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The project EPOPEE is embedded in the international project ASTAR to study direct and indirect climate effects of aerosols and clouds in the Arctic. The particular goals of the project EPOPEE are to experimentally characterize the ice phase in Arctic clouds (including the ice phase) in situ, to study the aerosol-cloud as well as cloud-radiation interactions, and to develop adequate methods to validate remote sensing cloud parameters. In 2004 the project EPOPEE is mainly organized around in situ observations of detailed microphysical and optical cloud properties onboard the Polar-2 aircraft during the transition from polluted Arctic haze (observed especially in late winter, early spring months) to clean summer aerosol conditions. The transition from Arctic haze to clean summer conditions is quite sharp (a large amount of aerosols coming from Eurasian industrial areas accumulate over the Arctic and cover the Arctic by a layer of a smog-like haze of the size of the continent of Africa) due to a radical change in atmospheric transport patterns and is, thus, easy to identify. During Arctic summer, the high latitudes are then more or less “protected” from long-range transport of air masses from lower latitudes. The principal scientific objective of the project EPOPEE in 2004 will focus on studying the aerosol-cloud interactions with particular attention given to the ice phase nucleation in Arctic mixed-phase clouds. The interpretation of the instrumental observations will broadly benefit from a very close cooperation with the LaMP modelling group for theoretically coupling small-scale processes (cloud particle nucleation) with meso-scale dynamics. Furthermore, the project will focus on cloud-radiation interaction and the development of adequate methods to validate cloud parameters retrieved from remote sensing techniques. Therein, we will experimentally answer the question of how the different ice crystal shapes govern the scattering phase function of respective crystals. Moreover, the in situ cloud measurements will allow to develop an adequate strategy for the interpretation of remote sensing data from a depolarisation Lidar onboard the same aircraft (Polar-2).
Mapping and monitoring of the snow cover with use of satellitte born optical instruments for (1) direct use of observations of climate change and (2) use of observations in climate modelling. Measurements of the snows spectral reflectance and other physical properties.
This technological program aims to collect permanent informations on local meteorology and aerosols particles at Corbel Station, Svalbard, 6km east of Ny alesund. 78 54 N, 12 07 E Programme 2004 – 2005 April 2004 : Prticmle counter installation and collect datas from meteo Station. Soar cels will be also instlled at the station to power these systems.
This technological program aims to collect permanent informations on local meteorology and aerosols particles at Corbel Station, Svalbard, 6km east of Ny alesund. 78 54 N, 12 07 E Programme 2004 – 2005 April 2004 : Prticmle counter installation and collect datas from meteo Station. Soar cels will be also instlled at the station to power these systems.
This technological program aims to get a better view of the Corbel site quality (78 54 N, 12 07 E, Svalbard close to Ny Alesunsd) for atmospheric chemistry. Nox and SO2 samplers are deployed on 16 places on a 4 km2 area around the Station (79°N, Svalbard), protected from snowscooters activity. The influence of Ny Alesund village is also studied. Programme 2004 April 2004 : poles installation and samplers deployment on the 16 stations; analysis will be made by CNR.
GPS has become an important tool both in navigation and in precise point positioning. One of the nuicance parameters limiting the accuracy of point determination is the water vapor content of the troposphere. On the other hand meteorologists are interested in the wet component of the troposphere as a valuable tool for Numerical Weather Prediction. Therefore GPS offers a low cost monitoring of water vapor with high temporal resolution. We make use of continuous measurements of the GPS/GLONASS reference station network in Austria, which currently consists of about 30 sites with distances ranging from 50 km to 120 km. We calculate the zenith wet delays for a period of 2 months (February and March 2002). Subsequently the results are compared to contributions of different processing centers of the COST-716 project ?Exploitation of Ground Based GPS for Climate and NWP? and with zenith path delay estimates provided by the IGS. As meteorologists need the water vapor within less than two hours, special attention is paid to the availability, reliability and especially to the quality of the satellite orbits used for the network calculations.
