Abstract
Incoherent scatter radar measurements of ionospheric temperature and density collected above Millstone Hill over the years 1976-2013 are analyzed to show the long-term trends in noontime neutral temperature and neutral O density over the height region 120-500 km. Exospheric temperature cooled by 69.3 ± 6.4 K over the period, an order of magnitude greater than that expected from greenhouse gas action. The O density dropped 0.081 ± 5.6% at 400 km altitude but rose by 36.9 ± 5.0% at 120 km over this period. This trend in density at 400 km agrees with that determined from satellite drag. The increase in density at 120 km counteracts the thermal contraction of the thermosphere expected to be associated with the cooling, resulting in only a small density response at 400 km. The long-term O density increase at 120 km may be caused by a long-term descent of the turbopause height of 4.2 km. Such a descent has been documented by a series of rocket mass spectrometer measurements. Key Points During 1976-2013 exospheric temperature declined 69 KO at 400 km changed little, and O at 120 km rose 37%The turbopause rose 4 km during this period
| Original language | English |
|---|---|
| Pages (from-to) | 7940-7946 |
| Number of pages | 7 |
| Journal | Journal of Geophysical Research: Space Physics |
| Volume | 119 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Jan 1 2014 |
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- Geophysics
- Forestry
- Oceanography
- Aquatic Science
- Ecology
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
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Cite this
Long-term trends in thermospheric neutral temperature and density above Millstone Hill. / Oliver, W. L.; Holt, J. M.; Zhang, S. R.; Goncharenko, Larisa Petrovna.
In: Journal of Geophysical Research: Space Physics, Vol. 119, No. 9, 01.01.2014, p. 7940-7946.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Long-term trends in thermospheric neutral temperature and density above Millstone Hill
AU - Oliver, W. L.
AU - Holt, J. M.
AU - Zhang, S. R.
AU - Goncharenko, Larisa Petrovna
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Incoherent scatter radar measurements of ionospheric temperature and density collected above Millstone Hill over the years 1976-2013 are analyzed to show the long-term trends in noontime neutral temperature and neutral O density over the height region 120-500 km. Exospheric temperature cooled by 69.3 ± 6.4 K over the period, an order of magnitude greater than that expected from greenhouse gas action. The O density dropped 0.081 ± 5.6% at 400 km altitude but rose by 36.9 ± 5.0% at 120 km over this period. This trend in density at 400 km agrees with that determined from satellite drag. The increase in density at 120 km counteracts the thermal contraction of the thermosphere expected to be associated with the cooling, resulting in only a small density response at 400 km. The long-term O density increase at 120 km may be caused by a long-term descent of the turbopause height of 4.2 km. Such a descent has been documented by a series of rocket mass spectrometer measurements. Key Points During 1976-2013 exospheric temperature declined 69 KO at 400 km changed little, and O at 120 km rose 37%The turbopause rose 4 km during this period
AB - Incoherent scatter radar measurements of ionospheric temperature and density collected above Millstone Hill over the years 1976-2013 are analyzed to show the long-term trends in noontime neutral temperature and neutral O density over the height region 120-500 km. Exospheric temperature cooled by 69.3 ± 6.4 K over the period, an order of magnitude greater than that expected from greenhouse gas action. The O density dropped 0.081 ± 5.6% at 400 km altitude but rose by 36.9 ± 5.0% at 120 km over this period. This trend in density at 400 km agrees with that determined from satellite drag. The increase in density at 120 km counteracts the thermal contraction of the thermosphere expected to be associated with the cooling, resulting in only a small density response at 400 km. The long-term O density increase at 120 km may be caused by a long-term descent of the turbopause height of 4.2 km. Such a descent has been documented by a series of rocket mass spectrometer measurements. Key Points During 1976-2013 exospheric temperature declined 69 KO at 400 km changed little, and O at 120 km rose 37%The turbopause rose 4 km during this period
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UR - http://www.scopus.com/inward/citedby.url?scp=84925339968&partnerID=8YFLogxK
U2 - 10.1002/2014JA020311
DO - 10.1002/2014JA020311
M3 - Article
AN - SCOPUS:84925339968
VL - 119
SP - 7940
EP - 7946
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - 9
ER -