Projects/Activities

The main objective of the project is to describe quantitatively with model calculations the global distribution behaviour of persistent organic contaminants, and to establish credibility in the results of these simulations.

Fluvial transport, its dynamics and structure, constitute a good indicator of the condition of the natural environment in various climatic zones. Analysis of fluvial transport components allows for precise determination of the rate and directions of transformations of geosystems of any importance. In the polar zone, very sensitive to global changes, it seems expedient to identify the mechanisms and structure of fluvial transport, particularly in the conditions of the observed glacier retreat, the main alimentation source of proglacial rivers. Studies carried out in the zone revealed difficulties in determination of fluvial transport structure, particularly the actual bedload of gravel-bed rivers based on direct measurements, resulting from: short measurement series, lack of standardization of research methods and measurement equipment, and strategy of selection of study objects and sampling. The research project presented concerns determination of mechanisms of fluvial transport and sediment supply to Arctic gravel-bed river channels. The mechanisms reflect the processes of adaptation of proglacial rivers of the Arctic zone to changing environmental conditions, and indicate the dominant directions of transformations of paraglacial geosystems of various importance. For studies on Arctic geosystems, the region of the south Bellsund (SW Spitsbergen) was selected due to extensive knowledge on its hydro-meteorological and glacial-geomorphological conditions, and long-term measurement series carried out by the research station of the MCSU, among others within the framework of the international monitoring network: SEDIBUD (IAG) and Small-CATCHMENT program. For detailed studies, rivers with various hydrological regimes were selected, functioning at the forefield of the Scott and Renard Glaciers. The Scott River glacial catchment and glacier-free catchments of the Reindeer Stream and the Wydrzyca Stream (with a snow-permafrost hydrological regime) meet the selection criteria for representative test catchments analyzed for the following programs: SEDIFLUX, SEDIBUD, and POP.

i. Determine mercury, metals and persistent organic contaminant pollutants (POPs) concentrations in lake trout harvested from two locations (West Basin near Hay River, East Arm at Lutsel K’e) and burbot harvested from one location (West Basin at Fort Resolution) in 2015 to further extend the long-term (1993-2013 (POPs) and 1993-2014 (mercury)) database. ii. Determine POPs trends in lake trout and burbot using our 1993-2014 data base. iii. Continue our investigations of mercury trends in predatory fish to include lakes in the Deh Cho, Great Bear Lake, and other lakes as opportunities arise. iv. Participate in and contribute information to AMAP expert work groups for trend monitoring for POPs and mercury. v. Integrate our mercury trend assessments with studies we are conducting in the western provinces as part of Canada’s Clear Air Regularly Agenda for its Mercury Science Assessment. vi. Work with communities in capacity building and training.

The project aims at producing an ENVISAT-1 mission-long monitoring of the inorganic chlorine (Cly) and fluorine (Fy) loading in the Earth’s middle atmosphere, based on FTIR vertical column abundance measurements of the key related species HCl, ClONO2, HF and COF2 at 10 ground-based NDSC sites distributed worldwide. These Cly and Fy inventories will be completed with ClO and OClO measurements expected as Level-2 products from ENVISAT-1. The column abundances of the source gases CFC-12 and HCFC-22 will be used to place the stratospheric Cly and Fy evolution in perspective with the more complete sets of organic chlorinated and fluorinated compounds measured at the ground by the in situ networks NOAA-CMDL and AGAGE. The assimilation of the retrieved geophysical data bases will be performed through 3-D model calculations incorporating physical, chemical and transport characteristics of the global atmosphere.

The present project aims at the geophysical validation, from pole to pole and on the long term, of key ozone-related level-2 products (O3, NO2, BrO, OClO, and ClO) from GOMOS, MIPAS and SCIAMACHY onboard ENVISAT-1, and at a contribution to the maturation of the related level-1b-to-2 data processors. Application data processing will be used to convert level-2 data into a more suitable format for validation and scientific end-users. The respective performances of the ENVISAT data products, and their sensitivity to various relevant parameters, will be investigated from the Arctic to the Antarctic, over a variety of geophysical conditions. The impact of these performances on specific atmospheric chemistry studies will be emphasised. The pseudo-global investigations will rely on correlative studies of ENVISAT data with high-quality ground-based, in situ and balloon observations associated with the Network for the Detection of Stratospheric Change (NDSC).

