Blar i Bergen Open Research Archive på forfatter "Tyssøy, Hilde Nesse"
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Cutoff latitude variation during solar proton events: Causes and consequences
Tyssøy, Hilde Nesse; Stadsnes, Johan (Peer reviewed; Journal article, 2015-01)To accurately quantify the effect of solar proton events (SPEs) on the atmosphere requires a good estimate of the particle energy deposition in the middle atmosphere (60–100 km) and how the energy is distributed globally. ... -
Determining Latitudinal Extent of Energetic Electron Precipitation Using MEPED On-Board NOAA/POES
Babu, Eldho Midhun; Tyssøy, Hilde Nesse; Smith-Johnsen, Christine; Maliniemi, Ville Aleksi; Salice, Josephine Alessandra; Millan, R.M.; Richardson, I.G. (Journal article; Peer reviewed, 2022)Energetic Electron Precipitation (EEP) from the plasma sheet and the radiation belts ionizes the polar lower thermosphere and mesosphere. EEP increases the production of NOx and HOx, which will catalytically destroy ozone, ... -
Direct and indirect electron precipitation effect on nitric oxide in the polar middle atmosphere, using a full-range energy spectrum
Smith-Johnsen, Christine; Tyssøy, Hilde Nesse; Hendrickx, Koen; Orsolini, Yvan; Kishore Kumar, Grandhi; Ødegaard, Linn-Kristine Glesnes; Sandanger, Marit Irene; Stordal, Frode; Megner, Linda (Peer reviewed; Journal article, 2017)In April 2010, a coronal mass ejection and a corotating interaction region on the Sun resulted in an energetic electron precipitation event in the Earth’s atmosphere. We investigate direct and indirect nitric oxide (NO) ... -
The Direct Effect of Medium Energy Electron Precipitation on Mesospheric Dynamics During a Sudden Stratospheric Warming Event in 2010
Zuniga Lopez, Hector Daniel; Tyssøy, Hilde Nesse; Smith-Johnsen, Christine; Maliniemi, Ville Aleksi (Journal article; Peer reviewed, 2022)Medium energy electron (MEE) (30–1,000 keV) precipitation enhances the production of nitric (NOx) and hydrogen oxides (HOx) throughout the mesosphere, which can destroy ozone (O3) in catalytic reactions. The dynamical ... -
Effects of enhanced downwelling of NOx on Antarctic upper-stratospheric ozone in the 21st century
Maliniemi, Ville Aleksi; Tyssøy, Hilde Nesse; Smith-Johnsen, Christine; Arsenovic, Pavle; Marsh, Daniel R. (Journal article; Peer reviewed, 2021)Ozone is expected to fully recover from the chlorofluorocarbon (CFC) era by the end of the 21st century. Furthermore, because of anthropogenic climate change, a cooler stratosphere decelerates ozone loss reactions and is ... -
Electron precipitation characteristics during isolated, compound, and multi-night substorm events
Partamies, Noora; Tesema, Fasil; Bland, Emma; Heino, Erkka; Tyssøy, Hilde Nesse; Kallelid, Erlend Salte (Journal article; Peer reviewed, 2021)A set of 24 isolated, 46 compound, and 36 multi-night substorm events from the years 2008–2013 have been analysed in this study. Isolated substorm events are defined as single expansion–recovery phase pairs, compound ... -
Energetic electron precipitation in weak to moderate corotating interaction region-driven storms
Ødegaard, Linn-Kristine Glesnes; Tyssøy, Hilde Nesse; Søraas, Finn; Stadnes, Johan; Sandanger, Marit Irene (Peer reviewed; Journal article, 2017-03)High-energy electron precipitation from the radiation belts can penetrate deep into the mesosphere and increase the production rate of NOx and HOx, which in turn will reduce ozone in catalytic processes. The mechanisms for ... -
Energetic Electron Precipitation into the Middle Atmosphere – Constructing the Loss Cone Fluxes from MEPED POES
Tyssøy, Hilde Nesse; Sandanger, Marit Irene; Stadsnes, Johan; Zawedde, Annet Eva; Ødegaard, Linn-Kristine Glesnes; Åsnes, Arne (Peer reviewed; Journal article, 2016-06)The impact of energetic electron precipitation (EEP) on the chemistry of the middle atmosphere (50–90 km) is still an outstanding question as accurate quantification of EEP is lacking due to instrumental challenges and ... -
A Generalized Method for Calculating Atmospheric Ionization by Energetic Electron Precipitation
Xu, Wei; Marshall, Robert A.; Tyssøy, Hilde Nesse; Fang, Xiaohua (Journal article; Peer reviewed, 2020)Accurate specification of ionization production by energetic electron precipitation is critical for atmospheric chemistry models to assess the resultant atmospheric effects. Recent model-observation comparison studies have ... -
