Trajectories of Major Martian Dust Storms

2020 ◽  
Author(s):  
Huiqun (Helen) Wang ◽  
Mark Richardson ◽  
Anthony Toigo
Keyword(s):  
Optical Depth ◽  
Dust Storm ◽  
General Circulation ◽  
Middle Atmosphere ◽  
Thermal Structure ◽  
Great Variability ◽  
Dust Storms ◽  
The Past ◽  
Annual Variability

<p>      Major dust storms – including large regional and global dust storms – dramatically influence atmospheric optical depth, thermal structure, and circulation. They represent probably the most significant inter-annual variability in the Martian lower / middle atmosphere and are of particular concern for spacecraft missions. Great variability is exhibited not only in their timing and magnitudes, but also in histories of their evolution. Mars Daily Global Maps (MDGMs) over the past Mars decade have shown that all major dust storms develop through a combination of dust storm sequences evolving along one or more trajectories, where each dust storm sequence is composed of multiple dust storm members of various sizes and durations along a trajectory. In this presentation, we will illustrate the trajectories of major dust storms observed in MDGMs and examine their relationship with the general circulation.</p>

scholarly journals On the role of dust storms in triggering atmospheric gravity waves observed in the middle atmosphere

2011 ◽  
Vol 29 (9) ◽  
pp. 1647-1654 ◽  
Author(s):  
S. K. Das ◽  
A. Taori ◽  
A. Jayaraman
Keyword(s):  
Gravity Waves ◽  
Dust Storm ◽  
Hot Spots ◽  
Middle Atmosphere ◽  
Thermal Structure ◽  
Dust Storms ◽  
Storm Events ◽  
Atmospheric Perturbations ◽  
Atmospheric Gravity

Abstract. Lower atmospheric perturbations often produce measurable effects in the middle and upper atmosphere. The present study demonstrates the response of the middle atmospheric thermal structure to the significant enhancement of the lower atmospheric heating effect caused by dust storms observed over the Thar Desert, India. Our study from multi-satellite observations of two dust storm events that occurred on 3 and 8 May 2007 suggests that dust storm events produce substantial changes in the lower atmospheric temperatures as hot spots which can become sources for gravity waves observed in the middle atmosphere.

scholarly journals An Observational Overview of Dusty Deep Convection in Martian Dust Storms

2019 ◽  
Vol 76 (11) ◽  
pp. 3299-3326 ◽  
Author(s):  
Nicholas G. Heavens ◽  
David M. Kass ◽  
James H. Shirley ◽  
Sylvain Piqueux ◽  
Bruce A. Cantor
Keyword(s):  
Dust Storm ◽  
Large Scale ◽  
Middle Atmosphere ◽  
Deep Convection ◽  
High Surface ◽  
Dust Storms ◽  
Radiative Heating ◽  
Storm Activity ◽  
Mesoscale Circulations ◽  
Convective Structures

Abstract Deep convection, as used in meteorology, refers to the rapid ascent of air parcels in Earth’s troposphere driven by the buoyancy generated by phase change in water. Deep convection undergirds some of Earth’s most important and violent weather phenomena and is responsible for many aspects of the observed distribution of energy, momentum, and constituents (particularly water) in Earth’s atmosphere. Deep convection driven by buoyancy generated by the radiative heating of atmospheric dust may be similarly important in the atmosphere of Mars but lacks a systematic description. Here we propose a comprehensive framework for this phenomenon of dusty deep convection (DDC) that is supported by energetic calculations and observations of the vertical dust distribution and exemplary dusty deep convective structures within local, regional, and global dust storm activity. In this framework, DDC is distinct from a spectrum of weaker dusty convective activity because DDC originates from preexisting or concurrently forming mesoscale circulations that generate high surface dust fluxes, oppose large-scale horizontal advective–diffusive processes, and are thus able to maintain higher dust concentrations than typically simulated. DDC takes two distinctive forms. Mesoscale circulations that form near Mars’s highest volcanoes in dust storms of all scales can transport dust to the base of the upper atmosphere in as little as 2 h. In the second distinctive form, mesoscale circulations at low elevations within regional and global dust storm activity generate freely convecting streamers of dust that are sheared into the middle atmosphere over the diurnal cycle.

