This work was supported by National Science Foundation (NSF) Grants AGS-1035968 and AGS-1035843 and New Jersey Agricultural Experiment Station Hatch Grant NJ07102. A.B. is currently supported by NSF Postdoctoral Fellowship AGS-1331375. S.M. acknowledges support from the National Oceanic and Atmospheric (U.S. Department of Commerce) Grant NA08OAR4320752, U.S. Department of Agriculture Grant 2011-67003-30373, and the Carbon Mitigation Initiative at Princeton University, sponsored by British Petroleum.
Journal of Climate
Soil moisture -- Mathematical models, Earth temperature -- Effect of soil moisture on, Evapotranspiration
Understanding how different physical processes can shape the probability distribution function (PDF) of surface temperature, in particular the tails of the distribution, is essential for the attribution and projection of future extreme temperature events. In this study, the contribution of soil moisture–atmosphere interactions to surface temperature PDFs is investigated. Soil moisture represents a key variable in the coupling of the land and atmosphere, since it controls the partitioning of available energy between sensible and latent heat flux at the surface. Consequently, soil moisture variability driven by the atmosphere may feed back onto the near-surface climate—in particular, temperature. In this study, two simulations of the current-generation Geophysical Fluid Dynamics Laboratory (GFDL) Earth System Model, with and without interactive soil moisture, are analyzed in order to assess how soil moisture dynamics impact the simulated climate. Comparison of these simulations shows that soil moisture dynamics enhance both temperature mean and variance over regional ‘‘hotspots’’ of land–atmosphere coupling.Moreover, higher-order distribution moments, such as skewness and kurtosis, are also significantly impacted, suggesting an asymmetric impact on the positive and negative extremes of the temperature PDF. Such changes are interpreted in the context of altered distributions of the surface turbulent and radiative fluxes. That the moments of the temperature distribution may respond differentially to soil moisture dynamics underscores the importance of analyzing moments beyond the mean and variance to characterize fully the interplay of soil moisture and near-surface temperature. In addition, it is shown that soil moisture dynamics impacts daily temperature variability at different time scales over different regions in the model.
Berg, Alexis; Lintner, Benjamin R.; Findell, Kirsten L.; Malyshev, Sergey; Loikith, Paul C.; and Gentine, Pierre, "Impact of Soil Moisture–Atmosphere Interactions on Surface Temperature Distribution" (2014). Geography Faculty Publications and Presentations. 57.