In this study,the climatology and long-term trends of middle atmospheric temperatures at mid-latitudes are investigated using Rayleigh/Sodium lidar observations collected from January 2010 to December 2021 over Hefei,...In this study,the climatology and long-term trends of middle atmospheric temperatures at mid-latitudes are investigated using Rayleigh/Sodium lidar observations collected from January 2010 to December 2021 over Hefei,China(32°N,117°E).The seasonal variations and vertical profiles of lidar-derived temperatures demonstrate strong agreement with temperature measurements from the Microwave Limb Sounder(MLS)instrument on the Earth Observing System(EOS)Aura satellite.In terms of seasonal variation,middle atmospheric temperatures primarily exhibit annual oscillations(AO)and semi-annual oscillations(SAO).Harmonic analysis of the lidar and MLS temperature data reveals close phase alignment for both AO and SAO,with AO amplitudes ranging from 2 to 6 K,and SAO amplitudes from 1 to 4 K.The dependence of temperature on solar forcing was analyzed using the F10.7 index as a proxy,showing positive solar response coefficients at all altitudes,with a maximum of 15±1.1 K/100 SFU observed near 42–44 km.After removing the temperature response to solar cycle variations,a cooling trend in mid-latitude temperatures is evident across all altitudes,ranging from 3 to 6 K/decade.展开更多
The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than ...The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than 9 years of mesopause temperatures and relative densities estimated by using ambipolar diffusion coefficient measurements observed by the Mengcheng meteor radar(33.4°N,116.5°E).The intercomparison between the meteor radar and Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere by Broadband Emission Radiometry(TIMED/SABER)and Earth Observing System(EOS)Aura/Microwave Limb Sounder(MLS)observations indicates that the meteor radar temperatures and densities agree well with the simultaneous satellite measurements.Annual variations dominate the mesopause temperatures,with the maximum during winter and the minimum during summer.The mesopause relative densities also show annual variations,with strong maxima near the spring equinox and weak maxima before the winter solstice,and with a minimum during summer.In addition,the mesopause density exhibits a structure similar to that of the zonal wind:as the zonal wind flows eastward(westward),the mesopause density decreases(increases).At the same time,the meridional wind shows a structure similar to that of the mesopause temperature:as the meridional wind shows northward(southward)enhancements,the mesopause temperature increases(decreases).Simultaneous horizontal wind,temperature,and density observations provide multiple mesospheric parameters for investigating mesospheric dynamics and thermodynamic processes and have the potential to improve widely used empirical atmospheric models.展开更多
基金supported by the National Natural Science Foundation of China(Grant 42125402,42174183 and 42304165)the National Key Technologies R&D Program of China(Grant 2022YFF0503703)+7 种基金the B-type Strategic Priority Program of CAS(Grant XDB0780000)the Chinese Meridian Projectthe Fundamental Research Funds for the Central Universitiesthe Joint Open Fund of Mengcheng National Geophysical Observatory(MENGO-202406,MENGO-202407)the National Natural Science Foundation of China(NSFC)Distinguished Overseas Young Talents ProgramBasic Research Project of the National Key Laboratory of Deep Space Exploration(NKLDSE2023A002)the Pre-research project on Civil Aerospace Technologies No.D010305 and D010301 funded by China National Space Administration(CNSA)Supported by the Specialized Research Fund for State Key Laboratory of Solar Activity and Space Weathe.
文摘In this study,the climatology and long-term trends of middle atmospheric temperatures at mid-latitudes are investigated using Rayleigh/Sodium lidar observations collected from January 2010 to December 2021 over Hefei,China(32°N,117°E).The seasonal variations and vertical profiles of lidar-derived temperatures demonstrate strong agreement with temperature measurements from the Microwave Limb Sounder(MLS)instrument on the Earth Observing System(EOS)Aura satellite.In terms of seasonal variation,middle atmospheric temperatures primarily exhibit annual oscillations(AO)and semi-annual oscillations(SAO).Harmonic analysis of the lidar and MLS temperature data reveals close phase alignment for both AO and SAO,with AO amplitudes ranging from 2 to 6 K,and SAO amplitudes from 1 to 4 K.The dependence of temperature on solar forcing was analyzed using the F10.7 index as a proxy,showing positive solar response coefficients at all altitudes,with a maximum of 15±1.1 K/100 SFU observed near 42–44 km.After removing the temperature response to solar cycle variations,a cooling trend in mid-latitude temperatures is evident across all altitudes,ranging from 3 to 6 K/decade.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42125402 and 42174183)the National Key Technologies R&D Program of China (Grant No. 2022YFF0503703)+5 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences (Grant No. XDB41000000)the foundation of the National Key Laboratory of Electromagnetic Environmentthe Fundamental Research Funds for the Central Universitiesthe Chinese Meridian Projectfunded by the Anhui Provincial Natural Science Foundation (Grant No. 2008085MD113)the Joint Open Fund of Mengcheng National Geophysical Observatory (No. MENGO-202209)
文摘The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than 9 years of mesopause temperatures and relative densities estimated by using ambipolar diffusion coefficient measurements observed by the Mengcheng meteor radar(33.4°N,116.5°E).The intercomparison between the meteor radar and Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere by Broadband Emission Radiometry(TIMED/SABER)and Earth Observing System(EOS)Aura/Microwave Limb Sounder(MLS)observations indicates that the meteor radar temperatures and densities agree well with the simultaneous satellite measurements.Annual variations dominate the mesopause temperatures,with the maximum during winter and the minimum during summer.The mesopause relative densities also show annual variations,with strong maxima near the spring equinox and weak maxima before the winter solstice,and with a minimum during summer.In addition,the mesopause density exhibits a structure similar to that of the zonal wind:as the zonal wind flows eastward(westward),the mesopause density decreases(increases).At the same time,the meridional wind shows a structure similar to that of the mesopause temperature:as the meridional wind shows northward(southward)enhancements,the mesopause temperature increases(decreases).Simultaneous horizontal wind,temperature,and density observations provide multiple mesospheric parameters for investigating mesospheric dynamics and thermodynamic processes and have the potential to improve widely used empirical atmospheric models.
