Simulation of a Severe Sand and Dust Storm Event in March 2021 in Northern China: Dust Emission Schemes Comparison and the Role of Gusty Wind

Northern China experienced a severe sand and dust storm (SDS) on 14/15 March 2021. It was difficult to simulate this severe SDS event accurately. This study compared the performances of three dust-emission schemes on simulating PM10 concentration during this SDS event by implementing three vertical dust flux parameterizations in the Comprehensive Air-Quality Model with Extensions (CAMx) model. Additionally, a statistical gusty-wind model was implemented in the dust-emission scheme, and it was used to quantify the gusty-wind contribution to dust emissions and peak PM10 concentration. As a result, the LS scheme (Lu and Shao 1999) produced the minimum errors for peak PM10 concentrations, the MB scheme (Marticorena and Bergametti 1995) underestimated the PM10 concentrations by 70–90%, and the KOK scheme (Kok et al. 2014) overestimated PM10 concentrations by 10–50% in most areas. The gusty-wind model could reasonably reproduce the probability density function of 2-min wind speeds. There were 5–40% more dust-emission flux and 5–40% more peak PM10 concentrations generated by the gusty wind than the hourly wind in the dust-source regions. The increase of peak PM10 concentration caused by gusty wind in the non-dust-source regions was higher than in the dust-source regions, with 10–50%. Implementing the gusty-wind model could help improve the LS scheme’s performance in simulating PM10 concentrations of this severe SDS event. More work is still needed to investigate the reliability of the gusty-wind model and LS scheme on various SDS events.

Respiratory and cardiovascular effects of ambient particulate matter from dust storm and non-dust storm periods in Kuwait

Epidemiological studies demonstrate a positive association between daily changes in concentrations of ambient airborne particulate matter (PM) and adverse respiratory and cardiovascular health effects. However, physicochemical properties of PM can vary greatly across geographical, atmospheric, and temporal conditions and influence the relative toxicity of airborne PM. The purpose of this study was to investigate the adverse pulmonary and cardiovascular health effects of ambient PM collected from discrete sampling sites in Kuwait during dust storm (DS) and non-dust storm (NDS) conditions. Collected dust samples were characterized for their chemical composition using atomic absorption, GC–MS, and HPLC–MS analyses. Male BALB/cJ mice were exposed to 100 µg of either NDS or dust storm (DS) PM in 50 µl of PBS by oropharyngeal aspiration. Lung function was measured and bronchoalveolar lavage was conducted at 1, 7, and 14 days post-exposure. Ischemia–reperfusion injury was performed 24 h after exposures by obstructing the left main coronary artery approximately 4 mm distal to its origin for 20 min, followed by 2 h. of reperfusion. Exposure to either NDS or DS PM resulted in airway hyperresponsiveness to acetylcholine compared to PBS controls. Total protein and cells in BAL fluid were elevated in both dust groups one day after exposure; however, DS PM induced a greater increase in cell numbers than did NDS PM, particularly in neutrophils, eosinophils, and lymphocytes. Representative lung sections exhibited positive staining for mucus in large airways at 7 days which resolved by 14 days in dust storm-exposed mice but persisted in NDS-exposed animals. Our findings suggest that NDS PM may be more effective in producing an adaptive immune response, while the early inflammation induced by DS PM may better resolve. We also observed a prolonged airway mucus response after exposure to NDS PM, suggesting it may produce more asthma-like features than dust storm PM. PM-induced changes to cardiac ischemia–reperfusion injury were not observed in this study. The lack of cardiovascular response may have been due to the limited exposure and single time point used in this study.

Evaluation and Analysis of Dust Storm Activity in Tianwen-1 Landing Area Based on the Moderate Resolution Imaging Camera Observations and Mars Daily Global Maps

The first Mars exploration mission from China (Tianwen-1) was launched on 23 July 2020 with the goal of “orbiting, landing, and roving”. The occurrence of dust storm activities is an important criterion of assessing atmospheric risk for the Tianwen-1 landing process. Dust storm activities from Mars Year (MY) 24 to MY32 in southern Utopia Planitia were identified. Most dust storms only appeared in one Mars Daily Global Map (MDGM), with a lifetime of less than or equal to solar longitude (Ls) = 0.5°. Only if the lifetime of a dust storm is greater than or equal to Ls = 1° can it reach the primary landing ellipse. From Ls = 0–50°, dust storms are mostly in the diffusion stage with a maximum speed of movement of 2479 km/Ls. Then, the speed gradually decreases to the minimum value of 368 km/Ls when the dust storm is in the dissipation stage. If a dust storm moves at an average speed of 750 km/Ls, the safe landing zone is a circle within a radius of 750 km centered on the primary landing ellipse. From March to May 2021, eight dust storms were identified in the Moderate Resolution Imaging Camera (MoRIC) mosaics. Because there was no dust storm activity in MoRIC mosaic on 13 May 2021, we concluded that there would be no dust storm in the primary landing ellipse on 15 May (MY36, Ls = 45.1°). Therefore, the landing time of the Tianwen-1 probe was finally determined as 15 May, which successfully landed in the south of the Utopia Planitia, and the in-situ investigation was carried out by the Zhurong Mars rover.

“My battery is low and it's getting dark”

The Mars Exploration Rover Opportunity operated on Mars from 2004 until it was disabled by a dust storm in 2018. Its demise was declared in February 2019 after months of unsuccessful recontact attempts by scientists at the National Aeronautics and Space Administration (NASA). This announcement sparked a global outpouring of grief that demonstrated people understood and related to the robot in a notably human-like manner. In short, it had been given a collectively understood persona. This paper presents a study of 100 digital postcards created by users on a NASA website that demonstrate the ways in which people expressed love, grief, hope, and thanks for Opportunity’s fourteen years of operation on another planet. In presenting this case study, the paper argues that certain personas are collective achievements. This is especially likely to occur for robots and other inanimate objects which have no centrally controlled or developed persona. The paper is situated within existing persona studies literature to extend and stretch the definition of persona studies and therefore expand the field in productive ways to incorporate the study of non-human personas.