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Various data sharing platforms are being developed to enhance the sharing of cohort data by addressing the fragmented state of data storage and access systems. However, policy challenges in several domains remain unresolved. The euCanSHare workshop was organized to identify and discuss these challenges and to set the future research agenda. Concerns over the multiplicity and long-term sustainability of platforms, lack of resources, access of commercial parties to medical data, credit and recognition mechanisms in academia and the organization of data access committees are outlined. Within these areas, solutions need to be devised to ensure an optimal functioning of platforms.

Africa's rapid population growth, and even more rapid urbanisation, creates serious sustainability challenges. Like many cities in other parts of the world, African cities try to become 'green', and promote change in urban design and lifestyles to encourage more sustainable living. Many of these initiatives are supported by international agencies and illustrated on agency websites. Studying these websites, we try to answer three related questions dealing with the inclusivity of those initiatives: the geographical coverage (which cities?), the thematic coverage (how 'holistic'?) and the social inclusivity (how inclusive in terms of social focus?). Both scholars and practitioners should become more inclusive in their approaches to sustainable cities in Africa.

To study interactions of airborne pathogens, e.g. Aspergillus (A.) fumigatus with upper and lower respiratory tract epithelial and immune cells, we set up a perfused 3D human bronchial and small airway epithelial cell system. Culturing of normal human bronchial or small airway epithelial (NHBE, SAE) cells under air liquid interphase (ALI) and perfusion resulted in a significantly accelerated development of the lung epithelia associated with higher ciliogenesis, cilia movement, mucus-production and improved barrier function compared to growth under static conditions. Following the accelerated differentiation under perfusion, epithelial cells were transferred into static conditions and antigen-presenting cells (APCs) added to study their functionality upon infection with A. fumigatus. Fungi were efficiently sensed by apically applied macrophages or basolaterally adhered dendritic cells (DCs), as illustrated by phagocytosis, maturation and migration characteristics. We illustrate here that perfusion greatly improves differentiation of primary epithelial cells in vitro, which enables fast-track addition of primary immune cells and significant shortening of experimental procedures. Additionally, co-cultured primary DCs and macrophages were fully functional and fulfilled their tasks of sensing and sampling fungal pathogens present at the apical surface of epithelial cells, thereby promoting novel possibilities to study airborne infections under conditions mimicking the in vivo situation.

The aerodynamic gradient method is widely used for flux measurements of ammonia, nitric acid, particulate ammonium nitrate (the NH3-HNO3-NH4NO3 triad) and other water-soluble reactive trace compounds. The surface exchange flux is derived from a measured concentration difference and micrometeorological quantities (turbulent exchange coefficient). The significance of the measured concentration difference is crucial for the significant determination of surface exchange fluxes. Additionally, measurements of surface exchange fluxes of ammonia, nitric acid and ammonium nitrate are often strongly affected by phase changes between gaseous and particulate compounds of the triad, which make measurements of the four individual species (NH3, HNO3, NH4+, NO3− necessary for a correct interpretation of the measured concentration differences. We present here a rigorous analysis of results obtained with a multi-component, wet-chemical instrument, able to simultaneously measure gradients of both gaseous and particulate trace substances. Basis for our analysis are two field experiments, conducted above contrasting ecosystems (grassland, forest). Precision requirements of the instrument as well as errors of concentration differences and micrometeorological exchange parameters have been estimated, which, in turn, allows the establishment of thorough error estimates of the derived fluxes of NH3, HNO3, NH4+, and NO3−. Derived median flux errors for the grassland and forest field experiments were: 39% and 50% (NH3), 31% and 38% (HNO3), 62% and 57% (NH4+), and 47% and 68% (NO3−), respectively. Additionally, we provide the basis for using field data to characterize the instrument performance, as well as subsequent quantification of surface exchange fluxes and underlying mechanistic processes under realistic ambient measurement conditions.

