Predicting SARS-CoV-2 Weather-Induced Seasonal Virulence from Atmospheric Air Enthalpy

Abstract

Following the coronavirus disease 2019 (COVID-19) pandemic, several studies have examined the possibility of correlating the virulence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, to the climatic conditions of the involved sites; however, inconclusive results have been generally obtained. Although either air temperature or humidity cannot be independently correlated with virus viability, a strong relationship between SARS-CoV-2 virulence and the specific enthalpy of moist air appears to exist, as confirmed by extensive data analysis. Given this framework, the present study involves a detailed investigation based on the first 20–30 days of the epidemic before public health interventions in 30 selected Italian provinces with rather different climates, here assumed as being representative of what happened in the country from North to South, of the relationship between COVID-19 distributions and the climatic conditions recorded at each site before the pandemic outbreak. Accordingly, a correlating equation between the incidence rate of the pandemic and the average specific enthalpy of atmospheric air was developed, and an enthalpy-based seasonal virulence risk scale was proposed as a tool to predict the potential danger of COVID-19 spread due to the persistence of weather conditions favorable to SARS-CoV-2 viability. For practical applications, a conclusive risk chart expressed in terms of coupled temperatures and relative humidity (RH) values was provided, showing that safer conditions occur in case of higher RH at the highest temperatures, and of lower RH at the lowest temperatures. The proposed risk scale was in agreement with the available infectivity data in the literature for a number of cities around the world.

Associations between indoor relative humidity and global COVID-19 outcomes

“…We here revealed an apparent association between indoor RH and COVID-19 at the global population scale, but additional ongoing work focuses on bridging macroscale and microscale results. On the one hand, follow-up top-down studies of population data could investigate the indoor RH hypothesis at higher spatial resolution to determine the robustness of the relationship as a function of scale; on the other hand, bottom-up biophysical experimental–theoretical investigations are needed to shed light on the multifaceted mechanisms and rationalize the inconsistent results so far reported [9,10,12].…”

Distinct weather conditions and human mobility impacts on the SARS-CoV-2 outbreak in Colombia: Application of an artificial neural network approach

“…Average temperature and relative humidity were used to calculate specific enthalpy ( based on the following psychrometric parameters: saturated vapour pressure ( ), vapour pressure ( ), total ambient pressure ( and mixing ratio ( . Specific enthalpy represents the total heat of a mass air (latent heat energy of the water vapour + specific heat of the dry air) and consequently the amount of energy required to change the psychrometric conditions of the air ( de Castro Júnior and Silva, 2021 ; Spena et al, 2020a , 2020b ).The empirical equations of these parameters are presented below: Saturated vapour pressure ( Alduchov and Eskridge, 1996 ): where is the saturated vapour pressure in hPa and T is the average temperature in °C. Vapour pressure ( Lawrence, 2005 ): where is the vapour pressure in hPa and RH is the relative humidity (%).…”

Virologic Microparticle Fluid Mechanics Simulation: COVID-19 Transmission in the Protected and Unprotected Conversations

“…Has a good effect. Therefore, this paper uses the RNG k-ε turbulence model to describe the turbulent flow [39,[61][62][63][64][65] and uses the wall function method to connect the physical quantities near the wall with the unknown quantities in the turbulent core area. The dimensionless distance between the node closest to the wall and the wall satisfies 30≤ y+≤300 [27][28][29].…”