The troposphere is the lowest layer of Earth's atmosphere, extending from the Earth's surface up to about 8 to 15 kilometers (5 to 9 miles) above sea level, with its height varying depending on geographical location and weather conditions. It contains approximately 75% of the atmosphere's mass and most of its water vapor, making it the layer where most weather events, such as clouds, rain, and storms, occur. The temperature in the troposphere generally decreases with altitude. #earth #atmosphere