1a.Objectives (from AD-416):
Science direction for SMAP mission. Specifically the investigation of applicability of the SMAP mission to watershed and ecosysytem management decisions in the southwest.
1b.Approach (from AD-416):
Using existing and developing data assimilation and data fusion techniques to
combine SMAP provided data and products with existing knowledge of the watershed
environment in a modeling framework to produce information and tools which will be of value to researchers and policymakers.
New satellite sensors are planned to measure plant fluorescence (F) to monitor plant health on a regular basis over large agricultural regions. We conducted a study to determine the relationship between photosynthesis (P) and F with changes in light intensity, and to define the optimum photosynthetic active radiation (PAR) range for assessing physiological plant status with F. This project contributes to objective 1 of the in-house parent project, "Improve watershed management by developing the capacity to more accurately predict soil and plant water dynamics utilizing a combination of remote sensing, modeling and in-situ measurements". A new analytical model was derived to explain the change in F due to varying light intensity. It was demonstrated that for PAR levels close to those used for plant growth, F was directly correlated with P, and differed significantly between the well-watered and water-deficit treatments. This new information provides a promising starting point for interpretation of seasonal changes in F using satellite-based sensors.