The project will provide a long-term, pseudo-global validation support to the ENVISAT-1 atmospheric measurements, based on mutually consistent high-quality solar and lunar observations from FTIR spectrometers operated at primary and a number of complementary NDSC stations. The validation is limited to a number of target species, most of which are primary NRT or OL level-2 products of the mission, with focus on NOy components: O3, NO2, NO, N2O, HNO3, HNO4, H2CO, CO and CH4. Synergistic use will be made of column and profile data from MIPAS, GOMOS and SCIAMACHY. The ground network will deliver mean vertical column abundances for all target species with NDSC-type quality, and height profile information for some target gases as secondary products to the PI's home institute, where the correlative analyses with the ENVISAT-1 products will be done. Asynoptic mapping tools will support the validation efforts.

The main objectives of ESAC II are the following: (1) Extend and improve the important existing Belgian contribution in atmospheric research started in the 50s, recognized internationally. (2) Investigate the chemistry of the atmosphere, to detect and understand its evolution, mainly with experimental means. Special attention will be paid to the evolution of the ozone layer and chemical species and processes with an impact on climate changes. (3) Support the Belgian policies and decisions regarding the Amendments to: - the Montreal Protocol on Substances that deplete the Ozone Layer; - the Kyoto Protocol on Greenhouse Gases (GHG) emissions.

EARLINET will establish a quantitative comprehensive statistical database of the horizontal, vertical, and temporal distribution of aerosols on a continental scale. The goal is to provide aerosol data with unbiased sampling, for important selected processes, and air-mass history, together with comprehensive analyses of these data. The objectives will be reached by implementing a network of 21 stations distributed over most of Europe, using advanced quantitative laser remote sensing to directly measure the vertical distribution of aerosols, supported by a suite of more conventional observations. Special care will be taken to assure data quality, including intercomparisons at instrument and evaluation levels. A major part of the measurements will be performed according to a fixed schedule to provide an unbiased statistically significant data set. Additional measurements will be performed to specifically address important processes that are localised either in space or time. Back-trajectories derived from operational weather prediction models will be used to characterise the history of the observed air parcels, accounting explicitly for the vertical distribution.

SOGE is an integrated system for observation of halogenated greenhouse gases in Europe. There are two objectives: (1) To develop a new cost-effective long-term European observation system for halocarbons. The results will be in support of the Kyoto and the Montreal protocols,in assessing the compliance of European regions with the protocol requirements. In particular the observation system will be set up to: - detect trends in the concentrations of greenhouse active and ozone-destroying halocarbons; - verify reported emissions and validate emission inventories; - develop observational capacity for all halocarbons included in the Kyoto protocol (PFC, SF6) for which this is presently not yet existing; - develop a strategy for a cost-effective long-term observation system for halocarbons in Europe. (2) To predict and assess impacts of the halocarbons on the climate and on the ozone layer. This implies extensive exploitation of existing data. The impact assessment will be aimed at providing guidance for development of the Kyoto protocol and to the further development of the Montreal protocol mendments, by: - modelling impacts of halocarbons on radiative forcing and their relative importance for climate change; - modelling impacts of emissions of CFCs and HCFCs on the ozone layer.

The aim of QUILT is to optimise the exploitation of the existing European UV-visible monitoring systems by which O3 and the related free radicals NO2, BrO and OClO can be measured. These monitoring systems include ground-based, balloon and satellite observations. QUILT is providing an assessment of the chemical ozone loss over the last decade and through 2000-2003. This is achieved through analysis improvements, consolidation of existing datasets and near real time integrations with chemical transport models.