Water vapor vertical profiles on Mars: Results from the first full Mars Year of TGO/NOMAD science operations

2020 ◽  
Author(s):  
Shohei Aoki ◽  
AnnCarine Vandaele ◽  
Frank Daerden ◽  
Geronimo Villanueva ◽  
Ian Thomas ◽  
...  
Keyword(s):  
Water Vapor ◽  
Vertical Distribution ◽  
Dust Storm ◽  
Middle Atmosphere ◽  
Dust Storms ◽  
High Spectral Resolution ◽  
Vertical Profiles ◽  
Geophysical Research ◽  
Solar Occultation ◽  
Science Operations

<p>Nadir and Occultation for Mars Discovery (NOMAD) onboard ExoMars Trace Gas Orbiter (TGO) started the science measurements on 21 April, 2018. We present results on the retrievals of water vapor vertical profiles in the Martian atmosphere from the first Mars year measurements of the TGO/NOMAD.</p><p>NOMAD is a spectrometer operating in the spectral ranges between 0.2 and 4.3 μm onboard ExoMars TGO. NOMAD has 3 spectral channels: a solar occultation channel (SO – Solar Occultation; 2.3–4.3 μm), a second infrared channel capable of nadir, solar occultation, and limb sounding (LNO – Limb Nadir and solar Occultation; 2.3–3.8 μm), and an ultraviolet/visible channel (UVIS – Ultraviolet and Visible Spectrometer, 200–650 nm). The infrared channels (SO and LNO) have high spectral resolution (λ/dλ~10,000–20,000) provided by an echelle grating used in combination with an Acousto Optic Tunable Filter (AOTF) which selects diffraction orders. The concept of the infrared channels are derived from the Solar Occultation in the IR (SOIR) instrument onboard Venus Express (VEx). The sampling rate for the solar occultation measurement is 1 second, which provides better vertical sampling step (~1 km) with higher resolution (~2 km) from the surface to 200 km. Thanks to the instantaneous change of the observing diffraction orders achieved by the AOTF, the SO channel is able to measure five or six different diffraction orders per second in solar occultation mode. In this study, we analyze the solar occultation measurements at diffraction order 134 (3011-3035 cm<sup>-1</sup>), order 136 (3056-3080 cm<sup>-1</sup>) and 168 (3775-3805 cm<sup>-1</sup>) acquired by the SO channel in order to investigate H<sub>2</sub>O vertical profiles.</p><p>Knowledge of the water vapor vertical distribution is important to understand the water cycle and escape processes. Solar occultation measurements by the two spectrometers onboard TGO - NOMAD and Atmospheric Chemistry Suite (ACS) - allow us to monitor daily the water vapor vertical profiles through one whole Martian Year and obtain a latitudinal map for every ~20° of Ls. In 2018, for the first time after 2007, a global dust storm occurred on Mars. It lasted for more than two months (from June to August). Moreover, following the global dust storm, a regional dust storm occurred in January 2019. TGO began its science operations on 21 April 2018. NOMAD observations therefore fully cover the period before/during/after the global and regional dust storms and offer a unique opportunity to study the trace gases distributions during such events. We have analyzed those datasets and found a significant increase of water vapor abundance in the middle atmosphere (40-100 km) during the global dust storm from June to mid-September 2018 and the regional dust storm in January 2019. In particular, water vapor reaches very high altitudes, at least 100 km, during the global dust storm (Aoki et al., 2019, Journal of Geophysical Research, Volume124, Issue12, Pages 3482-3497, doi:10.1029/2019JE006109). A GCM simulation explained that dust storm related increases of atmospheric temperatures suppress the hygropause, hence reducing ice cloud formation and so allowing water vapor to extend into the middle atmosphere (Neary et al., 2020, Geophysical Research Letters, 47, e2019GL084354., doi: 10.1029/2019GL084354). The current study presents the results obtained when considering the extended dataset, which covers a full Martian year. The extended dataset includes the recent aphelion season that involves interesting phenomena such as sublimation of water vapor from the northern polar cap and formation of the equatorial cloud belt, and is known as a key period to understand the large north-south hemispheric asymmetries of Mars water vapor. Yet, until now, only few papers reported the water vapor vertical distribution during the aphelion season. The extended dataset also includes the period when the global dust storm occurred the year before; this will allow us to compare the water vapor distributions under global dust storm conditions with those found during non-global dust storm years. In the presentation, we will discuss the H<sub>2</sub>O vertical profiles as well as the aerosols vertical distribution retrieved from the first full Martian year measurements of the TGO/NOMAD.</p><!-- COMO-HTML-CONTENT-END --> <p class="co_mto_htmlabstract-citationHeader"> <strong class="co_mto_htmlabstract-citationHeader-intro">How to cite:</strong> Aoki, S., Vandaele, A., Daerden, F., Villanueva, G., Thomas, I., Erwin, J., Trompet, L., Robert, S., Neary, L., Viscardy, S., Piccialli, A., Liuzzi, G., Crismani, M., Clancy, T., Smith, M., Ristic, B., Lopez-Valverde, M.-A., Patel, M., Bellucci, G., and Lopez-Moreno, J.-J.: Water vapor vertical profiles on Mars: Results from the first full Mars Year of TGO/NOMAD science operations, Europlanet Science Congress 2020, online, 21 September–9 Oct 2020, EPSC2020-392, 2020 </p>

