Pan evaporation

Pan evaporation is like when you leave a shallow dish of water outside in the sun and come back a few hours later, and there's less water than before. That's because the energy from the sun makes the water turn into a gas called water vapor, which floats away into the air.

Scientists use special pans that are designed to measure how much water evaporates over a certain amount of time, usually a day. They make sure the pan is out in the open and not covered, so it gets the same amount of sunlight and wind as the area around it. They also make sure the pan has a set amount of water in it at the beginning.

Then they measure how much water is left in the pan at the end of the day, and subtract that from the starting amount to find out how much water evaporated. They can use this information to study how much moisture is in the air and how much water is available for plants, animals, and people to use.