scholarly journals Meteorological Drivers of Permian Basin Methane Anomalies Derived from TROPOMI

2021 ◽  
Vol 13 (5) ◽  
pp. 896
Author(s):  
Erik Crosman
Keyword(s):  
The United States ◽  
Spatiotemporal Variations ◽  
Permian Basin ◽  
Wind Speeds ◽  
The North ◽  
Low Wind Speed ◽  
Westerly Winds ◽  
Meteorological Observations ◽  
Low Wind Speeds

The launch of the TROPOspheric Monitoring Instrument (TROPOMI) on the Sentinel-5 Precursor (S-5P) satellite has revolutionized pollution observations from space. The purpose of this study was to link spatiotemporal variations in TROPOMI methane (CH4) columns to meteorological flow patterns over the Permian Basin, the largest oil and second-largest natural gas producing region in the United States. Over a two-year period (1 December 2018–1 December 2020), the largest average CH4 enhancements were observed near and to the north and west of the primary emission regions. Four case study periods—two with moderate westerly winds associated with passing weather disturbances (8–15 March 2019 and 1 April–10 May 2019) and two other periods dominated by high pressure and low wind speeds (16–23 March 2019 and 24 September–9 October 2020)—were analyzed to better understand meteorological drivers of the variability in CH4. Meteorological observations and analyses combined with TROPOMI observations suggest that weakened transport out of the Basin during low wind speed periods contributes to CH4 enhancements throughout the Basin, while valley and slope flows may explain the observed western expansion of the Permian Basin CH4 anomaly.

scholarly journals Comparison of Weibull Estimation Methods for Diverse Winds

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ferhat Bingöl
Keyword(s):  
Wind Farm ◽  
Study Data ◽  
Distribution Functions ◽  
Likelihood Method ◽  
Estimation Methods ◽  
Weibull Function ◽  
Wind Speeds ◽  
Low Wind Speed ◽  
Low Wind Speeds ◽  
Wind Distribution

Wind farm siting relies on in situ measurements and statistical analysis of the wind distribution. The current statistical methods include distribution functions. The one that is known to provide the best fit to the nature of the wind is the Weibull distribution function. It is relatively straightforward to parameterize wind resources with the Weibull function if the distribution fits what the function represents but the estimation process gets complicated if the distribution of the wind is diverse in terms of speed and direction. In this study, data from a 101 m meteorological mast were used to test several estimation methods. The available data display seasonal variations, with low wind speeds in different seasons and effects of a moderately complex surrounding. The results show that the maximum likelihood method is much more successful than industry standard WAsP method when the diverse winds with high percentile of low wind speed occur.

scholarly journals The relationship between some meteorological parameters and the tropospheric concentrations of ozone in the urban area of Belgrade

2005 ◽  
Vol 70 (12) ◽  
pp. 1487-1495 ◽  
Author(s):  
Dragan Markovic ◽  
Dragan Markovic
Keyword(s):  
Meteorological Parameters ◽  
Wind Speeds ◽  
Ozone Concentrations ◽  
The North ◽  
Measuring Site ◽  
Ozone Transport ◽  
Photochemical Ozone ◽  
Low Wind Speeds ◽  
The Relationship ◽  
Tropospheric Concentrations

During the period between June and December 2002, the concentrations of ozone in the air at 4 measuring sites in Belgrade were measured. The measuring periods varied from 10 days to several weeks. The maximal measured daily concentrations of ozone ranged from 19ppbv (23 December 2002) to 118ppbv (23 June 2002).Ozone concentrations higher than, or equal to 90ppbv were registered at three measuring sites. It was shown that at measuring sites characterized as urban, maximal O3 concentrations equal to, or higher than 90ppbv occurred at high temperatures (higher than 30?C) and low wind speeds (mostly from the north). The measured ozone concentrations mostly showed characteristics usual for a daily photochemical ozone cycle, excluding the specificities influenced by the measuring site itself. Ozone transport was recorded at increased wind speeds, primarily from south-easterly directions. On the basis of he correlations between ozone concentration and the corresponding meteorological parameters, a validation of the measuring sites was performed from the aspect of their representativeness for the measurements.

scholarly journals Strategies for Enhancing the Low Wind Speed Performance of H-Darrieus Wind Turbine—Part 1

