At the time of an equinox, the subtropical jet streams in Earth's troposphere generally are located closest to

At the time of an equinox, the subtropical jet streams in Earth's troposphere are generally located closest to the Tropic of Cancer and the Tropic of Capricorn.

Here's a step-by-step explanation:

1. Jet streams are fast flowing, narrow air currents found in the atmosphere of some planets, including Earth. On Earth, the main jet streams are located near the altitude of the tropopause, the boundary between the troposphere (where weather occurs) and the stratosphere.

2. The subtropical jet streams are typically located at around 30 degrees latitude (north and south), which is approximately the location of the Tropic of Cancer in the Northern Hemisphere and the Tropic of Capricorn in the Southern Hemisphere.

3. During an equinox, which occurs twice a year around March 21 and September 23, the tilt of Earth's axis is inclined neither away from nor towards the Sun. This means that the Sun is directly over the equator, and day and night are of approximately equal length all over the planet.

4. Because the Sun is directly over the equator during an equinox, the subtropical jet streams, which are influenced by the position of the Sun, are generally located closest to the Tropic of Cancer and the Tropic of Capricorn. This is because these are the latitudes where the temperature gradient, and therefore the wind speed, is greatest.