19 April – Flow and Transport of Methane from Leaking Underground Pipelines: Effects of Soil Surface Conditions and Implications for Natural Gas Leak Classification.  Accepted for publication in Environmental Science & Technology Letters.

     Jayarathne, J. R. R. N., Kolodziej IV, R. S., Riddick, S. N., Zimmerle, D. J. and Smits, K. M.

3 April  – Evaluating Development of Empirical Estimates Using Two Top-Down Methods at Midstream Natural Gas Facilities

     Jenna A. Brown, Matthew R. Harrison, Tecle Rufael, Selina A. Roman-White, Gregory B. Ross, Fiji C. George, and Daniel Zimmerle 

29 February – Methane Emissions from Abandoned Oil and Gas Wells in Colorado

    Riddick, S. N., Mbua, M., Santos, A., Emerson, E. W., Cheptonui, F., Houlihan, C., Hodshire, A. L., Anand, A., Hartzell, W.  and Zimmerle, D. J. 

19 February  – Point Sensor Networks Struggle to Detect and Quantify Short Controlled Releases at Oil and Gas Sites

     Rachel Elizabeth Day, Ethan Emerson, Clay Bell, Daniel Zimmerle 

8 February  – Assessing the progress of the performance of continuous monitoring solutions under single-blind controlled testing protocol

     Chiemezie Ilonze, Ethan Emerson, Aidan Duggan, Daniel  Zimmerle 

5 February  – Potential Underestimate in Reported Bottom-up Methane Emissions from Oil and Gas Operations in the Delaware Basin

     Riddick, S.N.; Mbua, M.; Santos, A.; Hartzell, W.; Zimmerle, D.J. 


December 11 – Reconciling Top-down and Bottom-up Methane Emissions Estimates in the Delaware Basin 

     Riddick, S.N.; Mbua, M.; Santos, A.; Hartzell, W.; Zimmerle, D.J.

November 23 – Quantifying Non-steady State Natural Gas Leakage from the Pipelines Using an Innovative Sensor Network and Model for Subsurface Emissions – InSENSE

    Lo, J. H., Smits, K. M., Cho, Y., Duggan, G. and Riddick, S. N

November 17 – Uncertainty Quantification of Methods Used to Measure Methane Emissions of 1 g CH4 h−1

Stuart N. Riddick, Mercy Mbua, John C. Riddick, Cade Houlihan, Anna L. Hodshire, Daniel J. Zimmerle

October 30 – Unaddressed Uncertainties When Scaling Regional Aircraft Emissions Surveys to Basin Emission Estimates

    Daniel Zimmerle, Sonu Dileep, Casey Quinn 

October 29 – Using controlled subsurface releases to investigate the effect of leak variation on above-ground natural gas detection

    Mbua, M., Riddick, S. N., Tian, S., Cho, Y., Houlihan, C., Cheptonui, F., Zimmerle, D. J. and Smits, K. M. 

October 20 – Methane Emissions from Abandoned Oil and Gas Wells in Colorado

Stuart N. Riddick, Mercy Mbua, Arthur Santos, Ethan Emmerson, Fancy Cheptonui, Wendy Hartzell and Dan Zimmerle 

October 12 – Estimating the Below-Ground Leak Rate of a Natural Gas Pipeline Using Above-Ground Downwind Measurements: The ESCAPE−1 Model

Fancy Cheptonui,  Stuart N. Riddick, Anna L. Hodshire, Mercy Mbua, Kathleen M. Smits, Daniel J. Zimmerle 

September 20 – Informing Methane Emissions Inventories Using Facility Aerial Measurements at Midstream Natural Gas Facilities

Jenna A. Brown, Matthew R. Harrison, Tecle Rufael, Selina A. Roman-White, Gregory B. Ross, Fiji C. George, and Daniel Zimmerle

August 24 – Influence of soil-gas diffusivity on expansion of leaked underground natural gas plumes and application on simulation efforts

J.R.R. Navodi Jayarathne, Richard S. Kolodziej, Stuart N. Riddick, Daniel J. Zimmerle, Kathleen M. Smits 

April 4 – Signing of the Methane Metrology Agreement

March 28 – Performance of continuous emission monitoring solutions under single-blind controlled testing protocol

Clay S. Bell, Chiemezie Ilonze, Aidan Duggan, and Daniel J. Zimmerle

Feb. 15 – Informing methane emissions inventories using facility aerial measurements at midstream natural gas facilities

Jenna Brown, Tecle Rufael, Matthew Harrison, Selina Roman-White, Gregory Ross, Fiji George, Daniel Zimmerle 


Dec. 22 – Likely substantial underestimation of reported methane emissions from United Kingdom upstream oil and gas activities

Riddick, S. N. and Mauzerall, D. L. 

