thermometer
- in celsius or fahrenheit
International guidelines
- Place the thermometer at a height of between 1.25 and 2 metres above the ground
- Inside a white box called a Stevenson screen
How do meteorologists present temperature readings?
Usage of isotherm map (Line in a map that shows equal temperature.
Why are there international guidelines for measuring temperatures?
Make it possible to compare temperatures from place to place, because everyone takes measurements using the same method.
What is the definition of the keyword precipitation?
Water, in any chemical state, that falls from the atmosphere; including, drizzle, rain, snow and hail.
How is precipitation measured?
- Using rain gauge which captures the precipitation as it falls from the atmosphere -> makes it possible to measure the amount of waterthat has fallen
- measured in millimetres (mm)
What is the definition of the keyword wind?
The movement of air through the atmosphere.
How do you measure wind?
- Measure its direction on a compass rose
- Measure its speed in km/h or mph
- (Netherlands) measure strength with beaufort scale
What causes wind
- differences in atmospheric pressure
Give the definition of the keyword atmospheric pressure (+ measured)
- Pressure, or weight, of the air in the atmosphere.
- in certain places
- measured using a barometer
Law of Buys Ballot
- Flow of the wind is always from high pressure areas to low preasssure ares
- wind is deflected towards the right in the Northern Hemisphere and to the left in the Southern Hemisphere
How to meteorologists show wind?
- Use isobars (lines in a map that show equal atmospheric pressure)
- Isobars show the atmospheric pressure in a particular place
- isobars close together -> air will flow quickly from high to low pressure -> weather will change / creation strong winds or storms
How is cloud cover measured?
- By looking skywards and estimating how much of the sky is covered by cloud
- Measured using oktas (0 clear sky - 8 clompletely overcast)
How are clouds categorised
- according to their shape and altitudein the troposphere
Give the definition of high clouds (type of clouds + e.g.)
- e.g. cirrus clouds
- Look like feathers
- chicken you -> rain is coming
Give the definition of low clouds (type of clouds + e.g.)
- e.g. stratocumulus clouds
- Only bring rain when the cloud layer is sufficiently thick
Give the definition of vertical clouds (type of clouds + e.g.)
- Cumulonimbus clouds (bring thunderstorms)
- Reach the boundary of the troposphere -> spread out
Explain step 1 of the water cycle
- Water evaporates from surface water (oceans, rivers) and enters the atmosphere
- Water evaporated from tree leaves, grass and other plants and enters the atmosphere (10%)
Explain step 2a of the water cycle
- Part of the water falls straight back to wherre it came from
Explain step 2a of the water cycle
- Part of the water vapour rises up into the atmosphere and is transported to other places by the wind
- While water vapour rises the temperature drops -> watervapour condensate (<- cold air can contain less water vapour than warm air)
Explain step 3 of the water cycle
- Water droplets clump together around tiny dust particle in the atmosphere;clouds
Explain step 4 of the water cycle
From the clouds precipitation can occur when the air rises
Give the defition of the keywords evaporation
The change from a liquid to a gaseous chemical state.
Give the defition of the keywords evaporation
The change from a gaseous to a liquid chemical state.
