5.  Rakovec, J., R. ®abkar and M. ®agar: The role of advection and of work done by forces in the gustiness of the Bora flow.

Local wind changes within the flow of the Adriatic Bora are investigated in the case of 8 December 2001 that was simulated with the WRF/ARW model in a 333 m horizontal resolution and with all relevant model variables archived during a 3 h time interval with 1 s temporal resolution. Along a selected cross section, two locations of strong gusts in the lee of a Dinaric mountain ridge are found - the upper one on the slope and the other over the sea close to the coastline; in between the wind is considerably weaker. About 16 to 18 gusts developed in the 3 h interval at both locations with an average period of approximately 8.5 min. The advective transport of kinetic energy (KE), the work of the unbalanced part of the pressure gradient force and the diffusion and dissipation of KE cause the local change ΔKE, and their quasi-periodic fluctuations lead to gusts and lulls. The results of the numerical simulation enable an estimation of the contributions of advection, the work of forces and of turbulence and dissipation effects. Advective contributions to local changes are more or less in the phase with Δ˜˜KE and ahead of the phase of KE, while the contributions of work are generally smaller and in the opposite phase: so in general the advection and the work effects oppose each other. The advection and the work effects are not spatially homogeneous, i.e. they cease and even change their sign between the two locations of the strongest gusts and so there is no continuous displacement of KE from the upper to the lower location by either of the two effects: their contributions interchange with each other down the slope.

Keywords: bora gustiness, internal flow dynamics, WRF-ARW model

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6.  Kumar Das, A., M. Bhowmick, P. K. Kundu and S. K. Roy Bhowmik: Verification of WRF rainfall forecasts over India during monsoon 2010: CRA method.

The WRF model forecast during monsoon season 2010 has been verified with daily observed gridded rainfall analysis with 0.5º spatial resolution. Firstly, the conventional neighborhood technique has been deployed to calculate common scores like mean error and root mean square error. Along with, widely used two categorical skill scores have been computed for seven different rainfall thresholds. The scores only found the general nature of the model performance and depicted the degradation of forecast accuracy exceeding moderate rainfall category of 7.5 mm. The object oriented Contiguous Rain Area method also has been considered for the verification of rainfall forecasts to gather more information about model performance. The method similarly has endorsed that the performance of the model degrades along with the increase in rainfall amount. But at the same time, the decomposition of mean square error has pointed out that the maximum error occurred due the shifting of rain object or event in the forecast compared to observation. The volume error contributes less as compared to pattern error in 24 hour forecasts irrespective of rainfall thresholds. But in 48 hour forecasts, their values are comparable and change along with rainfall threshold. During whole monsoon season, all contiguous rain areas in model forecasts have been searched over observed rainfall analyses applying best-fit criteria. For contiguous rain areas below 50 mm more than 70 percent match was found.

Keywords: contiguous rain area

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7.  Shaltout, M. and A. Omstedt: Recent precipitation trends and future scenarios over the Mediterranean Sea.

This paper analyses current precipitation rates (PRs) and trends over the Mediterranean Sea region and their response to global climate change scenarios. The analysis uses 0.25º gridded PRs dataset over a 13-year period (1998–2010) based on remote sensing data from the Tropical Rainfall Measuring Mission. Future scenarios use the results of six global climate models (GCMs) under four representative concentration pathway scenarios (i.e., RCP26, RCP45, RCP60, and RCP85).

Results indicate that the Mediterranean Sea region displays a seasonally significant (insignificant) wetter trend during cold (hot) seasons, and exhibits annual spatial variation ranging from under 15 to over 100 mm month-1 over the period 1998–2010. Sea level pressure has two different effects on precipitation over the northern (inversely related to precipitation) versus southern (directly related to precipitation) Mediterranean Sea. However, sea surface temperature is anti-correlated with precipitation. The GCMs that describe the current Mediterranean Sea precipitation most realistically are GFDL-CM3-1, MIROC-ESM-CHEM, and HadGEM2-AO, which are used to calculate the ensemble mean for each representative concentration pathway scenario. The ensemble means realizations indicate that the study area will experience substantial drought in the 21st century. Uncertainty in the projected precipitation over the Mediterranean Sea was partitioned into four sources, of which the used scenario dominates.

Keywords: Mediterranean Sea, Black Sea, precipitation, climate models

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8.  Pandey, P. C., P. Kumar, M. Rani, S. Katiyar and V. Tomar: Fluoride-induced impact of aluminium industrial power plant on plants and human inhabiting areas.

Fluorine is a highly reactive common element that does not occur in nature in the elemental state. It exists in the form of fluorides and accounts for about 0.3 g/kg of the Earth's crust. Generally, it is found in the form of a number of minerals like fluorspar, cryolite and fluor-apatite. Fluoride has both positive and negative effects on individual health. Fluoride, in the form of fluorspar and cryolite is distributed extensively in the lithosphere, and is renowned as the thirteenth most common among elements in the earth's crust. Hydrogen fluorides in gaseous form accumulate in the leaves of generally sensitive plants against a concentration gradient and therefore, considered as a most phytotoxic air pollutant and affects plants at extremely low concentration. As per our study, it is found that the fluoride impacts on fauna are in normal condition, but in coming times it may have adverse impact on fauna and flora of surroundings of Hindalco Industries Limited.

Keywords: fluoride, human health, detrimental effects, social aspects

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