Methodology for atmospheric analysis and feedback correction

The overall objective of this report is to define the analysis needed to quantify the atmospheric corrections required for offline hydrological modelling. The theory of atmospheric feedback is summarised, including a review of previous studies. It is clear that there are two feedbacks that are key to water resources: feedback on the precipitation and on the evaporative demand. The precipitation feedback will often require a large scale three-dimensional model to study it. Previous model runs can be used to define where and how nudges to the precipitation fields will be needed. A one-dimensional model can be used if the precipitation is convective. The evaporative demand feedback may be quantified using a one-dimensional analytical model of the atmosphere. It is proposed that such a model will be built for use with the water resource models.