Influence of thermospheric effects of solar activity on the middle atmosphere circulation and stationary planetary waves

2020 ◽  
Author(s):  
Andrey Koval ◽  
Nikolai Gavrilov ◽  
Alexander Pogoreltsev ◽  
Nikita Shevchuk
Keyword(s):  
Solar Activity ◽  
Atmospheric Circulation ◽  
General Circulation ◽  
Large Scale ◽  
Middle Atmosphere ◽  
Thermal Structure ◽  
Planetary Waves ◽  
Boreal Winter ◽  
Zonal Wavenumber ◽  
The Mean

<p>Atmospheric large-scale disturbances, for instance planetary waves, play a significant role in atmospheric general circulation, influencing its dynamical and thermal conditions. Solar activity may influence the mean temperature at altitudes above 100 km and alter conditions of wave propagation and reflection in the thermosphere. Using numerical simulations of the general atmospheric circulation during boreal winter, statistically confident evidences are obtained for the first time, demonstrating that changes in the solar activity (SA) in the thermosphere at heights above 100 km can influence propagation and reflection conditions for stationary planetary waves (SPWs) and can modify the middle atmosphere circulation below 100 km. A numerical mechanistic model simulating  atmospheric circulation and SPWs at heights 0 – 300 km is used. To achieve sufficient statistical confidence, 80 pairs of 15-day intervals were extracted from an ensemble of 16 pairs of model runs corresponding to low and high SA. Results averaged over these intervals show that impacts of SA above 100 km change the mean zonal wind and temperature up to 10% at altitudes below 100 km. The statistically confident changes in SPW amplitudes due to SA impacts above 100 km reach up to 50% in the thermosphere and 10 – 15% in the middle atmosphere depending on zonal wavenumber. Changes in wave amplitudes correspond to variations of the EP-flux and may alter dynamical and thermal SPW impacts on the mean wind and temperature. Thus, variable conditions of SPW propagation and reflection at thermospheric altitudes may influence the middle atmosphere circulation, thermal structure and planetary waves at different altitudes.</p>

Water vapor vertical distributions on Mars: Results from three years of TGO/NOMAD science operations 

2021 ◽  
Author(s):  
Shohei Aoki ◽  
Ann Carine Vandaele ◽  
Frank Daerden ◽  
Geronimo Villanueva ◽  
Giuliano Liuzzi ◽  
...  
Keyword(s):  
Water Vapor ◽  
Dust Storm ◽  
Middle Atmosphere ◽  
Sampling Rate ◽  
Dust Storms ◽  
High Spectral Resolution ◽  
Geophysical Research ◽  
Solar Occultation ◽  
Science Operations ◽  
Vertical Distributions

