The measured C-14:C-12 isotopic ratio of atmospheric CO2 (and its associated derived Delta C-14 value) is an ideal tracer for determination of the fossil fuel derived CO2 enhancement contributing to any atmospheric CO2 measurement (C-ff). Given enough such measurements, independent top-down estimation of U.S. fossil fuel CO2 emissions should be possible. However, the number of Delta C-14 measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Delta C-14 is therefore measured in just a small fraction of samples obtained by flask air sampling networks around the world. Here we develop a projection pursuit regression (PPR) model to predict C-ff as a function of multiple surrogate gases acquired within the NOAA/Earth System Research Laboratory (ESRL) Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF6, and halocarbon and hydrocarbon acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 to 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi-square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Delta C-14 measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of uncertainties and potentially increase the number of C-ff estimates by approximately a factor of 3. Provided that these estimates are of comparable quality to Delta C-14-based estimates, we expect an improved determination of fossil fuel CO2 emissions.
LaFranchi, B. W.; McFarlane, K. J.; Miller, J. B.; Lehman, S. J.; Phillips, C. L.; Andrews, A. E.; Tans, P. P.; Chen, H.; Liu, Z.; Turnbull, J. C.; Xu, X.; Guilderson, T. P.;
Published Date:
2016
Source:
Journal of Geophysical Research-Biogeosciences, 121(8), 2275-2295.
Description:
Radiocarbon in CO2 ((CO2)-C-14) measurements can aid in discriminating between fast (< 1 year) and slower (> 5-10 years) cycling of C between the atmosphere and the terrestrial biosphere due to the 14C disequilibrium between atmospheric and terrestri...
Miller, S. M.; Miller, C. E.; Commane, R.; Chang, R. Y. W.; Dinardo, S. J.; Henderson, J. M.; Karion, A.; Lindaas, J.; Melton, J. R.; Miller, J. B.; Sweeney, C.; Wofsy, S. C.; Michalak, A. M.;
Published Date:
2016
Source:
Global Biogeochemical Cycles, 30(10), 1441-1453.
Description:
Methane (CH4) fluxes from Alaska and other arctic regions may be sensitive to thawing permafrost and future climate change, but estimates of both current and future fluxes from the region are uncertain. This study estimates CH4 fluxes across Alaska f...
Song, H.; Marshall, J.; Munro, D. R.; Dutkiewicz, S.; Sweeney, C.; McGillicuddy, D. J.; Hausmann, U.;
Published Date:
2016
Source:
Journal of Geophysical Research-Oceans, 121(9), 6635-6649.
Description:
We investigate the role of mesoscale eddies in modulating air-sea CO2 flux and associated biogeochemical fields in Drake Passage using in situ observations and an eddy-resolving numerical model. Both observations and model show a negative correlation...
Carbonyl sulfide (COS) has been suggested as a useful tracer for gross primary production as it is taken up by plants in a similar way as CO2. To explore and verify the application of this novel tracer, it is highly desired to develop the ability to ...
The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) aboard the Envisat satellite provided measurements from August 2002 until April 2012. SCIAMACHY measured the scattered or direct sunlight using different observatio...
McDuffie, E. E.; Edwards, P. M.; Gilman, J. B.; Lerner, B. M.; Dube, W. P.; Trainer, M.; Wolfe, D. E.; Angevine, W. M.; deGouw, J.; Williams, E. J.; Tevlin, A. G.; Murphy, J. G.; Fischer, E. V.; McKeen, S.; Ryerson, T. B.; Peischl, J.; Holloway, J. S.; Aikin, K.; Langford, A. O.; Senff, C. J.; Alvarez, R. J.; Hall, S. R.; Ullmann, K.; Lantz, K. O.; Brown, S. S.;
Published Date:
2016
Source:
Journal of Geophysical Research-Atmospheres, 121(14), 8712-8729.
Description:
Tropospheric O-3 has been decreasing across much of the eastern U.S. but has remained steady or even increased in some western regions. Recent increases in VOC and NOx emissions associated with the production of oil and natural gas (O&NG) may contrib...
Van Dam, B.; Helmig, D.; Doskey, P. V.; Oltmans, S. J.;
Published Date:
2016
Source:
Journal of Geophysical Research-Atmospheres, 121(13), 8055-8066.
Description:
Atmospheric turbulence quantities, boundary layer ozone (O-3) levels, and O-3 deposition to the tundra surface were investigated at Toolik Lake, AK, during the 2011 summer season. Beginning immediately after snowmelt, a diurnal cycle of O-3 in the at...
Butler, J. H.; Yvon-Lewis, S. A.; Lobert, J. M.; King, D. B.; Montzka, S. A.; Bullister, J. L.; Koropalov, V.; Elkins, J. W.; Hall, B. D.; Hu, L.; Liu, Y. N.;
Published Date:
2016
Source:
Atmospheric Chemistry and Physics, 16(17), 10899-10910.
Description:
Extensive undersaturations of carbon tetrachloride (CCl4) in Pacific, Atlantic, and Southern Ocean surface waters indicate that atmospheric CCl4 is consumed in large amounts by the ocean. Observations made on 16 research cruises between 1987 and 2010...
Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MI-PAS/4.62 and MIPAS/5.02 to MIPAS/5.06 lev...
Balloon-borne frost point hygrometers (FPs) and the Aura Microwave Limb Sounder (MLS) provide high-quality vertical profile measurements of water vapor in the upper troposphere and lower stratosphere (UTLS). A previous comparison of stratospheric wat...
