Atmosphere

Editorial

Jump to: Research

3 pages, 154 KiB

Open AccessEditorial

Special Issue Editorial: Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling

by Tai-Yin Huang

Atmosphere 2021, 12(2), 202; https://doi.org/10.3390/atmos12020202 - 03 Feb 2021

Viewed by 2009

Abstract

Airglow observations, experimentations, and theoretical studies have significantly advanced our understanding of airglow in recent decades [...] Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

Research

Jump to: Editorial

13 pages, 2391 KiB

Open AccessArticle

Trends in the Airglow Temperatures in the MLT Region—Part 2: SABER Observations and Comparisons to Model Simulations

by Tai-Yin Huang and Michael Vanyo

Atmosphere 2021, 12(2), 167; https://doi.org/10.3390/atmos12020167 - 28 Jan 2021

Cited by 4 | Viewed by 2025

Abstract

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature measurements at low latitudes from 89 km to 97 km were used to derive the F10.7 and Ap index trends, and the trends were compared to model simulations. The annual mean nonzonal [...] Read more.

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature measurements at low latitudes from 89 km to 97 km were used to derive the F10.7 and Ap index trends, and the trends were compared to model simulations. The annual mean nonzonal (e.g., at the model simulation location at 18° N, 290° E) SABER temperature showed a good-to-moderate correlation with F10.7, with a trend of 4.5–5.3 K/100 SFU, and a moderate-to-weak correlation with the Ap index, with a trend of 0.1–0.3 K/nT. The annual mean zonal mean SABER temperature was found to be highly correlated with the F10.7, with a similar trend, and moderately correlated with the Ap index, with a trend in a similar range. The correlation with the Ap index was significantly improved with a slightly larger trend when the zonal mean temperature was fitted with a 1-year backward shift in the Ap index. The F10.7 (Ap index) trends in the simulated O₂ and the O(¹S) temperature were smaller (larger) than those in the annual mean nonzonal mean SABER temperature. The trends from the simulations were better compared to those in the annual mean zonal mean temperature. The comparisons were even better when compared to the trend results obtained from fitting with a backward shift in the Ap index. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

15 pages, 710 KiB

Open AccessArticle

Daily Variability in the Terrestrial UV Airglow

by Thomas J. Immel, Richard W. Eastes, William E. McClintock, Steven B. Mende, Harald U. Frey, Colin Triplett and Scott L. England

Atmosphere 2020, 11(10), 1046; https://doi.org/10.3390/atmos11101046 - 30 Sep 2020

Cited by 2 | Viewed by 2142

Abstract

New capability for observing conditions in the upper atmosphere comes with the implementation of global ultraviolet (UV) imaging from geosynchronous orbit. Observed by the NASA GOLD mission, the emissions of atomic oxygen (OI) and molecular nitrogen (N

_{2}

) in the 133–168-nm range [...] Read more.

New capability for observing conditions in the upper atmosphere comes with the implementation of global ultraviolet (UV) imaging from geosynchronous orbit. Observed by the NASA GOLD mission, the emissions of atomic oxygen (OI) and molecular nitrogen (N

_{2}

) in the 133–168-nm range can be used to characterize the behavior of these major constituents of the thermosphere. Observations in the ultraviolet from the first 200 days of 2019 indicate that the oxygen emission at 135.6 nm varies much differently than the broader Lyman-Birge-Hopfield (LBH) emission of N

_{2}

. This is determined from monitoring the average instrument response from two roughly 1000 km

^{2}

areas, well separated from one another, at the same time of each day. Variations in the GOLD response to UV emissions in the monitored regions are determined, both in absolute terms and relative to a running 7-day average of GOLD measurements. We find that variations in N

_{2}

emissions in the two separate regions are significantly correlated, while oxygen emissions, observed in the same fixed geographic regions at the same universal time each day, exhibit a much lower correlation, and exhibit no correlation with the N

_{2}

emissions in the same regions. This indicates that oxygen densities in the airglow-originating altitude range of 150–200 km vary independently from the variations in nitrogen, which are so well correlated across the dayside to suggest a direct connection to variation in solar extreme-UV flux. The relation of the atomic oxygen variations to solar and geomagnetic activity is also shown to be low, suggesting the existence of a regional source that modifies the production of atomic oxygen in the thermosphere. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

