Environmental Science - Study Mode

[#336] In calm air the air temperature is -10 o C, if the wind speed should increase to 30 knots (with no change in air temperature) the thermometer would indicate:
Correct Answer

(C) A temperature of -10 o C

Explanation

Solution: In calm air the air temperature is -10o C, if the wind speed should increase to 30 knots (with no change in air temperature) the thermometer would indicate a temperature of -10 o C.

[#337] Infrared and visible satellite images might provide:
Correct Answer

(A) A way of determining cloud thickness and altitude.

Explanation

Solution: Infrared satellite technology works by sensing the temperature of infrared radiation being emitted into space from the earth and its atmosphere. Basically, all objects (including water, land, and clouds), radiate infrared light. However, our eyes are not "tuned" to see this kind of light, so we don't notice it. Weather satellites not only sense this infrared light, but they can also sense the temperature of the infrared emissions. Visible satellite images can be thought of as photographs of the earth from space. Since they are like a photograph, they are dependent on visible light (brought by the sun). As a result, visible satellite pictures only work during daylight hours. This is the greatest drawback to using visible imagery. Also, since a visible satellite picture is basically a photograph, thicker clouds (which reflect the most sunlight) show up very bright, while thinner clouds (like cirrus) are hard to distinguish.

[#338] At what time of day is the relative humidity normally at a minimum?
Correct Answer

(A) When the air temperature is highest

Explanation

Solution: Relative humidity is a measure of the water vapour content of the air at a given temperature. The amount of moisture in the air is compared with the maximum amount that the air could contain at the same temperature and expressed as a percentage.

[#339] The atmospheric greenhouse effect is produced mainly by the:
Correct Answer

(C) Absorption and re-emission of infrared radiation by the atmosphere

Explanation

Solution: The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere. Radiatively active gases (i.e., greenhouse gases) in a planet's atmosphere radiate energy in all directions. Part of this radiation is directed towards the surface, warming it. [3] The intensity of the downward radiation – that is, the strength of the greenhouse effect – will depend on the atmosphere's temperature and on the amount of greenhouse gases that the atmosphere contains.

[#340] The blueness of the sky is mainly due to:
Correct Answer

(A) The scattering of sunlight by air molecules

Explanation

Solution: A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colors because the blue light has been scattered out and away from the line of sight.