Studies of aerosol optical depth with the use of Microtops II sun photometers and MODIS detectors in coastal areas of the Baltic Sea

In this paper we describe the results of a research campaign dedicated to the studies of aerosol optical properties in different regions of both the open Baltic Sea and its coastal areas. During the campaign we carried out simultaneous measurements of aerosol optical depth at 4 stations with the use of the hand-held Microtops II sun photometers. The studies were complemented with aerosol data provided by the MODIS. In order to obtain the full picture of aerosol situation over the study area, we added to our analyses the air mass back-trajectories at various altitudes as well as wind fields. Such complex information facilitated proper conclusions regarding aerosol optical depth and Ångström exponent for the four locations and discussion of the changes of aerosol properties with distance and with changes of meteorological factors. We also show that the Microtops II sun photometers are reliable instruments for field campaigns. They are easy to operate and provide good quality results.     

Erroneous GNSS Strain Rate Patterns and their Application to Investigate the Tectonic Credibility of GNSS Velocities

The paper concerns investigation of the credibility of tectonic interpretation of GNSS strain rates. The analysis was focused on stable regions, where the crustal deformations are small and the reliability of GNSS velocities is questionable. We are showing how the unreliable motion of stations affects calculated strains around them. We expressed distribution of local principal strains by a sinusoidal function and used them to investigate the significance of strain distortion. Then we used this method to investigate real motions of GNSS stations. As a test object we used Polish GNSS stations belonging to the ASG-EUPOS network. Station velocities were estimated on the basis of the 4.5 years of observations. The results let us identify stations that disturb the obtained local GNSS strain rate field. After verification and exclusion of some stations, the new GNSS strains show a much greater internal compatibility and also better fit to the directions of lithosphere stresses.     

Are any granite landscapes distinctive of the humid tropics? Reconsidering multiconvex topographies

Geomorphologists have long debated over whether certain geomorphic types of landscapes may evolve only in certain climatic conditions, with granite terrains often chosen to illustrate such climate–relief relationships. The view deeming inselberg landscapes in particular to be distinctively tropical is difficult to sustain in the light of research demonstrating both the wide global distribution of inselbergs and evident rock control on their origins and development. However, another geomorphic type of granite landscapes has emerged as possibly specific to low latitude terrains, characterized by efficient deep weathering. In the context of the ongoing debate, this paper considers the case of multiconvex topography, consisting of low hills weathered throughout, which is widely distributed in South America, Africa and Southeast Asia but not yet reported from middle or high latitudes. Multiconvex landscapes require that weathering operates efficiently in all topographic settings and that dissection proceeds to maintain relative relief. Hence they tend to be associated with areas subject to moderate uplift. There is little chance for this type of relief to survive major environmental changes towards aridity or cooling because stripping of the weathering mantle will not be compensated by saprolite renewal.     

Tidal Heating and Convection in the Medium Sized Icy Satellites

Surface features of some icy satellites indicate that the satellites are modified due to the internally driven tectonic activity. Convection could be one of the processes responsible for the formation of the surface features. The potential sources of energy inside the satellites are discussed. For the medium sized icy satellites the radiogenic and tidal heat sources seem to be of primary importance. To investigate the problem, a 3D model of convection is developed based on the Navier–Stokes equation, the equation of thermal conductivity, the equation of continuity, and the equation of state. The model includes both the tidal and the radiogenic heating. It can be applied to the homogeneous, non-differentiated medium sized satellites. The 3D formulae for tidal heat generation and stress tensor based on the results of Peale and Cassen (1978) and others are applied. A new dimensionless number C _t is introduced. It measures the relative importance of tidal and radiogenic heat sources. The systematic investigation of the steady-state convection is performed for different values of the Rayleigh number and for 0C _t 1. The results indicate that the convection pattern for low Rayleigh number driven by tidal heating in the medium sized icy satellites consists of two cells. The pattern of tidally driven convection is oriented, that is, the regions of downward motion are situated at the center of the near- and of the far-side of the satellite.     