<div> <p>Nadir and Occultation for Mars Discovery (NOMAD) onboard ExoMars Trace Gas Orbiter (TGO) started  science measurements on 21 April, 2018. Here, we present results on the retrievals of water vapor vertical distributions in the Martian atmosphere from three years of TGO/NOMAD science operations.</p> </div> <p><strong> </strong></p> <p>NOMAD is a spectrometer operating in the spectral ranges between 0.2 and 4.3 μm onboard ExoMars TGO. NOMAD has 3 spectral channels: a solar occultation channel (SO – Solar Occultation; 2.3–4.3 μm), a second infrared channel capable of nadir, solar occultation, and limb sounding (LNO – Limb Nadir and solar Occultation; 2.3–3.8 μm), and an ultraviolet/visible channel (UVIS – Ultraviolet and Visible Spectrometer, 200–650 nm). The infrared channels (SO and LNO) have high spectral resolution (λ/dλ~10,000–20,000) provided by an echelle grating used in combination with an Acousto Optic Tunable Filter (AOTF) which selects diffraction orders. The sampling rate for the solar occultation measurement is 1 second, which provides a good vertical sampling step (~1 km) with higher resolution (~2 km) from the surface to 200 km. Thanks to the instantaneous change of the observing diffraction orders achieved by the AOTF, the SO channel is able to measure five or six different diffraction orders per second in solar occultation mode. In this study, we analyze the solar occultation measurements at diffraction order 134 (3011-3035 cm<sup>-1</sup>), order 136 (3056-3080 cm<sup>-1</sup>), order 168 (3775-3805 cm<sup>-1</sup>), and order 169 (3798-3828 cm<sup>-1</sup>) acquired by the SO channel in order to investigate water vapor vertical distributions.</p> <p>Knowledge of the water vapor vertical profile is important to understand the water cycle and its escape process. Solar occultation measurements by two new spectrometers onboard TGO - NOMAD and Atmospheric Chemistry Suite (ACS) - allows us to daily monitor the water vapor vertical distributions through the whole Martian Year and obtain a good latitudinal coverage for every ~20° of Ls. In 2018, for the first time after 2007, a global dust storm occurred on Mars. It lasted for more than two months (from June to August). Moreover, following the global dust storm, a regional dust storm occurred in January 2019. The NOMAD and ACS observations therefore fully cover the majority of the global and regional dust storms and offer a unique opportunity to study the trace gases distributions during the dust storms. We analyzed those datasets and found a significant increase of water vapor abundances in the middle atmosphere (40-100 km) during the global dust storm from June to mid-September 2018 and the regional dust storm in January 2019. In particular, water vapor reaches very high altitude, at least 100 km, during the global dust storm (Aoki et al., 2019, Journal of Geophysical Research, Volume124, Issue12, Pages 3482-3497, doi:10.1029/2019JE006109). A GCM simulation explained that dust storm related increases of atmospheric temperatures suppress the hygropause, hence reducing ice cloud formation and so allowing water vapor to extend into the middle atmosphere (Neary et al., 2020, Geophysical Research Letters, accepted, Volume47, Issue7, e2019GL084354, doi: 10.1029/2019GL084354). This study presents the results with the extended dataset, which covers a full Mars year. The extended dataset newly includes aphelion season that involves interesting phenomena such as sublimation of water vapor from the northern polar cap and formation of the equatorial cloud belt, which are known as key periods to understand the large north-south hemispheric asymmetries of Mars water vapor. Yet, only a few papers report the water vapor vertical distributions in the aphelion season. The extended dataset also includes the southern summer season (dusty season) in MY 35, which will allow us to compare the water vapor distributions in the global dust storm year with those in the non-global dust storm year. In the presentation, we will discuss the water vapor vertical profiles as well as the aerosols vertical distributions retrieved from the three-year measurements of the TGO/NOMAD.</p>

scholarly journals Observed characteristics of dust storm events over the western United States using meteorological, satellite, and air quality measurements

