GLEON Metabolism 1
GLEON WORKING GROUP
These tasks are associated with one subgroup under the GLEON Metabolism 1 Working Group, better known as the Catchment-Lake Age-of-Carbon THEORY Subgroup .
Participants: Tom Harmon, Paul Hanson, Gopal Bhatt, Stuart Jones, Sam Oliver, Hilary Dugan, Roxanna Ayllon, Yang Cui
===Workflow=== (outcome of G16 breakout sessions)
- Develop Conceptual Model [Tom, Paul, Gopal]
- Paul and Gopal reach out for AoW code
- Translation to r-coding: AoW to rAoW (ruh’ ow!) [Stuart, Sam, Hilary, Gopal]
- Lit. review targeting carbon transformation rates [Roxanna, Yang]
- Define model space [Sam]
- Lit. review of prospective study gradients [Roxanna, Kevin]
- Gradient Sensitivity Analysis (TBD at later date)
Skype Mtg #1 (12/30/14)
Attendees: Tom H, Kevin R, Stuart J, Hilary D
Summary - At G16, we decided to attempt to develop and use an Age of Carbon approach based on Duffy (2010), and use it to explore lake metabolism-catchment connections. In this Skype meeting, we revisited the method and Tom noted some good papers to read for people who want to come up to speed on the approach. Then, we discussed our approach to exploring the solution space of the "age" models we plan to develop.
The method is based on moment analysis, and results in relatively simple expressions (mathematically) for quantifying the age of water in idealized watersheds. Although Duffy (2010) opens the door to reactive transport, he stuck mainly with the age of water or conservative tracers. We decided to try to (1) reproduce the first two cases in Duffy (2010) and (2) extend the analysis to include 1st order decay of organic carbon constituents. The two cases involve a simplistic watershed characterized by a volume V and flow Q, and a similar but slightly more complex ideal watershed characterized by a mobile (Vm) and immobile (Vim) volumes--we decided that his might be one level of complexity that would be interesting to explore. Stuart and Tom are starting to work on the equations and Stuart (post-meeting) had some luck getting started with developing the solutions in Mathematica). Eventually, we may wish to develop R-scripts.
In terms of the solutions space, we discussed a broad approach associated with exploring key lake-catchment parameters. Kevin suggested the Wisconsin LTER lakes as a good set of lakes because they have long-term data on both the lakes and the catchments, and there is a reasonably good variety between Northern and Southern Wisconsin in terms of land use, vegetation, soils and geology. We decided to go with this suggestion and Kevin is getting some data organized. --Tom Harmon (talk) 12:23, 7 January 2015 (PST)
NOTE: Chris and his group have a good page on this site chronicling the approach in the paper and extending it: http://www.organicdatascience.org/ageofwater/index.php/Develop_mathematical_model_of_age_of_water_and_carbon#Concept
Post-Skype Mtg #1 Development
Paul requested the Mathematica scripts from Chris Duffy, and Chris is happy to help. Chris requested that Tom and Gopal sit in on their (Paul, Chris and Yolanda Gil) Organic Data Science project meeting. This will be an opportunity to learn a little more about Chris's analysis and we can fill him in on our proposed approach (and get some good feedback!). --Tom Harmon (talk) 12:23, 7 January 2015 (PST)
Skype Mtg #2 (02/18/2015)
Attendees: Tom, Paul, Stuart, Sam, Hilary
Summary: Stuart described version 1.0 of the the r-Age of Carbon (r-AoC) script and made the script available to the working group. Version 1.0 (based on Duffy 2010) does the following:
1) A conservative tracer model that doesn’t consider age; to remind myself and anyone else how these work 2) The conservative tracer model that includes Chris’s age moment 3) An adaptation of #2 with a first-order decay added 4) A model that allows for dynamic control volume, first order decay, and events in inlet discharge or concentration
* This model is a general model that can recreate the special cases #2 and #3 above * This model (with the decay parameter (d) set to zero) can recreate figures 2, 3, and 4 from Duffy 2010
Most of the group remarked that they were still digesting the "age" approach in Duffy (2010), and we charged everyone with practicing with r-AoC and, using the Wisconsin LTER lake-catchment data compiled by Kevin, try to come up with some potential applications of the AoC approach.
Paul suggested, and we all agreed, that once we become more familiar with the approach and r-AoC, we could try to gather for a concentrated effort/workshop aimed at crafting some research objectives, sorting out tasks, and making a leap in progress. We also agreed that it would be great to involve Chris Duffy soon to help with ideas and directions.
Skype Mtg #3 (03/25/2015)
Attendees: Tom, Sam, Hilary, Roxanna, Kevin, Paul
Summary: Picking up from the previous meeting, a couple of us presented what we had been able to get done with r-AoC. Sam ran the move for several of the LTER lakes, and we talked through the results, mainly trying to get everyone a feel for the model output (focusing mostly on concentration and age time series outputs). Sam posted the plots from these simulations as .pdf files (see top of the page).
