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Yaoxian Huang, Eric Kort, Anna Karion, John Ware, Kimberly Mueller, Sharon Gourdji
Methane (CH4) emissions from urban areas are increasingly recognized as a potentially important anthropogenic source, but we have limited observations of annual and seasonal emissions from these important regions. In this study, we quantify seasonal and
Aaron N. Johnson, Iosif I. Shinder, Bernard J. Filla, Joey T. Boyd, Rodney A. Bryant, Michael R. Moldover
Exhaust flows from coal-fired stacks are determined by measuring the flue gas velocity at prescribed points in the stack cross section. During the last 30+ years these velocity measurements have been made predominantly using S-type pitot probes. These
Kimberly L. Mueller, Vineet Yadav, Israel Lopez Coto, Anna Karion, Sharon M. Gourdji, Cory R. Martin, James R. Whetstone
There is increased interest in understanding urban greenhouse gas (GHG) emissions. However, to accurately estimate city emissions, the influence of exurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true
In situ observing networks are increasingly being used to study greenhouse gas emissions in urban environments. While the need for sufficiently dense observations has often been discussed, density requirements depend on the question posed and interact with
We combine sustained observations from a network of atmospheric monitoring stations with inverse modeling to uniquely obtain (3 km, 4 day) spatio-temporal estimates of methane emissions from the Los Angeles Megacity and the broader South Coast Air Basin
Ian Smith, Lucy Hutyra, Andrew Reinmann, jonathan thompson, David Allen
Forest fragmentation impacts carbon uptake and storage, however, the magnitude and direction of fragmentation impacts on soil respiration remain poorly characterized. We quantify soil respiration rates along edge-to-interior transects in two temperate
Esther Baumann, Edgar Perez, Gabriel M. Colacion, Fabrizio Giorgetta, Kevin Cossel, Gabriel Ycas, David Carlson, Kartik Srinivasan, Scott Papp, Ian Coddington, Nathan Newbury
Spectral broadening of compact robust Er+: fiber combs is demonstrated with tailored Si3N4 waveguides to obtain spectrally-smooth broadened light in the 2 μm 2.5 μm atmospheric water window for gas spectroscopy. This successfully extends the Er+ spectrum
Joseph M. Conny, Robert D. Willis, Diana Ortiz-Montalvo
We have determined optical properties of heterogeneous particles from aerosol samples collected at Mauna Loa Observatory (MLO) in Hawaii. Back trajectories, satellite imagery, and composition differences among particles from scanning electron microscopy
Anna Karion, Thomas Lauvaux, Israel Lopez Coto, Colm Sweeney, Kimberly L. Mueller, Sharon M. Gourdji, Wayne Angevine, Zachary R. Barkley, Aijun Deng, Ariel Stein, James R. Whetstone
Greenhouse gas emissions mitigation requires understanding dominant processes controlling fluxes of these trace gases into the atmosphere at increasingly finer spatial and temporal scales. Trace gas fluxes can be estimated using a variety of approaches
Jocelyn Turnbull, Anna Karion, Kenneth J. Davis, Thomas Lauvaux, Natasha Miles, Scott Richardson, Colm Sweeney, Kathryn McKain, Scott Lehman, Kevin Gurney, Risa Patarasuk, Jianming Liang, Paul Shepson, Alexie Heimburger, James Whetstone
Cory R. Martin, Ning Zeng, Anna Karion, Kimberly L. Mueller, Subhomoy Ghosh, Israel Lopez Coto, Kevin Gurney, Tomohiro Oda, Kuldeep R. Prasad, Yun Liu, Russell R. Dickerson, James R. Whetstone
Urban areas are major sources of carbon dioxide (CO2) emissions, contributing to the increase in global concentrations and leading to concerns about Earth's future climate. In recent years, several urban testbeds have been implemented to improve and
Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States, and as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present here a
Rodney A. Bryant, Aaron N. Johnson, John D. Wright, Tamae M. Wong, James R. Whetstone, Michael R. Moldover, Iosif I. Shinder, Scott Swiggard, Chris Gunning, David Elam, Tom Martz, Eric Harman, David Nuckols, Liang Zhang, Woong Kang, Salvator Vigil
The complex flow conditions inherent in power plant smokestacks make accurate flow measurements challenging, which in turn limits the accuracy of hazardous emissions measurements. While stack composition measurements are assessed daily via comparison to a
The specifications and performance of a ground-based differential absorption LIDAR (light detection and ranging) system (DIAL) using an optical parametric oscillator (OPO) are presented. The OPO is injection-seeded with the output of a confocal filter
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
The contribution of the U.S. oil and natural gas supply chain to global methane emissions - an important factor in climate warming - was estimated using ground-based measurements and validated with region-wide aircraft measurements in areas accounting for