Within the project EUropean Studies on Trace gases and Atmospheric CHemistry as a contribution to Large-scale Biosphere-atmosphere experiment in Amazonia (LBA-EUSTACH), we performed tower-based eddy covariance measurements of O3 flux above an Amazonian primary rain forest at the end of the wet and dry season. Ozone deposition revealed distinct seasonal differences in the magnitude and diel variation. In the wet season, the rain forest was an effective O3 sink with a mean daytime (midday) maximum deposition velocity of 2.3 cm s−1, and a corresponding O3 flux of −11 nmol m−2 s−1. At the end of the dry season, the ozone mixing ratio was about four times higher (up to maximum values of 80 ppb) than in the wet season, as a consequence of strong regional biomass burning activity. However, the typical maximum daytime deposition flux was very similar to the wet season. This results from a strong limitation of daytime O3 deposition due to reduced plant stomatal aperture as a response to large values of the specific humidity deficit. As a result, the average midday deposition velocity in the dry burning season was only 0.5 cm s−1. The large diel ozone variation caused large canopy storage effects that masked the true diel variation of ozone deposition mechanisms in the measured eddy covariance flux, and for which corrections had to be made. In general, stomatal aperture was sufficient to explain the largest part of daytime ozone deposition. However, during nighttime, chemical reaction with nitrogen monoxide (NO) was found to contribute substantially to the O3 sink in the rain forest canopy. Further contributions were from non-stomatal plant uptake and other processes that could not be clearly identified. Measurements, made simultaneously on a 22 years old cattle pasture enabled the spatially and temporally direct comparison of O3 dry deposition values from this site with typical vegetation cover of deforested land in southwest Amazonia to the results from the primary rain forest. The mean ozone deposition to the pasture was found to be systematically lower than that to the forest by 30% in the wet and 18% in the dry season.

Strengthened summer monsoon brought tropical/continental moisture as far south as 25oS during late-glacial and early Holocene times. Precipitation rates in the Altiplano of the western Andes (24oS) increased to 500 mm yr-1 compared to, Changements dans l'environnement holocène de l'Altiplano d'Atacama et implications paléoclimatiques Une mousson renforcée a transporté l'humidité continentale vers l'Altiplano chilien pendant le Tardiglaciaire et le début de l'Holocène. Les précipitations étaient de l'ordre de 500 mm par an, valeur à comparer aux moins de 200 mm actuels. Les conditions climatiques ont été plus arides que de nos jours entre 8 400 et 3 000 ans BP environ. À partir de cette dernière date, le climat moderne, caractérisé par une réintensification des pluies tropicales, s'est établi. Les raisons des changements du climat pendant l'Holocène sur l'Altiplano ne sont pas connues. Divers facteurs peuvent expliquer ces changements paléoclimatiques : des variations de la circulation dans l'Océan Pacifique, des téléconnexions avec l'hémisphère Nord ou bien avec les basses terres du Continent Américain, ou bien des changements dans le bilan radiatif sur l'Altiplano., Cambios medioambientales durante el holoceno en el altiplano de atacama e implicaciones paleoclimáticas. Estudios pluridisciplinarios han permitido reconstruir los cambios extremos en el balance hídrico experimentados en el Altiplano de Atacama durante el Holoceno. La intensificación del monzón de verano (invierno boliviano) aumentó la precipitación de origen continental en la región hasta los 25o S durante el Tardiglacial/ Holoceno temprano. La precipitación en la región de los Andes occidentales (24o S) se incrementó hasta 500 mm por año en comparación con los 200 mm anuales de la actualidad. Durante el período entre 8400 y 3000 BP aproximadamente, la extrema aridez y la escasa precipitación dominada por tormentas, muy intensas pero esporádicas, fueron responsables de un descenso dramático del nivel de los lagos. A partir de los 3000 a BP, el cinturón de lluvia tropical volvió a desplazarse hacia el norte en varias fases hasta su posición actual (isoyeta de 200 mm anuales a 24o S). Diversos factores se consideran para explicar esta evolución paleoclimática : teleconexiones con el hemisferio norte, cambios en la circulación oceánica en el Pacífico oriental, cambios ambientales en la cuenca amazónica donde se origina el vapor de agua, o diferencias en albedo y cubierta de nubes en la región de Atacama., Grosjean Martin, Messerli Bruno, Ammann Caspar, Geyh Mebus A., Graf Kurt, Jenny Bettina, Kammer Klaus, Núñez Atencio Lautaro, Schneider Hans, Schotterer Ueli, Schwalb Antje, Valero-Garcés Blas, Vuille Mathias. Holocene environmental changes in the Atacama Altiplano and paleoclimatic implications. In: Bulletin de l'Institut Français d'Études Andines, tome 24, N°3, 1995. Eaux, glaciers & changements climatiques dans les Andes tropicales. pp. 585-594.

