Late Pleistocene climate inferences from a water balance model of Jakes Valley, Nevada (USA)

Shorelines that formed in closed watershed–lake systems record past climate conditions. A simple monthly water balance model was used to explore the link between past climates, paleoclimate proxies, and the hydrologic system response of a closed watershed–lake system in the Great Basin, USA. The model was applied at a high spatial resolution and calibrated with available modern hydroclimate and watershed data and then used with existing paleolake shoreline estimates to investigate how climate and hydrologic conditions in the late Pleistocene differed from modern conditions. A range of climate conditions, ∆T (0 to −8 °C) and ∆P (1.9–2.4) from the modern climate, resulted in steady model simulations of the late Pleistocene lake highstand. Modeling results also indicate the watershed–lake system response is much more sensitive to changes in precipitation than to changes in temperature, and that the range of possible combinations of these variables can be reduced significantly when the results are compared with an independent modeling study that inferred paleoclimate conditions from glacial moraines in the Wind River Range near the eastern portion of the Great Basin. The modeling effort also revealed that physiographic heterogeneities and seasonality play a significant role in how the watershed–lake system responds to changes in precipitation and temperature, highlighting the importance of simulating the system behavior with an appropriate degree of spatial resolution. The significance of model calibration and performance evaluation over the modern period was demonstrated through a comparison of the calibrated model results with those obtained using default parameter values with the original model.