Active crown fire development

[slevis-lmwg]

Following @jkshuman's introduction of the Bessie and Johnson (1995)
formulation for determining the presence of passive crown fire (NGEET#572), I now add the same paper's formulation for determining the presence of active crown fire.

Description:

All changes are in subroutine crown_damage:
Where @jkshuman introduced Eq. 8 from Bessie and Johnson (1995) I also introduced Eq. 12.
Where @jkshuman introduced Eq. 14a from Bessie and Johnson (1995) I also introduced Eq. 14b.

These equations determine whether passive/active crown fire will occur. As of 9/6/2019, I have not included the effects of active crown fire, which is a topic of discussion for now.

Discussion here:
NGEET#573

Collaborators:

@jkshuman @lmkueppers @pollybuotte @rgknox @rosiealice @xuchongang @ckoven

Expectation of Answer Changes:

Answers will change once we include the effect of active crown fires, not just their presence.

Checklist:

• My change requires a change to the documentation.
• I have updated the in-code documentation .AND. (the technical note .OR. the wiki) accordingly.
• I have read the CONTRIBUTING document.
• FATES PASS/FAIL regression tests were run
• If answers were expected to change, evaluation was performed and provided

Test Results:

CTSM (or) E3SM (specify which) test hash-tag:

CTSM (or) E3SM (specify which) baseline hash-tag:

FATES baseline hash-tag:

Test Output:

[slevis-lmwg]

@rgknox somehow I opened this PR in @jkshuman's path of PRs. I don't know how...

[jkshuman]

Sam, Just going through the steps in case this helps. Not sure where things went awry, but we can fix it on Monday. After you fetch my “passive crown fire branch” to your local repo, create a new branch called “active crown fire” From your local branch for “active crown fire” use git push to send it to your repo. Depending on where things went off, you can also merge this work into a new branch on your repo. And then push it to your remote Git push sLevis-repo active-crown-fire Then create the pull request from your remote “slevis repo” You can always delete that pr and create a new one from your repo. Then I can pull “active crown fire” from your repo since you are doing the development. Will check in with you on Monday.

On Fri, Sep 6, 2019 at 7:17 PM Samuel Levis ***@***.***> wrote: @rgknox <https://github.com/rgknox> somehow I opened this PR in @jkshuman <https://github.com/jkshuman>'s path of PRs. I don't know how... — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#5?email_source=notifications&email_token=AFIUHBRSPHOQTMROVZLHFMTQIL6I5A5CNFSM4IUOHMVKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6EMW2Y#issuecomment-529058667>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFIUHBVGA2XUI5NQAW3P5WDQIL6I5ANCNFSM4IUOHMVA> .

-- Jacquelyn Shuman Terrestrial Sciences Section NCAR

[jkshuman]

Ok @slevisconsulting . Now I see that this is a PR to my jkshuman_repo. I think you will need to try to create a new PR to the FATES_repo. Not sure how this happened. Maybe @rgknox has insight...

[slevis-lmwg]

@jkshuman I will not delete this PR until I have created its replacement in slevis_repo (probably tomorrow) because I will copy&paste the description from here to the new one.

[jkshuman]

Of course. No problem at all

On Mon, Sep 9, 2019 at 5:55 PM Samuel Levis ***@***.***> wrote: @jkshuman <https://github.com/jkshuman> I will not delete this PR until I have created its replacement in slevis_repo (probably tomorrow) because I will copy&paste the description from here to the new one. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#5?email_source=notifications&email_token=AFIUHBWTN5XVSORDMTEQN2DQI3O7NA5CNFSM4IUOHMVKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6JMAVY#issuecomment-529711191>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFIUHBQT6NAZIPZANUG5QADQI3O7NANCNFSM4IUOHMVA> .

-- Jacquelyn Shuman Terrestrial Sciences Section NCAR

[slevis-lmwg]

@jkshuman working in my local branch active_crown_fire,
I merged the latest updates from your passive_crown_fire branch,
resolved conflicts, and then typed:
git commit
git push -u slevis_repo active_crown_fire
but I was not given the option to open a new PR.
The update showed up here even though git remote -v returns
slevis_repo https://github.com/slevisconsulting/fates.git (fetch)
slevis_repo https://github.com/slevisconsulting/fates.git (push)

I will be at NCAR the week of 9/23. Maybe we save cleaning this up for then?