We update the forcings for the PMIP3 experiments for the Last Millennium to include a new assessment of historical land use changes and discuss new suggestions for calibrating solar activity proxies to total solar irradiance.

We update the forcings for the PMIP3 experiments for the Last Millennium to include new assessments of historical land use changes and discuss new suggestions for calibrating solar activity proxies to total solar irradiance.

Despite recent evidence on an important role of volatile amines in the nucleation of particulate matter, very scarce information is available on their atmospheric abundance and source distribution. Previous measurements in animal housings had identified livestock husbandry as the main amine source, with trimethylamine (TMA) being the key component. This has led to the assumption that the agricultural sources for amines are similar as for ammonia, emitted throughout the cascade of animal excretion, storage and application in the field. In this study, we present the first micrometeorological flux measurements as well as dynamic enclosure experiments showing that the amine source strength from stored slurry is negligible, implying significant consequences for the global amine emission inventory. In the case of cattle, amine production is attributed to the animal's rumination activity and exhalation is suggested to be an important emission pathway, similar to the greenhouse gas methane. Fodder like hay and silage also emits volatile amines, potentially assigning these alkaloid compounds a key function in enhancing particle formation in remote areas. Citation: Kuhn, U., J. Sintermann, C. Spirig, M. Jocher, C. Ammann, and A. Neftel (2011), Basic biogenic aerosol precursors: Agricultural source attribution of volatile amines revised, Geophys. Res. Lett., 38, L16811, doi:10.1029/2011GL047958.

Representative values of the atmospheric NO2 photolysis frequency j(NO2) are required for the adequate calculation and interpretation of NO and NO2 concentrations and exchange fluxes near the surface. Direct measurements of j(NO2) at ground level are often not available in field studies. In most cases, modeling approaches involving complex radiative transfer calculations are used to estimate j(NO2) and other photolysis frequencies for air chemistry studies. However, important input parameters for accurate modeling are often missing, most importantly with regard to the radiative effects of clouds. On the other hand, solar global irradiance ("global radiation", G) is nowadays measured as a standard parameter in most field experiments and in many meteorological observation networks around the world. Previous studies mainly reported linear relationships between j(NO2) and G. We have measured j(NO2) using spectro- or filter radiometers and G using pyranometers side-by-side at several field sites. Our results cover a solar zenith angle range of 0–90°, and are based on nine field campaigns in temperate, subtropical and tropical environments during the period 1994–2008. We show that a second-order polynomial function (intercept = 0): j(NO2)=(1+α)× (B1×G+B2×G2), with α defined as the site-dependent UV-A surface albedo and the polynomial coefficients: B1=(1.47± 0.03)×10-5 W−1 m2 s−1 and B2=(-4.84±0.31)×10-9 W−2 m4 s−1 can be used to estimate ground-level j(NO2) directly from G, independent of solar zenith angle under all atmospheric conditions. The absolute j(NO2) residual of the empirical function is ±6×10-4 s−1(2σ). The relationship is valid for sites below 800 m a.s.l. and with low surface albedo (&alpha

Climate models suggest that enhanced greenhouse gas concentrations and aerosols have major impacts on the land energy and water cycles, and in particular on evapotranspiration (ET). Here we analyze how the main external drivers of ET (incident solar radiation and precipitation) vary regionally, using recent data from a eddy-covariance flux tower network (FLUXNET) and a multi-model re-analysis (GSWP-2). Trends in radiation (global "dimming'' and "brightening'') are expected to impact ET only in regions where ET correlates with radiation. In central Europe this correlation is particularly strong, and trends derived from weighing lysimeters and river-basin water budgets follow trends in radiation. In central North America the correlation is weak, and trends in precipitation rather than radiation explain trends in ET. Our results reconcile previous hypotheses by demonstrating the strongly regional and temporal differentiation of trends in evaporation. Citation: Teuling, A. J., et al. (2009), A regional perspective on trends in continental evaporation, Geophys. Res. Lett., 36, L02404, doi: 10.1029/2008GL036584. [References: 20]

International audience; Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities represents ecosystem water use efficiency. Its multiplication with mean daylight vapor pressure deficit (VPD) leads to a quantity which we call "inherent water use efficiency" (IWUE*). The dependence of IWUE* on environmental conditions indicates possible adaptive adjustment of ecosystem physiology in response to a changing environment. IWUE* is analyzed for 43 sites across a range of plant functional types and climatic conditions. IWUE* increases during short-term moderate drought conditions. Mean annual IWUE* varied by a factor of 3 among all sites. This is partly explained by soil moisture at field capacity, particularly in deciduous broad-leaved forests. Canopy light interception sets the upper limits to canopy photosynthesis, and explains half the variance in annual IWUE* among herbaceous ecosystems and evergreen needle-leaved forests. Knowledge of IWUE* offers valuable improvement to the representation of carbon and water coupling in ecosystem process models.

