Found 9972 publications. Showing page 228 of 399:
Mesospheric intrusion and anomalous chemistry during and after a major stratospheric sudden warming. NILU F
2011
Mesospheric intrusion and anomalous chemistry during and after a major stratospheric sudden warming. NILU F
2011
2012
2017
While observed mesospheric polar nitric acid enhancements have been attributed to energetic particle precipitation through ion cluster chemistry in the past, this phenomenon is not reproduced in current whole‐atmosphere chemistry‐climate models. We investigate such nitric acid enhancements resulting from energetic electron precipitation events using a recently developed variant of the Whole Atmosphere Community Climate Model (WACCM) that includes a sophisticated ion chemistry tailored for the D‐layer of the ionosphere (50–90 km), namely, WACCM‐D. Using the specified dynamics mode, that is, nudging dynamics in the troposphere and stratosphere to meteorological reanalyses, we perform a 1‐year‐long simulation (July 2009–June 2010) and contrast WACCM‐D with the standard WACCM. Both WACCM and WACCM‐D simulations are performed with and without forcing from medium‐to‐high energy electron precipitation, allowing a better representation of the energetic electrons penetrating into the mesosphere. We demonstrate the effects of the strong particle precipitation events which occurred during April and May 2010 on nitric acid and on key ion cluster species, as well as other relevant species of the nitrogen family. The 1‐year‐long simulation allows the event‐related changes in neutral and ionic species to be placed in the context of their annual cycle. We especially highlight the role played by medium‐to‐high energy electrons in triggering ion cluster chemistry and ion‐ion recombinations in the mesosphere and lower thermosphere during the precipitation event, leading to enhanced production of nitric acid and raising its abundance by 2 orders of magnitude from 10−4 to a few 10−2 ppb.
2018
2013
2015
2012
2018
On request from the Norwegian Environment Agency, a survey of atmospheric deposition of heavy metals around industrial enterprises in Norway has been carried out. The participation was voluntary and 22 industries located at 17 different sites financed their own participation. The survey is based on analysis of samples of naturally growing moss collected around the
enterprises during the summer of 2015 and includes 57 different elements. For a majority of the sites this survey is a followup of corresponding surveys carried out in 2000, 2005, and 2010. In general the results show that deposition of heavy metals close to the industries depends closely on the industrial processes used as well as the local topographic and meteorological conditions. The results are evaluated relative to corresponding background levels in moss in parts of Norway with low impact of air pollution. Like in previous surveys, the generally most polluted industrial location is Mo i Rana, followed by Odda. At most sites only minor general improvement is observed since the previous survey in 2010.
2017
Metaller, PCB, PAH og dioksiner i mose i Sør-Varanger. Moseundersøkelser 2008, 2015 og 2020
I 2008 samlet Svanhovd Miljøsenter inn mose ved 11 lokaliteter i grenseområdene mot Russland som NILU analyserte for 11 metaller, PCB, PAH og dioksiner. Formålet var å undersøke om det var andre kilder til forurensning i grenseområdene enn gruvedrift og smelteverksindustri. Prøvetaking og analyse ble gjentatt av NILU i 2015 og 2020, men kun for 60 (2015) og 56 (2020) metaller. For spormetallene Ni, Cu, Co og As er det et klart mønster med forhøyede konsentrasjoner nedstrøms Nikel og Zapolyarnyj. Organiske miljøgifter viser lave konsentrasjoner.
NILU
2025
2011
Metals in the environment as risk factors for infectious diseases. Gaps and opportunities. Strüngmann Forum Reports, 16
2015
2004
Meteorological and air quality data. Al Ain Flyover. Abu Dhabi Air Quality Management Study. NILU OR
2004
2004
2004