ARL Weekly News – May 28, 2021

Upcoming Events

HYSPLIT User Workshop June 15-18, 2021

A four-day HYSPLIT workshop will be given online from June 15 to 18, 2021. Monday, June 14, is set aside as a pre-workshop day for illustrating HYSPLIT installation and answering installation questions. The virtual workshop will be focused on the use of the most recent version of the model on the PC/Mac and its Graphical User Interface (GUI). The Workshop (Detailed Agenda) is designed to be ‘hands-on,’ with participants following along and carrying out HYSPLIT modeling on their own local computers. No prior modeling or experience with HYSPLIT is required. An overview of the installation, model GUI, meteorological display programs, and extensive training on how to solve atmospheric dispersion problems will be presented. As the Workshop proceeds, several real-world examples of increasing complexity will be explored. Participants will be encouraged to install the model and download course materials prior to attending.

More info, or to register:

Recent Events

Papers Accepted

Led by Hyun Cheol Kim, Atmospheric Chemistry and Physics has accepted the article: Quantitative assessment of changes in surface particulate matter concentrations and precursor emissions over China during the COVID-19 pandemic and their implications for Chinese economic activity.

Abstract. Sixty days after the lockdown of Hubei province, where the coronavirus was first reported, China’s true recovery from the pandemic remained an outstanding question. This study investigates how human activity changed during this period using observations of surface pollutants. By combining surface data with a three-dimensional chemistry model, the impacts of meteorological variations and variations in yearly emissions control are minimized, demonstrating how pollutant levels over China changed before and after the Lunar New Year from 2017 to 2020. The results show that the reduction in NO2 concentrations, an indicator of emissions in the transportation sector, was clearly deeper and longer in 2020 than in normal years, and started to recover after February 15. By contrast, PM2.5 emissions had not yet recovered by the end of March, showing a reduction around 30% compared with normal years. SO2 emissions were not affected significantly by the pandemic. Additional model study using a top-down emissions adjustment still confirms a reduction around 25% in unknown surface PM2.5 emissions over the same period, even after realistically updating SO2 and NOx emissions. This evidence suggests that different economic sectors in China may be recovering at different rates, with the fastest recovery in transportation and a slower recovery likely in agriculture. The apparent difference between the recovery timelines of NO2 and PM2.5 implies that monitoring a single pollutant alone (e.g. NOx emissions) is insufficient to draw conclusions on the overall recovery of the Chinese economy.