International audience; Afin de comprendre la nature et la cause de la variabilité naturelle du climat, il est important d'expliquer les variations passées du climat par des forçages. L'objectif principal de ce travail est de présenter une procédure automatisée d'assimilation qui permette d'estimer l'amplitude de perturbations fortes mais temporellement très courtes, telles que des éruptions volcaniques, en utilisant des série temporelles climatiques. La procédure d'extraction et de décomposition est exécutée sur des données réelles de sulfate issues de carottes glacières forées en différents sites du Groenland. Le sulfate propulsé par les éruptions volcaniques est transporté via la stratosphère jusque vers les pôles et déposé par sédimentation. Ainsi le sulfate extrait sur ces différents sites constitue un marqueur des plus importantes éruptions volcaniques qui se sont produites à travers le monde. De tels processus sont fortement non linéaires, que ce soit dans leurs dates mais aussi dans leurs amplitudes. Lorsqu'il ne sont pas correctement détectés/estimés, ces évènements rares et extrêmes peuvent être à l'origine d'erreur d'estimation des différentes tendances de l'atmosphère. Ce travail peut être considéré à la fois comme un travail d'estimation d'évènements extrêmes et comme une première étape d'estimation de tendance.

International audience

Flussi di isoprene e monoterpeni sono stati determinati in un sito della foresta Amazzonica mediante tre differenti metodi micro-meteorologici. Le misure degli isoprenoidi e dei loro prodotti di ossidazione ha permesso di stabilire che, in contrato con quello che si pensava comunemente, alte concentrazioni di radicali OH sono presenti nell'Atmospheric Boundary Layer di questi siti remoti. E' stato inoltre confermato che l'emissione di isoprenoidi rappresenta una frazione molto piccola della frazione di CO2 assimilata.

Soil/atmosphere exchange fluxes of nitrous oxide were monitored for a 3-year period at 10 grassland sites in eight European countries (Denmark, France, Hungary, Ireland, Italy, The Netherlands, Switzerland and United Kingdom), spanning a wide range of climatic, environmental and soil conditions. Most study sites investigated the influence of one or several management practices on N2O exchange, such as nitrogen fertilization and grazing intensity. Fluxes were measured using non-steady state chambers at most sites, and alternative measurement techniques such as eddy covariance and fast-box using tunable diode laser spectroscopy were implemented at some sites. The overall uncertainty in annual flux estimates derived from chamber measurements may be as high as 50% due to the temporal and spatial variability in fluxes, which warrants the future use of continuous measurements, if possible at the field scale. nnual emission factors for fertilized systems were highly variable, ranging from 0.01% to 3.56%, but the mean emission factor across all sites (0.75%) was substantially lower than the IPCC default value of 1.25%. Emission factors for individual fertilization events increased

