The star-forming content of the W3 giant molecular cloud

We have surveyed a ∼0.9 square degree area of the W3 giant molecular cloud (GMC) and star-forming region in the 850-μm continuum, using the Submillimetre Common-User Bolometer Array on the James Clerk Maxwell Telescope. A complete sample of 316 dense clumps were detected with a mass range from around 13 to  2500 M_⊙  . Part of the W3 GMC is subject to an interaction with the H  ii region and fast stellar winds generated by the nearby W4 OB association. We find that the fraction of total gas mass in dense, 850-μm traced structures is significantly altered by this interaction, being around 5–13 per cent in the undisturbed cloud but ∼25–37 per cent in the feedback-affected region. The mass distribution in the detected clump sample depends somewhat on assumptions of dust temperature and is not a simple, single power law but contains significant structure at intermediate masses. This structure is likely to be due to crowding of sources near or below the spatial resolution of the observations. There is little evidence of any difference between the index of the high-mass end of the clump mass function in the compressed region and in the unaffected cloud. The consequences of these results are discussed in terms of current models of triggered star formation.     

Climate and climate change in the Austrian–Swiss region of the European Alps during the twentieth century according to Feddema

We present a 1-km² gridded German dataset of hourly surface climate variables covering the period 1995 to 2012. The dataset comprises 12 variables including temperature, dew point, cloud cover, wind speed and direction, global and direct shortwave radiation, down- and up-welling longwave radiation, sea level pressure, relative humidity and vapour pressure. This dataset was constructed statistically from station data, satellite observations and model data. It is outstanding in terms of spatial and temporal resolution and in the number of climate variables. For each variable, we employed the most suitable gridding method and combined the best of several information sources, including station records, satellite-derived data and data from a regional climate model. A module to estimate urban heat island intensity was integrated for air and dew point temperature. Owing to the low density of available synop stations, the gridded dataset does not capture all variations that may occur at a resolution of 1 km². This applies to areas of complex terrain (all the variables), and in particular to wind speed and the radiation parameters. To achieve maximum precision, we used all observational information when it was available. This, however, leads to inhomogeneities in station network density and affects the long-term consistency of the dataset. A first climate analysis for Germany was conducted. The Rhine River Valley, for example, exhibited more than 100 summer days in 2003, whereas in 1996, the number was low everywhere in Germany. The dataset is useful for applications in various climate-related studies, hazard management and for solar or wind energy applications and it is available via doi: 10.5676/DWD_CDC/TRY_Basis_v001.     

From data to decision-making – experiences in Integrated Earth Observation (IEO)

Within the confines of Earth Observation Scientific Knowledge and Technology Transfer in Hungary (EKAT) titled ESA PECS project we gained forum for utilization of our earth observation (EO) knowledge and possibility for further development of experiences. The project aims the horizontal preparation of Hungary for ESA membership – for a dynamically developing sphere in the common part of science, technology and business. For the efficient transfer and dissemination, we preconceived target groups and principles to reach main take-up points and to open new forums of information exchange. Nowadays, user-friendly service, complex supply and real-validation process all have great importance. Joining units of suitable data choice, entire ingestion–processing chains and ergonomic interfaces can only offer a timely and professional solution for the challenges of industry and business sectors. It has to be clearly seen, that information and communication technologies (ICT) and information control becomes a more and more significant part of EO services.     

Practical evaluation of carbon sources of forest soils in Slovenia from stable and radio-carbon isotope measurements

Carbon sources were estimated by measuring carbon isotope ratios (??¹³C and ??¹⁴C) with accelerator mass spectrometry (AMS) in forest soils of different lithology. Six locations were selected in temperate deciduous and coniferous stands in Slovenia (?irovski vrh, Idrija, Ko?evski Rog, Pohorje, Gori?nica, and Rakitna), where carbonate rocks consisting of limestone and dolomite are abundant as underlying bedrock. Carbon isotope fractionation would not have occurred in two carbonaceous soils, since the values of both ??¹³C and ??¹⁴C changed consistently in these soils after thermal (550°C, 2?h) or chemical (1?M HCl, 24?h) treatments. Organic components were found to be predominant carbon sources (70?C100%) in the uppermost portions (0?C2?cm in depth). In deeper portions at a depth of about 30?C35?cm, soil carbon may be derived completely from underlying carbonate minerals in Idria, western part of Slovenia. The Combination of heat and chemical treatments with AMS provides practical information on soil carbon sources in carbonaceous soils.     

