COVID-19's Impact On Weather
https://en.wikipedia.org/wiki/Contrail I've blogged twice about the possible impact of weather on the coronavirus-
Now it's time to look at the coronavirus impact on weather and weather forecasting.
Meteorologist Marshall Shepherd wrote about this for Forbes Magazine. He points out that the reduction in air travel means a corresponding reduction in data that is fed into computer models that crunch numerous complex equations to give us a forecast. Numerical Weather Prediction or NWP is the most accurate forecast method we have but it is now being challenged by a degradation in data, or more to the point, a lack of data. As aircraft ascend and descend through various layers of the atmosphere instruments obtain valuable information about current weather conditions. The launch of radiosondes or weather balloons remains the mainstay method of gathering data through various levels of the atmosphere. The data normally collected from aircraft fill the gaps that that the radiosonde network can't.
The coronavirus is impacting not just weather forecasting but weather itself. The reduction in air traffic coupled with the reduction in vehicular traffic has had a significant impact on air pollution levels around the world. A CNN report quoted air quality researcher Fei Liu of NASA's Goddard Space Flight Center-
The reduction was first noticed in China and is now being observed in the US in major cities like Los Angeles, New York, Atlanta and here in Chicago.
The reduction in flights means a reduction in contrails or condensation trails. Studies done after the dramatic drop in contrails that followed 9/11 lead in part to a renewed interest in "global dimming". Pollutants and contrails reduce the amount of solar radiation that reaches the earth's surface. Global dimming was first written about in 1950 and studies that followed have shown the sun's energy has been reduced buy 10% in the US and nearly 30% in Russia since then. An unfortunate paradox means that a reduction in air pollution could lead to accelerated global warming.