Kamil Láska

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.

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.

Death age, seasonality, taphonomy and colonization of seal carcasses from Ulu Peninsula, James Ross Island, Antarctic Peninsula

Abstract The origin and nature of seal carcasses scattered around the Ulu Peninsula, James Ross Island, is examined using robust and novel multidisciplinary analysis. Spatial distribution analysis indicates their predominance at low elevations and on surfaces with negligible slope. The seals died throughout the last century. Dental cement increments indicate that the seals died in late winter, and we interpret this to show an influence of the persistence and break-up of sea ice and the appearance of pools/cracks in the northern Prince Gustav Channel on death. Specifically, after being trapped by a late winter freeze-up the seals search for open water, become disoriented by snow-covered flat valleys and move inland. Carcasses from all age groups of crabeater seal are found on land, but inland movement is less notable for Weddell and leopard seals. Although most carcasses appear to have remained unchanged during the last 10 years due to the cold and dry conditions, a few carcasses that are located in sites of snow accumulation and subsequent melting have undergone enhanced decay. Decaying seal carcasses represent loci of nutrient release in a nutrient deficient environment and are colonized by algae, cyanobacteria, lichens and mosses. This research suggests further useful studies for the future.

Seasonal hydrological and suspended sediment transport dynamics in proglacial streams, James Ross Island, Antarctica

ABSTRACT Rapid warming of the Antarctic Peninsula is producing accelerated glacier mass loss and can be expected to have significant impacts on meltwater runoff regimes and proglacial fluvial activity. This study presents analysis of the hydrology and suspended sediment dynamics of two proglacial streams on James Ross Island, Antarctic Peninsula. Mean water discharge during 8 January 2015 to 18 February 2015 reached 0.19 m3 s−1 and 0.06 m3 s−1 for Bohemian Stream and Algal Stream, respectively, equivalent to specific runoff of 76 and 60 mm month−1. The daily discharge regime strongly correlated with air and ground temperatures. The effect of global radiation on proglacial water discharge was found low to negligible. Suspended sediment concentrations of Bohemian Stream were very high (up to 2927 mg L−1) due to aeolian supply and due to the high erodibility of local rocks. Total sediment yield (186 t km−2 yr−1) was high for (nearly) deglaciated catchments, but relatively low in comparison with streams draining more glaciated alpine and arctic catchments. The sediment provenance was mostly local Cretaceous marine and aeolian sediments; volcanic rocks are not an important source for suspended load. High Rb/Sr ratios for some samples suggested chemical weathering. Overall, this monitoring of proglacial hydrological and suspended sediment dynamics contributes to the dearth of such data from Antarctic environments and offers an insight to the nature of the proglacial fluvial activity, which is likely to be in a transient state with ongoing climate change.

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%.

Active layer monitoring at CALM-S site near J.G.Mendel Station, James Ross Island, eastern Antarctic Peninsula

The Circumpolar Active Layer Monitoring - South (CALM-S) site was established in February 2014 on James Ross Island as the first CALM-S site in the eastern Antarctic Peninsula region. The site, located near Johann Gregor Mendel Station, is labelled CALM-S JGM. The grid area is gently sloped (<3°) and has an elevation of between 8 and 11ma.s.l. The lithology of the site consists of the muddy sediments of Holocene marine terrace and clayey-sandy Cretaceous sedimentary rocks, which significantly affect the texture, moisture content, and physical parameters of the ground within the grid. Our objective was to study seasonal and interannual variability of the active layer depth and thermal regime at the CALM-S site, and at two ground temperature measurement profiles, AWS-JGM and AWS-CALM, located in the grid. The mean air temperature in the period March 2013 to February 2016 reached -7.2°C. The mean ground temperature decreased with depth from -5.3°C to -5.4°C at 5cm, to -5.5°C to -5.9°C at 200cm. Active layer thickness was significantly higher at AWS-CALM and ranged between 86cm (2014/15) and 87cm (2015/16), while at AWS-JGM it reached only 51cm (2013/14) to 65cm (2015/16). The mean probed active layer depth increased from 66.4cm in 2013/14 to 78.0cm in 2014/15. Large differences were observed when comparing the minimum (51cm to 59cm) and maximum (100cm to 113cm) probed depths. The distribution of the active layer depth and differences in the thermal regime of the uppermost layer of permafrost at CALM-S JGM clearly show the effect of different lithological properties on the two lithologically distinct parts of the grid.

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.

Active layer monitoring in Antarctica: an overview of results from 2006 to 2015

Monitoring of active layer thawing depth and active layer thickness (ALT), using mechanical pronging and continuous temperature data logging, has been undertaken under the Circumpolar Active Layer ...