The 4-emission-core structure of dayside aurora oval observed by all-sky imager at 557.7 nm in Ny-Ålesund,Svalbard

A survey of dayside aurora excitation at 557.7 nm, which was acquired from an all-sky imager at Yellow River Station in Ny-Ålesund, Svalbard, shows that there are 4 intense emission maxima in the dayside oval, centered near 0630/76, 0830/76, 1400/75, and 1600/75 (unit: MLT/MLAT), respectively. Tracing the magnetospheric sources of these cores along geomagnetic field lines, the 0830- and 1400-MLT cores correspond with the prenoon and postnoon magnetospheric boundary layers (MBLs), and the 0630- and 1600-MLT cores are located at the dusk and dawn MBLs, respectively. The potential solar wind-magnetosphere dynamic processes resulting in these auroral features are discussed.     

The atmospheric effects of October 2003 solar proton event simulated with the chemistry–climate model SOCOL using complete and parameterized ion chemistry

October 2003 solar proton events (SPE) is rather well covered by the observations; therefore its studies represent a good way for model validation and intercomparison. Here we apply chemistry–climate model (CCM) SOCOL with complete (SOCOLⁱ) and parameterized ion chemistry to evaluate the accuracy of a commonly used ion chemistry parameterization scheme. We performed ensemble experiments with and without SPE to characterize the effect of the October 2003 SPE on the NO_x, HO_x, ClO_x and O₃ in the middle atmosphere. Preliminary comparison of the simulated effects against MIPAS observations revealed rather good general agreement for most of the species. Comparison of the results obtained with complete and parameterized ion chemistry representation showed that the model with parameterized ion chemistry underestimates the effect of SPE on chemical composition of the middle atmosphere by up to 40% for NO_x and N₂O, up to 70% for HO_x and ClO_x and up to 600% for HNO₃. The parameterization is more accurate for ozone, however the model with parameterized ion chemistry underestimates ozone depletion by up to 15% during the SPE in the mesosphere and by 10% 2 weeks later in the stratosphere, which can be important for the long-term effects of SPE on the ozone layer.     

Discussion of “A comparison of local and aggregated climate model outputs with observed data” A black eye for the Hydrological Sciences Journal

Abstract

A paper published by Anagnostopoulos et al. in volume 55 of the Hydrological Sciences Journal (HSJ) concludes that climate models are poor based on temporal correlation between observations and individual simulations. This interpretation hinges on a common misconception, that climate models predict natural climate variability. This discussion underlines fundamental differences between hydrological and climatological models, and hopes to clear misunderstandings regarding the proper use of climate simulations.

Citation Huard, D. (2011) A black eye for the Hydrological Sciences Journal. Discussion of ‘A comparison of local and aggregated climate model outputs with observed data’ by G.G. Anagnostopoulos et al. (2010, Hydrol. Sci. J. 55 (7), 1094–1110). Hydrol. Sci. J. 56(7), 1330–1333.     

Uncertainty estimation of a complex water quality model: The influence of Box–Cox transformation on Bayesian approaches and comparison with a non-Bayesian method

In urban drainage modelling, uncertainty analysis is of undoubted necessity. However, uncertainty analysis in urban water-quality modelling is still in its infancy and only few studies have been carried out. Therefore, several methodological aspects still need to be experienced and clarified especially regarding water quality modelling. The use of the Bayesian approach for uncertainty analysis has been stimulated by its rigorous theoretical framework and by the possibility of evaluating the impact of new knowledge on the modelling predictions. Nevertheless, the Bayesian approach relies on some restrictive hypotheses that are not present in less formal methods like the Generalised Likelihood Uncertainty Estimation (GLUE). One crucial point in the application of Bayesian method is the formulation of a likelihood function that is conditioned by the hypotheses made regarding model residuals. Statistical transformations, such as the use of Box–Cox equation, are generally used to ensure the homoscedasticity of residuals. However, this practice may affect the reliability of the analysis leading to a wrong uncertainty estimation. The present paper aims to explore the influence of the Box–Cox equation for environmental water quality models. To this end, five cases were considered one of which was the “real” residuals distributions (i.e. drawn from available data). The analysis was applied to the Nocella experimental catchment (Italy) which is an agricultural and semi-urbanised basin where two sewer systems, two wastewater treatment plants and a river reach were monitored during both dry and wet weather periods. The results show that the uncertainty estimation is greatly affected by residual transformation and a wrong assumption may also affect the evaluation of model uncertainty. The use of less formal methods always provide an overestimation of modelling uncertainty with respect to Bayesian method but such effect is reduced if a wrong assumption is made regarding the residuals distribution. If residuals are not normally distributed, the uncertainty is over-estimated if Box–Cox transformation is not applied or non-calibrated parameter is used.     

