Source signatures for determining N2O source processes

[Barthel Matti]

Dear authors of FRAME,

 

Thank you for creating this amazing tool. It is really helpful to streamline the modelling of N2O source processes within the community. I successfully ran the model thanks to the nice description and examples. There is, however, one issue I came across which I find hard to tackle. I am unsure which source signatures values I should assign to the various processes in the source file (N2O_sources.csv). The review of Yu et al., 2020 outlined the most recent numbers but there is a big discrepancy to the values used in the example file who is using a combination of values shown in Yu et al., 2020 and Toyoda et al., 2017. Is there a recommendation by the authors using one vs. the other?

 

Thank you for your help.

 

Best wishes,
Matti Barthel

 

Matti Barthel | ETH Zurich | SAE N₂O Stable Isotope Laboratory 

Sustainable Agroecosystems | Department of Environmental Systems Science

LFH A1, Universitätsstrasse 2, CH-8092 Zurich, Switzerland

www.sae.ethz.ch | Congo Biogeochemistry Observatory 

 

 

[Dominika Lewicka-Szczebak]

Dear Matti,

I am glad to hear that FRAME appears useful for your studies!

The example files for N2O are the files from my case studies (Lewicka-Szczebak et al., 2020), where I had a very specific isotopic signatures of ammonium, very enriched due to almost complete consumption. I have used the endmembers signatures as in Yu et al.,  but corrected them with my actual isotopic signatures of the sources - nitrate and ammonium (Tab. 1 in Lewicka-Szczebak et al., 2020, link, illustrates this correction). You should do similar correction with your measured values, if you do not have the measurements for substrates, it is usually most reasonable to assume 0 and use directly the values as in Yu et al., 2020.

hope this helps,

all the best,

Dominika

dr hab. Dominika Lewicka-Szczebak
PROFESOR UNIWERSYTETU
Zakład Geologii Stosowanej, Geochemii i Gospodarki Środowiskiem, Instytut Nauk Geologicznych, Wydział Nauk o Ziemi i Kształtowania Środowiska

Uniwersytet Wrocławski
ul. W. Cybulskiego
50-205 Wrocław
tel. +48 71 375 95 52

Wiadomość ta oraz wszelkie załączone do niej pliki są poufne i mogą być prawnie chronione. Jeżeli nie jest Pani/Pan zamierzonym adresatem niniejszej wiadomości, nie może Pani/Pan jej ujawniać, kopiować, dystrybuować ani też w żaden inny sposób udostępniać lub wykorzystywać. O błędnym zaadresowaniu wiadomości proszę niezwłocznie poinformować nadawcę i usunąć wiadomość.

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Od: Dominika Lewicka-Szczebak <dominika...@gmail.com>
Wysłane: poniedziałek, 10 lutego 2025 16:23
Do: Dominika Lewicka-Szczebak <dominika.lew...@uwr.edu.pl>
Temat: Fwd: Source signatures for determining N2O source processes

 

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[Barthel Matti]

Dear Dominika,

 

Perfect. This makes a lot of sense now. Thank you for your swift response!

 

Best wishes,
Matti

[Barthel Matti]

Dear Dominika,

 

I just had a quick meeting with Iris Feigenwinter re FRAME to work out some details but we are 95% there to run our respective models. There is just one last question which came up. In the input file ‘N2O_sources.csv’ are the spread columns and we do not know which values should be going in there. I also adapted the ranges in this file but this is not visible in the dual isotope plots of FRAME. Is the spread value the one which is plotted in the software instead of the range values?

 

Thank you again for your help.

Best,
Matti

 

 

From: Dominika Lewicka-Szczebak <dominika.lew...@uwr.edu.pl>

Date: Monday, 10 February 2025 at 17:06
To: Barthel Matti <mbar...@ethz.ch>
Cc: "frame-i...@googlegroups.com" <frame-i...@googlegroups.com>

[Dominika Lewicka-Szczebak]

Dear Matti,

There are 2 ways of defining sources: 

1. you give mean values +/- standard deviation - then in the FRAME graph this is shown as crosses - represented by width of given standard deviation
2. you give mean values +/- spread - then you see boxes in the FRAME graph

We now recommend to use the 1^st method, so mean +/- st dev, because the second one is giving too wide uncertainties (there is a small mistake, we have to correct - the results are ok, but the uncertainty is slightly overestimated). So, best if you just put 0 as the spread value (then you will see crosses on the graphs instead of rectangles). 

Hope this answers your question.

best,

Dominika

dr hab. Dominika Lewicka-Szczebak

PROFESOR UNIWERSYTETU
Zakład Geologii Stosowanej, Geochemii i Gospodarki Środowiskiem, Instytut Nauk Geologicznych, Wydział Nauk o Ziemi i Kształtowania Środowiska

Uniwersytet Wrocławski
ul. W. Cybulskiego
50-205 Wrocław
tel. +48 71 375 95 52

Wiadomość ta oraz wszelkie załączone do niej pliki są poufne i mogą być prawnie chronione. Jeżeli nie jest Pani/Pan zamierzonym adresatem niniejszej wiadomości, nie może Pani/Pan jej ujawniać, kopiować, dystrybuować ani też w żaden inny sposób udostępniać lub wykorzystywać. O błędnym zaadresowaniu wiadomości proszę niezwłocznie poinformować nadawcę i usunąć wiadomość.

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Od: Barthel Matti <mbar...@ethz.ch>
Wysłane: wtorek, 11 lutego 2025 17:02
Do: Dominika Lewicka-Szczebak <dominika.lew...@uwr.edu.pl>
DW: frame-i...@googlegroups.com <frame-i...@googlegroups.com>
Temat: Re: Source signatures for determining N2O source processes

 

[Barthel Matti]

Dear Dominika,

 

This makes perfect sense. I will opt for the 1^st method then.

Thanks again for your help. FRAME is really amazing and I will continue to advertise it.