Surface-meteorology instruments measure a variety of quantities near the earth's surface. The most commonly-deployed instruments monitor variables such as pressure, temerature, moisture, wind, and radiation.
For hydrological applications, additional instruments may be deployed to measure the amount, type, and size distribution of rain and snow, as well as the heat and water content of the soil. The latest advancements in GPS technology have also allowed for estimates of atmospheric water vapor to be obtained from a single surface-based reciever.
Sensors measuring atmospheric turbulence are also sometimes used to monitor the exchange (or flux) of heat, momentum, and moisture between the atmosphere and the Earth's surface.