Modeling preasymptotic transport in flows with significant inertial and trapping effects – The importance of velocity correlations and a spatial Markov model

We study solute transport in a periodic channel with a sinusoidal wavy boundary when inertial flow effects are sufficiently large to be important, but do not give rise to turbulence. This configuration and setup are known to result in large recirculation zones that can act as traps for solutes; these traps can significantly affect dispersion of the solute as it moves through the domain. Previous studies have considered the effect of inertia on asymptotic dispersion in such geometries. Here we develop an effective spatial Markov model that aims to describe transport all the way from preasymptotic to asymptotic times. In particular we demonstrate that correlation effects must be included in such an effective model when Péclet numbers are larger than O(100) in order to reliably predict observed breakthrough curves and the temporal evolution of second centered moments. For smaller Péclet numbers correlation effects, while present, are weak and do not appear to play a significant role. For many systems of practical interest, if Reynolds numbers are large, it may be typical that Péclet numbers are large also given that Schmidt numbers for typical fluids and solutes can vary between 1 and 500. This suggests that when Reynolds numbers are large, any effective theories of transport should incorporate correlation as part of the upscaling procedure, which many conventional approaches currently do not do. We define a novel parameter to quantify the importance of this correlation. Next, using the theory of CTRWs we explain a to date unexplained phenomenon of why dispersion coefficients for a fixed Péclet number increase with increasing Reynolds number, but saturate above a certain value. Finally we also demonstrate that effective preasymptotic models that do not adequately account for velocity correlations will also not predict asymptotic dispersion coefficients correctly.     

3D models of slow motions in the Earth’s crust and upper mantle in the source zones of seismically active regions and their comparison with highly accurate observational data: II. Results of numerical calculations

In the first part of the paper, a new method was developed for solving the inverse problem of coseismic and postseismic deformations in the real (imperfectly elastic, radially and horizontally heterogeneous, self-gravitating) Earth with hydrostatic initial stresses from highly accurate modern satellite data. The method is based on the decomposition of the sought parameters in the orthogonalized basis. The method was suggested for estimating the ambiguity of the solution of the inverse problem for coseismic and postseismic deformations. For obtaining this estimate, the orthogonal complement is constructed to the n-dimensional space spanned by the system of functional derivatives of the residuals in the system of n observed and model data on the coseismic and postseismic displacements at a variety of sites on the ground surface with small variations in the models. Below, we present the results of the numerical modeling of the elastic displacements of the ground surface, which were based on calculating Green’s functions of the real Earth for the plane dislocation surface and different orientations of the displacement vector as described in part I of the paper. The calculations were conducted for the model of a horizontally homogeneous but radially heterogeneous selfgravitating Earth with hydrostatic initial stresses and the mantle rheology described by the Lomnitz logarithmic creep function according to (M. Molodenskii, 2014). We compare our results with the previous numerical calculations (Okado, 1985; 1992) for the simplest model of a perfectly elastic nongravitating homogeneous Earth. It is shown that with the source depths starting from the first hundreds of kilometers and with magnitudes of about 8.0 and higher, the discrepancies significantly exceed the errors of the observations and should therefore be taken into account. We present the examples of the numerical calculations of the creep function of the crust and upper mantle for the coseismic deformations. We also demonstrate the results of estimating the ambiguity of the models of postseismic deformations in the vicinity of the source of the Great Tohoku earthquake of March 11, 2011, which were obtained by the method of orthogonalization described in the first part of the paper.     

Moving socio-hydrologic modelling forward: unpacking hidden assumptions,values and model structure by engaging with stakeholders: reply to “What is the role of the model in socio-hydrology?”*

The arguments presented in Melsen et al. advance ideas in the “Panta Rhei” decade (2013–2022) of the International Association of Hydrological Sciences, which focuses on change in hydrology and society. While we reiterate that, despite acknowledged shortcomings, the enterprise of integrating societal feedbacks into hydrological models is beneficial in prediction and adaptive management, we also agree with the sentiments of the authors. In response, we offer concrete steps the socio-hydrologic community can take to educate modellers to become aware about unconscious biases embedded in model structure and clearly communicate assumptions. We stress the need for “knowledge brokers” that can help modellers work with stakeholders, instead of doing everything themselves. We also caution, however, against the danger of over-reaching. Young scholars already pay a big price by having to master both the natural and social sciences. As coupled human–water problems increase in societal importance, along with calls for more holistic thinking, we also need to promote an academic culture that rewards reaching across the aisle.     

A long-term earthquake forecast for the Kuril-Kamchatka arc for the period from September 2011 to August 2016. The likely location,time, and evolution of the next great earthquake with M ≥ 7.7 in Kamchatka

We consider the results from the ongoing 2010–2011 work on long-term earthquake prediction for the Kuril-Kamchatka arc based on the pattern of seismic gaps and the seismic cycle. We develop a forecast for the next 5 years, from September 2011 to August 2016, for all segments of the Kuril-Kamchatka arc earthquake-generating zone. For 20 segments we predict the appropriate phases of the seismic cycle, the normalized rate of small earthquakes (A₁₀), the magnitudes of moderate earthquakes to be expected with probability 0.8, 0.5, and 0.15, and the maximum possible magnitudes and probability of occurrence for great (M ≥ 7.7) earthquakes. This study serves as another confirmation that it is entirely necessary to continue the work in seismic retrofitting in the area of Petropavlovsk-Kamchatskii.