Scheduled Downtime
On Tuesday 24 October 2023 @ 5pm MT the forums will be in read only mode in preparation for the downtime. On Wednesday 25 October 2023 @ 5am MT, this website will be down for maintenance and expected to return online later in the morning.
Normal Operations
The forums are back online with normal operations. If you notice any issues or errors related to the forums, please reach out to help@ucar.edu

WACCM6-MAM4 - difference between dst_a1 versus dst_c1, pom_c1 versus pom_a1, etc.

nstant

Noah Stanton
New Member
Hello!

I am looking for clarification between the different modes in MAM4.

I have the outputs of dst_c1 and dst_a1. What is the difference between c1 and a1?

I understand that a1, a2, a3, a4 --> Accumulation, Aitken, Coarse, Primary carbon.

Also if you can point me to any publications that verify this information, that would be very much appreciated.

Thank you

Sincerely,

Noah Stanton
 

mmills

CSEG and Liaisons
Staff member
dst_c1 is the mass mixing ratio of dust in the accumulation mode that is in cloud water. The long names for the variables are listed in the MASTER FIELD LIST that is printed out to the atm.log file every time the model is run, e.g.:

Code:
4942 dst_c1                           kg/kg              88 A  dst_c1 in cloud water

5032 pom_c1                           kg/kg              88 A  pom_c1 in cloud water
 

mmills

CSEG and Liaisons
Staff member
Here is the reference paper for MAM4:

Liu, X. et al. (2016), Description and evaluation of a new four-mode version of the Modal Aerosol Module (MAM4) within version 5.3 of the Community Atmosphere Model. Geoscientific Model Development Discussions 9, 505–522, doi:10.5194/gmd-9-505-2016.

https://gmd.copernicus.org/articles/9/505/2016/
 

nstant

Noah Stanton
New Member
dst_c1 is the mass mixing ratio of dust in the accumulation mode that is in cloud water. The long names for the variables are listed in the MASTER FIELD LIST that is printed out to the atm.log file every time the model is run, e.g.:

Code:
4942 dst_c1                           kg/kg              88 A  dst_c1 in cloud water

5032 pom_c1                           kg/kg              88 A  pom_c1 in cloud water

Just one more clarification about c1 versus a1 for aerosols in general.

Would a1 include the contribution from c1, or are c1 and a1 quantities separate?

So let's say I'd like to find the sum of all accumulation mode dust aerosols:

Would I sum (dst_a1 + dst_c1) or just use dst_a1?

Thanks!
 
Top