About Ozone diurnal

CMAQ
1

Hi,
I have a question about the CMAQ 5.3.2 output, diurnal profile of O3 seems strange, i see high concentration during the night while day time is low. It seems like there is a shift in 8-10 hours. I am wondering if I did any mistake in CMAQ/SMOKE settings. Can anyone suggest what could be the
issue? Thanks a lot.

|Hour|O3|
|0|42.42|
|1|42.69|
|2|40.55|
|3|36.59|
|4|31.08|
|5|28.28|
|6|29.00|
|7|31.55|
|8|25.56|
|9|28.66|
|10|25.61|
|11|25.73|
|12|26.76|
|13|24.60|
|14|29.01|
|15|31.13|
|16|32.27|
|17|33.35|
|18|34.77|
|19|36.34|
|20|36.85|
|21|37.42|
|22|37.59|
|23|38.10|

2

Did you check timezone?

3

Thanks for the quick response. You mean while running SMOKE? Where is that setting?

4

Please note the CMAQ output is UTC standard time. You need to shift the output timezone to the region which you are investigating. For example, the timezone for the UK in UTC is UTC+1 while for China it is UTC+8. It means that the CMAQ output at 0:00 am is 01:00 am in UK and 08:00 am in China.

1 Like
5

Thank you very much for the useful info