Temperature decadal trends, and their relation to diurnal variations in the lower thermosphere, stratosphere, and mesosphere, based on measurements from SABER on TIMED
-
Published:2021-04-01
Issue:2
Volume:39
Page:327-339
-
ISSN:1432-0576
-
Container-title:Annales Geophysicae
-
language:en
-
Short-container-title:Ann. Geophys.
Author:
Huang Frank T.,Mayr Hans G.
Abstract
Abstract. We have derived the behavior of decadal temperature trends over the 24 h of local time, based on zonal averages of SABER data, for the years 2012 to 2014, from 20 to 100 km, within 48∘ of the Equator. Similar results have not been available previously. We find that the temperature trends,
based on zonal mean measurements at a fixed local time, can be different from those based on measurements made at a different fixed local time. The
trends can vary significantly in local time, even from hour to hour. This agrees with some findings based on nighttime lidar measurements. This
knowledge is relevant because the large majority of temperature measurements, especially in the stratosphere, are made by instruments on
sun-synchronous operational satellites which measure at only one or two fixed local times, for the duration of their missions. In these cases, the
zonal mean trends derived from various satellite data are tied to the specific local times at which each instrument samples the data, and the trends
are then also biased by the local time. Consequently, care is needed in comparing trends based on various measurements with each other, unless the
data are all measured at the same local time. Similar caution is needed when comparing with models, since the zonal means from 3D models reflect
averages over both longitude and the 24 h of local time. Consideration is also needed in merging data from various sources to produce generic, continuous, longer-term records. Diurnal variations of temperature themselves, in the form of thermal tides, are well known and are due to
absorption of solar radiation. We find that at least part of the reason that temperature trends are different for different local times is that the
amplitudes and phases of the tides themselves follow trends over the same time span of the data. Many of the past efforts have focused on the
temperature values with local time when merging data from various sources and on the effect of unintended satellite orbital drifts, which result in
drifting local times at which the temperatures are measured. However, the effect of local time on trends has not been well researched. We also
derive estimates of trends by simulating the drift of local time due to drifting orbits. Our comparisons with results found by others (Advanced Microwave Sounding Unit, AMSU; lidar)
are favorable and informative. They may explain, at least in part, the bridge between results based on daytime AMSU data and nighttime lidar
measurements. However, these examples do not form a pattern, and more comparisons and study are needed.
Publisher
Copernicus GmbH
Subject
Space and Planetary Science,Earth and Planetary Sciences (miscellaneous),Atmospheric Science,Geology,Astronomy and Astrophysics
Reference24 articles.
1. Austin, J., Tourpali, K., Rozanov, E., Akiyoshi, H., Bekki, S., Bodeker, G., Brühl, C., Butchart, N., Chipperfield, M., Deushi, M., Fomichev, V. I., Giorgetta, M. A., Gray, L., Kodera, K., Lott, F., Manzini, E., Marsh, D., Matthes, K., Nagashima, T., Shibata, K., Stolarski, R. S., Struthers, H., and Tian, W.:
Coupled chemistry climate model simulations of the solar cycle in ozone and temperature,
J. Geophys. Res.,
113, D11306, https://doi.org/10.1029/2007JD009391, 2008. 2. Brasseur, G. P. and Solomon, S.:
Aeronomy of the Middle Atmosphere,
Springer, Dordrecht, the Netherlands, 2005. 3. Forbes, J. M., Zhang, X., Palo, S., Russell, J, Mertens, C. J., and Mlynczak, M.:
Tidal variability in the ionospheric dynamo region,
J. Geophys. Res.,
113, A02310, https://doi.org/10.1029/2007JA012737, 2008. 4. Funatsu, B. M., Claud, C., Keckhut, P., and Hauchecorne, A.:
Cross-validation of Advanced Microwave Sounding Unit and lidar for long-term upper-stratospheric temperature monitoring,
J. Geophys. Res.,
113, D23108, https://doi.org/10.1029/2008JD010743, 2008. 5. Funatsu, B. M., Claud, C., Keckhut, P., Hauchecorne, A., and Leblanc, T.:
Regional and seasonal stratospheric temperature trends in the last decade (2002–2014) from AMSU observations,
J. Geophys. Res.-Atmos.,
121, 8172–8185, https://doi.org/10.1002/2015JD024305, 2016.
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|