Question

9. Consider the following statements :
1.
Jet streams occur in the Northern
Hemisphere only
2.
Only some cyclones develop an eye.
3. The temperature inside the eye of a
cyclone is nearly 10°C lesser than that
of the surroundings.​

Answer 1

Explanation:

अम्ल वर्षा का कारण है

Answer 2

Only some cyclones develop an eye, is the true statement.

• A growing tropical cyclone's organisation and strength are virtually always indicated by the development of an eye.
• Forecasters, therefore, keep a keen eye out for evidence of eye formation in storms as they develop.
• But there isn't a single area in temperate or extratropical cyclones where the winds and precipitation aren't active (as in the case of Tropical Cyclones).

Hence, the second statement is correct.

• In the upper atmosphere, jet streams are comparatively small bands of very intense wind. Jet streams carry the winds from west to east, but the direction of the flow frequently changes to the north and south. Air temperature boundaries are followed by jet streams.
• Winter in the northern and southern hemispheres has the strongest jet streams because this is when these hot and cold air borders are most noticeable.

Therefore, assertion 1 is untrue.

• A strong tropical cyclone's "eye" is a roughly circular region of relatively calm winds and good weather that can be found there.
• The eye is the area with the lowest surface pressure and the warmest air temperatures (in the upper levels). In a tropical cyclone, the eye temperature may be up to 10 degrees Celsius higher than the surrounding air at an altitude of 12 kilometres but only 0 to 2 degrees Celsius higher at the surface (Hawkins and Rubsam 1968).

Therefore, assertion 3 is untrue.

So, the only statement only some cyclones develop an eye is true.

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