It is well known that tritium, the hydrogen isotope 3H, is part of nuclear weapons and was spread all over the world as a consequence of nuclear bomb explosions. Rarely it is regarded as being “natural”, but actually it is. Long time before humans appeared tritium already existed on earth for a long time. This “natural” tritium is the product of cosmic radiation interactions with the atmosphere (mainly N-14). Nowadays this kind of tritium production contributes only to a small extent to the atmospheric tritium. Tritium is radioactive and decays with a half-life of 4.500 days under the emission of a very low energetic beta-particle. In the atmosphere tritium can be found within water vapour (HTO), hydrogen (HT) or methane (CH3T). Yet, the main portion of tritium released during the 1960’s has already been eliminated from the atmosphere by radioactive decay and precipitation. A large amount is captured in the oceans. Indeed, today anthropogenic sources releasing tritium to the environment can still be found. At the end of the 1980‘s contacts with research institutes in former Eastern Bloc countries lead to the idea of establishing a tritium sampling network. The primary goal was the documentation of atmospheric tritium. Statements about potential releases and their sources and the radiation hazards associated should be obtained. Furthermore it might help with the verification of meteorological models. To acquire comparable results a standardised sampling device was developed. This system simultaneously collects samples of air humidity and hydrogen. It was planned to enlist the gathered data in a database and to use them for the following subjects: • observation of local and global tritium transport in the atmosphere • detecting tritium releases and locating their sources • radiation risk evaluation • examining the transmutation of elemental hydrogen into water under natural conditions With the breakdown of the Eastern Bloc the idea of this common network faded away. At the moment only at two stations in Austria air humidity and air hydrogen are collected as planned: since 1991 at Research Center Arsenal in Vienna and since 1999 at Hoher Sonnblick a high mountain station (3160 m). Currently we are working together with the IAEA on a project with the aim to find a model, which helps evaluating weather conditions and in particular the climatic processes. As for these investigations the stable isotopes H-2 and O-18 are used and the currently used device introduces fractionation a new method is developed right now. Since the specific tritium activity concentration is not affected by air pressure or humidity the values for the two locations can be compared directly. In general the measured values are similar but sometimes differ noticeably. For example a peak value for the tritium activity concentration observed during March 2000 at Sonnblick was not noticed in Vienna. In this context the attempt should be made to analyse the air flows with the help of trajectories. The tritium activity concentration of air humidity is primarily determined by the amount of humidity itself. Therefore the concentration is directly linked to the seasons. Only significant changes in the specific tritium activity concentration can be detected by the use of the tritium activity concentration. Seasonal variations within the tritium activity concentration of hydrogen could not be observed. The values vary around 10 mBq/m3.
Work program: Grab air samples will be collected in sampling sites not influenced by local emission sources for the determination of chlorofluorocarbons and of hydrogenated halocarbons. A 15 days sampling campaign is scheduled. Samples will be analysed in our Institution by using the analytical methodology here described and results obtained will be evaluated and compared with data obtained, by using the same analytical methodology, analysing air samples collected in other remote and semi remote sites. For the analysis of the hydrogenated halocarbon degradation products snow and water samples will be collected as well, according to the different season of the year. The collected samples will be then derivatized and analysed in our Institution for the evaluation of the presence of such compounds in remote areas.
The objectives of the project are the investigation of the ion concentration in the precipitation water as well as the determination of the ion entries belonged by the precipitation water. The temporal variability was described on the one hand on the basis the appropriate yearly variations (saisonality), on the other hand over the long-term behaviour (trend) with heavyweight on the main components (S- and N- connections). Additionally on basis of the data of the further Lands of the Federal Republic the spatial variability for the Austrian federal territory is represented.
The aims of the project are: - to evaluate the fluxes of radionuclides in the water column and their accumulation in the sediment, on a short-time scale; - to determine the C/N and delta13C-delta15N ratios in suspended and sedimentary matter, and test their use as tracers of origin, composition and transformation pathways of organic particles. The selected study area is the Kongsfjord-Krossfjord system, Svalbard, considered as representative test-site for studying processes occurring in Arctic fjords. The focus of the project will be on the processes occurring at the glacier-sea interface, where enhanced lithogenic and biogenic particle fluxes are reported in summer. Specific methods will be used to trace the particle sources. The rate of accumulation-resuspension processes will also be investigated from the inner fjord to the outer continental shelf.