22 pages, 7462 KiB

Open AccessArticle

Gravity Wave Investigations over Comandante Ferraz Antarctic Station in 2017: General Characteristics, Wind Filtering and Case Study

by Gabriel Augusto Giongo, José Valentin Bageston, Cosme Alexandre Oliveira Barros Figueiredo, Cristiano Max Wrasse, Hosik Kam, Yong Ha Kim and Nelson Jorge Schuch

Atmosphere 2020, 11(8), 880; https://doi.org/10.3390/atmos11080880 - 18 Aug 2020

Cited by 6 | Viewed by 2544

Abstract

This work presents the characteristics of gravity waves observed over Comandante Ferraz Antarctic Station (EACF: 62.1° S, 58.4° W). A total of 122 gravity waves were observed in 34 nights from March to October 2017, and their parameters were obtained by using the [...] Read more.

This work presents the characteristics of gravity waves observed over Comandante Ferraz Antarctic Station (EACF: 62.1° S, 58.4° W). A total of 122 gravity waves were observed in 34 nights from March to October 2017, and their parameters were obtained by using the Fourier Transform spectral analysis. The majority of the observed waves presented horizontal wavelength ranging from 15 to 35 km, period from 5 to 20 min, and horizontal phase speed from 10 to 70 ± 2 m·s⁻¹. The propagation direction showed an anisotropic condition, with the slower wave propagating mainly to the west, northwest and southeast directions, while the faster waves propagate to the east, southeast and south. Blocking diagrams for the period of April–July showed a good agreement between the wave propagation direction and the blocking positions, which are eastward oriented while the waves propagate mainly westward. A case study to investigate wave sources was conducted for the night of 20–21 July, wherein eight small-scale and one medium-scale gravity waves were identified. Reverse ray tracing model was used to investigate the gravity wave source, and the results showed that six among eight small-scale gravity waves were generated in the mesosphere. On the other hand, only two small-scale waves and the medium-scale gravity wave had likely tropospheric or stratospheric origin, however, they could not be associated with any reliable source. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

17 pages, 4396 KiB

Open AccessArticle

All-Sky Imager Observations of the Latitudinal Extent and Zonal Motion of Magnetically Conjugate 630.0 nm Airglow Depletions

by Carlos Martinis, Dustin Hickey, Joei Wroten, Jeffrey Baumgardner, Rebecca Macinnis, Caity Sullivan and Santiago Padilla

Atmosphere 2020, 11(6), 642; https://doi.org/10.3390/atmos11060642 - 16 Jun 2020

Cited by 1 | Viewed by 2713

Abstract

630.0 nm all-sky imaging data are used to detect airglow depletions associated with equatorial spread F. Pairs of imagers located at geomagnetically conjugate locations in the American sector at low and mid-latitudes provide information on the occurrence rate and zonal motion of airglow [...] Read more.

630.0 nm all-sky imaging data are used to detect airglow depletions associated with equatorial spread F. Pairs of imagers located at geomagnetically conjugate locations in the American sector at low and mid-latitudes provide information on the occurrence rate and zonal motion of airglow depletions. Airglow depletions are seen extending to magnetic latitudes as high as 25°. An asymmetric extension is observed with structures in the northern hemisphere reaching higher latitudes. By tracking the zonal motion of airglow depletions, zonal plasma drifts in the thermosphere can be inferred and their simultaneous behavior in both hemispheres investigated. Case studies using El Leoncito and Mercedes imagers in the southern hemisphere, and the respective magnetically conjugate imagers at Villa de Leyva and Arecibo, provide consistent evidence of the influence of the South Atlantic Magnetic Anomaly on the dynamics and characteristics of the thermosphere–ionosphere system at low and mid-latitudes. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

12 pages, 2733 KiB

Open AccessArticle

Trends in the Airglow Temperatures in the MLT Region—Part 1: Model Simulations

by Tai-Yin Huang and Michael Vanyo

Atmosphere 2020, 11(5), 468; https://doi.org/10.3390/atmos11050468 - 06 May 2020

Cited by 4 | Viewed by 2513

Abstract

Airglow intensity-weighted temperature variations induced by the CO₂ increase, solar cycle variation (F10.7 as a proxy) and geomagnetic activity (Ap index as a proxy) in the Mesosphere and Lower Thermosphere (MLT) region were simulated to quantitatively assess their influences on airglow temperatures. [...] Read more.

