Spatiotemporal Study of COVID-19 in Fars Province, Iran, October-November 2020: Establishment of Early Warning System.

Background: Using time series and spatiotemporal analyses, this study aimed to establish an Early Warning System (EWS) for COVID-19 in Fars province Iran.

Methods: A EWS was conducted on (i) daily basis city-level time series data including 53 554 cases recorded during 18 February-30 September 2020, which were applied to forecast COVID-19 cases during 1 October-14 November 2020, and (ii) the spatiotemporal analysis, which was conducted on the forecasted cases to predict spatiotemporal outbreaks of COVID-19.

Results: A total of 55 369 cases were forecasted during 1 October-14 November 2020, most of which (26.

Contribution of Organic Nitrates to Organic Aerosol over South Korea during KORUS-AQ.

The role of anthropogenic NO emissions in secondary organic aerosol (SOA) production is not fully understood but is important for understanding the contribution of emissions to air quality. Here, we examine the role of organic nitrates (RONO) in SOA formation over the Korean Peninsula during the Korea-United States Air Quality field study in Spring 2016 as a model for RONO aerosol in cities worldwide. We use aircraft-based measurements of the particle phase and total (gas + particle) RONO to explore RONO phase partitioning.

Vapor-pressure pathways initiate but hydrolysis products dominate the aerosol estimated from organic nitrates.

Organic nitrates contribute significantly to the total organic aerosol burden. However, the formation and loss mechanisms of particulate organic nitrates (PONs) remain poorly understood. In this study, with the CMAQ modeling system, we implement a detailed biogenic volatile organic carbon gas phase oxidation mechanism and an explicit representation of multiphase organic nitrate formation and loss, including both aqueous-phase uptake and vapor-pressure driven partitioning into organic aerosol as well as condensed-phase reactions.