This project plans to investigate a series of hypotheses via numerical modeling experiments linking carbon and hydrologic cycles across the globe, linking land and ocean, low and high latitudes. The hypotheses are: 1) Summertime droughts on interannual time-scales arise from changes in circulation and the delivery of moisture. 2) The resilience of ecosystems to droughts varies with ecosystem type and structure, so that the magnitude of the decadal-mean carbon sink and carbon-climate feedback is related to the frequency and duration of droughts. 3) Regional, climate warming driven changes in terrestrial runoff and precipitation will increase upper ocean stratification in subpolar and Arctic environments resulting in decreased ocean carbon dioxide (CO2) uptake. 4) Land surface modifications and increasing water demands of the 21st century will amplify drought conditions, increase carbon-climate feedbacks and accelerate global warming.
The project will use a series of fully coupled carbon-climate model simulations in the framework of the National Center for Atmospheric Research (NCAR) Community Climate System Model. The project will host a multi-disciplinary graduate student summer school on Coupled Biogeochemistry-Climate Modeling and will develop and test teaching modules in environmental science for high school students.
