The word precipitation means all the types of moisture which are naturally deposited on the Earth's surface. Of these, rain is by far the most important.
Rainfall occurs when the water vapour in the air condenses. These droplets of water can be seen in the sky as clouds. If the droplets become large enough they fall to the ground as rain.
We measure precipitation in millimetres (mm) using a rain gauge.
Rain falling on the funnel is collected in a bottle and this is measured each day.
We use a bar graph to record the total rainfall.
We can also show rainfall on maps using lines which we call isohyets ie :-
Most days of the year the winds bring air to us from the west. As this air has spent many days crossing over the Atlantic Ocean, it is full of moisture. When this air is forced to climb over the land it drops some of this moisture as rain (see the relief rainfall diagram on cloud + sunshine notes, Page 1). By the time this air reaches the east of the country, much of its moisture has already been dropped as rain. The western half of our country is thus much wetter than the eastern half.
Temperature and precipitation are often shown on the same graph with the scale for temperature marked on one side and that for precipitation marked on the other.
P. 1. Fill in your weather Summary Sheet for precipitation.
P. 2. Copy and complete the following note :-
"The word precipitation means ..............................................................................
................................................................
Of these, .............. is by far the most important."
P. 3. List seven different types of precipitation. (clue ;- look at Introduction Page)
P. 4. What type of graph do we use to record precipitation?
P. 5. a. What month is the wettest in Kilmarnock?
b. What is the average total rainfall for that month ?
c. What month is the driest in Kilmarnock?
d. What is the average total rainfall for that month ?
P. 6. Use graph 1 in your worksheet to draw a precipitation graph for :-
P. 7. What do we call lines on maps showing precipitation ?
P. 8. Copy and complete the following sentence :-
On a graph, the t..................... scale is always marked
on the left hand side and the precipitation scale is marked on
the ................ hand side.
P. 9. On the graph of Average Temperature and Precipitation
in Kilmarnock :-
a. What month was the driest ?
b. What was the hottest temperature ?
c. What was the lowest monthly precipitation ?
d. What month was the coldest ?
P. 10. Copy and complete the following sentence :-
In Kilmarnock, the climate has (hot / cold) (dry / wet) summers
and the winters are (hot / cold) (dry / wet).
[count hot as being over 12 degrees Celsius and cold as being
under 6 degrees Celsius]
[count wet as being over 50 mm. and dry as being less than 50
mm.].
