# Zero\_depth parameter in adiabatic initial temperature profile
**URL:** https://community.geodynamics.org/t/zero-depth-parameter-in-adiabatic-initial-temperature-profile/1537
**Category:** ASPECT
**Created:** [October 18, 2020, 3:03pm UTC](https://community.geodynamics.org/t/zero-depth-parameter-in-adiabatic-initial-temperature-profile/1537 "2020-10-18T15:03:31Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@cedrict](https://community.geodynamics.org/u/cedrict)
#### Post date: [October 18, 2020, 3:03pm UTC](https://community.geodynamics.org/t/zero-depth-parameter-in-adiabatic-initial-temperature-profile/1537/1 "2020-10-18T15:03:31Z")
Hi,
I am trying to understand what adiabatic.cc is really doing. Half way through the file, the parameter {\tt const double zero\_depth = 0.174} is hard coded in the context of subadiabaticity. It looks like it is a dimensionless parameter, but if I multiply it with 2891km I get ~503km , and if I multiply it by 6371km I get ~1108km. Does anybody remember where this 0.174 value come from?
Ce/
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### Author:  [@jdannberg](https://community.geodynamics.org/u/jdannberg)
#### Post date: [October 20, 2020, 3:32pm UTC](https://community.geodynamics.org/t/zero-depth-parameter-in-adiabatic-initial-temperature-profile/1537/2 "2020-10-20T15:32:12Z")
Hi Cedric,
this is one of the very first files I added to ASPECT (when I visited Wolfgang for the first time after I had just started my PhD in 2012). I don’t quite remember where the exact number comes from, but the goal was to be able to create a profile like I used in this [model](https://static-content.springer.com/esm/art%3A10.1038%2Fncomms7960/MediaObjects/41467_2015_BFncomms7960_MOESM491_ESM.pdf) (Supplementary Figure 2) in Citcom. Originally, I took the idea for the subadiabaticity from [this paper](https://doi.org/10.1016/j.pepi.2005.03.017) and tried to use a function that would create a temperature profile with a similar shape like the ones shown in Figure 1 of that paper.
So it’s very specific and the code could definitely be improved. Feel free to make this more general if you want to use it for something different.
Juliane
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### Author:  [@cedrict](https://community.geodynamics.org/u/cedrict)
#### Post date: [October 20, 2020, 5:39pm UTC](https://community.geodynamics.org/t/zero-depth-parameter-in-adiabatic-initial-temperature-profile/1537/3 "2020-10-20T17:39:34Z")
thanks! I will look into this.