|Title||An Environmental Determinant for Transmission of Viral Respiratory Disease|
|Publication Type||Conference Paper|
|Year of Publication||2020|
|Authors||Yeon-Woo Choi; Alexandre Tuel; Elfatih A. B. Eltahir|
|Conference Name||2020 AGU Fall Meeting|
Viral respiratory diseases (VRD), such as influenza and COVID-19, are known to be transmitted by droplets exhaled by infected hosts. This primary infection route suggests that environmental controls on droplet evaporation, evolution, and fate may play an important role in determining the spread of these diseases. Based on this mechanistic understanding of VRD transmission, we propose here a new atmospheric state-variable, named Air Drying Capacity (ADC) with significant and direct relation to the transmission of VRD. Under given temperature and humidity conditions, ADC directly constrains the evaporation of airborne droplets. The definition of this variable is motivated by droplet growth theory first developed by Maxwell. In this study, we present the climatology of ADC, and compare its observed distribution in space and time to the observed prevalence of influenza and COVID-19 from extensive global data sets. Globally, the transmission of the viruses responsible for COVID-19 and influenza is likely impacted by ADC. This study introduces a new environmental determinant, rooted in the mechanism of VRD transmission, with significant implications for predictions of the environmental conditions under which COVID-19 is likely to evolve.