Airglow intensity-weighted temperature variations induced by the CO₂ increase, solar cycle variation (F10.7 as a proxy) and geomagnetic activity (Ap index as a proxy) in the Mesosphere and Lower Thermosphere (MLT) region were simulated to quantitatively assess their influences on airglow temperatures. Two airglow models, MACD-00 and OHCD-00, were used to simulate the O(¹S) greenline, O₂(0,1) atmospheric band, and OH(8,3) airglow temperature variations induced by these influences to deduce the trends. Our results show that all three airglow temperatures display a linear trend of ~−0.5 K/decade, in response to the increase of CO₂ gas concentration. The airglow temperatures were found to be highly correlated with Ap index, and moderately correlated with F10.7, with the OH temperature showing an anti-correlation. The F10.7 and Ap index trends were found to be ~−0.7 ± 0.28 K/100SFU and ~−0.1 ± 0.02 K/nT in the OH temperature, 4.1 ± 0.7 K/100SFU and ~0.6 ± 0.03 K/nT in the O₂ temperature and ~2.0 ± 0.6 K/100SFU and ~0.4 ± 0.03 K/nT in the O1S temperature. These results indicate that geomagnetic activity can have a rather significant effect on the temperatures that had not been looked at previously. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

25 pages, 6396 KiB

Open AccessArticle

Model of Daytime Oxygen Emissions in the Mesopause Region and Above: A Review and New Results

by Valentine Yankovsky and Ekaterina Vorobeva

Atmosphere 2020, 11(1), 116; https://doi.org/10.3390/atmos11010116 - 19 Jan 2020

Cited by 10 | Viewed by 4604

Abstract

Atmospheric emissions of atomic and molecular oxygen have been observed since the middle of 19th century. In the last decades, it has been shown that emissions of excited oxygen atom O(¹D) and molecular oxygen in electronically–vibrationally excited states O₂(b [...] Read more.

Atmospheric emissions of atomic and molecular oxygen have been observed since the middle of 19th century. In the last decades, it has been shown that emissions of excited oxygen atom O(¹D) and molecular oxygen in electronically–vibrationally excited states O₂(b¹Σ⁺_g, v) and O₂(a¹Δ_g, v) are related by a unified photochemical mechanism in the mesosphere and lower thermosphere (MLT). The current paper consists of two parts: a review of studies related to the development of the model of ozone and molecular oxygen photodissociation in the daytime MLT and new results. In particular, the paper includes a detailed description of formation mechanism for excited oxygen components in the daytime MLT and presents comparison of widely used photochemical models. The paper also demonstrates new results such as new suggestions about possible products for collisional reactions of electronically–vibrationally excited oxygen molecules with atomic oxygen and new estimations of O₂(b¹Σ⁺_g, v = 0–10) radiative lifetimes which are necessary for solving inverse problems in the lower thermosphere. Moreover, special attention is given to the “Barth’s mechanism” in order to demonstrate that for different sets of fitting coefficients its contribution to O₂(b¹Σ⁺_g, v) and O₂(a¹Δ_g, v) population is neglectable in daytime conditions. In addition to the review and new results, possible applications of the daytime oxygen emissions are presented, e.g., the altitude profiles O(³P), O₃ and CO₂ can be retrieved by solving inverse photochemical problems when emissions from electronically vibrationally excited states of O₂ molecule are used as proxies. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

9 pages, 1157 KiB

Open AccessArticle

Mean Zonal Drift Velocities of Plasma Bubbles Estimated from Keograms of Nightglow All-Sky Images from the Brazilian Sector

by Fabio Vargas, Christiano Brum, Pedrina Terra and Delano Gobbi

Atmosphere 2020, 11(1), 69; https://doi.org/10.3390/atmos11010069 - 05 Jan 2020

Cited by 8 | Viewed by 3150

Abstract

We present in this work a method for estimation of equatorial plasma bubble (EPB) mean zonal drift velocities using keograms generated from images of the OI 6300.0 nm nightglow emission collected from an equatorial station–Cariri (7.4° S, 36.5° W), and a mid-latitude station–Cachoeira [...] Read more.