The overall objective of COSE is to provide the Earth Observation (EO) user community with a validated, consistent and well-documented data set of mainly stratospheric constituent columns and/or profiles, by co-ordination of ground-based observations at existing stations in Europe. The data set builds on past and ongoing time series, and will be archived in a dedicated database for immediate and future exploitation, e.g., satellite validation activities, data assimilation and scientific studies. Active participation of some representative EO customers will assure that the delivered data sets come up to their requirements.

The main specific objectives of UFTIR are: (1) To revise and homogenise the analyses of available experimental data for providing consistent time series of distinct tropospheric and stratospheric abundances of the target gases using new inversion algorithms. A common strategy for retrieval and characterisation of the vertical distributions of the target gases from FTIR ground-based measurements will be established. (2) To provide quantitative trends and associated uncertainties for the target gases over about the last decade, as a function of latitude throughout Western Europe, focusing on the troposphere. (3) To integrate the data in model assessments of the evolutions of tropospheric abundances. The measured burden and changes of the tropospheric gases will be compared with 3D model simulations, in order to help developing the latter, assist in explaining potential causes for the observed changes and to assess the consistencies between the trends at the surface to the free troposphere and lowermost stratosphere, and the agreement with known evolutions of emissions. UFTIR will make the community prepared to deliver tropospheric data for validation and synergistic exploitation of new satellite experiments like ENVISAT.

The general objective of the proposed project is to increase the understanding of the Mercury Depetion Events occoring in the Arctic sunrise and quntify the input of mercury to polar ecosystems during this events.

1. Analysis of existing data from the current shellfish monitoring programmes in order to design a suitable sampling strategy 2. Ideentification of toxic algal species in UK waters 3. Construction of a detailed time-series at several key sites in the UK for toxic phytoplankton and shellfish toxin occurence 4. Comparison of the genotype versus toxicity of suspected toxic species between sites

A dedicated study into the formation of new particles, PARFORCE (New particle formation and fate in the coastal environment), was conducted over a period from 1998-1999 at the Mace Head Atmospheric Research Station on the western coast of Ireland. Continuous measurements of new particle formation were taken over the two-year period while two intensive field campaigns were also conducted, one in September 1998, and the other in June 1999. New particle events were observed on »90% of days and occurred throughout the year and in all air mass types. These events lasted for, typically, a few hours, with some events lasting more than 8 hours, and occurred during daylight hours coinciding with the occurrence of low tide and exposed shorelines. During these events, peak aerosol concentrations often exceeded 10 6 cm -3 under clean air conditions while measured formation rates of detectable particle sizes (i.e. d > 3nm) were of the order of 10 4 -10 5 cm -3 s -1 . Nucleation rates of new particles were estimated to be, at least, of the order of 10 5 -10 6 cm -3 s -1 and occurred for sulphuric acid concentrations above 2 x 10 6 molecules cm -3 ; however, no correlation existed between peak sulphuric acid concentrations, low tide occurrence or nucleation events. Ternary nucleation theory of the H2SO4-H2O-NH3 system predicts that nucleation rates far in excess of 10 6 cm -3 s -1 can readily occur for the given sulphuric acid concentrations; however, aerosol growth modelling studies predict that there is insufficient sulphuric acid to grow new particles (of »1 nm in size) into detectable sizes of 3 nm. Hygroscopic growth factor analysis of recently-formed 8 nm particles illustrate that these particles must comprise some species significantly less soluble than sulphate aerosol. The nucleation-mode hygroscopic data, combined with the lack of detectable VOC emissions from coastal biota, the strong emission of biogenic halocarbon species, and the finger-printing of iodine in recently-formed (7 nm) particles suggest that the most likely species resulting in the growth of new particles to detectable sizes is an iodine oxide as suggested by previous laboratory experiments. It remains an open question whether nucleation is driven by self nucleation of iodine species, a halocarbon derivative, or whether first, stable clusters are formed through ternary nucleation of sulphuric acid, ammonia and water vapour, followed by condensation growth into detectable sizes by condensation of iodine species. Airborne measurements confirm that nucleation occurs all along the coastline and that the coastal biogenic aerosol plume can extend many 100s of km away from the source. During the evolution of the coastal plume, particle growth is observed up to radiatively-active sizes of 100 nm. Modelling studies of the yield of cloud-condensation nuclei suggest that the cloud condensation nuclei population can increase by »100%. Given that the production of new particles from coastal biogenic sources occurs at least all along the western coast of Europe, and possibly many other coastlines, it is suggested that coastal aerosols contribute significantly to the natural background aerosol population.

