Which fields in the atm output should I use

[Eric]

Hello,

If I want to know atmospheric CO2 concentration, which field in the atm output files should I look into? There is a field called CO2, but it is a three-dimensional variable and is in the unit of kg/kg (I expect it to be in ppmv). If this is the field I should look into, is there an equation that I can use to transfer it to atmospheric CO2 concentration?

If I want to calculate global mean surface air temperature (2m air temperature), which field should I look into? I didn't find this field in the atm output but I found it in the land output. If I want to calculate the global mean, do I need to separately calculate land surface air temperature and ocean surface air temperature, and then average these two values? (Or simply, which field should I use to calculate global mean surface air temperature as calculated in CMIP6?)

If I want to know the simulated precipitation, should I look into the field "TMQ"? This is "total vertically integrated precipitable water" in the unit of Kg/m2, however, the precipitation that we usually use is in the unit of mm/m2. This is the only field that is relevant to precipitation so I kind of want to do a confirmation.

Thank you!!

 

[strandwg]

Hello,

If I want to know atmospheric CO2 concentration, which field in the atm output files should I look into? There is a field called CO2, but it is a three-dimensional variable and is in the unit of kg/kg (I expect it to be in ppmv). If this is the field I should look into, is there an equation that I can use to transfer it to atmospheric CO2 concentration?

If I want to calculate global mean surface air temperature (2m air temperature), which field should I look into? I didn't find this field in the atm output but I found it in the land output. If I want to calculate the global mean, do I need to separately calculate land surface air temperature and ocean surface air temperature, and then average these two values? (Or simply, which field should I use to calculate global mean surface air temperature as calculated in CMIP6?)

If I want to know the simulated precipitation, should I look into the field "TMQ"? This is "total vertically integrated precipitable water" in the unit of Kg/m2, however, the precipitation that we usually use is in the unit of mm/m2. This is the only field that is relevant to precipitation so I kind of want to do a confirmation.

Thank you!!

You should have a field in your output called "co2vmr", which is the current CO2 value. It's a 1-D variable dimensioned only along time.

TREFHT is the 2m reference height temperature. There's also the field TS, which is the skin temperature calculated from the radiative fluxes.

The precipitation fields are PRECC, PRECL and PRECT - convective, large-scale and total precipitation, respectively.

 

[Eric]

Hi Gary,

Thanks for the help. May I ask what the unit of co2vmr is? For example, now it shows me a value of 0.000399. How can I transfer it to the CO2 concentration in ppmv?

Regarding the temperature, which field do scientists use when they draw the global mean air temperature cure and analyze global warming?

Regarding the precipitation, I noticed that PRECC and PRECL are precipitation rates. If my atm output frequency is yearly average and I want to calculate the annual precipitation amount, should I multiply it with 365*24*60*60?

And there is no field called PRECT. Should I just add up PRECC and PRECL to get the total precipitation?

Thank you!!

 

[strandwg]

Hi Gary,

Thanks for the help. May I ask what the unit of co2vmr is? For example, now it shows me a value of 0.000399. How can I transfer it to the CO2 concentration in ppmv?

Regarding the temperature, which field do scientists use when they draw the global mean air temperature cure and analyze global warming?

Regarding the precipitation, I noticed that PRECC and PRECL are precipitation rates. If my atm output frequency is yearly average and I want to calculate the annual precipitation amount, should I multiply it with 365*24*60*60?

And there is no field called PRECT. Should I just add up PRECC and PRECL to get the total precipitation?

Thank you!!

"co2vmr" is volume mixing ratio - multiply by 1.e6 to get PPM.

Usually "TS" is used for surface temperature.

All precipitation fields are in "m s-1" (meters per second) so if you sum and multiply by 86400 (seconds per year) you'll get total precipitation in meters.

PRECT is PRECC + PRECL, correct.

 

[Eric]

Thank you, Gary!

 

[CGL]

Hello,

If I want to know atmospheric CO2 concentration, which field in the atm output files should I look into? There is a field called CO2, but it is a three-dimensional variable and is in the unit of kg/kg (I expect it to be in ppmv). If this is the field I should look into, is there an equation that I can use to transfer it to atmospheric CO2 concentration?

If I want to calculate global mean surface air temperature (2m air temperature), which field should I look into? I didn't find this field in the atm output but I found it in the land output. If I want to calculate the global mean, do I need to separately calculate land surface air temperature and ocean surface air temperature, and then average these two values? (Or simply, which field should I use to calculate global mean surface air temperature as calculated in CMIP6?)

If I want to know the simulated precipitation, should I look into the field "TMQ"? This is "total vertically integrated precipitable water" in the unit of Kg/m2, however, the precipitation that we usually use is in the unit of mm/m2. This is the only field that is relevant to precipitation so I kind of want to do a confirmation.