Dec. 1 – Measurement of recreational N2O emissions from an urban environment in Manchester, UK

Barker, P. A. and Allen, G. Flynn, M., Riddick, S. N., and Pitt, J. R. 

Nov. 22 – Investigating detection probability of mobile survey solutions for natural gas pipeline leaks under different atmospheric conditions

Shanru Tian, Stuart N. Riddick, Younki Cho, Clay S. Bell, Daniel J. Zimmerle, Kathleen M. Smits 

Nov. 14 – Single-blind determination of methane detection limits and quantification accuracy using aircraft-based LiDAR

Clay Bell, Jeff Rutherford, Adam Brandt, Evan Sherwin, Timothy Vaughn, and Daniel Zimmerle 

Nov. 2 – A quantitative comparison of methods used to measure smaller methane emissions typically observed from superannuated oil and gas infrastructure

Stuart N. Riddick, Riley Ancona, Mercy Mbua, Clay S. Bell, Aidan Duggan, Timothy L. Vaughn, Kristine Bennett, and Daniel J. Zimmerle

Sept. 29 – Estimating Regional Methane Emission Factors from Energy and Agricultural Sector Sources Using a Portable Measurement System: Case Study of the Denver–Julesburg Basin

Stuart N. Riddick, Fancy Cheptonui, Kexin Yuan, Mercy Mbua, Rachel Day, Timothy L. Vaughn, Aidan Duggan, Kristine E. Bennett and Daniel J. Zimmerle 

Sept. 9 – For Leaks in Rain, Snow and Ice Conditions, Experiments Show Faster Gas Migration, Higher Gas Concentrations, and Continued Gas Migration Days after Leak was Stopped

Daniel Zimmerle, Kathleen Smits, Stuart Riddick (PDF)

Sept. 7 – A closer look at underground natural gas pipeline leaks across the United States

Younki Cho, Kathleen M. Smits, Nathaniel L. Steadman, Bridget A. Ulrich, Clay S. Bell, and Daniel J. Zimmerle 

Aug. 29 – Estimating methane emissions from underground natural gas pipelines using an atmospheric dispersion-based method

Shanru Tian, Kathleen M. Smits, Younki Cho, Stuart N. Riddick, Daniel J. Zimmerle, Aidan Duggan 

July 22 – A Methane Emission Estimation Tool (MEET) for predictions of emissions from upstream oil and gas well sites with fine scale temporal and spatial resolution: Model structure and applications

David T. Allen, Felipe J. Cardoso-Saldana, Yosuke Kimura, Qining Chen, Zhanhong Xiang, Daniel Zimmerle, Clay Bell, Chris Lute, Jerry Duggan, Matthew Harrison 

June 10 – Modeling air emissions from complex facilities at detailed temporal and spatial resolution: The Methane Emission Estimation Tool (MEET)

Daniel Zimmerle, Gerald Duggan, Timothy Vaughn, Clay Bell, Christopher Lute, Kristine Bennett, Yosuke Kimura, Felipe J. Cardoso-Saldaña, David T. Allen 

May 27 – A cautionary report of calculating methane emissions using low-cost fence-line sensors

Stuart N. Riddick, Riley Ancona, Fancy Cheptonui, Clay S. Bell, Aidan Duggan, Kristine E. Bennett, Daniel J. Zimmerle

March 22 – Calibration and field deployment of low-cost sensor network to monitor underground pipeline leakage

Younki Cho, Kathleen M. Smits, Stuart N. Riddick, Daniel J. Zimmerle 

April 26 – METEC controlled test protocol: survey emission detection and quantification

