Simulation of the water cycle in Biosphere 2

The budget of water flows and storages in Biosphere 2 was drawn in energy s ystems language to generate equations for a simple simulation model. Using data by others for calibration and a seasonal variation of sunlight, main f eatures of the seasonal water cycle were analyzed. The model result coincid ed with the observed patterns of seasonal variation in the water level of p rimary storage. Primary storage was more affected by changes in water manag ement, while other storages were mostly controlled by sunlight energy. A st able isotope model of water species simulated the trends in isotopic fracti onation in agreement with observations. Isotopic compositions of the reserv oirs reached steady state and were close to the measured values. (C) 1999 E lsevier Science B.V. All rights reserved.