@article{19376ddc931b40128938bd86f68ad079,
title = "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",
abstract = "A severe dust storm occurred over north India during 12–16 June 2018 is analyzed using satellite observations, reanalysis, ground-based measurements, and model (Meso-NH) simulations focusing on the dynamic processes that caused the dust-storm generation, uplift, and propagation as well as its impacts on air quality. The initial dust emission was triggered by strong near-surface southwesterlies (~15–20 m s−1) associated with the monsoon flow advancing northward, in response to the deepening of the thermal low over the Thar desert. The convergence between the northwesterlies and the monsoon flow along the Intertropical Discontinuity region caused high dust accumulation over northwest India in an area of weak winds. Convective mixing during daytime favors the vertical transport of dust to higher altitudes above the monsoon flow, but the towering Himalayas and the associated return northerly flow aloft play a blocking role leading to dust accumulation at heights between 1 and 3 km over northwest India. The prevailed northwesterlies in the middle troposphere favor the eastward transport of the dust plumes along the Ganges valley, helping to evacuate the dust toward east India. Based on Meso-NH model simulations, the dust storm was associated with dust loads higher than 30 gm−2 and AODs higher than 3, in agreement with MODIS observations. The impact of the dust storm on the spatial-temporal evolution of the PM10 and PM2.5 mass concentrations is studied using data from 23 air-quality stations over northern India, indicating daily PM10 peaks reaching at ~900 μg m−3, implying a severe degradation of air quality.",
keywords = "dust storm, intertropical front, Meso-NH model, monsoon flow, Thar desert, thermal low",
author = "Dumka, {U. C.} and Kaskaoutis, {D. G.} and D. Francis and Chaboureau, {J. P.} and A. Rashki and Suresh Tiwari and Sachchidanand Singh and E. Liakakou and N. Mihalopoulos",
note = "Funding Information: We thank the Director ARIES for supporting this work. We thank the European Centre for Medium Range Weather Forecasting for providing the ERA‐Interim reanalysis products which have been used in the current work ( https://www.ecmwf.int/en/forecasts/datasets/archive‐datasets/reanalysis‐datasets/era‐interim ). We wish to gratefully acknowledge the GMAO team for providing the MERRA‐2 reanalysis data sets via GEOS. The MODIS aerosol optical depth and MERRA‐2 reanalysis data used in this study are downloaded from the NASA Giovanni visualization online data system ( http://disc.sci.gsfc.nasa.gov/giovanni ). The authors also gratefully acknowledge the members of NASA Langley Research Centre Atmospheric Science Data Center for providing the CALIPSO profile data sets used in the current work. We would like to thank the Central Pollution Control Board (CPCB; https://cpcb.nic.in ), Ministry of Earth Science and Ministry of Environment, Forest and Climate Change, Government of India and India Meteorological Department, New Delhi, India for providing the air quality monitoring data through their data portal. Also, NCEP/NCAR reanalysis team members are highly appreciated for providing the surface wind speed and wind directions used in the current work. We would like to thanks the Prof. Zhanqing Li, Editor, JGR‐ Atmospheres and Prof. Pavel Kishcha and one anonymous reviewer for their constructive comments and suggestions to improve the manuscript. We would like to thank Ms. Tanya Patel, CSIR‐NPL for providing a geographical map of PM measurements. Funding Information: We thank the Director ARIES for supporting this work. We thank the European Centre for Medium Range Weather Forecasting for providing the ERA-Interim reanalysis products which have been used in the current work (https://www.ecmwf.int/en/forecasts/datasets/archive-datasets/reanalysis-datasets/era-interim). We wish to gratefully acknowledge the GMAO team for providing the MERRA-2 reanalysis data sets via GEOS. The MODIS aerosol optical depth and MERRA-2 reanalysis data used in this study are downloaded from the NASA Giovanni visualization online data system (http://disc.sci.gsfc.nasa.gov/giovanni). The authors also gratefully acknowledge the members of NASA Langley Research Centre Atmospheric Science Data Center for providing the CALIPSO profile data sets used in the current work. We would like to thank the Central Pollution Control Board (CPCB; https://cpcb.nic.in), Ministry of Earth Science and Ministry of Environment, Forest and Climate Change, Government of India and India Meteorological Department, New Delhi, India for providing the air quality monitoring data through their data portal. Also, NCEP/NCAR reanalysis team members are highly appreciated for providing the surface wind speed and wind directions used in the current work. We would like to thanks the Prof. Zhanqing Li, Editor, JGR- Atmospheres and Prof. Pavel Kishcha and one anonymous reviewer for their constructive comments and suggestions to improve the manuscript. We would like to thank Ms. Tanya Patel, CSIR-NPL for providing a geographical map of PM measurements. Publisher Copyright: {\textcopyright}2019. American Geophysical Union. All Rights Reserved.",
year = "2019",
month = dec,
day = "16",
doi = "10.1029/2019JD030836",
language = "British English",
volume = "124",
pages = "13197--13219",
journal = "Journal of Geophysical Research: Atmospheres",
issn = "2169-897X",
publisher = "Wiley-Blackwell Publishing Ltd",
number = "23",
}