Fig. 6.
Seven-day air mass back-trajectories as well as fire count graph on two different situations. a Before the lockdown period. b During the lockdown period, at altitude level of 500 m above ground level, over sampling side
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.