Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

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.

View full-text article in PMC

. 2021 Sep 4;264:118713. doi: 10.1016/j.atmosenv.2021.118713

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2021 The Authors

Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

PMC Copyright notice

Fig. 5 — Average absolute changes (2020–2019) for observed AirNow MDA8 O₃ (ppb) between a) March 15 – April 15, b) April 15 – May 15, c) May 15 – June 15, d) June 15 – July 15, e) July 15 – August 15, and f) August 15 – September 15. Average of all sites are shown in lower right corner of each panel. Supporting Fig. S4a shows the similar 2020–2019 spatial changes for hourly O₃.