TY - JOUR
T1 - On the Relationship Between E Region Scintillation and ENSO Observed by FORMOSAT-3/COSMIC
AU - Chang, Loren C.
AU - Chiu, Pei Yun
AU - Salinas, Cornelius Csar Jude H.
AU - Chen, Shih Ping
AU - Duann, Yi
AU - Liu, Jann Yenq
AU - Lin, Chien Hung
AU - Sun, Yan Yi
N1 - Funding Information:
This research was supported by grants 103-2111-M-008-019-MY3, 105-2111-M-008-001-MY3, and 106-2111-M-008-010 from the Taiwan Ministry of Science and Technology. Additional support for P.-Y. C. was from the 2016 NSPO summer internship program. The NCU Center for Astronautical Physics and Engineering is supported by the Taiwan Ministry of Education. We thank Huixin Liu (Kyushu University) for helpful discussions. COSMIC data are available via the COSMIC Data Analysis and Archive Center (http://cdaac-www.cosmic. ucar.edu). ONI is available via the NOAA Center for Weather and Climate Prediction (http://www.cpc.ncep. noaa.gov). RMOB data are available at http://www.rmob.org/. We thank the reviewers and the Editor for their helpful comments.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/5
Y1 - 2018/5
N2 - Global Navigation Satellite System radio occultation signals often show extremely strong levels of scintillation when passing through the ionospheric E region. This is related to sporadic E(Es)—dense layers of metallic ions that can form in the E region, influencing terrestrial and satellite radio propagation. In our report on the 2007–2014 variation of E region S4 amplitude fluctuation indices measured by the FORMOSAT-3/Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) satellite constellation, we find that the spatial and temporal variation of the maximum S4 index in the E region is proportionate to the occurrence rate of extreme scintillation and by extension, sporadic E. We also find that the monthly median extreme S4 amplitude fluctuation index in the E region midlatitudes shows a dependence on variation of the El Niño–Southern Oscillation (ENSO) in the troposphere that has not been previously reported. The ENSO-related variation of the E region median extreme S4 indices varies closely with the tropopause height, with both parameters lagging the Oceanic Niño Index by roughly 1 to 2 months, while also displaying a similar spectrum of periodicities. This similarity is especially strong in the southern midlatitudes. These results indicate that ENSO signatures can be transmitted to Es formation mechanisms, potentially through modulation of vertically propagating atmospheric tides that alter lower thermospheric wind shears. The end result is the modulation of the interannual variation of extreme Es values by ENSO.
AB - Global Navigation Satellite System radio occultation signals often show extremely strong levels of scintillation when passing through the ionospheric E region. This is related to sporadic E(Es)—dense layers of metallic ions that can form in the E region, influencing terrestrial and satellite radio propagation. In our report on the 2007–2014 variation of E region S4 amplitude fluctuation indices measured by the FORMOSAT-3/Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) satellite constellation, we find that the spatial and temporal variation of the maximum S4 index in the E region is proportionate to the occurrence rate of extreme scintillation and by extension, sporadic E. We also find that the monthly median extreme S4 amplitude fluctuation index in the E region midlatitudes shows a dependence on variation of the El Niño–Southern Oscillation (ENSO) in the troposphere that has not been previously reported. The ENSO-related variation of the E region median extreme S4 indices varies closely with the tropopause height, with both parameters lagging the Oceanic Niño Index by roughly 1 to 2 months, while also displaying a similar spectrum of periodicities. This similarity is especially strong in the southern midlatitudes. These results indicate that ENSO signatures can be transmitted to Es formation mechanisms, potentially through modulation of vertically propagating atmospheric tides that alter lower thermospheric wind shears. The end result is the modulation of the interannual variation of extreme Es values by ENSO.
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U2 - 10.1029/2018JA025299
DO - 10.1029/2018JA025299
M3 - Article
AN - SCOPUS:85046436307
SN - 2169-9402
VL - 123
SP - 4053
EP - 4065
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 5
ER -