Found 9983 publications. Showing page 116 of 400:
In contrast to previous studies that have tended to focus on the influence of the total Arctic sea-ice cover on the East Asian summer tripole rainfall pattern, the present study identifies the Barents Sea as the key region where the June sea-ice variability exerts the most significant impacts on the East Asian August tripole rainfall pattern, and explores the teleconnection mechanisms involved. The results reveal that a reduction in June sea ice excites anomalous upward air motion due to strong near-surface thermal forcing, which further triggers a meridional overturning wave-like pattern extending to midlatitudes. Anomalous downward motion therefore forms over the Caspian Sea, which in turn induces zonally oriented overturning circulation along the subtropical jet stream, exhibiting the east–west Rossby wave train known as the Silk Road pattern. It is suggested that the Bonin high, a subtropical anticyclone predominant near South Korea, shows a significant anomaly due to the eastward extension of the Silk Road pattern to East Asia. As a possible descending branch of the Hadley cell, the Bonin high anomaly ultimately triggers a meridional overturning, establishing the Pacific–Japan pattern. This in turn induces an anomalous anticyclone and cyclone pair over East Asia, and a tripole vertical convection anomaly meridionally oriented over East Asia. Consequently, a tripole rainfall anomaly pattern is observed over East Asia. Results from numerical experiments using version 5 of the Community Atmosphere Model support the interpretation of this chain of events.
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2018
CO2-rensing Klemetsrud. Beregning av nitros- og nitraminer.
Beregning av spredning og dannelse av nitros- og nitramin er gjennomført for et potensielt aminbasert CO2-fangst-anlegg på Klemetsrud. Det er utført beregninger for tre ulike aminer. Beregningene viser makismal utslippskonsentrasjon for de ulike aminene for å sikre overholdelse av anbefalte grenseverdier for nitros- og nitraminer i luft og vann. Høyeste utslippskonsentrasjon som ikke gir overskridelser av grenseverdiene, er mellom 1,1 ppmV og 11 ppmV avhengig av hvilket amin som benyttes.
NILU
2018
Prepared by Earth Observation Data Centre for Water Resources Monitoring (EODC) GmbH in cooperation with TU Wien, GeoVille, ETH Zürich, TRANSMISSIVITY, AWST, FMI, UCC and NILU
The ESA Climate Change Initiative Phase 2 Soil Moisture Project
2018
2018
Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models have been used in order to evaluate the respective impact of the observed Arctic sea ice and sea surface temperature (SST) variations on air temperature variations in mid and high latitude land areas. Two sets of experiments have been designed; in the first set (EXP1), observed daily sea ice concentration and SST variations are used as lower boundary forcing over 1982–2014 while in the second set (EXP2) the SST variations are replaced by the daily SST climatology. The observed winter 2 m air temperature (T2m) variations are relatively well reproduced in a number of mid and high latitude land areas in EXP1, with best agreement in southwestern North America and northern Europe. Sea ice variations are important for the interannual T2m variations in northern Europe but have limited impact on all other mid and high latitude land regions. In particular, sea ice variations do not contribute to the observed opposite variations in the Arctic and mid latitude in our model experiments. The spread across ensemble members is large and many ensemble members are required to reproduce the observed T2m variations over northern Europe in our models. The amplitude of T2m anomalies in the coldest observed winters over northern Europe is not reproduced by our multi-model ensemble means. However, the sea ice conditions in these respective winters and mainly the thermodynamic response to the ice anomalies lead to an enhanced likelihood for occurrence of colder than normal winters and extremely cold winters. Still, the main reason for the observed extreme cold winters is internal atmospheric dynamics. The coldest simulated northern European winters in EXP1 and EXP2 between 1982 and 2014 show the same large scale T2m and atmospheric circulation anomaly patterns as the observed coldest winters, indicating that the models are well able to reproduce the processes, which cause these cold anomalies. The results are robust across all six models used in this study.
2018
Altitude-temporal behaviour of atmospheric ozone, temperature and wind velocity observed at Svalbard
2018
Målet er å belyse hvilke kvalitetskrav som bør stilles til luftkvalitetsberegninger, kart og data til ulike bruksformål slik disse er formulert i norsk regelverk, herunder Forurensningsloven, Folkehelseloven, Plan- og bygningsloven, Retningslinje for behandling av luftkvalitet i arealplanlegging (T1520) m.fl. Miljødirektoratet ønsker å sikre god, enhetlig og sammenlignbar kvalitet og praksis på utredninger av luftkvalitet og har bedt om anbefalinger i form av denne rapporten.
For å få et best mulig grunnlag for å vurdere behovet for veiledning og kvalitetskriterier for ulike anvendelser, har det vært fokus på å innhente informasjon og innspill fra ulike brukergrupper og fagmiljøer. Det er gjennomført en spørreundersøkelse og det er arrangert flere møter og åpne kommentarrunder med ulike brukergrupper og fagmiljøer. Siden eventuelle kvalitetskrav vil kunne ha betydning for konkurranse i markedet og påvirke ressursbruken både hos private aktører og myndigheter, har brukermedvirkning vært et viktig element i dette arbeidet etter ønske fra oppdragsgiver.
NILU
2018
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