Story submitted by Eric Worrall
A new study from NASA’s JPL claims Asian air pollution causes worse storms in North America, especially during winter.
According to abstract, the study used a global climate-aerosol model to compare current conditions with modelled pre-industrial conditions.
Lead author Yuan Wang, from the Jet Propulsion Laboratory at the California Institute of Technology, said: “The effects are quite dramatic. The pollution results in thicker and taller clouds and heavier precipitation.”
The team said that tiny polluting particles were blown towards the north Pacific where they interacted with water droplets in the air.
Dr Yuan Wang said: “Since the Pacific storm track is an important component in the global general circulation, the impacts of Asian pollution on the storm track tend to affect the weather patterns of other parts of the world during the wintertime, especially a downstream region [of the track] like North America.”
Assessing the effects of anthropogenic aerosols on Pacific storm track using a multiscale global climate model
Increasing levels of air pollutants in Asia have recently drawn considerable attention, but the effects of Asian pollution outflows on regional climate and global atmospheric circulation remain to be quantified. Using a multiscale global aerosol–climate model (GCM), we demonstrate long-range transport of the Asian pollution, large resulting variations in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths; enhanced shortwave and longwave cloud radiative forcings; and increased precipitation and poleward heat transport. Our work provides, for the first time to the authors’ knowledge, a global multiscale perspective of the climatic effects of pollution outflows from Asia. The results reveal that the multiscale modeling framework is essential in simulating the aerosol invigoration effect of deep convective cloud systems by a GCM.
Atmospheric aerosols affect weather and global general circulation by modifying cloud and precipitation processes, but the magnitude of cloud adjustment by aerosols remains poorly quantified and represents the largest uncertainty in estimated forcing of climate change. Here we assess the effects of anthropogenic aerosols on the Pacific storm track, using a multiscale global aerosol–climate model (GCM). Simulations of two aerosol scenarios corresponding to the present day and preindustrial conditions reveal long-range transport of anthropogenic aerosols across the north Pacific and large resulting changes in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths. Shortwave and longwave cloud radiative forcing at the top of atmosphere are changed by −2.5 and +1.3 W m−2, respectively, by emission changes from preindustrial to present day, and an increased cloud top height indicates invigorated midlatitude cyclones. The overall increased precipitation and poleward heat transport reflect intensification of the Pacific storm track by anthropogenic aerosols. Hence, this work provides, for the first time to the authors’ knowledge, a global perspective of the effects of Asian pollution outflows from GCMs. Furthermore, our results suggest that the multiscale modeling framework is essential in producing the aerosol invigoration effect of deep convective clouds on a global scale.
The full paper: