Model-aided Lagrangian interpretation of non-synoptic estuarine observations

We propose a novel method for constructing a pseudo-synoptic view of estuarine features from non-synoptic observations captured by mobile platforms. The model-aided Lagrangian interpretation (MALI) method is based on relocating observations to a common reference moment in time along three-dimensional Lagrangian trajectories derived from a numerical model of estuarine circulation. The method relies on the model skill to capture large-scale circulation features, and on high-resolution in situ observations to characterize small-scale hydrographic structure. We demonstrate our technique by applying MALI to autonomous underwater vehicle observations in the Columbia River estuary, with the aid of a validated unstructured-grid finite-element numerical simulation. The method can be readily adapted to a broader range of environments, observational platforms, and model-data combinations.