Fig. 1
(a) Line graph shows the daily sentiment index for the whole world from January 1st, 2020, to December 31st, 2021. In general, the aggregated sentiment is floating around 0.6 and is gradually increasing after being impacted by COVID-19 on March 11th, 2020 (WHO declared the COVID-19 outbreak a global pandemic). (b) The area plot displays the daily number of geotagged posts used for generating the sentiment index during 2020 and 2021. On average, there are 2.64 million geotagged posts collected daily during these two years. (c) The world map illustrates the spatial distribution of collected geotagged posts at the country level for 2021. Countries with color closing to red generate more tweet traffic while color closing to green generates fewer tweets. Among all countries, the USA has the most geotagged tweets taking up 24% of the total traffic, followed by Brazil (14%) and Japan (9%). The uneven tweet generation is due to many reasons such as the number of users/population size or application preference (e.g., users in China prefer using Sina-Weibo).
