Publikasjoner

An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons.

Stohl, A.; Seibert, P.; Arduini, J.; Eckhardt, S.; Fraser, P.; Greally, B.R.; Lunder, C.; Maione, M.; Muhle, J.; O'Doherty, S.; Prinn, R.G.; Reimann, S.; Saito, T.; Schmidbauer, N.; Simmonds, P.G.; Vollmer, M.K.; Weiss, R.F.; Yokouchi, Y.

An Antarctic research station as a source of brominated and perfluorinated persistent organic pollutants to the local environment.

Wild, S.; McLagan, D.; Schlabach, M.; Bossi, R.; Hawker, D.; Cropp, R.; King, C.K.; Stark, J.S.; Mondon, J.; Nash, S.B.

An assessment of costs and benefits associated with mercury emission reductions from major anthropogenic sources.

Pacyna, J.M.; Sundseth, K.; Pacyna, E.G.; Jozewicz, W.; Munthe, J.; Belhaj, M.; Astrom, S.

An assessment of the contribution of air pollution to the weathering of limestone heritage in Malta

Grøntoft, Terje; Cassar, JoAnn

Malta is known for its limestone megalithic temples of which many are inscribed on the UNESCO World Heritage List. A variation of this limestone was historically, and until very few years ago, a primary building material in Malta. The temples are subject to various environmental influences which until recently have led to several collapses due in part to serious stone surface and infill loss. As a protection measure, open-sided shelters have been built over three of these temples. This work assesses the degrading influence of air pollution (nitrogen dioxide, ozone, particle matter, sulfur dioxide, and acidity in rain) on the temples, in combination and comparison with the influence of other environmental factors (relative humidity, temperature, precipitation, moisture, sea salt, wind) and in this respect evaluates the potential protective effect of the shelters. The variation in air pollution weathering of limestone exposed outdoor in Malta was calculated by exposure–response functions from the ICP-materials programme and compared with measured values, and its contribution to the deterioration of the temples was evaluated. The difference between urban and rural locations in Malta, in the first year of atmospheric chemical weathering of limestone due to air pollution, was found to be about one micrometer loss of stone surface. This is probably less than the annual variations due to the influence of natural climatic factors, and small compared to the present annual variations in continental Europe. The deposition of sea salt and presence of salts on and in the limestone megaliths and changes in salt-crystallization events due to relative humidity fluctuations, inside and outside the shelters, will account for more of the variations in the first year of weathering of Globigerina limestone than variations in air pollution. The deterioration will also be related to temperature (including condensation events), wind parameters and rainfall, as well as ground water replenished from areas beyond the shelter.

Springer

An assessment of urban vulnerability in the Amazon Delta and Estuary: a multi-criterion index of flood exposure, socio-economic conditions and infrastructure.

Mansur, A.V.; Brondízio, E.S.; Roy, S.; Hetrick, S.; Vogt, N.D.; Newton, A.

An early warning system for organic materials in museums, historic buildings and archives.

Grøntoft, T.; Dahlin, E.; Henriksen, J.F.; Rentmeister, S.; Hanko, M.; Heinze, J.; Taylor, J.; Blades, N.; Cassar, M.

An ecological assessment of the exposure of Northern predatory bird species to persistent organic pollutants.

Eulaers, I.; Covaci, A.; Halley, D.J. , Herzke, D.; Johnsen, T.V.; Jaspers, V.L.B.; Bustnes, J.O.; Eens, M.

An efficient use of a Lagrangian transport model for atmospheric inversions using satellite observations: case study using TROPOMI to estimate CH4 emissions over Siberia

Krishnankutty, Nalini; Thompson, Rona Louise; Pisso, Ignacio; Schneider, Philipp; Stebel, Kerstin; Sasakawa, Motoki; Platt, Stephen Matthew

An enantiomerically pure potential toxaphene congener: (1R,2S,3S,4R,7S)-2-endo,3-exo,5,5-tetrachloro-7-(chloromethyl)-1,7-bis(dichloromethyl)bicyclo[2.2.1]heptane.

Hansen, L.K.; Kallenborn, R.; Kiprianova, A.; Nikiforov, V.; Trukhin, A.

An evaluation of cloud affected UV radiation from polar orbiting and geostationary satellites at high latitudes.

Meerkotter, R.; Verdebout, J.; Bugliaro, L.; Edvardsen, K.; Hansen, G.