Clay Bell, Daniel Zimmerle 

April 14 – Open-Source High Flow Sampler for Natural Gas Leak Quantification

Daniel Zimmerle, Timothy Vaughn, Kristine Bennett, Cody Ross, Matthew Harrison, Aaron Wilson, Chris Johnson 

Feb. 22 – Quantitative comparison of methods used to estimate methane emissions from small point sources

Stuart N. Riddick, Riley Ancona, Clay Bell1, Aidan Duggan, Tim Vaughn, Kristine Bennett and Dan Zimmerle

Feb. 2 – Understanding Mid-to Large Underground Leaks from Buried Pipelines as Affected by Soil and Atmospheric Conditions – Field Scale Experimental Study

J. R. R. Navodi Jayarathne, Kathleen Smits, Stuart N. Riddick, Daniel J. Zimmerle, Younki Cho, Michelle Schwartz, Fancy Cheptonui, Kevan Cameron, Peter Ronney


Dec. 31 – Quantification of Methane Emissions from Marginal (Low Production Rate)  Oil and Natural Gas Wells 

Dec. 21 – Modeling temporal variability in the surface expression above a methane leak: The ESCAPE model

Stuart N. Riddick, Clay S. Bell, Aidan Duggan, Timothy L. Vaughn, Kathleen M. Smits, Younki Cho, Kristine Bennett, and Daniel J. Zimmerle 

Dec.A Different Beast: New Tools for Regulators to Handle Next Generation Leak Detection for Oil and Gas

Daniel Zimmerle

Dec.Methane detector network calibration and deployment for monitoring natural gas leaks from buried pipelines

Cho, Younki; Smits, Kathleen ; Riddick, Stuart ; Zimmerle, Daniel

July 7 Study of methane migration in the shallow subsurface from a gas pipe leak

Bo Gao, Melissa K. Mitton, Clay Bell, Daniel Zimmerle, T. K. K. Chamindu Deepagoda, Arsineh Hecobian, Kathleen M. Smits 

Jan. 7 Methane Exhaust Measurements at Gathering Compressor Stations in the United States

Timothy L. Vaughn, Benjamin Luck, Laurie Williams, Anthony J. Marchese, and Daniel Zimmerle 


Dec – Estimating natural gas emissions from underground pipelines using surface concentration measurements

Younki Cho, Bridget A. Ulrich, Daniel J. Zimmerle, Kathleen M. Smits 

Sept 22 – METEC controlled test protocol: continuous monitoring emission detection and quantification

Bell, Clay; Zimmerle, Daniel 

Sept – Variability observed over time in methane emissions from abandoned oil and gas wells

Riddick, S. N., Mauzerall, D.L., Celia, M., Kang, M., and Bandilla K.

Aug 7 – Detection Limits of Optical Gas Imaging for Natural Gas Leak Detection in Realistic Controlled Conditions

Daniel Zimmerle, Timothy Vaughn, Clay Bell, Kristine Bennett, Parik Deshmukh, and Eben Thoma 

July 20 – Evaluation of next generation emission measurement technologies under repeatable test protocols

Clay S. Bell, Timothy Vaughn, Daniel Zimmerle 

June 1 – The calibration and deployment of a low-cost methane sensor

Riddick, S. N., Mauzerall, D.L., Celia, M., Allen, G., Pitt, J., Kang and M., Riddick, J.C.

May 14 – Methane Emissions from Gathering Compressor Stations in the U.S.

Daniel Zimmerle, Timothy Vaughn, Ben Luck, Terri Lauderdale, Kindal Keen, Matthew Harrison, Anthony Marchese, Laurie Williams, and David Allen 

Jan 1 – Machine vision for natural gas methane emissions detection using an infrared camera

Jingfan Wanga, Lyne P. Tchapmib, Arvind P. Ravikumar, Mike McGuire, Clay S. Bell, Daniel Zimmerle, Silvio Savarese, Adam R. Brandt 


Oct – Characterization of methane emissions from gathering compressor stations: final report

Zimmerle, Daniel; Bennett, Kristine; Vaughn, Timothy; Luck, Ben; Lauderdale, Terri; Keen, Kindal; Harrison, Matthew; Marchese, Anthony; Williams, Laurie; Allen, David 

