On the latitudinal variations of AO, SAO, and ISOs in the MLT temperatures

IF 3.2 3区地球科学 Q2 ASTRONOMY & ASTROPHYSICS

Advances in Space Research Pub Date : 2026-07-01 Epub Date: 2025-10-09 DOI:10.1016/j.asr.2025.10.003

Kiran, Ravindra P. Singh

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Abstract

Analysis of two years of OH(3-1) rotational temperatures derived from the PRL Airglow InfraRed Spectrograph (PAIRS) at Ahmedabad (23°N, 72.6°E) reveals a clear presence of annual (AO) and semi-annual (SAO) oscillations, along with intraseasonal oscillations (ISOs) near an altitude of 87 km. Similar oscillations are also observed in SABER-derived temperatures centered over Ahmedabad. However, the NRLMSIS model captures only AO and SAO, failing to reproduce the observed ISOs. Notably, the 75-day oscillation is absent in both PAIRS and SABER temperatures over Ahmedabad, which motivated a broader investigation into the latitudinal distribution of these oscillations. A comprehensive analysis was carried out using longitudinally averaged SABER temperature data, organized at 10° latitude intervals from 80°N to 80°S. Lomb-Scargle spectral analysis was employed to extract the amplitudes of significant oscillations at each latitude band. The results show that the AO and SAO are present across all latitudes, with their amplitudes peaking at the poles and reaching a minimum near the equator, while SAO amplitudes show a secondary peak near the equator. ISOs exhibit strong latitude-dependent variations: the terannual oscillation (TAO) is prominent at low to mid-latitudes, the quarter-annual oscillation (QAO) appears at all latitudes with stronger amplitudes at high latitudes, the 75-day oscillation is confined to mid and high latitudes, and the 60-day oscillation is primarily observed at equatorial and low latitudes. These findings provide new observational evidence for the latitude-dependent amplitude variations of ISOs and quantify their characteristics using PAIRS and SABER temperature measurements in the MLT region.

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AO、SAO和iso在MLT温度中的纬度变化

对Ahmedabad(23°N, 72.6°E) PRL Airglow红外光谱仪（PAIRS）两年OH（3-1）旋转温度的分析显示，在海拔87 km附近明显存在年度（AO）和半年度（SAO）振荡，以及季节内振荡（iso）。在以艾哈迈达巴德为中心的saber衍生温度中也观察到类似的振荡。然而，NRLMSIS模型只捕获了AO和SAO，未能重现观测到的iso。值得注意的是，艾哈迈达巴德上空的pair和SABER温度都没有75天振荡，这促使人们对这些振荡的纬度分布进行更广泛的研究。利用从80°N到80°S的10°纬度间隔的纵向平均SABER温度数据进行了综合分析。采用Lomb-Scargle谱分析提取各纬度波段的显著振荡幅度。结果表明，AO和SAO在各纬度均存在，其振幅在两极达到峰值，在赤道附近达到最小值，而SAO振幅在赤道附近出现次峰值。ISOs表现出较强的纬度依赖性：低纬度至中纬度地区存在明显的三年振荡（TAO），高纬度地区出现较强的季度振荡（QAO）， 75天振荡仅限于中高纬度地区，60天振荡主要出现在赤道和低纬度地区。这些发现为iso振幅随纬度的变化提供了新的观测证据，并利用PAIRS和SABER在MLT地区的温度测量量化了其特征。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Advances in Space Research 地学天文-地球科学综合

CiteScore

5.20

自引率

11.50%

发文量

800

审稿时长

5.8 months

期刊介绍： The COSPAR publication Advances in Space Research (ASR) is an open journal covering all areas of space research including: space studies of the Earth''s surface, meteorology, climate, the Earth-Moon system, planets and small bodies of the solar system, upper atmospheres, ionospheres and magnetospheres of the Earth and planets including reference atmospheres, space plasmas in the solar system, astrophysics from space, materials sciences in space, fundamental physics in space, space debris, space weather, Earth observations of space phenomena, etc. NB: Please note that manuscripts related to life sciences as related to space are no more accepted for submission to Advances in Space Research. Such manuscripts should now be submitted to the new COSPAR Journal Life Sciences in Space Research (LSSR). All submissions are reviewed by two scientists in the field. COSPAR is an interdisciplinary scientific organization concerned with the progress of space research on an international scale. Operating under the rules of ICSU, COSPAR ignores political considerations and considers all questions solely from the scientific viewpoint.