An evaluation of European nitrogen and sulfur wet deposition and their trends estimated by six chemistry transport models for the period 1990–2010

Theobald, Mark R.; Vivanco, Marta G.; Aas, Wenche; Andersson, Camilla; Ciarelli, Giancarlo; Couvidat, Florian; Cuvelier, Kees; Manders, Astrid; Mircea, Mihaela; Pay, Maria-Teresa; Tsyro, Svetlana; Adani, Mario; Bergström, Robert; Bessagnet, Bertrand; Briganti, Gino; Cappelletti, Andrea; D'Isidoro, Massimo; Fagerli, Hilde; Mar, Kathleen; Otero, Noelia; Raffort, Valentin; Roustan, Yelva; Schaap, Martijn; Wind, Peter; Colette, Augustin

The wet deposition of nitrogen and sulfur in Europe for the period 1990–2010 was estimated by six atmospheric chemistry transport models (CHIMERE, CMAQ, EMEP MSC-W, LOTOS-EUROS, MATCH and MINNI) within the framework of the EURODELTA-Trends model intercomparison. The simulated wet deposition and its trends for two 11-year periods (1990–2000 and 2000–2010) were evaluated using data from observations from the EMEP European monitoring network. For annual wet deposition of oxidised nitrogen (WNOx), model bias was within 30 % of the average of the observations for most models. There was a tendency for most models to underestimate annual wet deposition of reduced nitrogen (WNHx), although the model bias was within 40 % of the average of the observations. Model bias for WNHx was inversely correlated with model bias for atmospheric concentrations of NH3+NH+4

, suggesting that an underestimation of wet deposition partially contributed to an overestimation of atmospheric concentrations. Model bias was also within about 40 % of the average of the observations for the annual wet deposition of sulfur (WSOx) for most models.

Decreasing trends in WNOx were observed at most sites for both 11-year periods, with larger trends, on average, for the second period. The models also estimated predominantly decreasing trends at the monitoring sites and all but one of the models estimated larger trends, on average, for the second period. Decreasing trends were also observed at most sites for WNHx, although larger trends, on average, were observed for the first period. This pattern was not reproduced by the models, which estimated smaller decreasing trends, on average, than those observed or even small increasing trends. The largest observed trends were for WSOx, with decreasing trends at more than 80 % of the sites. On average, the observed trends were larger for the first period. All models were able to reproduce this pattern, although some models underestimated the trends (by up to a factor of 4) and others overestimated them (by up to 40 %), on average. These biases in modelled trends were directly related to the tendency of the models to under- or overestimate annual wet deposition and were smaller for the relative trends (expressed as % yr−1 relative to the deposition at the start of the period).

The fact that model biases were fairly constant throughout the time series makes it possible to improve the predictions of wet deposition for future scenarios by adjusting the model estimates using a bias correction calculated from past observations. An analysis of the contributions of various factors to the modelled trends suggests that the predominantly decreasing trends in wet deposition are mostly due to reductions in emissions of the precursors NOx, NH3 and SOx. However, changes in meteorology (e.g. precipitation) and other (non-linear) interactions partially offset the decreasing trends due to emission reductions during the first period but not the second. This suggests that the emission reduction measures had a relatively larger effect on wet deposition during the second period, at least for the sites with observations.

An Evaluation of the EnKF vs. EnOI and the Assimilation of SMAP, SMOS and ESA CCI Soil Moisture Data over the Contiguous US

Blyverket, Jostein; Hamer, Paul David; Bertino, Laurent; Albergel, Clément; Fairbairn, David; Lahoz, William A.

A number of studies have shown that assimilation of satellite derived soil moisture using the ensemble Kalman Filter (EnKF) can improve soil moisture estimates, particularly for the surface zone. However, the EnKF is computationally expensive since an ensemble of model integrations have to be propagated forward in time. Here, assimilating satellite soil moisture data from the Soil Moisture Active Passive (SMAP) mission, we compare the EnKF with the computationally cheaper ensemble Optimal Interpolation (EnOI) method over the contiguous United States (CONUS). The background error–covariance in the EnOI is sampled in two ways: (i) by using the stochastic spread from an ensemble open-loop run, and (ii) sampling from the model spinup climatology. Our results indicate that the EnKF is only marginally superior to one version of the EnOI. Furthermore, the assimilation of SMAP data using the EnKF and EnOI is found to improve the surface zone correlation with in situ observations at a 95% significance level. The EnKF assimilation of SMAP data is also found to improve root-zone correlation with independent in situ data at the same significance level; however this improvement is dependent on which in situ network we are validating against. We evaluate how the quality of the atmospheric forcing affects the analysis results by prescribing the land surface data assimilation system with either observation corrected or model derived precipitation. Surface zone correlation skill increases for the analysis using both the corrected and model derived precipitation, but only the latter shows an improvement at the 95% significance level. The study also suggests that assimilation of satellite derived surface soil moisture using the EnOI can correct random errors in the atmospheric forcing and give an analysed surface soil moisture close to that of an open-loop run using observation derived precipitation. Importantly, this shows that estimates of soil moisture could be improved using a combination of assimilating SMAP using the computationally cheap EnOI while using model derived precipitation as forcing. Finally, we assimilate three different Level-2 satellite derived soil moisture products from the European Space Agency Climate Change Initiative (ESA CCI), SMAP and SMOS (Soil Moisture and Ocean Salinity) using the EnOI, and then compare the relative performance of the three resulting analyses against in situ soil moisture observations. In this comparison, we find that all three analyses offer improvements over an open-loop run when comparing to in situ observations. The assimilation of SMAP data is found to perform marginally better than the assimilation of SMOS data, while assimilation of the ESA CCI data shows the smallest improvement of the three analysis products.

MDPI