2019 ◽  
Vol 1 (1) ◽  
pp. 185-204 ◽  
Author(s):  
Palanisamy Mohan Kumar ◽  
Krishnamoorthi Sivalingam ◽  
Teik-Cheng Lim ◽  
Seeram Ramakrishna ◽  
He Wei
Keyword(s):  
Wind Speed ◽  
Poor Performance ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Wind Speeds ◽  
Low Wind Speed ◽  
Viable Solution ◽  
Speed Performance ◽  
Low Wind Speeds ◽  
Starting Characteristics

Small wind turbines are key devices for micro generation in particular, with a notable contribution to the global wind energy sector. Darrieus turbines, despite being highly efficient among various types of vertical axis turbines, received much less attention due to their starting characteristics and poor performance in low wind speeds. Radically different concepts are proposed as a potential solution to enhance the performance of Darrieus turbine in the weak wind flows, all along the course of Darrieus turbine development. This paper presents a comprehensive review of proposed concepts with the focus set on the low wind speed performance and critically assessing their applicability based on economics, reliability, complexity, and commercialization aspects. The study is first of its kind to consolidate and compare various approaches studied on the Darrieus turbine with the objective of increasing performance at low wind. Most of the evaluated solutions demonstrate better performance only in the limited tip speed ratio, though they improve the low wind speed performance. Several recommendations have been developed based on the evaluated concepts, and we concluded that further critical research is required for a viable solution in making the Darrieus turbine a low speed device.

scholarly journals Mechanism of Daytime Strong Winds on the Northern Slopes of Himalayas, near Mount Everest: Observation and Simulation

2018 ◽  
Vol 57 (2) ◽  
pp. 255-272 ◽  
Author(s):  
Fanglin Sun ◽  
Yaoming Ma ◽  
Zeyong Hu ◽  
Maoshan Li ◽  
Gianni Tartari ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Monsoon Season ◽  
Meteorological Data ◽  
Mount Everest ◽  
The North ◽  
China Academy ◽  
Westerly Winds ◽  
Meteorological Observations ◽  
Strong Winds ◽  
Academy Of Sciences

AbstractThe seasonal variability of strong afternoon winds in a northern Himalayan valley and their relationship with the synoptic circulation were examined using in situ meteorological data from March 2006 to February 2007 and numerical simulations. Meteorological observations were focused on the lower Rongbuk valley, on the north side of the Himalayas (4270 m MSL), where a wind profile radar was available. In the monsoon season (21 May–4 October), the strong afternoon wind was southeasterly, whereas it was southwesterly in the nonmonsoon season. Numerical simulations were performed using the Weather Research and Forecasting Model to investigate the mechanism causing these afternoon strong winds. The study found that during the nonmonsoon season the strong winds are produced by downward momentum transport from the westerly winds aloft, whereas those during the monsoon season are driven by the inflow into the Arun Valley east of Mount Everest. The air in the Arun Valley was found to be colder than that of the surroundings during the daytime, and there was a horizontal pressure gradient from the Arun Valley to Qomolangma Station (QOMS), China Academy of Sciences, at the 5200-m level. This explains the formation of the strong afternoon southeasterly wind over QOMS in the monsoon season. In the nonmonsoon season, the colder air from Arun Valley is confined below the ridge by westerly winds associated with the subtropical jet.

Using a new divergence method to quantify methane emissions with TROPOMI on Sentinel-5p

2021 ◽  
Author(s):  
Mengyao Liu ◽  
Ronald Van der A ◽  
Michiel Van Weele ◽  
Henk Eskes ◽  
Xiao Lu ◽  
...  
Keyword(s):  
Large Scale ◽  
A Priori ◽  
The United States ◽  
Global Scale ◽  
Methane Emissions ◽  
Atmospheric Methane ◽  
Permian Basin ◽  
Wind Speeds ◽  
Gas Fields ◽  
Oil Gas

<p>The high-resolution Tropospheric Monitoring Instrument (TROPOMI) satellite observations of atmospheric methane offer a powerful tool to identify emission hot spots and quantify regional emissions. The divergence of horizontal fluxes of NO<sub>2</sub> has already been proven to be an efficient way to resolve and quantify high sources on a global scale. Since the lifetime of CH<sub>4</sub> is in the order of 10 years, the sinks can be ignored at the synoptic time scale which makes the divergence method even more applicable to CH<sub>4 </sub>than to short-lived NO<sub>2</sub>. <br>Because plumes of newly emitted CH<sub>4 </sub>disperse within the Planetary Boundary Layer (PBL), we first convert the satellite observed total column average (XCH<sub>4</sub>) to a regional enhancement of methane in the PBL (∆XCH<sub>4_PBL</sub>) by using the CAMS global methane background reanalysis fields above the PBL. These model fields represent the transport- and chemically-modulated large-scale distribution of methane. Secondly, the divergence of ∆XCH<sub>4_PBL</sub> is derived by the use of the wind speeds halfway within the PBL. Based on the divergence, methane emissions are estimated on a 0.25°× 0.25° grid. We tested our new method for Texas in the United States and quantified methane emissions from the well-known oil-gas fields in the Permian Basin, as well as from – less well quantitatively established – oil-gas fields located in southern coastal areas. <br>Compared to traditional inverse methods, our method is not restricted by an a priori emission inventory and so far unidentified local sources (i.e. emissions from livestock in feed yards) may be found. Due to its computational efficiency, the method might be applied in the near future globally on the current spatial resolution.</p>