Resik: A Bent Crystal X-ray Spectrometer for Studies of Solar Coronal Plasma Composition

We describe the RESIK (REntgenovsky Spektrometr s Izognutymi Kristalami) instrument, consisting of two double-channel X-ray spectrometers, designed to observe solar active region and flare plasmas. RESIK is one of the instruments making up the scientific payload of the Russian CORONAS-F solar mission. The uncollimated spectrometer uses two silicon and two quartz bent crystals observing flare, active region and coronal spectra in four wavelength bands with a resolving power (/ ) of 1000. The wavelength coverage, 3.3–6.1 Å, includes emission lines of Si, S, Cl, Ar, and K and in the third diffraction order, the wavelength range includes He-like Fe lines (1.85 Å) and Ni lines (1.55 Å) with dielectronic satellites, emitted during intense, hot flares. The instrument is believed to be the best calibrated space-borne crystal spectrometer flown to date. The spectrometer dynamically adjusts the data gathering intervals from 1 s to 5 minutes, depending on the level of solar X-ray emission at the time of observation. The principal aims of RESIK are the measurements of relative and absolute element abundances in the emitting plasma and the temperature distribution of plasma (differential emission measure) over the temperature interval 3 and 50 MK. This paper summarizes the scientific objectives of RESIK and describes the design, characteristics, and performance of the instrument.     

Prediction of groundwater inflow into copper mines of the Lubin Głogów Copper District

 The Lubin Głogów copper district (lgom) is in an area of copper mining, where ore is mined at a depth of 600–1200 m below surface. Mine dewatering directly influences W-1 limestone aquifer of Permian (Zechstein) age and indirectly impacts a Triassic sandstone aquifer as well as water-bearing sediments interbeded with the coals. The prediction of groundwater inflow into mines has been performed using methods of mathematical modelling. In succeeding steps of the approach, the scheme of the hydrogeological framework was changed starting from the one-layer model up to the four-layer model. The evolution of this hydrogeological schematization is presented in this paper. The latest scheme characterizes such levels of details that allows the following predictions: (1) expansion of depression in all aquifers is influenced by dewatering, (2) the widest extent of depression is in the southern direction, (3) groundwater inflow to the Lubin and Rudna mines will remain at the same level, while the inflow to the Polkowice mine will increase by 25%. Reliable prediction can be achieved by incorporating the entire recharge and drainage area characteristics of the aquifer influenced by mine dewatering into the model. Received: 7 March 1998 · Accepted: 7 December 1998     

Contamination of tsunami sediments in a coastal zone inundated by the 26 December 2004 tsunami in Thailand

Tsunami sediments deposited in a coastal zone of Thailand by the 26 December 2004 tsunami wave were sampled within 50 days after the event. All surface and ground waters in tsunami- inundated zone revealed significant salinity at that time. The tsunami sediments, composed mainly of fine to medium sand, contain significantly elevated contents of salts (Na⁺, K⁺, Ca⁺², Mg⁺², Cl and SO ₄ ⁻² ) in water-soluble fraction, and of Cd, Cu, Zn, Pb in the bioavailable fraction and As in the exchangeable fraction in relation to the reference sample. The origin of contaminants is marine, as well as litho- and anthropogenic. The salts and Pb, Zn and Cu reveal high correlation to each other and to the mean grain size (pore size and porosity). Serious environmental hazard exists in that region because, due to gentle morphology, there is a risk of migration of the contaminants into ground waters and food chain.     

Geostatistical evaluation of lead and zinc concentration in soils of an old mining area with complex land management

This study is aimed at detailed statistical and geostatistical investigation of lead and zinc concentration in an old mining area located in the eastern part of the Upper Silesian Industrial Region. This area is rich in lead and zinc ores whose intense extraction dates back to the tenth century ad. The complexity of the area results from historical and current mining activities, as well as from a variety of different types of land management and complex geological conditions. Almost 1,000 collected soil cores were divided into two subsets: those collected at the depth of up to 20 cm and the those collected at the depth from 40 to 60 cm. Extensive analyses considered geological substrata in terms of spatial variability and spatial distributions, the type of land management, geoaccumulation indexes and enrichment factors. Lead and zinc concentration was several times higher on depths ranging from 40 to 60 cm beneath the soil surface than in the 20-cm topsoil. The results showed that clearer spatial dependence was observed for deeper soil layers then for the topmost ones, especially near mines where anthropogenic factors predominated over lithogenic ones. Weak spatial dependence was accompanied by high values of the geoaccumulation index. The lowest concentrations of pollution with geoaccumulation index below 0 and enrichment factor up to 5 observed in the forest were caused by low anthropogenic pressure and the presence of sandy soils, less capable of accumulating heavy metals.