The low-latitude sodium layer:comparative data from lidar observations at Hainan,China and São Paulo,Brazil  

作　　者：Fang Wu Jing Jiao GuoTao Yang LiFang Du ZhengKuan Liu HaoRan Zheng JiXin Guo ShaoHua Gong YaJun Zhu 

机构地区：[1]State Key Laboratory of Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China [2]Hainan National Field Science Observation and Research Observatory for Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]China-Brazil Joint Laboratory for Space Weather,NSSC/INPE,São Josédos Campos 12227-010,Brazil [5]School of Physics and Electronics Engineering,Hainan Normal University,Haikou 571158,China

出　　处：《Earth and Planetary Physics》2025年第1期39-53,共15页地球与行星物理（英文版）

基　　金：supported by the NSFC (42374204, 42004143,42364012);the Project of Stable Support for Youth Team in Basic Research Field,Chinese Academy of Sciences (Grant No.YSBR-018);the Scientific Projects of Hainan Province(KJRC2023C05, ZDYF2021GXJS040);the Innovational Fund for Scientific and Technological Personnel of Hainan Province;the Chinese Meridian Project;Pandeng Program of National Space Science Center,Chinese Academy of Sciences

摘　　要：Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude ionosphere.Metallic sodium detected by lidar can yield clues to dynamic and chemical processes in these spatial layers above the Earth’s atmosphere.This paper is based on sodium layer data collected at two low-latitude stations,one in the northern hemisphere and one in the southern.The low-latitude sodium layer exhibits conspicuous seasonal variations in shape,density,and altitude;these variations are similar between Earth’s hemispheres:sodium layer density at both stations reaches its seasonal maximum in autumn and minimum in summer.However,maximal Na density over Brazil is greater than that over Hainan.Nocturnal variations of Na density above the two low-latitude stations are also similar;at both,maxima are observed before sunrise.Some variations of the Na layer over Brazil that differ from those observed in the northern hemisphere may be related to the South Atlantic Magnetic Anomaly(SAMA)or fountain effect.We suggest that low-latitude Na layer data may provide useful additional evidence that could significantly improve the low-latitude part of the WACCM-Na model.

关 键 词：metallic sodium layer seasonal variation nocturnal variation LIDAR 

分 类 号：P35[天文地球—空间物理学]