On the hypothetical utilization of atmospheric potential energy

Atmospheric potential energy is typically divided into an available and a nonavailable part. In this article a hypothetical utilization of a fraction of the nonavailable potential energy is described. This part stems from the water vapor that can be converted into the liquid phase. An energy gain results when the potential energy of the condensate relative to a reference height exceeds the energy necessary to condensate the water vapor. It is shown that this can be the case in a saturated atmosphere without convective available potential energy. Finally, simulations with the numerical cloud model HURMOD are performed to estimate the usability of the device in practice. Indeed, a positive energy output results in a simulation with immediate gathering of the condensate. On the contrary, potential energy gained falls significantly short of the necessary energy for forming the condensate when a realistic cloud microphysical scheme allowing re-evaporation of condensate is applied. Taken together it can be concluded that, a utilization of atmospheric potential energy is hypothetically possible but the practical realization is probably not feasible

The Message in Our Music : What Popular Congregational Songs Say about Our Beliefs

Congregational singing is a source of basic theological instruction, both reflecting and shaping what we believe. It is crucial, therefore, that we say what we believe when we sing. In this study, the authors focused on the songs most accessed by users of the Christian Copyright Licensing, Inc. (CCLI) service between 2006-2012. Twenty songs were identified as having received significant usage during this time period. The results of this study found that a representative sampling of the lyrics of the most popular congregational songs did not sufficiently express foundational concepts of the Christian faith. Although individual congregations may have a systematic plan for teaching Christian theology in other parts of the church service than congregational singing, the high comparative use of the top songs listed suggests that very few systematic plans are used for congregational singing; that instead, a random selection of songs are used, with little regard to any formal theological training for the congregation, or to even attempt to more comprehensively reflect a specific doctrinal teaching in any single service. It is incumbent on pastors to avoid treating congregational singing as the “warm-up” for the “real” teaching time. It is also incumbent on church music leaders to either choose or compose songs that connect to a specific theological concept in a comprehensive, systematic, and not haphazard way

Komposition - ein Thema für den allgemeinbildenden Musikunterricht

The author differentiates between two methods of composition: a) composing a score (e.g. traditional composition and comparable techniques in contemporary music: composition based on principles of melody, harmony, form, instrumentation and - eventually - technical sound manipulation in the studio) b) organising sound events (e.g. composition of tape music: collection of sound material - selection - technical transformation - disposition of musical form). Both methods are of equal importance for modern music theory and instruction they can be developed on the basis of a) traditional and modern theories of composition. (e.g. A. B. Marx, K. Stockhausen) and b) theory and practice of composing electroacoustical music concrète, electronic music, tape music, etc. (DIPF/Orig.

Dynamical downscaling of CMIP5 1 Global Circulation Models over CORDEX-Africa with COSMO-CLM: evaluation over the present climate and analysis of the added value.

In this work we present the results of the application 8 of the Consor- tium for Small-scale Modeling (COSMO) Regional Climate Model (COSMO-CLM, hereafter, CCLM) over Africa in the context of the Coordinated Regional Climate Downscaling Experiment (CORDEX). An ensemble of climate change projections has been created by downscaling the simulations of four Global ClimateModels (GCM), namely:MPI-ESM-LR, HadGEM2- ES, CNRM-CM5, and EC-Earth. Here we compare the results of CCLM to those of the driving GCMs over the present climate, in order to investigate whether RCMs are effectively able to add value, at regional scale, to the performances of GCMs. It is found that, in general, the geographical distribution of mean sea level pressure, surface temperature and seasonal precipitation is strongly affected by the boundary conditions (i.e. driving GCMs), and seasonal statistics are not always improved by the downscaling. However, CCLM is generally able to better represent the annual cycle of precipitation, in particular over Southern Africa and the West Africa Monsoon (WAM) area. By performing a Singular Spectrum Analysis (SSA) it is found that CCLM is able to reproduce satisfactorily the annual and sub-annual principal components of the precipitation time series over the Guinea Gulf, whereas the GCMs are in general not able to simulate the bimodal distribution due to the passage of the WAM and show a unimodal precipitation annual cycle. Furthermore, it is shown that CCLM is able to better reproduce the Probability Distribution Function (PDF) of precipitation and some impact-relevant indices such as the number of consecutive wet and dry days, and the frequency of heavy rain events.JRC.H.7-Climate Risk Managemen

Optimal spectral nudging for global dynamic downscaling

AbstractThis study analyzes a method to construct a homogeneous, high-resolution global atmospheric hindcast. The method is the spectral nudging technique which was applied to a state-of-the-art general circulation model (ECHAM6, T255L95). Large spatial scales of the global climate model prognostic variables were spectrally nudged towards a reanalysis data set (NCEP1, T62L28) for the last decades. The main idea is the addition of dynamically consistent regional weather details to the coarse grid NCEP1 reanalysis. A large number of sensitivity experiments were performed, using different nudging e-folding times, vertical profiles, wave numbers, and variables. Comparisons with observations and several reanalyses showed a high dependency on the variations of the nudging configuration. At the global scale, the accordance is very high for extra-tropical regions and lower in the tropics. A wave number truncation of 30, a relatively short e-folding time of 50 min and a plateau-shaped nudging profile applied only to divergence and vorticity generally yielded the best results. This is one of the first global spectral nudging hindcast studies and the first applying an altitude-dependent profile to selected prognostic variables. The method can be applied to reconstruct the history of extreme events such as intense storms in the context of ongoing climate change

De principiis Astronomiae et Cosmographiae...

ColofónSign.: A-O8, P4Grab. en port. -- Il. insertas en el texto. -- Inic. grab