[jkshuman]

Or try Ryan. He is the git master...

On Wed, Sep 11, 2019 at 3:09 PM Samuel Levis ***@***.***> wrote: @jkshuman <https://github.com/jkshuman> working in my local branch active_crown_fire, I merged the latest updates from your passive_crown_fire branch, resolved conflicts, and then typed: git commit git push -u slevis_repo active_crown_fire but I was not given the option to open a new PR. The update showed up here even though git remote -v returns slevis_repo https://github.com/slevisconsulting/fates.git (fetch) slevis_repo https://github.com/slevisconsulting/fates.git (push) I will be at NCAR the week of 9/23. Maybe we save cleaning this up for then? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#5?email_source=notifications&email_token=AFIUHBQM3ZHCBR73YVK2KT3QJFNBLA5CNFSM4IUOHMVKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6P455A#issuecomment-530566900>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFIUHBWCZELPLDHVLNCEM5TQJFNBLANCNFSM4IUOHMVA> .

-- Jacquelyn Shuman Terrestrial Sciences Section NCAR

[jkshuman]

@slevisconsulting what is the status of moving this PR to the NGEET_repo?

[slevis-lmwg]

@slevisconsulting what is the status of moving this PR to the NGEET_repo?

It's on the agenda for my next call with @rgknox. We have not set up such a call, because moving the PR has felt to me like a low priority issue. Since Jackie brought this up though, Ryan, pls email me a few convenient times in the next week or so when we may resolve this. Thanks!

[rgknox]

sounds good, I took a quick look at https://github.com/slevisconsulting/fates/tree/active_crown_fire and don't expect any major issues.

[jkshuman]

@rgknox @slevisconsulting I am not advocating for pulling it into ngeet_repo/master, just putting it in the PR list on the ngeet_repo. Just want to be clear I am not trying to speed this along. this NGEET#573 still has a fair bit of development and has changes to the param file, so should be added with other PRs that have param changes.

[slevis-lmwg]

First testing of crown fire at CZ2 in a 1979-2015 simulation.
Effects of active crown fire not included.
Currently, when passive crown fire occurs, fraction_crown_burned = 1.0

I have found that passive crown fire may occur for height_cbb ~< 1.3 m
and active crown fire may then occur for crown_fuel_bulkd >~ 0.98 kg leaf biomass/m3 canopy

Incidentally the crown fire simulation returns identical model results as the NO crown fire simulation. I have determined that this is because the same conditions that lead to passive crown fire in the crown fire simulation also lead to 100% scorch damage in the NO crown fire simulation. My intuition tells me that this is due to the characteristics of this ecosystem. I will look into this further.

[slevis-lmwg]

I will look into this further.

So I'm finding that scorch damage is more likely than passive crown fire (seems reasonable), and that the model...

• may simulate up to 100% scorch damage due to a tall Scorch Height (SH) at a time when passive crown fire cannot occur due to low Fire Intensity (FI), and it
• will simulate 100% scorch damage (in the NO crown fire simulation) every time that a passive crown fire can occur in the crown fire simulation

So what we've done with the passive crown fire code is simply reclassify some 100% scorch cases to passive crown fire cases.

When we scale passive crown fire effects to less than 100% this will reduce crown damage relative to current simulations.

[pollybuotte]

That's really interesting @slevisconsulting! Do we know yet how the current, no passive crown fire, simulations perform compared to observations? Since there's no fire at the CZ2 site, maybe we need to run over the ponderosa domain. We'll need to decide how to create the stand initialization files for that domain if we are going to compare to observed fire. One option is to give the entire domain the CZ2 stand structure. Or we could see if there are any FIA plots near grid cells with observed fire and run those grid cells only.

[jkshuman]

@slevisconsulting you are correct that passive crown fire is the same as 100% scorch damage. In reality there are situations where the FI is enough to cause crown fire.
@slevisconsulting @pollybuotte I would also look at the assumptions in the parameters triggering crown fire. These are from a different system I think, and should be updated for CA. https://github.com/slevisconsulting/fates/blob/402dfd00d96b76448bec4313b4156525bc14da9f/fire/SFMainMod.F90#L936-L944