2014 ◽  
Vol 14 (15) ◽  
pp. 7847-7857 ◽  
Author(s):  
H. Lei ◽  
J. X. L. Wang
Keyword(s):  
Air Quality ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Dust Storm ◽  
Dust Storms ◽  
Satellite Observations ◽  
Data Sets ◽  
Air Quality Measurements ◽  
Quality Measurements

Abstract. To improve dust storm identification over the western United States, historical dust events measured by air quality and satellite observations are analyzed based on their characteristics in data sets of regular meteorology, satellite-based aerosol optical depth (AOD), and air quality measurements. Based on the prevailing weather conditions associated with dust emission, dust storm events are classified into the following four typical types: (1) The key feature of cold front-induced dust storms is their rapid process with strong dust emissions. (2) Events caused by meso- to small-scale weather systems have the highest levels of emissions. (3) Dust storms caused by tropical disturbances show a stronger air concentration of dust and last longer than those in (1) and (2). (4) Dust storms triggered by cyclogenesis last the longest. In this paper, sample events of each type are selected and examined to explore characteristics observed from in situ and remote-sensing measurements. These characteristics include the lasting period, surface wind speeds, areas affected, average loading on ground-based optical and/or air quality measurements, peak loading on ground-based optical and/or air quality measurements, and loading on satellite-based aerosol optical depth. Based on these analyses, we compare the characteristics of the same dust events captured in different data sets in order to define the dust identification criteria. The analyses show that the variability in mass concentrations captured by in situ measurements is consistent with the variability in AOD from stationary and satellite observations. Our analyses also find that different data sets are capable of identifying certain common characteristics, while each data set also provides specific information about a dust storm event. For example, the meteorological data are good at identifying the lasting period and area impacted by a dust event; the ground-based air quality and optical measurements can capture the peak strength well; aerosol optical depth (AOD) from satellite data sets allows us to better identify dust-storm-affected areas and the spatial extent of dust. The current study also indicates that the combination of in situ and satellite observations is a better method to fill gaps in dust storm recordings.

Solar Semidiurnal Tide in the Dusty Atmosphere of Mars

2006 ◽  
Vol 63 (7) ◽  
pp. 1798-1817 ◽  
Author(s):  
Jeffrey M. Forbes ◽  
Saburo Miyahara
Keyword(s):  
General Circulation ◽  
Middle Atmosphere ◽  
General Circulation Models ◽  
Dust Storms ◽  
Dynamical Structure ◽  
Semidiurnal Tide ◽  
Vertical Coupling ◽  
Eddy Diffusivities ◽  
Pressure Perturbations ◽  
Winter Hemisphere

Abstract Vertical coupling due to the solar semidiurnal tide in Mars's atmosphere, and effects on zonal mean temperature and wind structures, are investigated using a numerical model. The model provides self-consistent solutions to the coupled zonal mean and tidal equations from the surface to 250 km. Breaking (convective instability) of the semidiurnal tide is parameterized using a linear saturation scheme with associated eddy diffusivities. Thermal forcing in the model gives rise to surface pressure perturbations and middle-atmosphere zonal mean winds and temperatures that are consistent with available measurements and general circulation models. Results presented here primarily focus on globally elevated dust levels during Southern Hemisphere summer, conditions similar to those experienced by the Viking 1 and Viking 2 landers during the 1977 global dust storms. Semidiurnal temperature and wind amplitudes maximize in the winter hemisphere and exceed 50 K and 100 m s−1 above 150 km and are typically 10–20 K and 10–20 m s−1 at 50 km. Perturbation densities are of order 50%–70% between 90 and 150 km, and thus contribute significantly to variability of the aerobraking regime in Mars's atmosphere. Eddy diffusivities associated with the breaking parameterization reach values of order 103–104 m2 s−1 between 100 and 150 km, and can be of order 1–10 m2 s−1 between 0 and 50 km. Dissipation of the semidiurnal tide induces zonal mean westward winds of order 10–30 m s−1 below 100 km, and in excess of 200 m s−1 above 150 km. The corresponding temperature perturbations range between −20 and −70 K over most of the thermosphere, with 10–20-K increases in temperature at high winter latitudes between 50 and 100 km. All of the wave and zonal mean perturbations noted above represent very significant modifications to the thermal and dynamical structure of Mars's atmosphere. Estimates are also provided for the eastward-propagating diurnal tides with zonal wavenumbers s = −1 and s = −2. These waves also have long vertical wavelengths and hence are capable of effectively coupling the lower and upper atmospheres of Mars. However, the perturbation and zonal mean effects of these waves are a factor of 2 or more smaller than those cited above for the semidiurnal tide under dusty conditions.