The impact of energetic electron precipitation on mesospheric hydroxyl during a year of solar minimum
Zawedde, Annet Eva; Tyssøy, Hilde Nesse; Hibbins, Robert Edward; Espy, Patrick Joseph; Degaard, L-K.; Sandanger, Marit Irene; Stadsnes, Johan (Peer reviewed; Journal article, 2016-06)In 2008 a sequence of geomagnetic storms occurred triggered by high-speed solar wind streams from coronal holes. Improved estimates of precipitating fluxes of energetic electrons are derived from measurements on board the ... -
In-flight calibration of NOAA POES proton detectors - Derivation of the MEPED correction factors
Sandanger, Marit Irene; Ødegaard, Linn-Kristine Glesnes; Tyssøy, Hilde Nesse; Stadsnes, Johan; Søraas, Finn; Oksavik, Kjellmar; Aarsnes, Kjell (Peer reviewed; Journal article, 2015-11-25)The MEPED instruments on board the NOAA POES and MetOp satellites have been continuously measuring energetic particles in the magnetosphere since 1978. However, degradation of the proton detectors over time leads to an ... -
Intercomparison of the POES/MEPED Loss Cone Electron Fluxes With the CMIP6 Parametrization
Tyssøy, Hilde Nesse; Haderlein, Astrid; Sandanger, Marit Irene J.; Stadsnes, Johan (Peer reviewed; Journal article, 2019)Quantitative measurements of medium energy electron (MEE) precipitation (>40 keV) are a key to understand the total effect of particle precipitation on the atmosphere. The Medium Energy Proton and Electron Detector (MEPED) ... -
Nitric Oxide Response to the April 2010 Electron Precipitation Event: Using WACCM and WACCM‐D With and Without Medium‐Energy Electrons
Smith-Johnsen, Christine; Marsh, Daniel R.; Orsolini, Yvan; Tyssøy, Hilde Nesse; Hendrickx, Koen; Sandanger, Marit Irene J.; Ødegaard, Linn-Kristine Glesnes; Stordal, Frode (Peer reviewed; Journal article, 2018-06-07)Energetic electrons from the magnetosphere deposit their energy in the atmosphere and lead to production of nitric oxide (NO) in the mesosphere and lower thermosphere. We study the atmospheric NO response to a geomagnetic ... -
Observations of Electron Precipitation During Pulsating Aurora and Its Chemical Impact
Kebede, Fasil Tesema; Partamies, Noora; Tyssøy, Hilde Nesse; Kero, Antti; Smith-Johnsen, Christine (Journal article; Peer reviewed, 2020)Pulsating auroras (PsAs) are low‐intensity diffuse aurora, which switch on and off with a quasiperiodic oscillation period from a few seconds to ∼10 s. They are predominantly observed after magnetic midnight, during the ... -
Observations of precipitation energies during different types of pulsating aurora
Kebede, Fasil Tesema; Partamies, Noora; Tyssøy, Hilde Nesse; McKay, Derek (Journal article; Peer reviewed, 2020)Pulsating aurora (PsA) is a diffuse type of aurora with different structures switching on and off with a period of a few seconds. It is often associated with energetic electron precipitation (>10 keV) resulting in the ... -
The Predictive Capabilities of the Auroral Electrojet Index for Medium Energy Electron Precipitation
Tyssøy, Hilde Nesse; Partamies, Noora; Babu, Eldho Midhun Babu Eldho Midhun; Smith-Johnsen, Christine; Salice, Josephine Alessandra (Journal article; Peer reviewed, 2021)The chemical imprint of the energetic electron precipitation on the atmosphere is now acknowledged as a part of the natural forcing of the climate system. It has, however, been questioned to which degree current proxies ... -
Space Weather impact on the degradation of NOAA POES MEPED proton detectors
Ødegaard, Linn-Kristine Glesnes; Tyssøy, Hilde Nesse; Sandanger, Marit Irene; Stadsnes, Johan; Søraas, Finn (Peer reviewed; Journal article, 2016-06-07)The Medium Energy Proton and Electron Detector (MEPED) on board the National Oceanic and Atmospheric Administration Polar Orbiting Environmental Satellites (NOAA POES) is known to degrade with time. In recent years a lot ... -
Will Climate Change Impact Polar NOx Produced by Energetic Particle Precipitation?
Maliniemi, Ville Aleksi; Marsh, Daniel R.; Tyssøy, Hilde Nesse; Smith-Johnsen, Christine (Journal article; Peer reviewed, 2020)Energetic electron precipitation (EEP) is an important source of polar nitrogen oxides (NOx) in the upper atmosphere. During winter, mesospheric NOx has a long chemical lifetime and is transported to the stratosphere by ...