Red dawn: smog blanket turns Sydney into Beijing
Red dawn: smog blanket turns Sydney into Beijing
21 October 2016
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Australia Residents living in parts of Sydney could have been forgiven for thinking they were waking this morning in Beijing, Delhi or Mexico City when thick smog engulfed parts of the city.
Rob Sharpe, a forecaster with Weatherzone, said the worst of the pollution occurred just after dawn this morning when the air pollution in parts of Sydney was comparable to the worlds smog capitals.
For some people in places like Rozelle and Lindfield from 6am until 8am, it would have been like being in Beijing or Delhi when they woke, he said.
At that time, the air pollution reading was 350 or 360, although I have known it to be higher. That is a common reading in a heavily polluted city such as Beijing, where it can even reach up to 500 on a really bad day.
Air pollution levels in Rozelle, Randwick, Lindfield, Earlwood and Chullora hit the hazardous mark after smoke from reduction burns blanketed the city.
In Sydney’s south-west, the air quality was rated as “very poor”.
The NSW Office of Environment and Heritage advised residents in those areas with heart or lung disease, older adults and children to avoid exercising outdoors.
Although Beijing is most commonly known as the most polluted city in the world due to its rapid population growth, the super cities in India and Pakistan such as Delhi, Raipur, Karachi and Peshawar dominate the global pollution league table.
Air pollution has been recognised as a growing hazard for Australians. This year the inaugural National Air Quality and Health meeting took place in Melbourne, bringing together scientists, doctors, lawyers and the Lung Foundation.
The blast of Chinese style smog this morning was caused by hazard reduction burn offs around Sydney including a 183-hectare burn in the Ku-ring-gai Chase National Park.
Rural fire service volunteers also took advantage of the clear weather to burn hazardous shrubbery at Clifton Gardens, in Mosman, Loftus in Sydney’s south and at Norah Head on the Central Coast.
Mr Sharpe said the thick smog was caused by a temperature inversion where the normal layer of cool air on the surface is replaced by warmer air.
In the case this morning, the warmer air became trapped at a level of about 500 metres above the surface, causing the smoke and haze.
Relief for Sydneysiders is arriving this afternoon in the form of a sea breeze which is expected to clear any remaining smog.
Winters have started approaching the northern region of India that also includes Delhi-NCR along with Punjab and Haryana. Due to this, minimums have also started dropping in many parts of North India including Delhi and NCR. In fact, as per the temperatures recorded on October 15 and October 17, the minimums ofDelhi and NCR went down to 17°C.
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As per experts, an increase in the pollution level normally occurs during the winter months. However, there are a few reasons that could enhance the pollution level in Delhi and the adjoining areas. The very first reason that can be attributed to an increase in pollution level in the national capital is crop fires in the neighboring state ofHaryana andPunjab.
These two states lie in northwest proximity of Delhi and normal pattern of winds during this season is northwesterly. These winds drag the smoke and fine particles of the burnt crop and mix them with Delhis atmosphere. Moreover, the temperatures also start dipping, therefore, the air near the earths surface tends to condense leading to formation of haze.
Whenever the winds are light or calm, these air pollutants get mixed with the haze or mist and forms a blanket of smoke haze which remains suspended for few hours in the mornings. Thereafter, the haze disappears as the sun rises and temperatures increases during the day.
But as the winter progresses in the month of December and January, the duration of haze, mist or fog gets extended and these pollutants remain suspended in the atmosphere for longer duration of time. Other factors including the smoke emitting from vehicles and factories and dust from construction sites also add to the rising pollution levels.
Sometimes this situation can continue for days altogether. However, relief is expected only when a strong Western Disturbance gives rain over the region. It is then that these pollutants settle down for a few days.
Another criterion which reduces the pollution levels is the strong and moderate dry winds from northwest or west which carry away these pollution particles. In a nutshell, it can be said that in October, intensity and duration of pollution remain less though increases in November as winters sets in.
– See more at: http://www.skymetweather.com/content/weather-news-and-analysis/delhis-pollution-level-increases-as-winter-approaches/#sthash.FRlJsEib.dpuf