A one-dimensional multi-layer scheme describing the coupled exchange of energy and CO2, the emission of isoprene and the dry deposition of ozone is applied to a rain forest canopy in southwest Amazonia. The model was constrained using mean diel cycles of micrometeorological quantities observed during two periods in the wet and dry season 1999. Predicted net fluxes and concentration profiles for both seasonal periods are compared to observations made at two nearby towers. The predicted day- and nighttime thermal stratification of the canopy layer is consistent with observations in dense canopies. The observed and calculated net fluxes above and H2O and CO2 concentration profiles within the canopy show a good agreement. The predicted net carbon sink decreases from 2.5 t C ha-1yr-1 for wet season conditions to 1 t C ha-1yr-1 for dry season conditions, whereas observed and predicted midday Bowen ratio increases from 0.5 to 0.8. The evaluation results confirmed a seasonal variability of leaf physiological parameters, as already suggested in the companion study. The predicted midday canopy net flux of isoprene increased from 7.1 mg C m-2h-1 during the wet season to 11.4 mg C m-2h-1 during the late dry season. Applying a constant emission capacity in all canopy layers, resulted in a disagreement between observed and simulated profiles of isoprene concentrations, suggesting a smaller emission capacity of shade adapted leaves and deposition to the soil or leaf surfaces. Assuming a strong light acclimation of emission capacity, equivalent to a 66% reduction of the standard emission factor for leaves in the lower canopy, resulted in a better agreement of observed and calculated concentration profiles and a 30% reduction of the canopy net flux. The mean calculated ozone flux for dry season condition at noontime was ?12 nmol m-2s-1, agreeing well with observed values. The corresponding deposition velocity increased from 0.8 cm s-1 to >1.6 cm s-1 in the wet season, which can not be explained by increased stomatal uptake. Considering reasonable physiological changes in stomatal regulation, the predicted value was not larger than 1.05 cm s-1. Instead, the observed fluxes could be explained with the model by decreasing the cuticular resistance to ozone deposition from 5000 to 1000 s m-1. For doubled atmospheric CO2 concentrations the model predicts a strong increase of surface temperatures (0.1?1°C) and net assimilation (22%), a considerable shift in the energy budget (?25% decreasing transpiration and increasing sensible heat), a slight increase of isoprene emissions (10%) and a strong decrease of ozone deposition (35%).

The present study focuses on the description of the vertical dispersion of trace gases within the Amazon rain forest. A Lagrangian approach is parameterised using in-canopy turbulence measurements made at a site in Rondônia (Reserva Jaru). In contrast to common scaling schemes that solely depend on friction parameters measured above the canopy, a combined scaling that also includes night-time free convective mixing in the lower part of dense vegetation canopies is proposed here. 222Rn concentration profiles and soil flux measurements made at a second site near Manaus (Reserva Cuieiras) are used to evaluate the derived parameterisation and the uncertainties of the forward (prediction of concentration profiles) and inverse (prediction of vertical source/sink distributions) solution of the transfer equations. Averaged day- and night-time predictions of the forward solution agree with the observations within their uncertainty range. During night-time, a weak, but effective free convective mixing process in the lower canopy ensures a relatively high flushing rate with residence times of

The present study focuses on the description of the vertical dispersion of trace gases within the Amazon rain forest. A Lagrangian approach is parameterised using in-canopy turbulence measurements made at a site in Rondônia (Reserva Jaru). In contrast to common scaling schemes that solely depend on friction parameters measured above the canopy, a combined scaling that also includes night-time free convective mixing in the lower part of dense vegetation canopies is proposed here. 222Rn concentration profiles and soil flux measurements made at a second site near Manaus (Reserva Cuieiras) are used to evaluate the derived parameterisation and the uncertainties of the forward (prediction of concentration profiles) and inverse (prediction of vertical source/sink distributions) solution of the transfer equations. Averaged day- and night-time predictions of the forward solution agree with the observations within their uncertainty range. During night-time, a weak, but effective free convective mixing process in the lower canopy ensures a relatively high flushing rate with residence times of

Texto completo: acesso restrito. p. 1-18 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-01-20T13:36:12Z No. of bitstreams: 1 S. T. Oliva.pdf: 832024 bytes, checksum: 9a86f8b018199ee559be5e2d9298d5e5 (MD5) Made available in DSpace on 2014-01-20T13:36:12Z (GMT). No. of bitstreams: 1 S. T. Oliva.pdf: 832024 bytes, checksum: 9a86f8b018199ee559be5e2d9298d5e5 (MD5) Previous issue date: 2002 As part of the project LBA-EUSTACH (European Studies on Trace gases and Atmospheric Chemistry as a contribution to the Large-Scale Biosphere-Atmosphere experiment in Amazonia), the exchange of formic acid and acetic acid between vegetation and the atmosphere was investigated in the wet-to-dry season transition and the dry-to-wet season transition periods in 1999 in Rondônia, Brazil. Direct exchange measurements on the branch level mainly exhibited uptake of formic acid and acetic acid for all plant species in both seasons, although diel, seasonal, and interspecies variations were observed. Even though other physiological and physico-chemical parameters may have contributed, the uptake of organic acids was found to be primarily a function of the ambient atmospheric mixing ratios. The linear dependence suggests a bidirectional exchange behavior of the plants and calculated deposition velocities (0.17–0.23 cm s−1), compensation point mixing ratios (0.16–0.30 ppb), and potential emission rates under purified air conditions (0.013–0.031 nmol m−2 s−1) are discussed. Vertical profile measurements in and above the primary forest canopy further strengthened the assumption that the forest is rather a sink than a source for organic acids. The generally lower mixing ratios observed within the canopy were indicative of an uptake by vegetation and/or the soil surface. Continuous measurements of the ambient atmospheric mixing ratios at the canopy top revealed strong diel variations in both seasons and a marked seasonality with higher mixing ratios during the dry season, both being mirrored in the variation of observed uptake rates of the plants. High atmospheric concentrations during the dry season were attributed to biomass burning. During the wet season, when biomass burning activity was low, indirect emission by the vegetation, i.e., photochemical oxidation of primarily emitted biogenic reactive hydrocarbons, was assumed to dominantly contribute to the atmospheric burden of the organic acids. The high degree of correlation between atmospheric formic acid and acetic acid indicated that similar atmospheric processes were affecting their mixing ratios.

Texto completo: acesso restrito. p. 1-18 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-01-20T13:36:12Z No. of bitstreams: 1 S. T. Oliva.pdf: 832024 bytes, checksum: 9a86f8b018199ee559be5e2d9298d5e5 (MD5) Made available in DSpace on 2014-01-20T13:36:12Z (GMT). No. of bitstreams: 1 S. T. Oliva.pdf: 832024 bytes, checksum: 9a86f8b018199ee559be5e2d9298d5e5 (MD5) Previous issue date: 2002 As part of the project LBA-EUSTACH (European Studies on Trace gases and Atmospheric Chemistry as a contribution to the Large-Scale Biosphere-Atmosphere experiment in Amazonia), the exchange of formic acid and acetic acid between vegetation and the atmosphere was investigated in the wet-to-dry season transition and the dry-to-wet season transition periods in 1999 in Rondônia, Brazil. Direct exchange measurements on the branch level mainly exhibited uptake of formic acid and acetic acid for all plant species in both seasons, although diel, seasonal, and interspecies variations were observed. Even though other physiological and physico-chemical parameters may have contributed, the uptake of organic acids was found to be primarily a function of the ambient atmospheric mixing ratios. The linear dependence suggests a bidirectional exchange behavior of the plants and calculated deposition velocities (0.17–0.23 cm s−1), compensation point mixing ratios (0.16–0.30 ppb), and potential emission rates under purified air conditions (0.013–0.031 nmol m−2 s−1) are discussed. Vertical profile measurements in and above the primary forest canopy further strengthened the assumption that the forest is rather a sink than a source for organic acids. The generally lower mixing ratios observed within the canopy were indicative of an uptake by vegetation and/or the soil surface. Continuous measurements of the ambient atmospheric mixing ratios at the canopy top revealed strong diel variations in both seasons and a marked seasonality with higher mixing ratios during the dry season, both being mirrored in the variation of observed uptake rates of the plants. High atmospheric concentrations during the dry season were attributed to biomass burning. During the wet season, when biomass burning activity was low, indirect emission by the vegetation, i.e., photochemical oxidation of primarily emitted biogenic reactive hydrocarbons, was assumed to dominantly contribute to the atmospheric burden of the organic acids. The high degree of correlation between atmospheric formic acid and acetic acid indicated that similar atmospheric processes were affecting their mixing ratios.

A weakly-onedimensional heterostructure is a quantum wire structure tailored so that the carriers are tightly confined in a direction, weakly confined in another and free to move in the third. The electronic bound states are computed using the envelope function approximation in the frame on the k.p. theory and the adiabatic approximation. Transition rates of the electrons from ally bound stale to ally other bound state mediated bg the LO-phonons are then evaluated. The lifetimes of excited levels and average energy with respect to time are computed.

Simulations of climate over the Last Millennium (850–1850 CE) have been incorporated into the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). The drivers of climate over this period are chiefly orbital, solar, volcanic, changes in land use/land cover and some variation in greenhouse gas levels. While some of these effects can be easily defined, the reconstructions of solar, volcanic and land use-related forcing are more uncertain. We describe here the approach taken in defining the scenarios used in PMIP3, document the forcing reconstructions and discuss likely implications.