-Quantify changes in ice dynamics and characteristics resulting from the switch in AO phase -Establish a climate record for the region north of Greenland through the retrieval and analysis of sediment cores -Improve an existing dynamic-thermodynamic sea ice model, focusing on the heavily deformed ice common in the region -Relate the region-specific changes which have occurred to the larger-scale Arctic variablity pattern -Place the recent ice and climate variability for this critical region into the context of long term climate record, as reconstructed from sediment cores
A millimeter wave radiometer is started operation at the Swedish Institute of Space Physics, Kiruna, Sweden. The location of the instrument (67.8 N, 20.4 E) allows continuous observation of the evolution of ozone and ozone related trace gases in the Arctic polar stratosphere. It is designed for measurements of thermal emission lines around 204 Ghz. At this frequency observations include of ozone, chlorine monoxide, nitrous oxide, and nitric acid.
Objective: to determine how solar activity influences temperatures, winds, electric currents and minor constituents and to allow possible anthropogenic influences to be determined. Uses primarily measurements by the ESRAD and EISCAT radars, plus ground-based and balloon-borne measurements of atmospheric electric fields and currents.
The focus of this project is the improvement of water vapour measurement techniques in the upper troposphere and lower stratosphere. Routine measurements of water vapour with high accuracy in these altitudes are an unsolved problem of meteorological measurements up to now. Water vapor is the dominant greenhouse gas in the earth's atmosphere. Recent model calculations show that observed water vapour increases in the stratosphere contribute significantly both to surface warming and stratospheric cooling. In addition to climate change both the direct chemical and indirect radiative effects of stratospheric water changes in ozone chemistry are important as well. Despite of many activities in the past ten years, accuracies of the available methods for measuring the water vapour vertical profile in the free atmosphere are still not sufficient. Therefore one of the aims of the forthcoming EU COST Action 723 "The Role of the Upper Troposphere and Lower Stratosphere in Global change", is to improve sounding and remote sensing techniques of water vapour (see http://www.sat.uni-bremen.de/cost/). Another example of the planned work focusing on water vapour is proposed GEWEX (Global Energy an Water Cycle Experiment) Water Vapour Project (GVaP). See [SPARC 2000] and the references therein. The idea of LAUTLOS-WAVVAP comparison/validation experiment which brings together lightweight hygrometers developed in different research groups, which could be used as research-type radiosondes in UTLS region. These include the following instruments: Meteolabor Snow White hygrometer, NOAA frostpoint hygrometer, CAO Flash Lyman alpha hygrometer, Lindenberg FN sonde (a modification of Vaisala radiosonde) and the latest version of regular Vaisala radiosonde with humicap-polymer sensor. The experimental plan of LAUTLOS-WAVVAP is based on the regular launches of multi-sensor payloads from the Sodankylä meteorological balloon launch facility in January -February 2004. The aim is to study the effect of atmospheric conditions such as ambient temperature, water vapour or relative humidity, pressure or solar radiation for each participating hygrometer/radiosonde. Both night and daytime launches are planned. Apart from the intercomparison/validation experiment the campaign also have an scientific aim of studying the stratospheric PSC occurrence and their dependence on local temperature and the water vapour content. The campaign will be hosted by FMI Arctic Research Centre Sodankylä assisted by Vaisala Oyj and is a part of planned Finnish contribution to Cost 723 project. The campaign in Sodankylä is partly funded from LAPBIAT Facility, which belong to the EU program: Access to Research Infrastructures (see: http://www.sgo.fi/lapbiat/). References: SPARC Assessment of Upper Tropospheric and Stratospheric Water Vapor/SPARC Report No2/ December 2000
Polar stratospheric clouds play a key-role in polar ozone destruction. Cold temperatures in the vortex allow formation of these clouds. Depending on the PSC-type different formation-temperatures have to be reached. Synoptic temperatures do not always fall to these formation-temperatures, but waves in the atmosphere can lead to additional cooling of several 10 K, which allows PSC-formation. Whereas the wave-activity at the ESRANGE is very high due to hilly surrounding area, the orographic wave-activity at ALOMAR is expected to be rather small. Waves with long wavelengths will be present at both stations simultaneously. Coordinated measurements of temperature and aerosols will show both the large-scale wave-part and also the locally induced wave-part. Such measurements should allow identification of the different wavelngth scales and in addition contribute to a better estimate of the importance of wave-induced clouds for PSC-formation.
