Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions

Oltmans, S. J.; Cheadle, Lucy; Helmig, Detlev; Angot, Hélène; Pétron, Gabrielle; Montzka, S. A.; Miller, Benjamin R.; Hall, B. D.; Schnell, R. C.; Kofler, J.; Wolter, S.; Crotwell, Molly; Siso, Carolina; Tans, Pieter P.; Andrews, A. E.

doi:10.1525/elementa.2020.00136

Cited by 5 publications

(15 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A linear regression through this data for 2003-2012 yields a statistically insignificant trend of 1.25 ± 1.8 ppb. Oltmans et al (2021) found no significant trend in BAO CH 4 near Erie in the southwest portion of the Wattenberg from 2008 through mid-2016. We also found no significant trend for the DDJB AIRS enhancement from 2008 through 2016.…”

Section: Annual Statistics and Trends In Ch 4 And Ethanementioning

confidence: 71%

“…Oltmans et al. (2021) found no significant trend in BAO CH 4 near Erie in the southwest portion of the Wattenberg from 2008 through mid‐2016. We also found no significant trend for the DDJB AIRS enhancement from 2008 through 2016.…”

Section: Resultsmentioning

confidence: 98%

“…Average differences drop below −40 ppb in February and March and are above 30 ppb in July and August. BAO differences for 2008–2016 are positive (see Oltmans et al., 2021, Figure 8), and BAO median mole fractions for CH 4 for daytime samples exceeded the NWR median by 65 ppb when winds were from the O&G field (Oltmans et al., 2021). Keep in mind that BAO is within the O&G field and the AIRS data represent a larger area, and this could affect the relative magnitudes of the enhancements.…”

Section: Data Sources and Methodsmentioning

confidence: 99%

“…We computed June-August averages from these monthly means. Oltmans et al (2021) also used NWR data for western continental background estimates in their assessment of CH 4 trends at the BAO tower near Erie, Colorado. They point out that upslope conditions at NWR during July led to somewhat elevated concentrations that likely overestimated background.…”

Section: Data Sources and Study Areamentioning

confidence: 99%

See 3 more Smart Citations

Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data

Reddy

Taylor

2022

Earth and Space Science

View full text Add to dashboard Cite

The oil and gas (O&G) sector is estimated to be the largest contributor to anthropogenic methane (CH4) emissions in Colorado. Since 2004, the State of Colorado has implemented multiple regulations to significantly reduce emissions from the O&G sector. The Denver‐Julesburg Basin (DJ Basin) is a significant O&G producing region in northern Colorado, and O&G production here has steadily increased over the last decade. To assess CH4 trends in Northern Colorado, we selected CH4 retrievals from the NASA Atmospheric Infrared Sounder (AIRS) instrument for 2003–2020. The study grid cell includes Denver, Boulder, and much of the dense O&G production in the DJ Basin. We computed mean June‐August ascending node AIRS 700 hPa CH4 for each year and subtracted mean June–August CH4 sampled at NOAA's Niwot Ridge (NWR) station, a high‐altitude background site. Differences represent estimated enhancement over background. Linear regression shows an annual change of −2.84 ppb ± 0.8 ppb from 2012 to 2020 (R2 0.90) and an estimated reduction of 56% for 2012–2020, despite substantial increases in O&G production. Local CH4 enhancement is strongly correlated with surface measurements of ethane at Platteville which is in the center of the O&G fields (correlation coefficient 0.96), and this is evidence that reductions in O&G emissions are driving reductions in CH4. We conclude that AIRS CH4 can be used to measure the efficacy of emissions control programs in this region and that regulatory requirements are having an effect.

show abstract

Section: Annual Statistics and Trends In Ch 4 And Ethanementioning

confidence: 71%

Section: Resultsmentioning

confidence: 98%

Section: Data Sources and Methodsmentioning

confidence: 99%

Section: Data Sources and Study Areamentioning

confidence: 99%

See 2 more Smart Citations

Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data

Reddy

Taylor

2022

Earth and Space Science

View full text Add to dashboard Cite

show abstract

“…As we consider recent changes in emissions, however, changes in emissions per unit of production must also be considered. A recent study in the Northeastern Colorado Denver-Julesburg Basin showed little change in atmospheric hydrocarbons, including propane, in 2008-2016 despite a 7fold increase in oil production and a nearly tripling of natural gas production, suggesting a significant decrease in leak and/or venting rate per unit of production (Oltmans et al, 2021). While we cannot reliably estimate how propane emissions might have changed during this recent period, these two influences, combined together, could explain the observed temporary pause in the growth of atmospheric propane.…”

Section: Oandng Activitiesmentioning

confidence: 99%

Temporary pause in the growth of atmospheric ethane and propane in 2015–2018

et al. 2021

Self Cite

View full text Add to dashboard Cite

Abstract. Atmospheric non-methane hydrocarbons (NMHCs) play an important role in the formation of secondary organic aerosols and ozone. After a multidecadal global decline in atmospheric mole fractions of ethane and propane – the most abundant atmospheric NMHCs – previous work has shown a reversal of this trend with increasing atmospheric abundances from 2009 to 2015 in the Northern Hemisphere. These concentration increases were attributed to the unprecedented growth in oil and natural gas (O&NG) production in North America. Here, we supplement this trend analysis building on the long-term (2008–2010; 2012–2020) high-resolution (∼3 h) record of ambient air C2–C7 NMHCs from in situ measurements at the Greenland Environmental Observatory at Summit station (GEOSummit, 72.58 ∘ N, 38.48 ∘ W; 3210 m above sea level). We confirm previous findings that the ethane mole fraction significantly increased by +69.0 [+47.4, +73.2; 95 % confidence interval] ppt yr−1 from January 2010 to December 2014. Subsequent measurements, however, reveal a significant decrease by −58.4 [−64.1, −48.9] ppt yr−1 from January 2015 to December 2018. A similar reversal is found for propane. The upturn observed after 2019 suggests, however, that the pause in the growth of atmospheric ethane and propane might only have been temporary. Discrete samples collected at other northern hemispheric baseline sites under the umbrella of the NOAA cooperative global air sampling network show a similar decrease in 2015–2018 and suggest a hemispheric pattern. Here, we further discuss the potential contribution of biomass burning and O&NG emissions (the main sources of ethane and propane) and conclude that O&NG activities likely played a role in these recent changes. This study highlights the crucial need for better constrained emission inventories.

show abstract

Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data

Reddy¹,

Taylor

2022

Preprint

View full text Add to dashboard Cite

The oil and gas (O&G) sector is estimated to be the largest contributor to anthropogenic methane (CH4) emissions in Colorado. Since 2004, the State of Colorado has implemented multiple regulations to significantly reduce emissions from the O&G sector.The Denver-Julesburg Basin (DJ Basin) is a significant O&G producing region in northern Colorado, and O&G production here has steadily increased over the last decade. To assess CH4 trends in Northern Colorado, we selected CH4 retrievals from the NASA Atmospheric Infrared Sounder (AIRS) instrument for 2003-2020. The study grid cell includes Denver, Boulder, and much of the dense O&G production in the DJ Basin. We computed mean June-August ascending node AIRS 700 hPa CH4 for each year and subtracted mean June-August CH4 sampled at NOAA's Niwot Ridge (NWR) station, a high-altitude background site. Differences represent estimated enhancement over background. Linear regression shows an annual change of -2.84 ppb +/-0.8 ppb from 2012-2020 (R-squared 0.90) and an estimated reduction of 56% for 2012-2020, despite substantial increases in O&G production. Local CH4 enhancement is strongly correlated with surface measurements of ethane at Platteville which is in the center of the O&G fields (correlation coefficient 0.96), and this is evidence that reductions in O&G emissions are driving reductions in CH4. We conclude that AIRS CH4 can be used to measure the efficacy of emissions control programs in this region and that regulatory requirements are having an effect.

show abstract

Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions

Cited by 5 publications

References 29 publications

Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data

Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data

Temporary pause in the growth of atmospheric ethane and propane in 2015–2018

Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data

Contact Info

Product

Resources

About