Oct – Methane emissions from gathering and boosting compressor stations in the U.S. Supporting volume 3: Emission factors, station estimates, and national emissions

Daniel Zimmerle, Timothy Vaughn, Benjamin Luck, Terri Lauderdale, Kindal Keen, Matthew Harrison, Anthony Marchese, Laurie Williams, and David Allen 

Sept 19 – Single-blind inter-comparison of methane detection technologies – results from the Stanford/EDF Mobile Monitoring Challenge

Arvind P. Ravikumar, Sindhu Sreedhara, Jingfan Wang, Jacob Englander, Daniel Roda-Stuart, Clay Bell, Daniel Zimmerle, David Lyon, Isabel Mogstad, Ben Ratner, Adam R. Brandt 

Aug 19 – Methane emissions from oil and gas platforms in the North Sea 

6. Riddick, S. N., Mauzerall, D. L., Celia, M., Harris, N. R. P., Allen, G., Pitt, J., Staunton-Sykes, J., Forster, G. L., Kang, M., Lowry, D., Nisbet, E. G., and Manning, A. J. 

Aug 15 – Constraining the Accuracy of Flux Estimates Using OTM 33A

Rachel Edie, Anna M. Robertson, Robert A. Field, Jeffrey Soltis, Dustin A. Snare, Daniel Zimmerle, Clay S. Bell, Timothy L. Vaughn, and Shane M. Murphy 

July 19 – A methane emissions reduction equivalence framework for alternative leak detection and repair programs

Thomas A. Fox, Arvind P. Ravikumar, Chris H. Hugenholtz, Daniel Zimmerle, Thomas E. Barchyn, Matthew R. Johnson, David Lyon, Tim Taylor 

June 27 – Natural Gas Emissions from Underground Pipelines and Implications for Leak Detection

Bridget A. Ulrich, Melissa Mitton, Emily Lachenmeyer, Arsineh Hecobian, Daniel Zimmerle, and Kathleen M. Smits 

April 30 – Multiday Measurements of Pneumatic Controller Emissions Reveal the Frequency of Abnormal Emissions Behavior at Natural Gas Gathering Stations

Benjamin Luck, Daniel Zimmerle, Timothy Vaughn, Terri Lauderdale, Kindal Keen, Matthew Harrison, Anthony Marchese, Laurie Williams, and David Allen 

April 5 – Methane source attribution in a U.S. dry gas basin using spatial patterns of ground and airborne ethane and methane measurements

Ingrid Mielke-Maday, Stefan Schwietzke, Tara I. Yacovitch, Benjamin Miller, Steve Conley, Jonathan Kofler, Philip Handley, Eryka Thorley, Scott C. Herndon, Bradley Hall, Ed Dlugokencky, Patricia Lang, Sonja Wolter, Eric Moglia, Molly Crotwell, Andrew Crotwell, Michael Rhodes, Duane Kitzis, Timothy Vaughn, Clay Bell, Dan Zimmerle, Russ Schnell and Gabrielle Pétron 

Feb 15 – Measuring methane emissions from abandoned and active oil and gas wells in West Virginia

Riddick, S. N., Mauzerall, D., Celia, M., Bressler, K., Chu, C., Gum, C. and Kang, M. 

2019 – Automated Identification of Oil Field Features using CNNs

Sonu Dileep, Daniel Zimmerle, J Ross Beveridge, Timothy Vaughn


Dec – Deep Learning to Classify Methane Leak Size At Oil and Gas Facilities

Wang, J. ; Ravikumar, A. P. ; Sreedhara, S. ; Tchapmi, L. P. ; McGuire, M. ; Bell, C. ; Zimmerle, D. ; Brandt, A. R.

Dec – Testing the Next Generation of Leak Detection and Quantification Technologies

Zimmerle, D. ; Bell, C. ; Vaughn, T. L.

