Atmospheric Effects from the September 2005 Solar Flares and Solar Proton Event
Abstract
Studies have shown that space weather events can have significant impacts on the middle atmosphere. In particular, ionization from precipitating electrons and solar protons leads to the production of odd nitrogen and odd hydrogen, which in turn can destroy ozone in the stratosphere and mesosphere. This study uses the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model in its specified dynamics mode (SD-WACCM) to investigate an active space weather event in September of 2005. This event was chosen because of five large solar flares that occurred during the first nine days of the month, including an enormous X-17 flare on the 9th, plus a moderate solar proton event (SPE) that occurred on the 8th. Flare ionization was calculated in WACCM based on the input of photon spectra with a 5-minute cadence. Proton measurements from the Geostationary Operational Environmental Satellite (GOES) system were used to compute solar proton ionization rates. Simulations with and without the solar flares and solar protons were compared in order to calculate the atmospheric impact of the solar flares relative to the SPE. In addition, comparisons are made between the fully forced simulation and observational data to evaluate the veracity of the model for this particular time period. Results show that atmospheric effects caused by flares even as large as an X-17 are still dwarfed by the effects caused by a moderate SPE event at high latitudes. However, this result reverses at low latitudes, where increases in odd nitrogen mixing ratios can are shown to be as high as 100% in the upper mesosphere due exclusively to the flares.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSA54A..08P
- Keywords:
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- 0340 Middle atmosphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 1650 Solar variability;
- GLOBAL CHANGEDE: 7514 Energetic particles;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMYDE: 7538 Solar irradiance;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY