Question

Why are thermometers that are used in weather stations shielded from the sunshine? What does a thermometer measure if it is shielded from the sunshine? What does it measure if it is not?

(a) Shielding reduces convection
(b) Shielding reduces radiation
(c) Measures air temperature when shielded, measures radiation when not
(d) Measures radiation when shielded, measures air temperature when not

Answer 1

Weather station thermometers are shielded to accurately measure air temperature, without the influence of direct sunlight which can add radiant heat and cause inaccurate readings.

Step-by-step explanation:

Thermometers used in weather stations are shielded from the sunshine to measure the air temperature accurately. If a thermometer is shielded from the sunshine, it measures the air temperature only.

This is because the shielding prevents direct exposure to sunlight, which can cause the thermometer to absorb additional heat from the sun, leading to a reading that reflects the combined effects of the air temperature and the radiation. On the other hand, without shielding, the thermometer primarily measures the combined effect of air temperature and radiant heat from the sun, which is not an accurate representation of just the air temperature.