Fossil Fuel Emissions Verification
Back in April, while still at LLNL, I was working on a proposed project to improve methods and observations for fossil fuel emissions verification (FFEV). AB32, California’s landmark climate change legislation, requires fossil fuel emissions verification, as well as including mandatory source reporting. Part of FFEV is modeling where emissions are transported by winds. This video-only animation shows such a simulation for emissions from LA (red) and San Francisco (blue) for the first week of January 2006. Several wind patterns can be seen during the week.
I made the original individual graphics images using IDL’s object-oriented volume rendering. The individual images, as was the model output, were three hours apart. The opacity for the the LA and SF air basin emissions increases nonlinearly with the concentrations. I used a gamma correction of 1.5 to create a display that showed concentration details away from the source without filling the entire display. The animation was created by importing the still images into Adobe Premiere Elements and using a dissolve time between images equal to the image display time. The result was a continual interpolation in time rather than a “slide-show” appearance.
Wind flow modeling, as displayed in this video, is only part of FFEV. Bottom-up source estimates are made from reporting of the types of fuel being used and how the fuel is burned. This can vary from season to season and from region to region in California. A model, such as WRF-Chem, along with analyzed wind fields, is used to turn the source estimates into concentration estimates. The concentration estimates can then be compared with actual measurements of local carbon dioxide. Inverse problem mathematics then allow using the discrepancy between the concentration estimates and the actual measurements to improve the estimates of the emissions. By including measurements of different carbon isotopes, more information can be gained about the strengths of fossil fuel sources and biogenic sources and sinks. For example, because all the carbon-14 in fossil fuel has decayed away (5700 year half-life), burning fossil fuel creates a carbon-14 “hole”. This is called the “Suess Effect”, after Hans Suess. The high accuracy isotope measurements are based on the technology at the Center for Accelerator Mass Spectrometry (CAMS). Tom Guilderson of CAMS is heading the proposal and would be the contact for more information.
Hi Keith, I followed your link from the NASW site. This is an excellent animation, most interesting to me is how I can see the change of the emission flow as the temperature gradient between the land and the ocean shifts.
But I can’t tell if that gradient is over 24 hours or 365 days. Do you have a version that includes a time scale?
Thanks.
Hi Mike,
The entire animation is over one week, based on model output from WRF-Chem every three hours. So what I first produced were 56 still images covering the week. There were other air basins in the data, but I focused on the LA and SF ones just for importance and visibility/display.
Thus was supposed to be just an initial prototype, but became popular enough within the project that I ran it through review and release so we could distribute it. I’d done the stills to include in the project proposal for internal funding, but immediately was getting “suggestions” to animate it. So I just dragged it all into Premiere Elements, played with the display and dissolve times, and it came together.
I hadn’t done one with a time indicator, although we’d discussed it. At this point, I’m not at LLNL anymore and don’t have access to IDL, so, at least for me, it’s not a simple redo. At some point, I may try to do more with it using, perhaps, Python and VTK. After doing this animation, I’d been focusing more on the inversions methods and including C-13 and C-14 in those.
The shifts you see, however, are all in the span of that first week in January 2006. The winds, taken, from one of the weather reanalyses. At one point, emissions from the SF basin split, with part going up the coast and part up the central valley. Also, at one point, the LA emissions came up the coast to SF while the SF emissions went up the coast to Eureka. Catching the offshore flow from LA underlined the importance of having a flask sampler on Catalina Island.
It’s timely research and the methodology could have uses far beyond just California. It’s not clear what funding it will get, however. There’s other inversion work on carbon dioxide occurring out there. Key words would be TransCom and Carbon Tracker. The strong points that LLNL has is the accuracy of measuring the isotopes at CAMS. Tom has also tied in with other people doing CO2 measurements.