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Tech helps get on top of forecasting

Real-time space-ground monitoring used for sandy, dusty weather events

By HOU LIQIANG houliqiang@chinadaily.com.cn

China has established an integrated space-ground system for the monitoring and forecast of sand and dust weather events, the increase of which has been a factor to blame for air quality declines in the country this year.

Analyses based on the system showed that Mongolia was a major contributor of sand and dust in these events, according to the Ministry of Ecology and Environment.

In addition to national real-time monitoring facilities, 1,225 monitoring stations at county and township levels that are close to sand and dust sources have been incorporated into the country’s monitoring network for particulate matter, said Jiang Huohua, deputy director of the ministry’s department of environmental monitoring.

This means that all county-level cities near these sources in the six provincial-level regions in the northwestern part of the country have been essentially covered by the monitoring network, he continued.

China’s capability to monitor and forecast sand and dust weather events has been further enhanced by satellite remote sensing, he said.

Thanks to the polar orbit and geostationary satellites, he said, China is able to monitor these weather events via remote sensing around the clock.

Every winter and spring, the seasons when the country most frequently experiences sand and dust weather events, the ministry cooperates with meteorological departments to closely follow and analyze these events to learn about their sources, paths, ranges of influence and intensity changes, he said.

Monitoring showed that the country was hit by 12 sand and dust weather events from January to April, with half of them occurring last month. “Accumulatively, these events troubled 267 cities in 27 provincial regions for 4,892 days, which is the highest in the past five years for the same period of time,” he said.

Jiang noted the desert area in southern Mongolia as a major contributor to these polluting events, though northwestern China also attracts some of the blame.

The two severe sand and dust weather events that hit Beijing in March, for example, both originated in southern Mongolia, he said. During the event that lasted from March 19 to 23, the hourly concentration of PM10 particulate matter in the capital city even reached 1,667 micrograms per cubic meter at its peak.

Experts estimated that Mongolia contributed to 70 percent of the PM10 densities in Beijing during the event, he noted. As to Northeast China and areas in central and eastern China that were also affected, sand and dust from China’s neighbor were to blame for half of the peak PM10 concentrations.

The official vowed to beef up the ministry’s cooperation with meteorological departments to further improve space-ground monitoring for sand and dust weather events. The ministry will strive to forecast the polluting weather events and issue early warnings as early as possible, he said.

According to the ministry, on average, the 339 prefecture-level cities across the country enjoyed fairly good air quality — considered to be below 100 on the 0-500 air quality index scale — in 80.4 percent of days in the first four months of this year, compared with 85.1 percent in the same period last year.

The average density of PM10 in these cities during the time stood at 73 mcg/ cubic m, up by 15.9 percent, it said.

It said sand and dust weather events were responsible for 7.1 percent of days in these cities with excessive densities of air pollutants.

CHINA

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2023-05-30T07:00:00.0000000Z

2023-05-30T07:00:00.0000000Z

https://chinadaily.pressreader.com/article/281646784517637

China Daily