We present in this work a method for estimation of equatorial plasma bubble (EPB) mean zonal drift velocities using keograms generated from images of the OI 6300.0 nm nightglow emission collected from an equatorial station–Cariri (7.4° S, 36.5° W), and a mid-latitude station–Cachoeira Paulista (22.7° S, 45° W), both in the Brazilian sector. The mean zonal drift velocities were estimated for 239 events recorded from 2000 to 2003 in Cariri, and for 56 events recorded over Cachoeira Paulista from 1998 to 2000. It was found that EPB zonal drift velocities are smaller (≈60 ms⁻¹) for events occurring later in the night compared to those occurring earlier (≈150 ms⁻¹). The decreasing rate of the zonal drift velocity is ≈10 ms⁻¹/h. We have also found that, in general, bubble events appearing first in the west-most region of the keograms are faster than those appearing first in the east-most region. Larger zonal drift velocities occur from 19 to 23 LT in a longitude range from −37° to −33°, which shows that the keogram method can be used to describe vertical gradients in the thermospheric wind, assuming that the EPBs drift eastward with the zonal wind. The method of velocity estimation using keograms compares favorably against the mosaic method developed by Arruda, D.C.S, 2005, but the standard deviation of the residuals for the zonal drift velocities from the two methods is not small (≈15 ms⁻¹). Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

10 pages, 443 KiB

Open AccessArticle

Growth Rate of Gravity Wave Amplitudes Observed in Sodium Lidar Density Profiles and Nightglow Image Data

by Fabio Vargas, Guotao Yang, Paulo Batista and Delano Gobbi

Atmosphere 2019, 10(12), 750; https://doi.org/10.3390/atmos10120750 - 28 Nov 2019

Cited by 5 | Viewed by 2673

Abstract

Amplitude growth rates of quasi-monochromatic gravity waves were estimated and compared from multiple instrument measurements carried out in Brazil. Gravity wave parameters, such as the wave amplitude and growth rate in distinct altitudes, were derived from sodium lidar density and nightglow all-sky images. [...] Read more.

Amplitude growth rates of quasi-monochromatic gravity waves were estimated and compared from multiple instrument measurements carried out in Brazil. Gravity wave parameters, such as the wave amplitude and growth rate in distinct altitudes, were derived from sodium lidar density and nightglow all-sky images. Lidar observations were carried out in São Jose dos Campos (23

^{\circ}

S, 46

^{\circ}

W) from 1994 to 2004, while all-sky imagery of multiple airglow layers was conducted in Cachoeira Paulista (23

^{\circ}

S, 45

^{\circ}

W) from 1999–2000 and 2004–2005. We have found that most of the measured amplitude growth rates indicate dissipative behavior for gravity waves identified in both lidar profiles and airglow image datasets. Only a small fraction of the observed wave events (4% imager; 9% lidar) are nondissipative (freely propagating waves). Our findings also show that imager waves are strongly dissipated within the mesosphere and lower thermosphere region (MLT), decaying in amplitude in short distances (<12 km), while lidar waves tend to maintain a constant amplitude within that region. Part of the observed waves (16% imager; 36% lidar) showed unchanging amplitude with altitude (saturated waves). About 51.6% of the imager waves present strong attenuation (overdamped waves) in contrast with 9% of lidar waves. The general saturated or damped behavior is consistent with diffusive filtering processes imposing limits to amplitude growth rates of the observed gravity waves. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

17 pages, 9620 KiB

Open AccessArticle

Preliminary Dual-Satellite Observations of Atmospheric Gravity Waves in Airglow

by Jia Yue, Septi Perwitasari, Shuang Xu, Yuta Hozumi, Takuji Nakamura, Takeshi Sakanoi, Akinori Saito, Steven D. Miller, William Straka and Pingping Rong

Atmosphere 2019, 10(11), 650; https://doi.org/10.3390/atmos10110650 - 28 Oct 2019

Cited by 11 | Viewed by 3082

Abstract

Atmospheric gravity waves (AGWs) are among the important energy and momentum transfer mechanisms from the troposphere to the middle and upper atmosphere. Despite their understood importance in governing the structure and dynamics of these regions, mesospheric AGWs remain poorly measured globally, and largely [...] Read more.

Atmospheric gravity waves (AGWs) are among the important energy and momentum transfer mechanisms from the troposphere to the middle and upper atmosphere. Despite their understood importance in governing the structure and dynamics of these regions, mesospheric AGWs remain poorly measured globally, and largely unconstrained in numerical models. Since late 2011, the Suomi National Polar-orbiting Partnership (NPP) Visible/Infrared Imaging Radiometer Suite (VIIRS) day–night band (DNB) has observed global AGWs near the mesopause by virtue of its sensitivity to weak emissions of the OH* Meinel bands. The wave features, detectable at 0.75 km spatial resolution across its 3000 km imagery swath, are often confused by the upwelling emission of city lights and clouds reflecting downwelling nightglow. The Ionosphere, Mesosphere, upper Atmosphere and Plasmasphere (IMAP)/ Visible and near-Infrared Spectral Imager (VISI) O₂ band, an independent measure of the AGW structures in nightglow based on the International Space Station (ISS) during 2012–2015, contains much less noise from the lower atmosphere. However, VISI offers much coarser resolution of 14–16 km and a narrower swath width of 600 km. Here, we present preliminary results of comparisons between VIIRS/DNB and VISI observations of AGWs, focusing on several concentric AGW events excited by the thunderstorms over Eastern Asia in August 2013. The comparisons point toward suggested improvements for future spaceborne airglow sensor designs targeting AGWs. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

