Despite significant enhancements in observational capability, substantial uncertainties remain in surface fluxes of carbon and water due to the lack of a single, consistent framework that models both the carbon and water cycles to make use of new observations, reflecting the disciplinary separation between the hydrological and carbon sciences. The investigators will develop an analysis system that simultaneously quantifies regional-scale carbon and water fluxes by combining observations from numerous aircraft campaigns, satellite sensors, and ground-based platforms with state-of-the-art models of the atmosphere and land surface. The objectives are to quantify and significantly reduce uncertainties in past and future estimates of surface carbon and water fluxes and extract information on the carbon-water cycles from simultaneous use of multiple data streams.
The integrated forward and inverse modeling framework will be anchored to both carbon- and hydrologic observations. First, the investigators will implement a forward modeling system SiBRAMS over a North American domain, which is centered over the WLEF eddy covariance measurement tower where a number of support satellite towers are available, to facilitate the gathering of observational information for model evaluation and improvement. Second, they will build the joint carbon-water inversion system by (a) adding water and its atmospheric sources/sinks to STILT-based inversion system, (b) examining errors resulting from linear approximation in carbon-water inversion, (c) conducting initial inversion analysis of joint carbon-water fluxes, and (d) comparing inversion results with well-constraint observations from IHOP and COBRA experiments.
Main deliverables from this project include the development of an analysis framework, which includes both forward and inverse models and makes use of both carbon- and hydrologically related observations, and estimates of mutually-consistent carbon and water fluxes over a North American domain centered around WLEF tower.
Broad impacts of this project are educational and in the potential to bridge the hydrology-carbon communities and foster new research directions.
