At sea level pressure, which best expresses the relationship between temperature and saturation mixing ratio?

The relationship between temperature and saturation mixing ratio is fundamental to understanding atmospheric moisture. As air temperature increases, the capacity of the air to hold water vapor also increases. This phenomenon occurs because warm air molecules have more energy and can support a greater amount of water in vapor form before reaching saturation. Therefore, the saturation mixing ratio, which measures how much water vapor is present in the air compared to how much it could potentially hold at a given temperature, rises with increasing temperature.

This relationship highlights why the correct answer states that the warmer the air, the higher the saturation mixing ratio. In contrast, cooler temperatures limit the amount of water vapor that air can hold, resulting in a lower saturation mixing ratio. Hence, as temperatures rise, so does the potential for greater moisture content in the air, illustrating the direct correlation between temperature and saturation mixing ratio.