California air quality officials have passed two new measures aimed at reducing pollution from diesel trucks and ships. One rule introduces new emissions standards for heavy-duty diesel trucks, while the other requires more ships docked at ports to either plug into electric power or use other technology to reduce harmful emissions. The state has the worst-polluted air in the country, The Los Angeles Times reported.

The “Heavy-Duty Low NOx Omnibus Regulation” requires truck manufacturers to comply with tougher emissions standards, revamp engine testing procedures, and further extend engine warranties to ensure emissions are reduced, according to a statement from the California Air Resources Board. The rule targets nitrogen oxides, which are a major component of smog. Once the rule is fully phased in by 2031, CARB expects it will reduce nitrogen oxide emissions in the state by more than 23 tons per day.

You’ve probably heard stories of skies and water clearing up while most people stay at home during the COVID-19 pandemic, but how much have things improved, really? Scientists are about to rely on NASA technology to find out. The space agency is funding four research projects that will rely on satellites and various data resources to understand how pandemic lockdowns have affected pollution worldwide.

One project will study uneven gains in air quality around the world by connecting satellite data to weather, traffic and other info. Another effort will meld satellite and meteorological data to gauge how reduced air pollution has affected the atmosphere. A third initiative will determine what if any effect lowered air pollution has had on water quality, while a fourth will use light pollution satellite data to examine socioeconomic impacts and the effectiveness of stay-at-home orders.

Maps of the Wuhan region from January 1st to February 25th, 2019 show a noticeable drop in air pollution during the Lunar New Year. However, pollution levels quickly rebounded, as seen in the dark red images from the same time last year.

This year has been another story, however. The virus story started to explode early in the New Year, after Chinese authorities had confirmed that the illness was caused by a new coronavirus similar to those that caused the SARS and MERS outbreaks. By January 23rd, the government had shut down all transportation into and out of Wuhan, while closing local businesses and factories in an effort to slow the spread of the virus.

As a result, NASA’s NO2 maps of the region during the same period in 2020 show very light levels of pollution (as blue, rather than yellow and red) on the maps. Another key indicator of pollution, ozone, shows a similar result, according to NASA. Liu said that the agency has mapped pollution drops around Beijing during the 2008 Olympics, and in other nations around the 2007-2009 economic recession, but never to that level.

One of the great values of an airborne observatory is that scientists can assess pollution events and compare them to past periods. “There is always this general slowdown around this time of the year,” said NASA air quality scientist Barry Lefer, an air quality scientist at NASA. “Our long-term OMI data allows us to see if these amounts are abnormal and why.”

This time, the decrease is more than a holiday-related dropoff compared to past events going back to 2005. Overall, NO2 values during the COVID-19 outbreak were from 10 to 30 percent lower than what is normally seen at this time of year.

While that provides some breathing relief for residents, the coronavirus has devastated the region, causing nearly 3,000 deaths so far in China. “I am not surprised [about the pollution drop] because many cities nationwide have taken measures to minimize spread of the virus,” said Liu.