Description:
<jats:title>Abstract</jats:title><jats:p>In order to analyze the relationship between atmospheric tides and the ionospheric day‐to‐day variations, this paper mainly presents the meteorological scale (period is shorter than 60 days) correlation relationship between the daily longitudinal structure wavenumber 4 (<jats:italic>WN</jats:italic><jats:sub>4</jats:sub>) in the ionosphere and the daily diurnal eastward propagating with zonal wavenumber 3 (DE3) tide in the upper atmosphere. We deduce the latitudinal integration of total electron content from the global ionospheric maps in the middle‐ to low‐latitude ionosphere and the upper atmospheric temperature from Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics\Sounding of the Atmosphere using Broadband Emission Radiometry observations in the MLT region. Applying new techniques proposed by Li et al. (2015, <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1002/2015JA021577">https://doi.org/10.1002/2015JA021577</jats:ext-link>), we extract the daily WN<jats:sub>4</jats:sub> structure and daily DE3 tide, respectively. We found that (1) the meteorological scale cross‐correlation coefficients are symmetric about the equator and dominate at the low latitudes; (2) there is a remarkable valley value around sunrise: the amplitudes in day time are a little larger than those at night; the phases in day time are stable and change slowly at night and dramatically before dawn; (3) they vary gradually with altitudes, and the vertical propagating wavelength is about 35‐km altitude; (4) they present an obvious annual variation that the amplitudes are larger from June solstice to early north autumn, and the phases are stable in these months; and (5) they display an obvious quasi‐biennial oscillation phenomenon, and in June to August of 2008–2009 the amplitudes almost disappear before dawn.</jats:p>