Ultraviolet-visible and fluorescence spectral evidence of natural organic matter (NOM) changes along an estuarine salinity gradient

A transect of the St Marys River estuary from above the point of maximum salt wedge penetration to coastal salinities was conducted in July 1999. None of the parameters examined—dissolved organic carbon (DOC) content, UV light absorbance at 254 nm, and Total Luminescence spectra—follow the rule of conservative mixing. The characteristics of the different molecular size fractions of the St Marys River natural organic matter (NOM), as well as the results of a laboratory mixing experiment, provided evidence that loss of larger molecular size compounds from riverine NOM may occur by coagulation at salinities up to 10. An apparent gain of carbon in the lower estuary was attributed to exports from abundant coastal marshes in this area. The Total Luminescence spectra of the riverine NOM can be described by two peaks, centered respectively around 340/445 nm, and 230/430 nm Excitation/Emission Wavelength Pair (EEWP), which are characteristic of humic materials of aquatic origin. The samples from the high salinity stations exhibit peaks at lower emission wavelength EEWP 320/424 nm, which can be considered as marine humic-like material. The presence of amino acid-tryptophan like peaks were observed, with EEWP 300/350 nm in some of the high salinity samples. This peak was of high relative fluorescence intensity. It is hypothesized that the intense biological activity of the salt marsh and near coastal area is responsible for the carbon addition as well as the appearance of the highly fluorescence amino acid-protein like material.     

Identification of groundwater recharge sources and processes in a heterogeneous alluvial aquifer: results from multi‐level monitoring of hydrochemistry and environmental isotopes in a riverside agricultural area in Korea

We evaluated sources and pathways of groundwater recharge for a heterogeneous alluvial aquifer beneath an agricultural field, based on multi‐level monitoring of hydrochemistry and environmental isotopes of a riverside groundwater system at Buyeo, Korea. Two distinct groundwater zones were identified with depth: (1) a shallow oxic groundwater zone, characterized by elevated concentrations of NO₃^? and (2) a deeper (>10–14 m from the ground surface) sub‐oxic groundwater zone with high concentrations of dissolved Fe, silica, and HCO₃^?, but little nitrate. The change of redox zones occurred at a depth where the aquifer sediments change from an upper sandy stratum to a silty stratum with mud caps. The δ¹⁸O and δ²H values of groundwater were also different between the two zones. Hydrochemical and δ¹⁸O? δ²H data of oxic groundwater are similar to those of soil water. This illustrates that recharge of oxic groundwater mainly occurs through direct infiltration of rain and irrigation water in the sandy soil area where vegetable cropping with abundant fertilizer use is predominant. Oxic groundwater is therefore severely contaminated by agrochemical pollutants such as nitrate. In contrast, deeper sub‐oxic groundwater contains only small amounts of dissolved oxygen (DO) and NO₃^?. The ³H contents and elevated silica concentrations in sub‐oxic groundwater indicate a somewhat longer mean residence time of groundwater within this part of the aquifer. Sub‐oxic groundwater was also characterized by higher δ¹⁸O and δ²H values and lower d‐excess values, indicating significant evaporation during recharge. We suggest that recharge of sub‐oxic groundwater occurs in the areas of paddy rice fields where standing irrigation and rain water are affected by strong evaporation, and that reducing conditions develop during subsequent sub‐surface infiltration. This study illustrates the existence of two groundwater bodies with different recharge processes within an alluvial aquifer. Copyright © 2009 John Wiley & Sons, Ltd.     

Tracing depositional consequences of environmental radionuclides (137Cs and 210Pb) in Slovenian forest soils

Depth distribution profiles of environmental radionuclides (¹³⁷Cs and ²¹⁰Pb) have been investigated in soil to elucidate the underlying environment of semi-natural temperate deciduous and/or coniferous forest soils in Slovenia (?irovski vrh, Idrija, Ko?evski Rog, Pohorie, Gori?nica and Rakitna). Surface enrichment of both nuclides was observed at all the sites investigated in this study, suggesting that the soils had undergone little natural or anthropogenic disturbance for at least the last several decades. Apparent annual burial rates of ¹³⁷Cs (0.1–0.2 cm y^??1) were estimated to be about 1.3 times higher than those of ²¹⁰Pb at individual sites of different lithology, which suggests strong affinity of ²¹⁰Pb to soil organic matter. Variability of the vertical distribution profiles of these nuclides depends not only on “in situ” pedology but also on geographical and meteorological conditions, especially precipitation and wind direction.