Description
Evapotranspiration (ET) is the process by which the land surface returns water to the atmosphere in the form of moisture. ET is a very important part of the water cycle in the Earth system. It is the sum of evaporation from bare soil and transpiration from vegetation.
For a given watershed, the supply of water from precipitation, surface, and groundwater can be depleted via ET. Therefore, estimating the amount of ET is crucial for calculating the overall water budget and for effective water management. Since ET indicates loss of moisture from the soil and vegetation, monitoring ET on agricultural fields helps with crop irrigation activities and water conservation.
Because ET depends on land surface characteristics such as type of vegetation and soil moisture, available heat energy from sunlight, and atmospheric weather conditions; it is not possible to measure ET directly. Remote sensing observations provide several of the land and atmospheric parameters useful for estimating ET.
Several methodologies have been developed using various satellite observations to estimate ET over the past two decades. These ET products are used for a variety of applications from the farm scale to the watershed scale.
This training, led by NASA's Applied Remote Sensing Training (ARSET) program, focuses on introducing ET products derived from remote sensing observations. It specifically covers a web portal called OpenET, which includes ET products estimated by using six models as well as Landsat satellite observations. These ET products cover the Western United States.
In addition, information about global ET products derived from ECOsystem Spaceborne Thermal Radiometer Experiment on the Space Station (ECOSTRESS) are covered. The training sessions provide detail about OpenET and ECOSTRESS ET products, demonstrations and hands-on exercises for data access and analysis, and examples of applications of the data.