scholarly journals Impact of photochemical hazes and gases on exoplanet atmospheric thermal structure

2021 ◽  
Vol 502 (4) ◽  
pp. 5643-5657
Author(s):  
P Lavvas ◽  
A Arfaux
Keyword(s):  
General Circulation ◽  
Middle Atmosphere ◽  
Thermal Structure ◽  
Local Heating ◽  
General Circulation Models ◽  
Lower Atmosphere ◽  
Temperature Changes ◽  
Hot Jupiters ◽  
Visible Part ◽  
The Impact

ABSTRACT We investigate the impact of photochemical hazes and disequilibrium gases on the thermal structure of hot Jupiters, using a detailed 1D radiative-convective model. We find that the inclusion of photochemical hazes results in major heating of the upper and cooling of the lower atmosphere. Sulphur containing species, such as SH, S2, and S3, provide significant opacity in the middle atmosphere and lead to local heating near 1 mbar, while OH, CH, NH, and CN radicals produced by the photochemistry affect the thermal structure near 1 $\mu$bar. Furthermore, we show that the modifications on the thermal structure from photochemical gases and hazes can have important ramifications for the interpretation of transit observations. Specifically, our study for the hazy HD 189733 b shows that the hotter upper atmosphere resulting from the inclusion of photochemical haze opacity imposes an expansion of the atmosphere, thus a steeper transit signature in the ultraviolet–visible part of the spectrum. In addition, the temperature changes in the photosphere also affect the secondary eclipse spectrum. For HD 209458 b, we find that a small haze opacity could be present in this atmosphere, at pressures below 1 mbar, which could be a result of both photochemical hazes and condensates. Our results motivate the inclusion of radiative feedback from photochemical hazes in general circulation models for a proper evaluation of atmospheric dynamics.

The Impact of Dust Storms on Aerosol Optical Depth and Radiative Forcing

2020 ◽  
Vol 16 (1) ◽  
pp. 1-14
Author(s):  
Monim Jiboori ◽  
Nadia Abed ◽  
Mohamed Abdel Wahab
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Dust Storms ◽  
The Impact

Impact of dust and sand storms on the aviation operation and assessment of conditions for their occurrence at aerodromes in European Russia

2020 ◽  
Vol 4 ◽  
pp. 78-95
Author(s):  
A.R. Ivanova ◽  
◽  
E.N. Skriptunova ◽  
N.I. Komasko ◽  
A.A. Zavialova ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Dust Storms ◽  
European Russia ◽  
Air Transport ◽  
Review Of Literature ◽  
Dust Transport ◽  
Air Masses ◽  
The Past ◽  
Sand Storm ◽  
The Impact

A review of literature on the impact of dust and sand storms on the air transport operation is presented. Observational data on dust storms at the aerodromes of European Russia for the period of 2001-2019 are analyzed. The seasonal variations in dust transport episodes at aerodromes and its relationship with visibility changes are discussed. The characteristics of dusty air masses and advection are given. It is concluded that the frequency of dust transfer episodes for the aerodromes under study has decreased over the past five years, except for Gumrak aerodrome (Volgograd). Keywords: dust storm, sand storm, aviation, visibility, seasonal variations, aerodrome оf European Russia

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