Found 9764 publications. Showing page 57 of 391:
2016
2013
2014
2006
2006
Supersite network and data management. Report series in aerosol science, vol. 71A
2004
SuperDARN Radar Wind Observations of Eastward-Propagating Planetary Waves
An array of SuperDARN meteor radars at northern high latitudes was used to investigate the sources and characteristics of eastward-propagating planetary waves (EPWs) at 95 km, with a focus on wintertime. The nine radars provided the daily mean meridional winds and their anomalies over 180 degrees of longitude, and these anomalies were separated into eastward and westward waves using a fast Fourier transform (FFT) method to extract the planetary wave components of zonal wavenumbers 1 and 2. Years when a sudden stratospheric warming event with an elevated stratopause (ES-SSW) occurred during the winter were contrasted with years without such events and composited through superposed epoch analysis. The results show that EPWs are a ubiquitous—and unexpected—feature of meridional wind variability near 95 km. Present even in non-ES-SSW years, they display a regular annual cycle peaking in January or February, depending on the zonal wavenumber. In years when an ES-SSW occurred, the EPWs were highly variable but enhanced before and after the onset.
MDPI
2024
Using meteor wind data from the Super Dual Auroral Radar Network (SuperDARN) in the Northern Hemisphere, we (1) demonstrate that the migrating (Sun‐synchronous) tides can be separated from the nonmigrating components in the mesosphere and lower thermosphere (MLT) region and (2) use this to determine the response of the different components of the semidiurnal tide (SDT) to sudden stratospheric warming (SSW) conditions. The radars span a limited range of latitudes around 60°N and are located over nearly 180° of longitude. The migrating tide is extracted from the nonmigrating components observed in the meridional wind recorded from meteor ablation drift velocities around 95‐km altitude, and a 20‐year climatology of the different components is presented. The well‐documented late summer and wintertime maxima in the semidiurnal winds are shown to be due primarily to the migrating SDT, whereas during late autumn and spring the nonmigrating components are at least as strong as the migrating SDT. The robust behavior of the SDT components during SSWs is then examined by compositing 13 SSW events associated with an elevated stratopause recorded between 1995 and 2013. The migrating SDT is seen to reduce in amplitude immediately after SSW onset and then return anomalously strongly around 10–17 days after the SSW onset. We conclude that changes in the underlying wind direction play a role in modulating the tidal amplitude during the evolution of SSWs and that the enhancement in the midlatitude migrating SDT (previously reported in modeling studies) is observed in the MLT at least up to 60°N.
American Geophysical Union (AGU)
2019
Sunnere byer: – Jeg ville prioritert enkel, bilfri tilgang til alt du trenger i hverdagen
Norges forskningsråd
2025
2004
2009
2009
Summary Report: Air Quality in the Classroom. 2009 Scandinavian student-based research campaign. NILU OR
2010
1999
NILU - Norwegian Institute for Air Research and the Chief Inspectorate of Environmental Protection in Poland ¿ GIOS are implementing the project on ¿Strengthening the air quality assessment system in Poland based on Norwegian experience¿, as a part of the program on ¿Improving Environmental Monitoring and Inspection¿ within the framework of the European Economic area 2009 - 2014.
Various tasks carried out during the performance of the project within Activities 1 through 6 are summarized here.
2015
NILU - Norwegian Institute for Air Research and the Chief Inspectorate of Environmental Protection in Poland - GIOS are implementing the project on "Strengthening the air quality assessment system in Poland based on Norwegian experience", as a part of the program on "Improving Environmental Monitoring and Inspection" within the framework of the European Economic area 2009 - 2014.
Various tasks carried out during the performance of the project within Activities 1 through 6 are summarized here.
2015
2023
Sulphur dioxide: from protection of human lungs to remote lake restoration. Environmental issue report, 22
2001