Oct 29 – Temporal variability largely explains top-down/bottom-up difference in methane emission estimates from a natural gas production region

Timothy L. Vaughn, Clay S. Bell, Cody K. Pickering, and Dag Nummedal 

Aug 17 – A measurement-based verification framework for UK greenhouse gas emissions: an overview of the Greenhouse gAs Uk and Global Emissions (GAUGE) project

Palmer, P., O’Doherty, S., et al. 

June 21 – Improved characterization of methane emissions from the U.S. oil and gas supply chain

Ramon A. Alvarez, Daniel Zavala-Araiza, David R. Lyon, David T. Allen, Zachary R. Barkley, Adam R. Brandt, Kenneth J. Davis, Scott C. Herndon, Daniel J. Jacob, Anna Karion, Eric A. Kort, Brian K. Lamb, Thomas Lauvaux, Joannes D. Maasakkers, Anthony J. Marchese, Mark Omara, Stephen W. Pacala, Jeff Peischl, Allen L. Robinson, Paul B. Shepson, Colm Sweeney, Amy Townsend-Small, Steven C. Wofsy, Daniel Zimmerle, Steven P. Hamburg 

March – Development of a low-maintenance measurement approach to continuously estimate methane emissions: A case study

12. Riddick, S. N., Hancock, B. R., Robinson, A. D., Connors, S., Davies, S., Allen, G., Pitt, J. and Harris, N. R. P. 

Jan 19 – “Good versus Good Enough?” Empirical Tests of Methane Leak Detection Sensitivity of a Commercial Infrared Camera

Arvind P. Ravikumar , Jingfan Wang, Mike McGuire, Clay S. Bell, Daniel Zimmerle, and Adam R. Brandt


Nov 24 – Comparing facility-level methane emission rate estimates at natural gas gathering and boosting stations

Timothy L. Vaughn, Clay S. Bell, Tara I. Yacovitch, Joseph R. Roscioli, Scott C. Herndon, Stephen Conley, Stefan Schwietzke, Garvin A. Heath, Gabrielle Pétron, Daniel Zimmerle

Nov 24 – Natural gas facility methane emissions: measurements by tracer flux ratio in two US natural gas producing basins

Tara I. Yacovitch, Conner Daube, Timothy L. Vaughn, Clay S. Bell, Joseph R. Roscioli, W. Berk Knighton, David D. Nelson, Daniel Zimmerle, Gabrielle Pétron, Scott C. Herndon

Nov 24 – Gathering pipeline methane emissions in Fayetteville shale pipelines and scoping guidelines for future pipeline measurement campaigns

Daniel J. Zimmerle, Cody K. Pickering, Clay S. Bell, Garvin A. Heath, Dag Nummedal, Gabrielle Pétron, Timothy L. Vaughn 

Oct 25 – CH4 emission estimates from an active landfill site inferred from a combined approach of CFD modelling and in situ FTIR measurements

Sonderfeld, H., Bösch, H., Jeanjean, A. P. R., Riddick, S. N., et al. 

July 20 – Comparison of methane emission estimates from multiple measurement techniques at natural gas production pads

Clay S. Bell, Timothy L. Vaughn, Daniel Zimmerle, Scott C. Herndon, Tara I. Yacovitch, Garvin A. Heath, Gabrielle Pétron, Rachel Edie, Robert A. Field, Shane M. Murphy, Anna M. Robertson, Jeffrey Soltis 

June 19 – Variation in Methane Emission Rates from Well Pads in Four Oil and Gas Basins with Contrasting Production Volumes and Compositions

Anna M. Robertson, Rachel Edie, Dustin Snare, Jeffrey Soltis, Robert A. Field, Matthew D. Burkhart, Clay S. Bell, Daniel Zimmerle, and Shane M. Murphy 

June 17 – Estimating the size of a methane emission point source at different scales: from local to landscape

Riddick, S. N., Connors, S., Robinson, A. D., Manning A., Jones, P. S. D., Lowry, D., Nisbet, E.G., Skelton, R. L., Allen, G., Pitt, J. and Harris, N. R. P. 

