Equifinality of formal (DREAM) and informal (GLUE) Bayesian approaches in hydrologic modeling?

In recent years, a strong debate has emerged in the hydrologic literature regarding what constitutes an appropriate framework for uncertainty estimation. Particularly, there is strong disagreement whether an uncertainty framework should have its roots within a proper statistical (Bayesian) context, or whether such a framework should be based on a different philosophy and implement informal measures and weaker inference to summarize parameter and predictive distributions. In this paper, we compare a formal Bayesian approach using Markov Chain Monte Carlo (MCMC) with generalized likelihood uncertainty estimation (GLUE) for assessing uncertainty in conceptual watershed modeling. Our formal Bayesian approach is implemented using the recently developed differential evolution adaptive metropolis (DREAM) MCMC scheme with a likelihood function that explicitly considers model structural, input and parameter uncertainty. Our results demonstrate that DREAM and GLUE can generate very similar estimates of total streamflow uncertainty. This suggests that formal and informal Bayesian approaches have more common ground than the hydrologic literature and ongoing debate might suggest. The main advantage of formal approaches is, however, that they attempt to disentangle the effect of forcing, parameter and model structural error on total predictive uncertainty. This is key to improving hydrologic theory and to better understand and predict the flow of water through catchments.     

Variations in solar radiation in the solar activity cycle: Response of Earth’s atmospheric parameters (numerical modeling and analysis of observational data)

The results of a three-dimensional numerical simulation of changes in the temperature and wind within a height range of up to 100 km caused by changes in fluxes in the solar ultraviolet (UV) radiation in the 23rd solar activity cycle (which was characterized by unusually low values of UV-radiation fluxes) and also of global changes in the ozone content are presented. The simulation results showed that the response of the temperature to variations in the UV radiation are substantially of a nonzonal character, which is caused by the presence in the model of sources of quasi-stationary waves corresponding to the observational data.     

Distribution of ~(226)Ra in the Arctic Ocean and the Bering Sea and its hydrologic implications

The Arctic Ocean, the northernmost parts of the earth, covers the total surface area of 14.79 million square kilometers and amounts to only about 4% of global ocean surface area. Although its surface area is the smallest in the four major oceans, the Arct…     

Reply to “Comments on the paper “A crustal-upper mantle model for southeastern Sicily (Italy) from the integration of petrologic and geophysical data” by ”

We reply to the comments of Beccaluva et al. (2013) on the paper “A crustal-upper mantle model for southeastern Sicily (Italy) from the integration of petrologic and geophysical data” by Manuella et al. (2013). We entirely reject their speculative comments and strongly confirm our viewpoint on the aged oceanic nature of the lithospheric basement of southeastern Sicily and its offshore area.     

Reply to the Discussion of “Effects of temporal resolution on hydrological model parameters and its impact on prediction of river discharge” by Littlewood et al.

Citation Wang, Y., He, B. & Takase, K. (2011) Reply to the Discussion of “Effects of temporal resolution on hydrological model parameters and its impacts on prediction of river discharge” by I. G. Littlewood, B. F. W. Croke & P. C. Young. Hydrol. Sci. J. 56(3), 525–528.     

Comment on “Slowness-azimuth corrections of teleseismic events for IMS primary arrays in China” by Hao and Zheng

Knowledge about backazimuth and slowness deviations at seismic arrays can be used as a tool to study subsurface lateral heterogeneity and improve the ability to locate events. Recently, Hao and Zheng (J Seismol 13:437–448, 2009) estimated the backazimuth and slowness deviations for teleseismic P waves recorded by the HILR array and the LZDM array using f–k analysis. They attributed the significant deviations at the LZDM array to dipping structures beneath the array. However, another possible factor, namely the altitude variations of array elements, was not taken into consideration during the slowness estimation process. For the LZDM array, the maximum altitude difference is ~15% of the array aperture and not negligible. In this study, we made some numerical experiments to investigate the difference between the estimated and theoretical slowness vectors when ignoring the altitude difference. The results reveal that remarkable artificial slowness shift is produced. Assuming a P-wave velocity of 5.4 km/s immediately beneath the array, the magnitude of slowness shift increases from 1.4 to 2.2 s/° when the theoretical slowness decreases from 16 to 4 s/°. For a 10° emergence angle, the backazimuth deviation reaches nearly 40°, and the relative slowness deviation can be greater than 60%. It is also shown that ignoring the altitude difference gives rise to a northeastward slowness shift, opposite to the southwestward shift proposed by Hao and Zheng, suggesting that they have heavily underestimated the slowness residuals at the LZDM array. Note that the elevation of one of the array stations is much lower than others. Avoiding the use of this station, the elevation variation range of array stations decreases by nearly one half, and the artificial backazimuth and slowness deviations decrease by more than one half.