Question

1. an air temperature of -75°c exists in which layer? type a response

Explanation:

The Earth's atmosphere has layers with distinct temperature profiles. The stratosphere has the ozone layer, but the mesosphere (above stratosphere) has temperatures decreasing with altitude, reaching around -75°C or lower. Alternatively, the stratosphere's lower part is warmer, but the mesosphere (or sometimes the stratosphere's upper regions? Wait, correction: The mesosphere is the layer where temperatures can be as low as -90°C, and -75°C is typical there. Also, the stratosphere's temperature increases with altitude (due to ozone absorbing UV), so the mesosphere (above stratosphere, below thermosphere) has temperatures dropping to very low values, including -75°C. Also, the troposphere is lower, stratosphere has increasing temp, mesosphere decreasing (to ~-90°C), thermosphere increasing. So -75°C is likely in the mesosphere. Also, sometimes the stratosphere's upper part? Wait, no: Troposphere (temp decreases with altitude), stratosphere (temp increases with altitude, up to ~0°C at stratopause), then mesosphere (temp decreases with altitude, to ~-90°C at mesopause), then thermosphere (temp increases). So -75°C is in the mesosphere. Also, another thought: The stratosphere's temperature at the top (stratopause) is around 0°C, so below that, in stratosphere, temp is lower? No, stratosphere's temp increases with altitude. So troposphere: surface to ~12km, temp decreases (e.g., -50°C at tropopause). Stratosphere: 12 - 50km, temp increases (from -50°C to 0°C at stratopause). Mesosphere: 50 - 85km, temp decreases (from 0°C to -90°C at mesopause). So -75°C is in the mesosphere (since mesosphere's temp range is from ~0°C at stratopause to ~-90°C at mesopause, so -75°C is within that). Also, sometimes the stratosphere's upper part? No, stratosphere's temp is increasing, so at 50km (stratopause) it's ~0°C, so below that (in stratosphere), temp is lower? Wait, no: at 12km (tropopause), temp is ~-50°C, then in stratosphere, as altitude increases, temp increases (due to ozone heating), so at 20km, temp is ~-30°C, at 30km ~-10°C, at 50km ~0°C. So stratosphere's temp is from -50°C (at 12km) up to 0°C (at 50km). So -75°C is lower than -50°C, so it can't be in stratosphere. Troposphere: at 12km, temp is -50°C, so below that (lower troposphere) temp is higher (e.g., 15°C at surface). So troposphere's temp range is 15°C (surface) to -50°C (tropopause). So -75°C is lower than -50°C, so it's in the mesosphere (which is above stratosphere, 50 - 85km, temp decreasing from 0°C to -90°C). So -75°C is in the mesosphere. Also, another possibility: the stratosphere? No, because stratosphere's temp increases with altitude, so the lowest temp in stratosphere is at tropopause (-50°C), then it increases. So -75°C is lower than that, so it's in the mesosphere.

Answer:

The air temperature of \(-75^\circ\text{C}\) exists in the mesosphere (a layer of Earth’s atmosphere). In the mesosphere (extending from ~50–85 km above Earth’s surface), temperature decreases with increasing altitude, and values like \(-75^\circ\text{C}\) (or lower, approaching \(-90^\circ\text{C}\) at the mesopause) are typical. (Note: Some sources may also associate very low temperatures in the upper stratosphere, but the mesosphere is the primary layer with such frigid temperatures consistent with \(-75^\circ\text{C}\).)