Pavel Prošek

Climatic and ecological characteristics of deglaciated area of James Ross Island, Antarctica, with a special respect to vegetation cover

Since 2006, year-round measurements of climatic parameters of characteristic ecosystems of James Ross Island, such as (1) coastal vegetation oases, (2) volcanic mesas have been performed by automatic weather stations. Simultaneously, prospection, classification and mapping of vegetation cover have been made annually within the period of Czech Antarctic expeditions lasting from January to March. In this paper, description of the two typical terrestrial ecosystems, characteristics of their microclimate and overview of vegetation cover are given. Daily and monthly means and extreme values of 2-m air temperature, surface temperature and relative humidity are reported for coastal locations and volcanic mesas (300–400 m a.s.l.). Species composition of lichen and moss flora in coastal and mesa locations is characterized and discussed in relation to local topography and microclimate.

Mass spectrometry of humic substances of different origin including those from Antarctica A comparative study.

Mass spectra of humic acids (HA) from different sampling sites (Antarctica, Brazil, Czech Republic, Mexico and USA) and origin (plant, soil, peat, and coal derived) were obtained by laser desorption/ionization time of flight mass spectrometry (LDI-TOF MS). Optimisation of the experimental conditions are given as the optimal value of the laser energy at approximately 20-30% higher than the threshold. Under these conditions, reproducible mass spectra of HA samples were obtained. In the mass spectra the majority of the peaks are observed in the m/z region 100-1000Da. Mass spectra fingerprints of HA were analyzed and, in spite of the differences in their origin, a number of common features and profiles (patterns of peaks) were observed in most of the samples. Very similar structural groups (patterns) of the peaks are present in the m/z range 717-918Da for HA samples of quite different origins, countries or continents. The tandem LDI-TOF MS and multivariate statistical tools allowed us to extract and elucidate underlying information contained in the mass spectra of the HA samples under study. Applying principal components and cluster analysis, it was, e.g. demonstrated that most of the Antarctica HA samples show distinguishable differences when compared with humic acids from other continents and of different origin.

Separation and characterization of humic acids from Antarctica by capillary electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry: Inclusion complexes of humic acids with cyclodextrins

A new capillary electrophoresis procedure based on micellar electrokinetic capillary chromatography for the separation of humic acids (HAs) isolated from Antarctica soil was developed. The HAs were separated and characterized using a background electrolyte containing 0.09 M borate+0.09 M Tris+0.001 M EDTA (BTE) of pH 8.3, modified with alpha-, beta-, or gamma-cyclodextrins (CDs) and sodium dodecyl sulfate. It was found that from alkaline solution of HAs in the presence of CDs, the HAs are not completely precipitated with a strong acid and a certain part (some fractions) remains soluble. Mass spectrometry shows that HAs contain 15-25 simple low-Mr compounds and several families of compounds with similar structure (m/z approximately 800-1200). Comparison of HA analysis from Antarctica soil with those of soil HAs from the American continent show a high similarity between the samples and confirm several identical compounds and some with very similar structural units.

Global validation of a forecast model for irradiance of solar, erythemally effective ultraviolet radiation

Alois W. SchmalwieserGu¨nther SchaubergerUniversity of Veterinary MedicineInstitute of Medical Physics andBiostatisticsVeterina¨rplatz 1, A-1210 ViennaAustriaE-mail: alois.schmalwieser@vu-wien.ac.atMichal JanouchCzech Hydrometeorological InstituteSolar and Ozone ObservatoryHvezdarna 456 500 08 Hradec Kralove 8Czech RepublicManuel NunezUniversity of Tasmania, AustraliaSchool of Geography and EnvironmentalStudiesGPO Box 252-78Hobart, Tasmania 7001AustraliaTapani KoskelaFinnish Meteorological InstituteOzone and UV ResearchP.O. Box 503 FIN-00101 HelsinkiFinlandDaniel BergerSolar Light Incorporated721 Oak LanePhiladelphia, Pennsylvania 19126Gabriel KaramanianUshuaia GAW StationPO Box 187, 9410, Ushuaia-TDFArgentinaPavel ProsekKamil LaskaMasaryk UniversityDepartment of GeographyKotla ´rˇska 2, 611 37 BrnoCzech RepublicAbstract. A worldwide forecast of the global solar erythemally effectiveUV irradiance, also called UV Index, under clear skies is presented. Theforecast was established to inform the public about the expected amountof erythemally effective ultraviolet radiation for the next day. The forecastenables the user to choose the appropriate sun protection tool and toadopt the personal behavior to reduce the risk of health damage. Theforecast as well as the radiation model are validated using measure-ments from a Robertson-Berger meter made at four continents (Antarc-tica, Australia, America, and Europe). The measurements cover the lati-tudinal range from 67.4°N to 60.1°S. Since the UV Index wasdetermined to quantify UV radiation protection, the goal of a forecastscheme is to avoid underestimation. Therefore the frequency of under-estimation was used as quality criteria also. The Austrian forecast modelshows less than 7.3% underestimation in all cases, whereas 5.0% resultfrom the radiation model and 2.3% from the used value of the total ozonecontent of the atmosphere.