Wiggins, E. B.; Veraverbeke, S.; Henderson, J. M.; Karion, A.; Miller, J. B.; Lindaas, J.; Commane, R.; Sweeney, C.; Luus, K. A.; Tosca, M. G.; Dinardo, S. J.; Wofsy, S.; Miller, C. E.; Randerson, J. T.;
Published Date:
2016
Source:
Journal of Geophysical Research-Biogeosciences, 121(11), 2793-2810.
Description:
Relationships between boreal wildfire emissions and day-to-day variations in meteorological variables are complex and have important implications for the sensitivity of high-latitude ecosystems to climate change. We examined the influence of environm...
Atmospheric Chemistry and Physics, 16(9), 5665-5683.
Description:
National annual total CO2 emissions from combustion of fossil fuels are likely known to within 5-10aEuro-% for most developed countries. However, uncertainties are inevitably larger (by unknown amounts) for emission estimates at regional and monthly ...
Karion, A.; Sweeney, C.; Miller, J. B.; Andrews, A. E.; Commane, R.; Dinardo, S.; Henderson, J. M.; Lindaas, J.; Lin, J. C.; Luus, K. A.; Newberger, T.; Tans, P.; Wofsy, S. C.; Wolter, S.; Miller, C. E.;
Published Date:
2016
Source:
Atmospheric Chemistry and Physics, 16(8), 5383-5398.
Description:
Northern high-latitude carbon sources and sinks, including those resulting from degrading permafrost, are thought to be sensitive to the rapidly warming climate. Because the near-surface atmosphere integrates surface fluxes over large ( aEuro-500-100...
Alden, C. B.; Miller, J. B.; Gatti, L. V.; Gloor, M. M.; Guan, K.; Michalak, A. M.; van der Laan-Luijkx, I. T.; Touma, D.; Andrews, A.; Basso, L. S.; Correia, C. S. C.; Domingues, L. G.; Joiner, J.; Krol, M. C.; Lyapustin, A. I.; Peters, W.; Shiga, Y. P.; Thoning, K.; van der Velde, I. R.; van Leeuwen, T. T.; Yadav, V.; Diffenbaugh, N. S.;
Published Date:
2016
Source:
Global Change Biology, 22(10), 3427-3443.
Description:
Understanding tropical rainforest carbon exchange and its response to heat and drought is critical for quantifying the effects of climate change on tropical ecosystems, including global climate-carbon feedbacks. Of particular importance for the globa...
Frankenberg, C.; Thorpe, A. K.; Thompson, D. R.; Hulley, G.; Kort, E. A.; Vance, N.; Borchardt, J.; Krings, T.; Gerilowski, K.; Sweeney, C.; Conley, S.; Bue, B. D.; Aubrey, A. D.; Hook, S.; Green, R. O.;
Published Date:
2016
Source:
Proceedings of the National Academy of Sciences of the United States of America, 113(35), 9734-9739.
Description:
Methane (CH4) impacts climate as the second strongest anthropogenic greenhouse gas and air quality by influencing tropospheric ozone levels. Space-based observations have identified the Four Corners region in the Southwest United States as an area of...
Feingold, G.; McComiskey, A.; Yamaguchi, T.; Johnson, J. S.; Carslaw, K. S.; Schmidt, K. S.;
Published Date:
2016
Source:
Proceedings of the National Academy of Sciences of the United States of America, 113(21), 5812-5819.
Description:
The topic of cloud radiative forcing associated with the atmospheric aerosol has been the focus of intense scrutiny for decades. The enormity of the problem is reflected in the need to understand aspects such as aerosol composition, optical propertie...
Sweeney, C.; Dlugokencky, E.; Miller, C. E.; Wofsy, S.; Karion, A.; Dinardo, S.; Chang, R. Y. W.; Miller, J. B.; Bruhwiler, L.; Crotwell, A. M.; Newberger, T.; McKain, K.; Stone, R. S.; Wolter, S. E.; Lang, P. E.; Tans, P.;
Published Date:
2016
Source:
Geophysical Research Letters, 43(12), 6604-6611.
Description:
Continuous measurements of atmospheric methane (CH4) mole fractions measured by NOAA's Global Greenhouse Gas Reference Network in Barrow, AK (BRW), show strong enhancements above background values when winds come from the land sector from July to Dec...
Parazoo, N. C.; Commane, R.; Wofsy, S. C.; Koven, C. D.; Sweeney, C.; Lawrence, D. M.; Lindaas, J.; Chang, R. Y. W.; Miller, C. E.;
Published Date:
2016
Source:
Proceedings of the National Academy of Sciences of the United States of America, 113(28), 7733-7738.
Description:
With rapid changes in climate and the seasonal amplitude of carbon dioxide (CO2) in the Arctic, it is critical that we detect and quantify the underlying processes controlling the changing amplitude of CO2 to better predict carbon cycle feedbacks in ...
Miller, S. M.; Commane, R.; Melton, J. R.; Andrews, A. E.; Benmergui, J.; Dlugokencky, E. J.; Janssens-Maenhout, G.; Michalak, A. M.; Sweeney, C.; Worthy, D. E. J.;
Published Date:
2016
Source:
Biogeosciences, 13(4), 1329-1339.
Description:
Existing estimates of methane (CH4) fluxes from North American wetlands vary widely in both magnitude and distribution. In light of these differences, this study uses atmospheric CH4 observations from the US and Canada to analyze seven different bott...