Universal power law of the gravity wave manifestation in the AIM CIPS polar mesospheric cloud images

Abstract

Abstract. We aim to extract a universal law that governs the gravity wave manifestation in polar mesospheric clouds (PMCs). Gravity wave morphology and the clarity level of display vary throughout the wave population manifested by the PMC albedo data. Higher clarity refers to more distinct exhibition of the features, which often correspond to larger variances and a better-organized nature. A gravity wave tracking algorithm based on the continuous Morlet wavelet transform is applied to the PMC albedo data at 83 km altitude taken by the Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument to obtain a large ensemble of the gravity wave detections. The horizontal wavelengths in the range of ∼ 20-60 km are the focus of the study. It shows that the albedo (wave) power statistically increases as the background gets brighter. We resample the wave detections to conform to a normal distribution to examine the wave morphology and display clarity beyond the cloud brightness impact. Sample cases are selected at the two tails and the peak of the normal distribution to represent the full set of wave detections. For these cases the albedo power spectra follow exponential decay toward smaller scales. The high-albedo-power category has the most rapid decay (i.e., exponent = −3.2) and corresponds to the most distinct wave display. The wave display becomes increasingly blurrier for the medium-and low-power categories, which hold the monotonically decreasing spectral exponents of −2.9 and −2.5, respectively. The majority of waves are straight waves whose clarity levels can collapse between the different brightness levels, but in the brighter background the wave signatures seem to exhibit mildly turbulentlike behavior.

AIM CIPS PMC tracking wind product retrieval approach and first assessment

“…The correlation coefficient would have a one-to-one correspondence to the displacement of a cloud pattern if the dominant spatial scale is wavenumber-1 in a sinusoidal form and the wind advection is the sole mechanism to drive the cloud pattern variation. The large scale dominance over smaller scales within a 400-500 km frame is proven to be the case in the CIPS clouds in Rong et al [2018].…”

The MATS satellite mission – gravity wave studies by Mesospheric Airglow/Aerosol Tomography and Spectroscopy

“…Basic wave parameters have been inferred from NLC observations by the UVIST instrument on board the MSX satellite (Carbary et al, 2000). On the AIM satellite, the CIPS instrument has provided comprehensive gravity wave information from near-nadir imaging of NLCs, resulting in wave climatologies covering horizontal wavelengths both above 100 km (Rusch et al, 2008;Chandran et al, 2009) and below 100 km (Rong et al, 2018). MLT gravity wave analysis based on nadir nightglow observations has been reported from the VIIRS instrument on board the NOAA/NASA Suomi satellite Azeem et al, 2015), and the IMAP/VISI instrument on board the International Space Station (Perwitasari et al, 2016).…”

“…At the same time, ground-based and space-based observations of NLCs are a primary source of our knowledge about gravity wave activ-ity in the middle atmosphere (e.g. Witt, 1962;Chandran et al, 2009;Rong et al, 2018;Gumbel and Karlsson, 2011). Gravity waves may also play an important role in explaining other dynamical NLC features like so-called ice fronts or ice voids .…”

“…Chen, 1992;Forbes and Leveroni, 1992) and gravity waves (e.g. Röttger, 1977;Park et al, 2014;Forbes et al, 2016;Trinh et al, 2018;. A basic open question concerns the relative importance of primary, secondary, and higher-order gravity waves in propagating from the middle atmosphere to the thermosphere and ionosphere through a multi-step vertical coupling process Becker, 2018, 2019).…”

The MATS Satellite Mission – Gravity Waves Studies by Mesospheric Airglow/Aerosol Tomography and Spectroscopy

“…information from near-nadir imaging of NLC, resulting in wave climatologies covering horizontal wavelengths both above 100 km (Rusch et al, 2008;Chandran et al, 2009) and below 100 km (Rong et al, 2018). MLT gravity wave analysis based on nadir nightglow observations has been reported from the VIIRS instrument onboard the NOAA/NASA Suomi satellite (Yue et al, 2014;Miller et al, 2015), and the IMAP/VISI instrument on-board the International Space Station (Perwitasari et al, 2016).…”