The International Panel on Climate Change (IPCC) has very recently revised the prediction of global average temperature increase during the next century from 1.0-3.5 to 1.4-5.8 K. The increase in the upper limit of the prediction is largely due to the role of aerosols in the climate of the Earth: it is believed that reduction of pollution will result in reduced direct and indirect (via clouds) scattering of sunlight back to the space. However, as can be seen from the large uncertainty of the estimated temperature increase, not enough is known about the role of natural and anthropogenic aerosols in climate processes. This is also reflected in the Key Action 2, under the RTD priority 2.1.1, calling for ”… quantification and prediction of … concentration of … aerosols, in particular the fine fraction of particles and their precursors”. The concentration of aerosols is controlled by their sources and sinks, and thus the prediction of particle concentration requires the quantification of aerosol source terms. The main objective of QUEST is to quantify the number of new secondary aerosol particles formed through homogeneous nucleation in the European boundary layer, and the relative contributions of natural and anthropogenic sources. The role of homogeneous nucleation in the formation of new atmospheric particles was realized in the 1990s, and considerable effort has been devoted to studies of aerosol formation in various parts of the Globe. The longest continuous data series of nucleation events has been obtained at a forest field station in Finland, where aerosol size distributions between 3 and 150 nm in diameter have been recorded in 10 minute intervals since the beginning of 1996 [1]. Nucleation events occur in this rather clean Boreal area roughly 50-60 times per year, the highest event frequency taking place in the spring months (March-May). The concentration of new particles per cc of air formed during one event varies between roughly 100-10 000. Taking the average number to be one thousand, and assuming that the nucleation takes place in a well mixed boundary layer having a height of 1000 m, it can be estimated that the aerosol source term in the Boreal forest area is on the order of 51013 m-2 per year. This is on the same order as the global aerosol yield estimated from primary emissions [2]. The number given here is very crude as we can at present only guess the vertical extent of the nucleation zone; however, it clearly shows that homogeneous nucleation events influence atmospheric particle concentrations at least at regional scales, and possibly also globally. Many features of the Boreal nucleation events have been revealed thus far. Necessary (but not sufficient) conditions include sunny weather, vertical mixing of air in the morning (prior to the detection of the event) [1], and a treshold value of a quantity that depends on radiation intensity (vapor source) and pre-existing aerosol size distribution (vapor sink) [3]. The springtime events always seem to take place in Polar or Arctic air masses [4], but so far it is unclear whether the meteorology is similar during other seasons. Aerosol flux measurements [5] indicate that the particles are formed aloft, but the vertical extent of the nucleation layer is unknown. However, there is clear evidence from simultaneous measurements at various locations, that the horizontal extent of the areas in which the nucleation takes place can be hundreds and in some cases even thousands of kilometers [1]. No direct correlation of nucleation events with SO2 concentrations has been found; however the product of SO2 concentration, ammonia concentration, and calculated OH concentration correlates with the events (personal communication). These results hint that the recently suggested ternary sulfuric acid-ammonia-water nucleation mechanism of small clusters, followed by the growth of the clusters due to condensation of other (possibly organic) vapors [6], may be operational in the Boreal forest area. Furthermore, there is experimental evidence that nucleation event particles in the 4-5 nm range are soluble in butanol (working fluid of condensation particle counters), which indicates organic composition. However, the confirmation of the ternary nucleation hypothesis requires simultaneous measurements of sulfuric acid vapor and ammonia, and further studies of the composition of the nucleated particles. Furthermore, to facilitate large-scale modelling studies, the vertical extent of the nucleation events, as well as the meteorological conditions during non-springtime events have to be investigated. Measurements of nucleation