Method of estimating solar UV radiation in high-latitude locations based on satellite ozone retrieval with an improved algorithm

The effects of the cloudiness and satellite-based ozone measurements on erythemally effective ultraviolet (EUV) radiation were examined using a non-linear regression model. Instead of the widely used ozone transmissivity exponential function, we proposed a new approach based on a quantum transmission model using hyperbolic attenuation of the EUV radiation. The radiation data were collected at the Czech Johann Gregor Mendel Station, James Ross Island, Antarctica (63° 48′ S, 57° 53′ W), between 14 March 2007 and 3 March 2009. The total ozone content and effective surface reflectivity at 360 nm were obtained from the Ozone Monitoring Instrument on board the EOS-Aura spacecraft for the geographical coordinates of the J. G. Mendel Station. The model predicted 98.6% variability of the EUV radiation. The residuals between the measured and predicted EUV radiation intensities were evaluated separately for the ranges of solar elevation angle, total ozone content and surface reflectivity. The results of this study were compared to previous findings where the influence of ground-based and satellite-based ozone measurements and model usefulness was discussed.

Estimation of solar UV radiation in maritime Antarctica using a nonlinear model including cloud effects

A new approach to the estimation of erythemally effective ultraviolet (EUV) radiation for all sky conditions that occur in maritime Antarctica is reported. The spatial variability of the total ozone content (TOC) and attenuation of the EUV radiation in the atmosphere are taken into consideration. The proposed nonlinear regression model of EUV radiation is described by a hyperbolic transmission function. The first results and the model validation for Vernadsky Station (formerly the British Faraday Station) during the period 2002–2005 show very good agreement with the measured values (R 2 = 99.2). The developed model was evaluated using daily doses of EUV radiation with respect to solar elevation angle and cloudiness. The mean average prediction error (MAPE) for cloudy (4.1–7.0 oktas) and overcast skies (7.1–8.0 oktas) varied between 4.0% and 4.3%, while for partly cloudy days (0–4.0 oktas) with high variability of cloud types during a day, MAPE reached 5.9%.

Facilities of J. G. Mendel Antarctic station: Technical and technological solutions with a special respect to energy sources

In this paper, we focus on technical facilities and technologies used at the Johann Gregor Mendel station (James Ross Island, Antarctica) with a special respect to energy sources used for running the station. Construction of the station is evaluated from energy demand and energy loss points of view. Detailed description of main energy sources, i.e. wind turbines, solar thermal panels, and diesel generators is given. Water management and combustible solid waste management are described as well. Brief overview of future plans related to energy sources at the Johann Gregor Mendel station including an increase in the exploitation of solar energy from photovoltaic panels is given.

Components of the energy balance of the ground surface and their effect on the thermics of the substrata of the vegetation oasis at Henryk Arctowski Station, King George Island, South Shetland Islands

Presentation of results of completly mneaurement of radiation and heat balance components on the vegetation oasis surface and their reflections in soil climate.

Worldwide forecast of the biologically effective UV radiation: UV index and daily dose

Since October 1995 a global daily forecast of the UV index and the daily dose, as the irradiance of the biologically effective ultraviolet radiation, for clear sky is calculated. The Austrian model as well as the input parameters are described. By connecting the daily dose with the sensitivity of the photobiological skin types, a recommendation is given to select an appropriate sun protection factor of a sunscreen to avoid overexposure of the skin. The validation of the Austrian forecast model is done by long-term measurements of the biologically effective ultraviolet radiation. Measurements were taken from 6 different sites at 4 continents (Antarctica, Australia, America and Europe) covering the latitudinal range from 67 degree(s)N to 60 degree(s)S. By using the underestimation as criteria in the sense of radiation protection, the Austrian model shows less than 12% underestimation over the whole period for the UV index and less than 10% for the daily dose. The evaluation shows further that the forecast of the daily dose is much more influenced by the attenuation due to clouds than the UV index.