Subtropical Dust Storms and Downslope Wind Events

Pokharel, Ashok Kumar; Kaplan, Michael L.; Fiedler, Stephanie

doi:10.1002/2017jd026942

Cited by 18 publications

(14 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Sistan Basin is highly affected by strong katabatic winds from the southern lee slopes of the Hazarajat Mountains to the plains ( Figure 10). The cold katabatic wind currents accelerated toward the plains and formed high turbulent winds, which caused uplift of thick dust plumes [71,97]. Figure 11a shows the time series of the hourly AOD 500 values in Karachi as a function of AE 440-870 during 4-10 February 2019.…”

Section: Characteristics Of the Dust Stormmentioning

confidence: 99%

Atmospheric Dynamics from Synoptic to Local Scale During an Intense Frontal Dust Storm over the Sistan Basin in Winter 2019

et al. 2019

View full text Add to dashboard Cite

The Sistan Basin has been recognized as one of the most active dust sources and windiest desert environments in the world. Although the dust activity in Sistan maximizes during the summer, rare but intense dust storms may also occur in the winter. This study aims to elucidate the atmospheric dynamics related to dust emission and transport, dust-plume characteristics, and impacts on aerosol properties and air quality during an intense dust storm over Sistan in February 2019. The dust storm was initiated by strong northerly winds (~20 ms−1) associated with the intrusion of a cold front from high latitudes. The upper-level potential vorticity (PV)-trough evolved into a cut-off low in the mid and upper troposphere and initiated unstable weather over Afghanistan and northern Pakistan. At the surface, density currents emanating from deep convective clouds and further strengthened by downslope winds from the mountains, caused massive soil erosion. The passage of the cold front reduced the temperature by ~10 °C and increased the atmospheric pressure by ~10 hPa, while the visibility was limited to less than 200 m. The rough topography played a major role in modulating the atmospheric dynamics, wind field, dust emissions, and transport pathways. Meso-NH model simulates large amounts of columnar mass dust loading (> 20 g m−2) over Sistan, while the intense dust plume was mainly traveling below 2 km and increased the particulate matter (PM10) concentrations up to 1800 µg m−3 at Zabol. The dust storm was initially moving in an arc-shaped pathway over the Sistan Basin and then it spread away. Plumes of dust covered a large area in southwest Asia, reaching the northern Arabian Sea, and the Thar desert one to two days later, while they strongly affected the aerosol properties at Karachi, Pakistan, by increasing the aerosol optical depth (AOD > 1.2) and the coarse-mode fraction at ~0.7.

show abstract

Section: Characteristics Of the Dust Stormmentioning

confidence: 99%

Atmospheric Dynamics from Synoptic to Local Scale During an Intense Frontal Dust Storm over the Sistan Basin in Winter 2019

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Despite the large and increasing number of studies on dust transport, its impact on the Earth system remains very uncertain (see e.g., [39,[75][76][77][78][79][80]). Dust redistributes energy by scattering and absorbing both solar and terrestrial radiation.…”

Section: The Dustiness Of the Atmosphere And Climatementioning

confidence: 99%

Dust Devils: Structural Features, Dynamics and Climate Impact

Onishchenko

Fedun

Horton

et al. 2019

Climate

View full text Add to dashboard Cite

According to modern concepts, the main natural sources of dust in the atmosphere are dust storms and associated dust devils—rotating columns of rising dust. The impact of dust and aerosols on climate change in the past, present and future is one of the poorly understood and, at the same time, one of the fundamental elements needed for weather and climate forecasting. The purpose of this review is to describe and summarise the results of the study of dust devils in the Earth’s atmosphere. Special attention is given to the description of the 3D structures, the external flows and atmospheric gradients of temperature that lead to the generation and maintenance of the dust devils.

show abstract

“…Changes in surface wind speed and direction have significant implications for water cycle components [4], air pollution [6], arid and semiarid environments [7][8][9][10][11][12], fire activity [13], and wind energy production [14]. Moreover, changes in surface wind extremes and gusts have direct implications for buildings, infrastructure, agriculture, power lines, desert, and forestry [8][9][10][11][12][15][16][17][18][19][20]. Despite these implications, relatively fewer studies have focused on projected changes to wind characteristics compared to the temperature and precipitation fields [21,22].…”

Section: Introductionmentioning

confidence: 99%

Projected Changes to Mean and Extreme Surface Wind Speeds for North America Based on Regional Climate Model Simulations

Jeong

Sushama

2019

Atmosphere

View full text Add to dashboard Cite

This study evaluates projected changes to surface wind characteristics for the 2071–2100 period over North America (NA), using four Global Environmental Multiscale regional climate model simulations, driven by two global climate models (GCMs) for two Representative Concentration Pathway scenarios. For the current climate, the model simulates well the climatology of mean sea level pressure (MSLP) and associated wind direction over NA. Future simulations suggest increases in mean wind speed for northern and eastern parts of Canada, associated with decreases in future MSLP, which results in more intense low-pressure systems situated in those regions such as the Aleutian and Icelandic Lows. Projected changes to annual maximum 3-hourly wind speed show more spatial variability compared to seasonal and annual mean wind speed, indicating that extreme wind speeds are influenced by regional level features associated with instantaneous surface temperature and air pressure gradients. The simulations also suggest some increases in the future 50-year return levels of 3-hourly wind speed and hourly wind gusts, mainly due to increases in the inter-annual variability of annual maximum values. The variability of projected changes to both extreme wind speed and gusts indicate the need for a larger set of projections, including those from other regional models driven by many GCMs to better quantify uncertainties in future wind extremes and their characteristics.

show abstract

Subtropical Dust Storms and Downslope Wind Events

Cited by 18 publications

References 37 publications

Atmospheric Dynamics from Synoptic to Local Scale During an Intense Frontal Dust Storm over the Sistan Basin in Winter 2019

Atmospheric Dynamics from Synoptic to Local Scale During an Intense Frontal Dust Storm over the Sistan Basin in Winter 2019

Dust Devils: Structural Features, Dynamics and Climate Impact

Projected Changes to Mean and Extreme Surface Wind Speeds for North America Based on Regional Climate Model Simulations

Contact Info

Product

Resources

About