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Pavel Ichim, Liviu Apostol, Lucian Sfîcă, Adriana-Lucia Kadhim-Abid and Vasilică Istrate

Abstract

Temperature inversions represent complex phenomena, specific for depression forms of relief which introduce changes in vertical zoning (Apăvăloae, Apostle, Pîrvulescu, 1986 by stable air stratification (Erhan, 1981), because of their morphological features, this is due to the interdependence of general movement and characteristics of the active surface, being the cause of their production (Apăvăloae, et. al., 1984, 1986, 1987). The generation of thermal inversions, their intensity and frequency is a consequence of altitude topography, morphology, fragmentation, orientation and degree of closure to external drives. (Apăvăloae, Apostle, Pîrvulescu, 1988). Thermal inversions represent complex phenomena, specific to depression landforms that introduce changes within the vertical zoning (Apăvăloae, Apostol, Pîrvulescu, 1986) by stable air stratification (Matveev, 1958, Erhan, 1981, Yinghui Liu, 2002) where vertical thermal gradient is negative (Matveev, 1958), due to their morphological features, also as a consequence of the interdependance of general circulation and characteristics of the active surface, the cause of their generation (Apăvăloae, et. al., 1984, 1986, 1987).

Open access

Lucian Sfîcă, Pavel Ichim, Liviu Apostol and Ovidiu Machidon

Abstract

This study is based on 3 years of hourly observations of global solar radiation (2014-2016), at a new weather station installed in the region of Central Moldavian Plateau, at Mădârjac (47.05°N, 27.25°E, 270 m). The main characteristics of annual, monthly and daily regime of global radiation were emphasized using for comparison similar data from Iașioficial weather station. Smaller annual amount of global solar radiation than those observed in previous studies were observed, reaching 4734 MJ/m2 in Iași and 4454 MJ/m2 in Mădârjac. An altidudinal gradient of global solar radiation close to 140 MJ/m2 was identified for the hilly region of Moldova. Despite the overall higher values in Iași, 30% of days indicates higher values of this parameter at Mădârjac weather station. These results can be used for the evaluation of the photo-voltaic potential in the region, but also to understand the altitudinal differences of solar radiation in the hilly region in Moldavia, since the only long-range actinometric stations from this part of Romania, Iași and Galați, are located at low altitudes.

Open access

Lucian Sfîcă, Iulian Iordache, Pavel Ichim, Alina Leahu, Marius-Mihai Cazacu, Silviu Gurlui and Cătălin-Răzvan Trif

Abstract

The aim of this study is to evaluate the role of the weather conditions and local climate on the temporal and spatial variability of particulate matters (PM 10) in Iași city which is facing major pollution problems in the recent years. Daily data from 4 monitoring stations of Environmental Protection Agency-Iași–for main weather parameters and particulate matters – and the temperature from an inner temperature and relative humidity observation network inside the city were used for a three year study (2013-2015). Linear correlation, composite analysis and multiple regression are the main statistical methods applied in the analysis. In brief, the most important meteorological parameters enhancing air pollution in Iași seem to be represented by thermal inversions developing in the region strongly related to local climate conditions. The Pearson correlation coefficient (stronger than -0.40) between PM10 and thermal gradient, the difference in the PM10 concentration exceeding 20 μg/m3 between strong thermal inversions and unstable conditions and the leading role of thermal gradients in multiple regression are the main indicators of the great role of thermal inversion in generating and sustaining pollution conditions in this area. The maximum concentrations of PM10 occur in May and March, gathering more than 30% of the days for the entire year. Complementary studies were taken into account in order to analyse the aerosol optical properties retrieved from Aerosol Robotic Network (AERONET-NASA).

Open access

Adrian Ursu, Marius Andrei, Dan Adrian Chelaru and Pavel Ichim

Abstract

The study analyses the spatial and temporal changes occurred in the builtup area of Iași city and its surrounding areas using cartographic materials from different time periods. The paper aims to highlight the areas where the most significant changes took place by identifying the main evolution patterns, generated by certain natural or human-driven factors. The results of the study were achieved by using specific photo-interpretation methods of the available orthophotomaps form 2006 and 2012, mainly using the professional GIS softwares TNT Mips 7.2., ArcGIS 10.2 and Global Mapper 11. The changes have lead on the one hand to the conversion of the former industrial areas and thus, the urban regeneration, but also to the periurbanization phenomenon, with major functional and structural effects.