During the past years, atmospheric research in high latitudes has been focussed on processes causing ozone loss in the polar winter lower stratosphere1). Recent research efforts also dealt with regions up to the lower mesosphere, and studied the effects of charged particle precipitation on NO and ozone2)-5). However, the measurement techniques and hence the database for studying such processes in this altitude range are very limited. The Airborne SUbmillimeter Radiometer ASUR6),7) of the Institute of Environmental Physics of the University of Bremen has recently been equipped with a high-resolution spectrometer that will enable the retrieval of vertical profiles of ozone up to an altitude of about 65 - 70 km. Its measurement capabilities comprise also several other species of interest, especially NO. This makes the measurement technique particularly suitable for upper stratospheric/lower mesospheric studies. The lidar at ALOMAR is capable of measuring highly resolved vertical profiles of ozone up to an altitude of 60 km, thus giving the rare opportunity for intercomparison and validation studies in an altitude range reaching from the lower stratosphere to the lower mesosphere. Therefore we propose to perform simultaneous ozone measurements of the ASUR instrument with the ALOMAR lidar, supported by launches of ozone sondes.
Noctilucent clouds (NLC) remain a fascinating phenomenon of the upper atmosphere to study. The questions about the typical particle density and particle size distribution within a NLC are very prominent ones, to which a number of answers have been given, though some of the answers contradict each other. The parameters of particle size distributions can be derived from groundbased lidar measurements of the spectral dependence of the volume backscatter coefficient of an NLC. Such studies have been performed during a number of NLC events by e.g. the ALOMAR Rayleigh/Mie/Raman (RMR) lidar (von Cossart et al., GRL, 26, 1513, 1999). A drawback of these experiments is the wavelength limitation of the RMR lidar, the shortest wavelength of which is 355 nm. At this wavelength, the sensitivity of the lidar to particles with sizes smaller than, say, 25 nm is minimal. Because a considerable part of the entire particle population may have sizes below that threshold, a lingering question remains whether or not this drawback matters for typical NLC distributions. Using the ALOMAR ozone lidar, a measurement of the NLC volume backscatter coefficient at 308 nm becomes possible. Due to the l-4 -dependence of the backscatter coefficients, the latter are almost a factor of 2 larger at this wavelength than at 355 nm. For this reason and in order to gain a fourth wavelength to the spectral distribution, we aim at using the ozone lidar for the outlined project.
These investigations confirm the fact that in the stratosphere the ozone is considerably influenced by dynamical processes and it is a good indicator of them. In this context the main objectives of the proposed study are: 1) to investigate the possible relationship between stratospheric ozone perturbations and the temperature enhancement in the upper mesosphere, observed by Shepherd et al. (2001); 2) to examine whether changes in ozone, concomitant with the phenomenon, take place and how and when they would be manifested; and 3) to investigate the stratospheric ozone behaviour during the equinox atmospheric transition in the North Hemisphere, for better understanding of the middle atmosphere dynamics.
Study of the energy exchange between atmosphere, sea ice and ocean during freezing and melting conditions; within that, measurements of solar radiation (visible and UV) and optical properties, snow and sea ice characteristics, vertical heat and salt fluxes, oceanographic parameters.
To investigate arctic foxes physiological adaptations to life at high latitudes. Resting and running metabolic rates, body weight, food intake, body core temperature, heart rate, and blood parameters were examined during different seasons and during periods of food deprivation.