When reading the development of the Corona figures on a daily basis the distribution of new infections in Germany is reminiscent of an elevated high-altitude relief map of Germany. Austria and Switzerland show similar pictures.
This coincidence could be coincidental, nevertheless it seemed worth considering an analysis of previous publications to be performed. Is there any relation of the disease to the meteorological data, especially the air temperature, water vapor saturation and UV radiation?
Based on our observations, we developed the working hypothesis:
There is a correlation between COVID-19 incidence, air temperature, water vapor saturation and UV radiation.
Switzerland and Austria show similar pictures
CORONA IN THE MOUNTAINS
FACT
Temperature decreases with altitude, in dry air more than in clouds.
Up to the end of the troposphere at an altitude of about 11 km, the temperature decreases evenly in a linear fashion, always assuming that the weather is stable weather situation.
Basics:
per 100 meters, the temperature decreases by about 1°C in dry air. When this air mass condenses during the ascent due to cooling energy is released.
This process lowers the cooling rate of rising air per 100 m to approx. 0.7 °C. In the process, the air becomes dryer.
Temperature and Pressure Rates
In addition an analysis of the meteorologically and geographically given conditions: Different sea levels should be seen epidemiologically differently. Temperature, humidity and UV radiation are different at different altitudes.
Another point that can influence the spread of the virus is the air flow.
In strong air currents (westerly wind, easterly wind), the virus is transported by the wind in an aerosol with a lifespan of up to four days.
Air currents can also lead to a deviation of the congruence of the Corona infection map with the geographic relief map, depending on the wind direction, air currents cantilever over the mountains and transport viruses in aerosols.
STUDY FROM CHINA
While searching for correlations, we found a study from China on the Internet with an interesting result:
1 °C increase in temperature makes a reduction in the infection rate from 3 %
The relationship of temperature and humidity to the incidence of COVID-19 infection/disease is not consistent; however, in the literature several studies have shown a decrease of infections.
The work of Wu (Effects of temperature and humidity on the daily new cases and new deaths of COVID-19 in 166 countries ) describes effects that may be consistent with the observations described above.
Effects of temperature and humidity on the daily new cases and new deaths of COVID-19 in 166 countries
Yu Wu 1, Wenzhan Jing 1, Jue Liu 1, Qiuyue Ma 1, Jie Yuan 1, Yaping Wang 1 Min Du 1, Min Liu 2 Affiliations
PMID: 32361460
PMCID: PMC7187824
DOI: 10.1016/j.scitotenv.2020.139051 Free PMC article
STUDY FROM USA
There is much longer virus persistence in cold air than at higher temperatures.
The effect of humidity overlaps the curve. Persistence is lowest at a relative humidity of 60%; this is true at both high temperatures and low, with the effect of humidity being less pronounced at low temperatures than at higher temperatures.
Correlation of virus titer, temperature and relative humidity:
2020 Nov 16;2020.11.13.20231472.
doi: 10.1101/2020.11.13.20231472. Preprint
Role of air temperature and humidity in the transmission of SARS-CoV-2 in the United States
Yiqun Ma, Sen Pei, Jeffrey Shaman, Robert Dubrow, Kai Chen
PMID: 33236018
PMCID: PMC7685329
DOI: 10.1101/2020.11.13.20231472
Dylan et al. make a dependence of the infectivity of SARS-CoV-2 on air temperature and humidity highly probable.
INFLUENCE UV-RADIATION
We found a calculator for the estimated airborne decay of SARS-CoV-2 under a range of temperatures, relative humidity and UV-Index on the official website of the Department of Homeland Security in the United States.
Homeland Security adds to temperature and relative humidity a third criterion: UV radiation and developed a calculator.
CORONA-DECAY • UV-RADIATION
wetter.de has probably adopted the Homeland Security algorhythm.
This weather report gives the corona decay in hours.
This information is likely to be based on the SARS-CoV-2 Surface Decay Calculator of the Homeland Security of the USA.
Note the occultation and solar irradiance in relation to the Corona decay
Weather report from wetter.de with indication of the Corona decay index.
Under cloud cover, the decay time of the corona virus is 12 hours; under sunny conditions, it is 2 hours.
STUDY FROM CYPRUS
Impact of climatic conditions on the transmission dynamics of viruses
Summary of this study:
"Epidemic models do not take into account the impact of climatic conditions on the transmission dynamics of viruses."