May 26 – Improved Mechanistic Understanding of Natural Gas Methane Emissions from Spatially Resolved Aircraft Measurements

Stefan Schwietzke, Gabrielle Pétron, Stephen Conley, Cody Pickering, Ingrid Mielke-Maday, Edward J. Dlugokencky, Pieter P. Tans, Tim Vaughn, Clay Bell, Daniel Zimmerle, Sonja Wolter, Clark W. King, Allen B. White, Timothy Coleman, Laura Bianco, and Russell C. Schnell 

Jan 16 – Super-emitters in natural gas infrastructure are caused by abnormal process conditions

Daniel Zavala-Araiza, Ramón A Alvarez, David R. Lyon, David T. Allen, Anthony J. Marchese, Daniel J. Zimmerle & Steven P. Hamburg 


Dec 7 – Mid-continent basin – methane emissions reconciliation: facility level emissions

Daniel Zimmerle


Dec 7 – Reconciling divergent estimates of oil and gas methane emissions

Daniel Zavala-Araiza, David R. Lyon, Ramón A. Alvarez, and Steven P. Hamburg 

Aug 18 – Methane Emissions from United States Natural Gas Gathering and Processing

Anthony J. Marchese, Timothy L. Vaughn, Daniel J. Zimmerle, David M. Martinez, Laurie L. Williams, Allen L. Robinson, Austin L. Mitchell, R. Subramanian, Daniel S. Tkacik, Joseph R. Roscioli, and Scott C. Herndon 

July 21 – Methane Emissions from the Natural Gas Transmission and Storage System in the United States

Daniel J. Zimmerle, Laurie L. Williams, Timothy L. Vaughn, Casey Quinn, R. Subramanian, Gerald P. Duggan, Bryan Willson, Jean D. Opsomer, Anthony J. Marchese, David M. Martinez, and Allen L. Robinson 

July 7 – Constructing a Spatially Resolved Methane Emission Inventory for the Barnett Shale Region

David R. Lyon, Daniel Zavala-Araiza, Ramon A. Alvarez, Robert Harriss, Virginia Palacios, Xin Lan, Robert Talbot, Tegan Lavoie, Paul Shepson, Tara I. Yacovitch, Scott C. Herndon, Anthony J. Marchese, Daniel Zimmerle, Allen L. Robinson, and Steven P. Hamburg 

May 7 – Measurements of methane emissions from natural gas gathering facilities and processing plants: measurement methods

J. R. Roscioli, T.I. Yacovitch, C. Floerchinger, A. L. Mitchell, D.S. Tkacik, R. Subramanian, D. M. Martinez, T.L. Vaughn, L. Williams, D. Zimmerle, A.L. Robinson, S.C. Herndon, and A.J. Marchese 

Feb 10 – Methane Emissions from Natural Gas Compressor Stations in the Transmission and Storage Sector: Measurements and Comparisons with the EPA Greenhouse Gas Reporting Program Protocol

R. Subramanian, Laurie L. Williams, Timothy L. Vaughn, Daniel Zimmerle, Joseph R. Roscioli, Scott C. Herndon, Tara I. Yacovitch, Cody Floerchinger, Daniel S. Tkacik, Austin L. Mitchell, Melissa R. Sullivan, Timothy R. Dallmann, and Allen L. Robinson 

Feb 10 – Measurements of Methane Emissions from Natural Gas Gathering Facilities and Processing Plants: Measurement Results

Austin L. Mitchell, Daniel S. Tkacik, Joseph R. Roscioli, Scott C. Herndon, Tara I. Yacovitch, David M. Martinez, Timothy L. Vaughn, Laurie L. Williams, Melissa R. Sullivan, Cody Floerchinger, Mark Omara, R. Subramanian, Daniel Zimmerle, Anthony J. Marchese, and Allen L. Robinson 


Moving Towards Improved Basin-level Oil and Gas Inventories and Reconciliation with Measurements

Amnon Bar-Ilan, John Grant, Rajashi Parikh, Ralph Morris, Garvin Heath, Viktor Diakov, Dan Zimmerle, Lee Gribovicz

Measurement Analysis of GC-FID Methane Network in East Anglia

Sarah Connors, Neil Harris, Andrew Robinson, Stuart Riddick, Alistair Manning 


Dec 22 – Flare Gas Utilization at Combined Oil-Gas Well Sites

Casey Quinn, Daniel Zimmerle, Daniel B. Olsen