events at a more Central European location indicate that SO2 levels increase during the majority of nucleation events [7]. It can be hypothesized that a part of observed nucleation events (minority in Central Europe, majority in the Boreal area) are ”natural” and a part are affected (or even caused) by pollution (majority in Central Europe, minority in the Boreal area). The confirmation of this hypothesis and implementation of the pollution type nucleation mechanism into a large-scale model requires carefully designed measurements from a location which is preferably Southern European as there is very little available nucleation data from this area. One of the few observations of new particles in Southern Europe [8] is from the Italian site where we plan to study the frequency, meteorology, vertical extent, and chemical precursors of nucleation events. Another type of nucleation events has been observed all along the western coast of Europe and have been studied more particularly at the west coast of Ireland [9]. These events, which have a duration of the order of 4 hours and up to 8 hours, occur almost daily around low tide and under conditions of solar radiation, indicating photochemical source. Incredibly, the peak new particle concentrations often exceed 106 cm-3, making this the strongest natural source region of atmospheric particles. The exact chemical mechanisms leading to the production of coastal particles still remains an open question. As in other environments, there appears to be sufficient sulphuric acid vapour to participate in ternary nucleation with ammonia and water, however, there is insufficient sulphuric acid to grow these particles to detectable sizes [9]. The most probable chemical species involved in the production or growth of these particles is Iodine, or an Iodine Oxide, produced photochemically from biogenic halocarbon emissions [9]. The production of particles from the photolysis of CH2I2 in the presence of ozone has been confirmed by recent smog chamber experiments [10]. While the concentration of new particles in this environment is extraordinarily high, its impact on background particle and CCN contribution remains unclear and needs to be quantified. A limited single study [11] has shown that the coastal aerosol plume is detectable up to several hunderds of km downwind and that the new coastal particles readily grow into CCN sizes (larger than 100 nm). An intensive campaign at the coast of Ireland will quantify the flux of both biogenic halocarbon precursor gases and the yield of new, and radiatively-active particles in the European coastal boundary layer. The objective of QUEST is to determine the source strength of new particle formation in the three above mentioned cases. The specific objectives are: 1) To fill in gaps that exist in the understanding of chemical and physical pathways leading to homogeneous nucleation of new aerosol particles; 2) To understand the meteorological conditions required for the events to take place and to be able to predict the horizontal and vertical extent of the events; 3) To implement parametrized representations of the nucleation mechanisms, based on the information from 1) and 2), to an European scale model in order to determine the source strength of homogeneous nucleation of aerosol particles in the European boundary layer.

The Submarine Operational And Research Environmental Database (SOARED)is comprised of a fixed relational environmental database using unclassified data collected during the Science Ice Exercises (SCICEX) during the past several years. It also includes publicly accessible gridded historical sound velocity, temperature and salinity data from 1900 from the US National Oceanographic Data Center. This project is a demonstration system to show ways to retrieve and analyze sound velocity, temperature and salinity profiles, bathymetry and ice thickness data using a mouse-driven GIS-based query.

The principal aim of the project is to establish a link between the marine carbon and sulphur cycles, for which the marine phytoplankton taxon Phaeocystis sp. was chosen as a model organism. This colony forming alga is an important source of the volatile organic sulphur compound dimethyl sulphide (DMS), and its dense blooms can act as a carbon sink. By combining the expertise of researchers working on the carbon and sulphur cycles a thorough inventory of these chemicals will be made. This should result in a better understanding of the role of Phaeocystis blooms in the escape of DMS in the atmosphere and of carbon from the photic zone, and consequently of its role in climate control.