The Role of the Intertropical Discontinuity Region and the Heat Low in Dust Emission and Transport Over the Thar Desert, India: A Premonsoon Case Study

Dumka, U. C.; Kaskaoutis, Dimitris G.; Francis, Diana; Chaboureau, Jean‐Pierre; Rashki, Alireza; Tiwari, Suresh; Singh, Sachchidanand; Liakakou, Eleni; Mihalopoulos, Nikos

doi:10.1029/2019jd030836

Cited by 55 publications

(30 citation statements)

References 112 publications

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“…It is to be noted here that the enhanced aerosol loading over the IGB is usually the main cause of increase loading over the BoB through IGB-outflow ( Srinivas et al, 2011 ; Tiwari et al, 2016 ; Singh et al, 2020 ). Furthermore, the IGB is situated in the vicinity of the Desert regions, and thus largely impacted by the frequent occurrence of dust aerosols during March-June ( Pandithurai et al, 2008 ; Srivastava et al, 2014 ; Dumka et al, 2019 ) even though negative change in aerosol loading indicate that anthropogenic aerosol emission override the natural local or transported aerosols. The Sentinel - 5 P satellite observations also illustrated the improved air quality of Indian subcontinent during COVID-19 lockdown time period ( Shehzad et al, 2020 ).…”

Section: Resultsmentioning

confidence: 99%

Improved air quality during COVID-19 at an urban megacity over the Indo-Gangetic Basin: From stringent to relaxed lockdown phases

Srivastava¹,

Bhoyar

Kanawade

et al. 2021

Urban Climate

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The enforced lockdown amid COVID-19 pandemic eased anthropogenic activities across India. The satellite-derived aerosol optical depth (AOD) and absorption AOD showed a significant reduction of ~30% over the Indo-Gangetic Basin (IGB) in north India during the lockdown period in 2020 with respect to the previous year 2019, when no such lockdown was in effect. Further, near-surface air pollutants were investigated at an urban megacity Delhi during 01 March to 31 May 2020. Except O 3 , a drastic reduction in PM 10 , PM 2.5 , NO, NO 2 and CO concentrations were observed by ~58%, 47%, 76%, 68% and 58%, respectively during the lockdown period of 2020 as compared to 2019. While, O 3 was low in the initial phase and gradually increased with progression of lockdown phases, the mean O 3 during the entire lockdown period was nearly similar in both the years. Though, all the measured pollutants showed significant reduction during the entire lockdown, a phase-wise enhancement, associated with the conditional relaxations was observed in their concentrations. Thus, the present results may help, not only to assess the impact of outbreak on air quality, but also in designing the mitigation policies in urban megacities in more efficient ways to combat the air pollution problems.

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Section: Resultsmentioning

confidence: 99%

Improved air quality during COVID-19 at an urban megacity over the Indo-Gangetic Basin: From stringent to relaxed lockdown phases

Srivastava¹,

Bhoyar

Kanawade

et al. 2021

Urban Climate

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“…Multiple reports suggested that an increase in the nonaccidental mortality by up to more than 10% due to prolonged (≥3 days) high PM10 episodes (Kim et al, 2018a(Kim et al, , 2018bPizzo & Clerico, 2012;Wang et al, 2018;Wong et al, 2017;Zhang et al, 2017;Zhou et al, 2015), much higher than the mortality rate caused by shorter duration events (<3 days). (ii) Severe widespread prolonged dust events are triggered and maintained by persistent synoptic circulations (e.g., Beegum et al, 2018;Dumka et al, 2019;Hamidi et al, 2017Hamidi et al, , 2014Houssos et al, 2015;Knippertz & Fink, 2006;Knippertz & Stuut, 2014;Shao et al, 2010;Solomos et al, 2017). A synoptic circulation should sustain at least 3 days to reach its persistent nature (e.g., Guemas et al, 2010Guemas et al, , 2009Kyselý & Domonkos, 2006;Miller et al, 2020).…”

Section: Identification Of Extreme Dust Eventsmentioning

confidence: 99%

Major Changes in Extreme Dust Events Dynamics Over the Arabian Peninsula During 2003–2017 Driven by Atmospheric Conditions

et al. 2020

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Dust is the dominant aerosol species by mass in the Earth's atmosphere, and emissions from the deserts and arid regions across the globe range between 1,000 and 4,000 Tg yr −1 annually (e.g., Huneeus et al., 2011; Urban et al., 2018). Dust aerosols play an important role in the Earth's climate dynamics (e.g., Kok et al., 2018; Sokolik et al., 2001), affecting the Earth's radiative balance, and also rainfall (Shepherd et al., 2016). Dust also enriches oceanic biological productivity by supplying micronutrients, which in turn helps the oceans to act as carbon sinks by reducing atmospheric carbon dioxide concentrations (e.g.,

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“…Thermal heat lows and convergence zones between moist and dry air masses are ubiquitous features of tropical and subtropical regions (i.e. Flamant et al, 2007;Dumka et al, 2019). They play a crucial role in modulating the mesoscale meteorological features in these regions, such as the mesoscale convection, dust storms and monsoon surge and associated rain (e.g.…”

Section: Introductionmentioning

confidence: 99%

Climatology of the heat low and the intertropical discontinuity in the Arabian Peninsula

Fonseca

Francis

Temimi

et al. 2021

Intl Journal of Climatology

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In this article, the climatological state and the seasonal variability of the Arabian heat low (AHL) and the intertropical discontinuity (ITD) are investigated over the Arabian Peninsula using the 1979-2019 ERA-5 reanalysis data.The AHL is a summertime feature, mostly at 15 -35 N and 40 -60 E, exhibiting a clear strengthening over the last four decades in line with the observed increase in surface temperature. However, no clear shift in its position is detected. The AHL, driven by both thermodynamic and dynamic forcing, is broader and stronger during daytime and exhibits considerable variability on day-to-day timescales, likely due to the convection associated with the Asian summer monsoon. The ITD is the boundary between the hot and dry desert air and the cooler and more moist air from the Arabian Sea. It lies along the Arabian Peninsula's southern coastline in the cold season but reaches up to 28 N between 50 and 60 E in the summer months. While in the former it has a rather small diurnal variability; in the latter it shows daily fluctuations of up to 10 in latitude. The presence of the Sarawat Mountains over southwestern Saudi Arabia precludes a northward migration of the ITD in this area. The ITD exhibited a weak northward migration in the 41-year period, likely due to the increased sea surface temperatures in the Arabian Sea. On inter-annual timescales, the El Niño-Southern Oscillation, the Indian Ocean Dipole, and solar-geomagnetic effects play an important role in the AHL's and ITD's variability.

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The Role of the Intertropical Discontinuity Region and the Heat Low in Dust Emission and Transport Over the Thar Desert, India: A Premonsoon Case Study

Cited by 55 publications

References 112 publications

Improved air quality during COVID-19 at an urban megacity over the Indo-Gangetic Basin: From stringent to relaxed lockdown phases

Improved air quality during COVID-19 at an urban megacity over the Indo-Gangetic Basin: From stringent to relaxed lockdown phases

Major Changes in Extreme Dust Events Dynamics Over the Arabian Peninsula During 2003–2017 Driven by Atmospheric Conditions

Climatology of the heat low and the intertropical discontinuity in the Arabian Peninsula

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