Thank you!!

Where can I find the CO2 filed( a three-dimensional variable)? I only can find co2vmr in CAM. By the way, the CESM output is setted by default. I didn't change the usr_nl file.

 

[peverley]

Hi,

You should be able to grab the CO2 field by adding "CO2" to your history field list in your user_nl_cam file per this documentation: 7. Model Output: — camdoc documentation

Courtney

 

[CGL]

Hi,

You should be able to grab the CO2 field by adding "CO2" to your history field list in your user_nl_cam file per this documentation: 7. Model Output: — camdoc documentation

Courtney

Thanks. By the way, I used the F2000climo model. I saw the componet is CLM5-SP. That's mean the clm componet don't have exchange with cam model?

 

[erik]

Thanks. By the way, I used the F2000climo model. I saw the componet is CLM5-SP. That's mean the clm componet don't have exchange with cam model?

No, what CLM50%SP means is that it's using CLM with clm5_0 physics, and SP mode (or Satellite Phenology). Satellite Phenology means plant growth is prescribed with Satellite data (from MODIS). There are a few other options, but they all have to do with how CLM is being run rather than anything about the interaction between CLM and CAM. The main interaction that you can control between CAM and CLM has to do with how CO2 is handled and dealt with between components.

 

[CGL]

No, what CLM50%SP means is that it's using CLM with clm5_0 physics, and SP mode (or Satellite Phenology). Satellite Phenology means plant growth is prescribed with Satellite data (from MODIS). There are a few other options, but they all have to do with how CLM is being run rather than anything about the interaction between CLM and CAM. The main interaction that you can control between CAM and CLM has to do with how CO2 is handled and dealt with between components.

Thanks,@erik! That's helpful!

 

[CGL]

Hi,

You should be able to grab the CO2 field by adding "CO2" to your history field list in your user_nl_cam file per this documentation: 7. Model Output: — camdoc documentation

Courtney

I add the "CO2" field to the use_nl_cam as :
fincl1 = "CO2"

---

But I got the erro as below:
intht:nfmaster= 2175
FLDLST: CO2 in fincl(1, 1) not found
ERROR: FLDLST: 1 errors found, see log

---

I want to output the CO2 variale which reflect the Interaction between CLM and CAM model in the F2000climo. I find the related post and the CAM6.3 Namelist Definitions. I don't see the variable named "CO2_LND". What format should I use to output the CO2 variables I want?

 

[peverley]

Hi, can you remove the fincl line of your user_nl_cam, run it, and check the run/atm.log.* file for the "MASTER FIELD LIST"? That will tell you all of the fields that are available to you to include (via fincl). You may have to play around a bit to figure out which one you need. If the field has the "I" indicator in the 5th column, that means that it's an instantaneous value, while an "A" indicates an average field. It may be that you want to use "pbuf_CO2" depending on what your master field list looks like.

 

[CGL]

Hi, can you remove the fincl line of your user_nl_cam, run it, and check the run/atm.log.* file for the "MASTER FIELD LIST"? That will tell you all of the fields that are available to you to include (via fincl). You may have to play around a bit to figure out which one you need. If the field has the "I" indicator in the 5th column, that means that it's an instantaneous value, while an "A" indicates an average field. It may be that you want to use "pbuf_CO2" depending on what your master field list looks like.

Thanks for reply! I find the m_CO2_C filed in the "MASTER FIELD LIST". I will add this field to the use_nl_cam as :fincl1 = "m_CO2_C". Is that right?How do I know it's fincl1 and not other(like fincl2...)?

 

[peverley]

A valid question! The "x" in "finclx" just refers to the particular history file you're wanting to generate (you can have several). You can refer to this documentation for all the history configuration options (precision, avg/instantaneous/min/max/etc, frequency of output, etc): 7. Model Output: — camdoc documentation

 

[CGL]

A valid question! The "x" in "finclx" just refers to the particular history file you're wanting to generate (you can have several). You can refer to this documentation for all the history configuration options (precision, avg/instantaneous/min/max/etc, frequency of output, etc): 7. Model Output: — camdoc documentation

I see... The finclX just let the user difinit the configuration options(like frequency or specific variable,etc), not for the NEW variables for the MASTER FIELD LIST do not have. Is that right?

 

[peverley]

Correct. The master field list contains all the variables that are AVAILABLE to be added to the history files via finclx. Some users need multiple history files at different frequencies and/or types (instantaneous vs average, etc), thus the need for more than one history file (x > 1)

 

[CGL]

Correct. The master field list contains all the variables that are AVAILABLE to be added to the history files via finclx. Some users need multiple history files at different frequencies and/or types (instantaneous vs average, etc), thus the need for more than one history file (x > 1)

That's very helpful! Thanks for your kindness reply.