Sub-Tropical Jet stream flows from

a. West to East in Southern hemisphere

b. East to West in Northern hemisphere

c. East to West in Southern hemisphere

d. West to East in Northern hemisphere

ANSWER: West to East in Northern hemisphere

Explanation:

Sub-Tropical Jet stream (STJ) is a narrow band of fast moving air flowing from west to east (Westerlies).

STJ in northern hemisphere flows between 25° to 35° N in the upper troposphere at a height of about 12-14 kmph.