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CO2 Unchanged

Posted: Mon Aug 19, 2019 9:02 pm
by alhashem90
Hi,
I have placed CO2 of 400PPM in background concentration with other pollutants.
But in Leonardo all pollutants had different dispersion across my model while CO2 looked constant with the same 400PPM across the whole model !!
I have tried to search it or read about physical reasons, but I did not reach an explanation of why it would be stable even when placing different vegetation across the model.
Thanks

Re: CO2 Unchanged

Posted: Tue Aug 20, 2019 8:34 am
by Tim
Hi,

It should definitely change within the model if you the model area features plants. Could you attach some screenshots?

Best regards,
Tim

Re: CO2 Unchanged

Posted: Tue Oct 01, 2019 12:44 pm
by alhashem90
HI Tim,
I have attached pictures for the Basic case with no greens at all, living wall with percentage of 50% of all facades and 50% trees of all areas.
The living wall did not change CO2 at all, while the 50% trees have slightly decreased the CO2 emission in some areas at human level which is not logical as well to find around 15mg/m3 decrease only out of 763mg/m3 !?
Similar findings happened for Particulate matters (PPM) as well but I did not attach pictures, so is there an explanation for it as well?
Thanks

Re: CO2 Unchanged

Posted: Tue Oct 01, 2019 1:40 pm
by Tim
Hi,

I'd say the CO² reduction caused by the trees looks fine.
Greening on facades do not yet reduce CO² amount as far as I can see that.

Best regards,
Tim

Re: CO2 Unchanged

Posted: Tue Oct 01, 2019 2:49 pm
by enviadmin
The living wall plant are a system of itself and - so far- do not interact with the CO2
Michael

Re: CO2 Unchanged

Posted: Tue Oct 15, 2019 8:20 pm
by alhashem90
Hi Prof Bruse and Tim,
I wonder if there is an explanation of why would CO2 concentration would increase from 410ppm in background concentrations which I have placed before running simulations.
But after checking results within different alternatives I have found that CO2 increased to be 420-422ppm in average within different green systems alternatives?

Re: CO2 Unchanged

Posted: Wed Oct 16, 2019 8:20 am
by Tim
Hi,

I think that I do not understand what you analyzed and how you simulated it. What did you alter? The CO2 background concentration? The plants? How are they modified?
Changing the year does not affect the CO2 background concentration.

Best regards,
Tim

Re: CO2 Unchanged

Posted: Wed Oct 16, 2019 1:09 pm
by alhashem90
HI Tim,
- I have run different greenery alternatives ( trees, living facade (LF), etc) with different percentages (0% Basic case, 25% green and 50% green) to see how they would reflect on CO2 ppm in the environment for year 2050 and year 2080 which is hotter.
- CO2 ppm concentration is 410ppm.

I have noticed that:
1- CO2 ppm concentration increased in total to reach 422ppm by 2050 and decreased to be 420 by 2080 ( is there any reason that they change with years/ more heat stress and temperature ?)
2- CO2 ppm concentration increased within human levels more than background concentration in the whole model which was 410ppm.

Thanks

Re: CO2 Unchanged

Posted: Wed Oct 16, 2019 1:31 pm
by Tim
Hi,

Maybe I would check the stomata resistance. Because of more heat stress, plants cannot open their stomatas during longer periods of the day which could also affect the photosynthesis rates and thus CO2 concentrations. You will have to analyze all aspects of the plant modelling in ENVI-met and compare it with other research findings. I cannot help you analyze that in detail.

Best regards,
Tim

Re: CO2 Unchanged

Posted: Thu Oct 17, 2019 8:27 am
by enviadmin
About what time of day are you talking?

Greenery reduces CO2 during the day, but increases it during the night.
In total, the plants are neither a sink nor a source of CO2 in ENVI-met as they do not grow (convert CO2 to their biomass)

Michael