Explained: How Ethiopian volcanic ash travelled to India and which regions were affected

A rare volcanic eruption in Ethiopia on Sunday sent a massive ash plume soaring high into the atmosphere and drifting thousands of kilometres across the Middle East before entering India on Monday eveningThe cloud carried by strong upperlevel winds passed over Gujarat Rajasthan northwest Maharashtra DelhiNCR Haryana and Punjab before gradually moving towards the Himalayas Authorities briefly monitored the situation for possible aviation disruptions while the India Meteorological Department IMD assured that conditions would normalise by Tuesday eveningHerersquos a detailed explainer on what the volcanic ash is how it travelled to India which regions were affected and when the impact will fadeWhat is the Ethiopian volcanic ashThe ash originated from the Hayli Gubbi volcano located in Ethiopiarsquos Afar region near the Red Sea The volcanomdashdormant for nearly 10000 to 12000 yearsmdasherupted explosively on Sunday morningUnlike lavaflow eruptions this one was dominated byVolcanic ash fine fragments of pulverised rock and glassSulphur dioxide SO2 and traces of carbon dioxideVery fine particles capable of rising to altitudes of 15ndash14 km 45000 ftThicker or heavier particles fall near the eruption site But very fine ash and gases get lifted high into the atmosphere as hot air from the eruption column rises vertically at great speedAt these heightsmdash15 km and abovemdashpowerful jetstream winds quickly disperse the ash horizontally across continents allowing the plume to travel over vast distances without falling to the groundThe Hayli Gubbi plume did exactly this it rose high remained suspended in upper air layers and began drifting eastward alongside fastmoving windsHow did the volcanic ash travel all the way to IndiaOnce the ash reached the upper troposphere and lower stratosphere it was transported by strong highlevel windsTracking by the Toulouse Volcanic Ash Advisory Centre VAAC and IMD shows the plumersquos journey as follows Sunday Ethiopia Ash rose up to 14 km over the Afar region Crossed the Red Sea Winds carried the plume toward Yemen and Oman Moved over the Arabian Sea Jet streams steered the cloud eastwards Entered India around Monday evening First sighted over Jamnagar Gujarat at 530 pm Shifted northeast Passed over Rajasthan northwest Maharashtra DelhiNCR Haryana and Punjab by about 10 pm Continued toward China The ash cloud is expected to fully exit Indian airspace by 730 pm Tuesday moving toward Tibet and western ChinaThe elevation of the plumemdashbetween 15000 and 25000 ft rising to 45000 ft in layersmdashplaced it directly in typical longdistance flight corridors prompting temporary air traffic advisoriesWhich Indian regions were impactedWhile the ash remained far above ground level and did not pose a health hazard its movement across western and northern India did affect flight planningIMDrsquos SIGMET Significant Meteorological Information bulletins indicated movement over Gujarat Rajasthan DelhiNCR Punjab HaryanaParts of northwest MaharashtraSkies appeared hazy or darker than usual in some pockets due to highaltitude scattering of sunlight though this did not translate into poor groundlevel air qualityImpact on aviation Because volcanic ash can damage aircraft engines sensors and filters several precautionary steps were taken Airlines altered flight routes and cruising altitudes Some flights were delayed diverted or cancelled IndiGo cancelled six services DGCA issued an advisory directing operators to avoid affected airspace and monitor VAAC bulletins continuously Airports were told to inspect runways and aprons if any ash deposition was suspected though none was reported Notably experts stressed that passengers faced no direct inhalation risk as planes have highly sophisticated air filtration systemsWhen will the volcanic ash lessenmdashand why the impact is shortlived Volcanic plume movement is typically a shortduration atmospheric eventAccording to IMD Director General Mrutyunjay Mohapatra The ash cloud is already drifting toward China It will fully leave Indian skies by 730 pm on Tuesday No significant groundlevel accumulation is expected in IndiaWhy the impact fades quickly Fine ash particles disperse rapidly in the upper atmosphere and become too diluted to pose a threat Wind shear and jet stream variations cause the plume to stretch and thin out Clouds and rainfall further wash out residual ash SO2 and CO2 emissions from this eruption are not high enough to meaningfully alter regional air quality or climateShould India worryNo The plume travelled at high altitudes posing minimal risk to people on the ground The primary concern was aviation safety which was addressed through international and domestic advisoriesThe eruption itself appears to have subsided and forecasts show airspace normalisation within hours