Details

Autor(en) / Beteiligte

• Perrone, Loredana
• Mikhailov, Andrey V.

Titel

Long‐Term Variations of June Column Atomic Oxygen Abundance in the Upper Atmosphere Inferred From Ionospheric Observations

Ist Teil von

• Journal of geophysical research. Space physics, 2019-07, Vol.124 (7), p.6305-6312

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Wiley Online Library

Beschreibungen/Notizen

• For the first time, atomic oxygen column content [O]col has been inferred from June daytime monthly median foF1 and foF2 observations at Rome, Juliusruh, Sodankylä, and Boulder to analyze its long‐term variations for the period of ~6 solar cycles. The analysis is interesting in the light of possible anthropogenic impact on the upper atmosphere. After the removal of solar and geomagnetic activity effects from the inferred [O]col variations, the residual linear trends are negative and statistically insignificant at middle latitudes. It is shown that ~93% (the corresponding correlation coefficient is 0.964 ± 0.03) of the whole [O]col variability is explained by solar and geomagnetic activity long‐term variations and only ~7% may be attributed to other processes (reasons) including the anthropogenic impact. Solar and geomagnetic activity contributions to [O]col long‐term variations decrease with time, and this may be related to the low solar activity epoch, which we have entered. The main conclusion is that the long‐term variations of the atomic oxygen column content inferred from ionospheric observations are due to solar and geomagnetic activity; that is, they have a natural origin. Plain Language Summary Anthropogenic impact on the upper atmosphere is increasing mainly via the CO2 concentration increase. What is going on with atomic oxygen (the main constituent in the upper atmosphere) under this impact? Solving an inverse problem of aeronomy atomic oxygen long‐term variations were retrieved from June daytime monthly median foF1 and foF2 observations for the period of ~6 solar cycles. The obtained results have shown that solar and geomagnetic activity contribute ~93% to the total [O]col variability at middle latitudes and only ~7% of [O]col variability may be attributed to other processes (reasons) including the anthropogenic impact. As we have entered the epoch of low solar activity the contribution of solar and geomagnetic activity to the [O]col variability decreases with years. The main conclusion is that the atomic oxygen column content long‐term variations are due to solar and geomagnetic activity; that is, they have a natural origin. Key Points 93% of the column atomic oxygen content long‐term variations are due to solar and geomagnetic activity The contribution of solar and geomagnetic activity to the [O]col variability decreases with years [O]col long‐term variations have a natural origin