Fig. 2.
a Back-trajectory analysis for 3 September 2002 calculated at Rzeszów, Kraków and Poznań. b Bi-hourly Ambrosia pollen counts recorded at the three sites during the same period
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.