Found 9887 publications. Showing page 163 of 396:
On the coupling between polar and tropical regions during springtime: variability of tropical intrusion and Frozen In Anticyclones. Poster P-1108-04
Abstract : Recent observational and modeling transport studies of Arctic stratospheric final warming have shown that tropical/subtropical air masses can be transported to high latitudes and remain confined within a long-lived ¿frozen- in¿ anticyclone (FriaC), embedded in the summer easterlies for several months. We first present a climatology of these sporadic events over the period 1960-2011 using era-40 and era interim reanalyses. this study highlights stratospheric favorable preconditioning for FrIACs occurrence, that is: i) early and abrupt final warming, ii) no stratospheric major warming during the previous winter, and iii) east phase of the Quasi-Biennial Oscillation. We will present in detail the FriaC in spring 2011, which was the largest ever recorded. Our climatology further suggests that the frequency of occurrence of FriaCs has increased over the last decade (among the nine cases detected over the period 1960- 2011, five occurred between 2002 and 2011). A chemistry climate model is then used for the first time to investigate FriaCs characteristics and variability. simulations were performed with the nCar¿s Community earth system Model (CesM, version 1.0.2), a coupled model system including the Whole Atmosphere Community Climate Model (WACCM). FrIACs characteristics (i.e. spatial extent and duration), are overall consistent by comparing with FriaCs detected era-40 meteorological reanalyses. Dynamical analysis reveals that FriaCs are associated with an abrupt and early winter-to-summer stratospheric circulation transition, characterized by an amplification of planetary wave activity. Furthermore, our model results confirm that FrIACs occur preferentially under the easterly phase of the QBO and in absence of MSW during the preceding
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PFASs in house dust. NILU OR
NILU has, on behalf of the Norwegian Environment Agency, performed sampling and analysis of house dust from Norwegian households. The goal was to study concentration ranges, and variability between- and within-houses of anionic and volatile per- and polyfluorinated alkyl substances (PFASs), including the regulated PFOA, as well as for total extractable organic fluorine (TEOF). The sampling was done in six separate rooms in six different households. The analysis covered a suite of 20 targeted PFASs; ten of these were consistently detected in most samples while the other ten were below detection limit in the major part of the samples. A range of the targeted PFASs were detected in all rooms except in one room in one household in which all PFASs were below detection. The concentrations of individual PFASs as well as the sum of PFASs were lower than a previous study in Norway. The results show significant variability between houses for the anionic and volatile PFASs as well as for TEOF. For anionic PFASs, the results also indicate within-house variability with higher concentrations in dust from bedrooms (children and parents) and living rooms than in dust from bathroom, kitchen and entrances. For the volatile PFASs and TEOF, no significant difference between rooms were found. These results indicate that factors like building materials and consumer products (e.g., furniture, textiles etc.) affect the levels of PFASs in house dust but the reason for the findings are not further evaluated in this report. Anionic PFASs seem to contribute significantly to the TEOF (10-100%) in house dust.
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The health state of the Norwegian forests. Results from the national forest damage monitoring 2014. NIBIO rapport, vol. 1, nr. 15
2015