12 pages, 2409 KiB

Open AccessArticle

Airglow Derived Measurements of Q-Branch Transition Probabilities for Several Hydroxyl Meinel Bands

by Christoph Franzen, Patrick Joseph Espy, Niklas Hofmann, Robert Edward Hibbins and Anlaug Amanda Djupvik

Atmosphere 2019, 10(10), 637; https://doi.org/10.3390/atmos10100637 - 22 Oct 2019

Cited by 4 | Viewed by 3035

Abstract

Spectroscopic measurements of the hydroxyl (OH) airglow emissions are often used to infer neutral temperatures near the mesopause. Correct Einstein coefficients for the various transitions in the OH airglow are needed to calculate accurate temperatures. However, studies showed experimentally and theoretically that the [...] Read more.

Spectroscopic measurements of the hydroxyl (OH) airglow emissions are often used to infer neutral temperatures near the mesopause. Correct Einstein coefficients for the various transitions in the OH airglow are needed to calculate accurate temperatures. However, studies showed experimentally and theoretically that the most commonly used Einstein spontaneous emission transition probabilities for the Q-branch of the OH Meinel (6,2) transition are overestimated. Extending their work to several Δv = 2 and 3 transitions from v′ = 3 to 9, we have determined Einstein coefficients for the first four Q-branch rotational lines. These have been derived from high resolution, high signal to noise spectroscopic observations of the OH airglow in the night sky from the Nordic Optical Telescope. The Q-branch Einstein coefficients calculated from these spectra show that values currently tabulated in the HITRAN database overestimate many of the Q-branch transition probabilities. The implications for atmospheric temperatures derived from OH Q-branch measurements are discussed. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

15 pages, 867 KiB

Open AccessArticle

A Comparison of Einstein A Coefficients for OH Rotational Temperature Measurements Using a Large Astronomical Data Set

by Murdock Hart

Atmosphere 2019, 10(10), 569; https://doi.org/10.3390/atmos10100569 - 22 Sep 2019

Cited by 3 | Viewed by 2674

Abstract

The Einstein A coefficients are considered to be a significant source of uncertainty in the measurement of

OH

rotational temperatures. Using simultaneous ground and spaced-based observations of

OH

emission, five sets of Einstein A coefficients were examined for their impact upon rotational temperature [...] Read more.

The Einstein A coefficients are considered to be a significant source of uncertainty in the measurement of

OH

rotational temperatures. Using simultaneous ground and spaced-based observations of

OH

emission, five sets of Einstein A coefficients were examined for their impact upon rotational temperature calculations. The ground-based observations are taken from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) instrument which is a high resolution,

r = λ

/

Δ λ

\geq 20, 000

, spectrograph operating in the H-band from approximately 1.5 to 1.7

μ

m. APOGEE collected over one-hundred-and-fifty-thousand spectra of the night sky over a period from June 2011 to June 2013. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite has made simultaneous atmospheric measurements with the APOGEE spectrograph. SABER observes the

OH

volume emission rate (VER) around 1.6

μ

m, providing measurements coincident with those of the

OH

emission in the APOGEE sky spectra. Four of the five sets of Einstein A coefficients tested yielded statistically identical mean rotational temperatures of approximately 195 K for the

OH (4 - 2)

transition. The Einstein A coefficients were found to have a significant impact upon the measured

OH (v^{'} = 4)

vibrational populations with some sets of coefficients yielding populations over 50% greater. Simultaneous SABER observations were used to determine which set of Einstein A coefficients best reflected atmospheric temperatures, and four of the five tested coefficients yielded nearly identical results. The difference between

OH

rotational temperatures and SABER temperatures was on average 1 K. Full article

(This article belongs to the Special Issue Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Atmospheric Airglow—Recent Advances in Observations, Experimentations, and Modeling

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (12 papers)

Editorial

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI