Methane Estimates in the Northeastern US using Continuous Measurements from a Regional Tower Network

Author(s):  
Kimberly Mueller ◽  
Subhomoy Ghosh ◽  
Anna Karion ◽  
Sharon Gourdji ◽  
Israel Lopez-Coto ◽  
...  

<p>In the past decade, there has been a scientific focus on improving the accuracy and precision of methane (CH4) emission estimates in the United States, with much effort targeting oil and natural gas producing basins. Yet, regional CH4 emissions and their attribution to specific sources continue to have significant associated uncertainties. Recent urban work using aircraft observations have suggested that CH4 emissions are not well characterized in major cities along the U.S. East Coast; discrepancies have been attributed to an under-estimation of fugitive emissions from the distribution of natural gas. However, much of regional and urban research has involved the use of aircraft campaigns that can only provide a spatio-temporal snapshot of the CH4 emission landscape. As such, the annual representation and the seasonal variability of emissions remain largely unknown. To further investigate CH4 emissions, we present preliminary CH4 emissions estimates in the Northeastern US as part of NIST’s Northeast Corridor (NEC) testbed project using a regional inversion framework. This area encompasses over 20% of the US and contains many of the dominant CH4 emissions sources important at both regional and local scales.  The atmospheric inversion can estimate sub-monthly 0.1-degree emissions using observations from a regional network of up to 37 in-situ towers; some towers are in non-urban areas while others are in cities or suburban areas. The inversion uses different emission products to help provide a prior constraint within the inversion including anthropogenic emissions from both the EDGAR v42 for the year 2008 and the US EPA for the year 2012, and natural wetland CH4 emissions from the WetCHARTs ensemble mean for the year 2010. Results include the comparison of synthetic model simulated CH4 concentrations (i.e., convolutions of the emission products with WRF-STILT footprints + background) to mole-fractions measured at the regional in-situ sites. The comparison provides an indication as to how well our prior understanding of emissions and incoming air flow matches the atmospheric signatures due to the underlying CH4 sources.  We also present a preliminary set of CH4 fluxes for a selected number of urban centers and discuss challenges estimating highly-resolved methane emissions using high-frequency in-situ observations for a regional domain (e.g. few constraints, skewness in underlying fluxes, representing incoming background, etc.). Overall, this work provides the basis for a year-long inversion that will yields regional CH4 emissions over the Northeast US with a focus on Eastern urban areas.</p>

Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
C. S. Foster ◽  
E. T. Crosman ◽  
J. D. Horel ◽  
S. Lyman ◽  
B. Fasoli ◽  
...  

This study presents a meteorologically-based methodology for quantifying basin-scale methane (CH4) emissions in Utah’s Uintah Basin, which is home to over 9,000 active and producing oil and natural gas wells. Previous studies in oil and gas producing regions have often relied on intensive aircraft campaigns to estimate methane emissions. However, the high cost of airborne campaigns prevents their frequent undertaking, thus providing only daytime snapshots of emissions rather than more temporally-representative estimates over multiple days. Providing estimates of CH4 emissions from oil and natural gas production regions across the United States is important to inform leakage rates and emission mitigation efforts in order to curb the potential impacts of these emissions on global climate change and local air quality assessments. Here we introduce the Basin-constrained Emissions Estimate (BEE) method, which utilizes the confining topography of a basin and known depth of a pollution layer during multi-day wintertime cold-air pool episodes to relate point observations of CH4 to basin-scale CH4 emission rates. This study utilizes ground-based CH4 observations from three fixed sites to calculate daily increases in CH4, a laser ceilometer to estimate pollution layer depth, and a Lagrangian transport model to assess the spatial representativity of surface observations. BEE was applied to two cold-air pool episodes during the winter of 2015–2016 and yielded CH4 emission estimates between 44.60 +/– 9.66 × 103 and 61.82 +/– 19.76 × 103 kg CH4 hr–1, which are similar to the estimates proposed by previous studies performed in the Uintah Basin. The techniques used in this study could potentially be utilized in other deep basins worldwide.


2021 ◽  
Vol 13 (4) ◽  
pp. 1618
Author(s):  
Anneliese Dyer ◽  
Amelia Christine Miller ◽  
Brianna Chandra ◽  
Juan Galindo Maza ◽  
Carley Tran ◽  
...  

With traditional natural gas being one of the top options for heating in the United States and the present threat of climate change, there is a demand for an alternative clean fuel source. A Renewable Natural Gas Implementation Decision-Making Conceptual Model was created to provide a framework for considering the feasibility of renewable natural gas (RNG) projects and applied to New Jersey, specifically investigating landfills and wastewater treatment plants (WWTPs). Data from the US EPA’s Landfill Methane Outreach Program and New Jersey’s Department of Environmental Protection Sewage Sludge databases were used to identify seven landfills and 22 WWTPs as possible locations for RNG projects. Landfills were found to have a higher potential for producing RNG, on average potentially producing enough RNG to heat 12,792 homes per year versus 1227 for the average WWTP. Additionally, landfills, while having higher capital expenses, have lower projected payback periods, averaging 5.19 years compared to WWTP’s 11.78 years. WWTPs, however, generally are located closer to existing natural gas pipelines than landfills and when they produce more than 362 million standard cubic feet per year (MMSCFY) of biogas are financially feasible. RNG projects at Monmouth County Reclamation Center, Ocean County Landfill, and Passaic Valley Sewerage Commission WWTP show the greatest potential. Greenhouse gas emission reductions from RNG projects at these facilities utilizing all available biogas would be 1.628 million metric tons CO2 equivalents per year, synonymous to removing over 351,000 passenger vehicles from the road each year. In addition, expanding federal and state incentives to encompass RNG as a heating fuel is necessary to reduce financial barriers to RNG projects throughout the US. Overall, this paper supports the hypothesized conceptual model in examining the feasibility of RNG projects through examples from New Jersey and confirms the potential for RNG production utilizing existing waste streams.


2009 ◽  
Vol 9 (4) ◽  
pp. 1125-1141 ◽  
Author(s):  
J. Chen ◽  
J. Avise ◽  
B. Lamb ◽  
E. Salathé ◽  
C. Mass ◽  
...  

Abstract. A comprehensive numerical modeling framework was developed to estimate the effects of collective global changes upon ozone pollution in the US in 2050. The framework consists of the global climate and chemistry models, PCM (Parallel Climate Model) and MOZART-2 (Model for Ozone and Related Chemical Tracers v.2), coupled with regional meteorology and chemistry models, MM5 (Mesoscale Meteorological model) and CMAQ (Community Multi-scale Air Quality model). The modeling system was applied for two 10-year simulations: 1990–1999 as a present-day base case and 2045–2054 as a future case. For the current decade, the daily maximum 8-h moving average (DM8H) ozone mixing ratio distributions for spring, summer and fall showed good agreement with observations. The future case simulation followed the Intergovernmental Panel on Climate Change (IPCC) A2 scenario together with business-as-usual US emission projections and projected alterations in land use, land cover (LULC) due to urban expansion and changes in vegetation. For these projections, US anthropogenic NOx (NO+NO2) and VOC (volatile organic carbon) emissions increased by approximately 6% and 50%, respectively, while biogenic VOC emissions decreased, in spite of warmer temperatures, due to decreases in forested lands and expansion of croplands, grasslands and urban areas. A stochastic model for wildfire emissions was applied that projected 25% higher VOC emissions in the future. For the global and US emission projection used here, regional ozone pollution becomes worse in the 2045–2054 period for all months. Annually, the mean DM8H ozone was projected to increase by 9.6 ppbv (22%). The changes were higher in the spring and winter (25%) and smaller in the summer (17%). The area affected by elevated ozone within the US continent was projected to increase; areas with levels exceeding the 75 ppbv ozone standard at least once a year increased by 38%. In addition, the length of the ozone season was projected to increase with more pollution episodes in the spring and fall. For selected urban areas, the system projected a higher number of pollution events per year and these events had more consecutive days when DM8H ozone exceed 75 ppbv.


Urban Studies ◽  
2020 ◽  
Author(s):  
A. Kristen Foster

Cities in America’s early republic developed on the edge of two worlds. The majority of these urban areas had been born in colonies that belonged to European powers, including England, France, Spain, and the Netherlands. In this colonial world, cities hugged the Atlantic coast and served the interests of Europe’s mercantile empires. After the American Revolution, however, urban areas developed in line with the interests of the United States, expanding geographically, economically, politically, socially, and culturally. The cities of the early republic were central to the first debates about the fate of the fast-changing republic. On 23 September 1800, on the verge of wresting power from the first generation of Federalist politicians, the Republican Thomas Jefferson wrote to his old friend Dr. Benjamin Rush that he viewed “great cities as pestilential to the morals, the health and the liberties of man.” Jefferson, ever the champion of the independent farmer, argued that cities “nourish some of the elegant arts; but the useful ones can thrive elsewhere, and less perfection in the others with more health virtue & freedom would be my choice.” As president, Jefferson tried to expand his agrarian empire of liberty by purchasing the Louisiana Territory from France in 1803, but he could not stay the growth of cities. After the War of 1812, Americans moved westward in unprecedented numbers and used trading hubs and cities to center and connect their own economic growth. The story of cities in America’s early republic thus unfolds in two parts: the first follows the American Revolution and is anchored by its participants’ belief that republican theories and individual virtue would tie the populace together; the second part is paced by the energy unleashed in the 19th century as liberalism and the boundless possibilities of market capitalism sent Americans across a continent, building, dispossessing, and re-envisioning what it meant to be American. This population remained predominantly rural over the course of the early republic, but the nation’s urban centers often anchored and drove change. While early histories focused more intently on urban development and city planning, recent studies have expanded into an eclectic mix of social history topics, including class development, political culture, immigration, religious development, urban slavery, gender relations, and sexuality. In the end, however, studies dedicated to specific cities have remained at the center of historical inquiry about urban development and life in America’s early republic. One yet unexplored avenue for study that might shift conceptualizations of urban spaces would be to examine dense indigenous population centers in the early republic. Looking at Tippecanoe or the southwestern pueblos, for instance, might alter the heavy association of the word urban with European cultures alone and open new conceptualizations of indigenous America and Euro-America.


2019 ◽  
Vol 11 (14) ◽  
pp. 3858
Author(s):  
Yixuan Guo ◽  
Yidong Wang ◽  
Shufeng Chen ◽  
Shunan Zheng ◽  
Changcheng Guo ◽  
...  

Livestock and poultry farming sectors are among the largest anthropogenic methane (CH4) emission sources, mainly from enteric fermentation and manure management. Previous inventories of CH4 emission were generally based on constant emission factor (EF) per head, which had some weaknesses mainly due to the succession of breeding and feeding systems over decades. Here, more reliable long-term changes of CH4 emissions from livestock and poultry farming in Beijing are estimated using the dynamic EFs based on the Intergovernmental Panel on Climate Change (IPCC) Tier 2 method, and high-resolution spatial patterns of CH4 emissions are also estimated with intensive field survey. The results showed that the estimated CH4 emissions derived by dynamic EFs were approximately 13–19% lower than those based on the constant EF before 2010. After 2011, however, the dynamic EFs-derived CH4 emissions were a little higher (3%) than the constant EF method. Temporal CH4 emissions in Beijing had experienced four developing stages (1978–1988: stable; 1989–1998: slow growth; 1999–2004: rapid growth and reached hot moments; 2005–2014: decline) during 1978–2014. Over the first two decades, the contributions of pigs (45%) and cattle (46%) to annual CH4 emission were similar; subsequently, the cattle emitted more CH4 compared to the pigs. At a spatial scale, Shunyi, Daxing, and Tongzhou districts with more cattle and pigs are the hotspots of CH4 emission. In conclusion, the dynamic EFs method obviously improved the spatio-temporal estimates of CH4 emissions compared to the constant EF approach, and the improvements depended on the period and aquaculture structure. Therefore, the dynamic EFs method should be recommended for estimating CH4 emissions from livestock and poultry farming in the future.


2008 ◽  
Vol 5 (3) ◽  
pp. 184 ◽  
Author(s):  
E.Keith Bigg

Environmental context. Decreasing trends in rainfall over large areas of eastern and south-western Australia have resulted in critical water shortages. Three reasons have been suggested. The first is a change in atmospheric circulation as a result of greenhouse gas forcing. The second is that changes in land usage have affected surface moisture, albedo and cloud formation. Another, the subject of this study, is that airborne particulates associated with urban areas have acted to decrease the mean efficiency of rainfall, the growth of urban areas thereby causing an underlying decreasing trend in rainfall. Abstract. Trends in rainfall in the 35 years 1970–2004 have been calculated for all 350 available rainfall stations having sufficiently complete records that lie between latitudes 26–30°S and longitudes 150–154°E. The area contains two major urban centers, Brisbane with a rapidly growing population approaching two million and the Gold Coast with a population of ~500 000. Statistically highly significant negative trends were found in the vicinity of Brisbane, with decreases exceeding 40% of mean daily rainfall in the 35 years, and in a smaller area inland from the Gold Coast. The spatial distribution of trends was consistent with aerosol production from human activities, the prevailing winds and losses due to the topography. A previously published observation using satellite data showed that cloud properties were affected by urban aerosols in a way that is likely to reduce precipitation. The results of this study reinforce the suggestion made then that monitoring of aerosol concentrations and properties and in-situ observations of rain formation processes in the area should be undertaken as a matter of urgency.


2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 313-313 ◽  
Author(s):  
Fatima Hamid ◽  
Hammad Shafqat ◽  
Kalyan Mantripragada ◽  
Thomas Guerrero ◽  
Ponnandai Somasundar ◽  
...  

313 Background: Management of gallbladder cancer (GBCA) is largely based on small observational studies, and it is unknown how various treatment modalities are applied in the community. The objective of this study was to describe the utilization of surgery (S), chemotherapy (Ct) and chemoradiation (CRT), and associated overall survival (OS) in the US. Methods: We selected adult patients (pts) with GBCA diagnosed in 2004-2012 from the NCDB—a population-wide registry capturing > 70% of incident cancers in the US. We identified pts undergoing S, Ct and concurrent CRT. We assumed adjuvant (Adj) therapy if it was started within 4 months (mo) of S. Stage was grouped as: T1-T3N0, node-positive (N+), T4 (N0 or N+) or metastatic (M1). OS was calculated from diagnosis, with 95% confidence intervals (CI). Results: We identified 22,574 GBCA pts. Median age was 71 years. There were 69% women, 71% white non-Hispanic, 10% white Hispanic, 14% black and 4% Asian pts. Distribution of stage groups was: in situ, 4%; T1N0, 8%; T2N0, 16%; T3N0, 13%; N+, 14%; T4, 3%; M1, 38%; unknown, 4%. Most non-metastatic pts underwent S, but only a minority received Adj Ct or CRT (Table). Among M1 and T4 pts, 44% received Ct, but 29% got no cancer-directed therapy. Median OS for M+ or T4 pts was 4 and 7 mo, respectively. It was 8 and 11 mo, respectively, if Ct was given. Conclusions: These OS estimates provide realistic prognosis for GBCA pts treated with various modalities in the US. Adj therapy is rarely delivered in locally advanced (T3N0 or T1-3N+) GBCA. Survival in T4 and M1 GBCA remains poor even with palliative Ct. Novel therapeutic approaches for GBCA of all stages are needed. [Table: see text]


2012 ◽  
Vol 616-618 ◽  
pp. 767-769
Author(s):  
Jian Guo Wang ◽  
Hai Jie Zhang ◽  
Cui Cui Liu ◽  
Li Xia Lou

China is facing a severe situation of energy resources. High oil dependency is seriously threatening our economy’s fast and stable development. The US has successfully achieved the commercial development of shale gas, which has decreased its oil dependency, and also contributed to its natural gas geology and petroleum engineering technology development. Both Chinese and U.S. geological experts predict that China has similar quantities of shale gas reserves as founded in the United States. This paper aims to clarify that producing shale gas resources has economic significance of energy security and environment protection, and scientific significance of promoting the further development of natural gas geology and petroleum engineering subjects.


2021 ◽  
Author(s):  
Jessica T Davis ◽  
Matteo Chinazzi ◽  
Nicola Perra ◽  
Kunpeng Mu ◽  
Ana Pastore y Piontti ◽  
...  

Given the narrowness of the initial testing criteria, the SARS-CoV-2 virus spread through cryptic transmission in January and February, setting the stage for the epidemic wave experienced in March and April, 2020. We use a global metapopulation epidemic model to provide a mechanistic understanding of the global dynamic underlying the establishment of the COVID-19 pandemic in Europe and the United States (US). The model is calibrated on international case introductions at the early stage of the pandemic. We find that widespread community transmission of SARS-CoV-2 was likely in several areas of Europe and the US by January 2020, and estimate that by early March, only 1-3 in 100 SARS-CoV-2 infections were detected by surveillance systems. Modeling results indicate international travel as the key driver of the introduction of SARS-CoV-2 with possible importation and transmission events as early as December, 2019. We characterize the resulting heterogeneous spatio-temporal spread of SARS-CoV-2 and the burden of the first COVID-19 wave (February-July 2020). We estimate infection attack rates ranging from 0.78%-15.2% in the US and 0.19%-13.2% in Europe. The spatial modeling of SARS-CoV-2 introductions and spreading provides insights into the design of innovative, model-driven surveillance systems and preparedness plans that have a broader initial capacity and indication for testing.


2021 ◽  
Author(s):  
Xiao Lu ◽  
Daniel J. Jacob ◽  
Haolin Wang ◽  
Joannes D. Maasakkers ◽  
Yuzhong Zhang ◽  
...  

Abstract. We quantify methane emissions and their 2010–2017 trends by sector in the contiguous United States (CONUS), Canada, and Mexico by inverse analysis of in situ (GLOBALVIEWplus CH4 ObsPack) and satellite (GOSAT) atmospheric methane observations. The inversion uses as prior estimate the national anthropogenic emission inventories for the three countries reported by the US Environmental Protection Agency (EPA), Environment and Climate Change Canada (ECCC), and the Instituto Nacional de Ecologia y Cambio Climatico (INECC) in Mexico to the United Nations Framework Convention on Climate Change (UNFCCC), and thus serves as an evaluation of these inventories in terms of their magnitudes and trends. Emissions are optimized with a Gaussian mixture model (GMM) at 0.5° × 0.625° resolution and for individual years. Optimization is done analytically using log-normal error forms. This yields closed-form statistics of error estimates and information content on the posterior (optimized) estimates, allows better representation of the high tail of the emission distribution, and enables construction of a large ensemble of inverse solutions using different observations and assumptions. We find that GOSAT and in situ observations are largely consistent and complementary in the optimization of methane emissions for North America. Mean 2010–2017 anthropogenic emissions from our base GOSAT + in situ inversion, with ranges from the inversion ensemble, are 36.9 (32.5–37.8) Tg a−1 for CONUS, 5.3 (3.6–5.7) Tg a−1 for Canada, and 6.0 (4.7–6.1) Tg a−1 for Mexico. These are higher than the most recent reported national inventories of 26.0 Tg a−1 for the US (EPA), 4.0 Tg a−1 for Canada (ECCC), and 5.0 Tg a−1 for Mexico (INECC). The correction in all three countries is largely driven by a factor of 2 underestimate in emissions from the oil sector with major contributions from the south-central US, western Canada, and southeast Mexico. Total CONUS anthropogenic emissions in our inversion peak in 2014, in contrast to the EPA report of a steady decreasing trend over 2010–2017. This reflects combined effects of increases in emissions from the oil and landfill sectors, decrease from the gas, and flat emissions from the livestock and coal sectors. We find decreasing trends in Canadian and Mexican anthropogenic methane emissions over the 2010–2017 period, mainly driven by oil and gas emissions. Our best estimates of mean 2010–2017 wetland emissions are 8.4 (6.4–10.6) Tg a−1 for CONUS, 9.9 (7.8–12.0) Tg a−1 for Canada, and 0.6 (0.4–0.6) Tg a−1 for Mexico. Wetland emissions in CONUS show an increasing trend of 2.6 (1.7–3.8) % a−1 over 2010–2017 correlated with precipitation.


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