Earl Grey’s Public Diplomacy

2018 ◽  
Author(s):  
Stephen Bowman
Keyword(s):  
New York ◽  
Public Diplomacy ◽  
The United States ◽  
Benjamin Franklin ◽  
Fishing Rights ◽  
Cultural Assumptions ◽  
The North ◽  
The Us ◽  
The North Atlantic

This chapter focuses on the banquet held by the New York branch of the Pilgrims Society in March 1906 at the Waldorf-Astoria Hotel for Earl Grey, the Governor General of Canada. This dinner provides a case study of the ways in which the Society served as a network for British and American diplomats and provides one of the clearest examples of its public diplomacy activities. The banquet was held during a dispute between Britain, Canada, and the United States over fishing rights in the North Atlantic and the speeches given at the dinner by Earl Grey and Elihu Root, the US Secretary of State, were designed to mobilise public opinion in an effort to bring the dispute to an amicable end. Part of this public diplomacy effort was Earl Grey’s heavily-publicised gift to the US of a portrait of Benjamin Franklin that had been in his family’s possession since the American Revolution. The rhetoric surrounding this gift provides evidence about the cultural assumptions underpinning the Pilgrims’ public and cultural diplomacy.

Effect of Swell on Wind Stress for Light to Moderate Winds

2020 ◽  
Vol 77 (11) ◽  
pp. 3759-3768
Author(s):  
Charles L. Vincent ◽  
Hans C. Graber ◽  
Clarence O. Collins
Keyword(s):  
Wind Speed ◽  
Gulf Of Mexico ◽  
Inflection Point ◽  
Friction Velocity ◽  
Flow Transition ◽  
Wind Speeds ◽  
Impact Stress ◽  
Low Wind Speed ◽  
Wind Sea ◽  
Low Wind Speeds

AbstractBuoy observations from a 1999 Gulf of Mexico field program (GOM99) are used to investigate the relationships among friction velocity u*, wind speed U, and amount of swell present. A U–u*sea parameterization is developed for the case of pure wind sea (denoted by u*sea), which is linear in U over the range of available winds (2–16 m s−1). The curve shows no sign of an inflection point near 7–8 m s−1 as suggested in a 2012 paper by Andreas et al. on the basis of a transition from smooth to rough flow. When observations containing more than minimal swell energy are included, a different U–u* equation for U < 8 m s−1 is found, which would intersect the pure wind-sea curve about 7–8 m s−1. These two relationships yield a bilinear curve similar to Andreas et al. with an apparent inflection near 7–8 m s−1. The absence of the inflection in the GOM99 experiment pure wind-sea curve and the similarity of the GOM99 swell-dominated low wind speed to Andreas et al.’s low wind speed relationship suggest that the inflection may be due to the effect of swell and not a flow transition. Swell heights in the range of only 25–50 cm may be sufficient to impact stress at low wind speeds.

scholarly journals An Experimental Field Dataset with Buoyant, Neutral, and Dense Gas Atmospheric Releases and Model Comparisons in Low–Wind Speed (Diffusion) Conditions

2010 ◽  
Vol 49 (9) ◽  
pp. 1805-1817
Author(s):  
Veronica E. Wannberg ◽  
Gustavious Williams ◽  
Patrick Sawyer ◽  
Richard Venedam
Keyword(s):  
Wind Speed ◽  
Field Measurements ◽  
Release Rates ◽  
Wind Speeds ◽  
Low Wind Speed ◽  
Current State ◽  
Practice Models ◽  
Atmospheric Releases ◽  
Low Wind Speeds ◽  
Atmospheric Concentrations

Abstract A unique field dataset from a series of low–wind speed experiments, modeling efforts using three commonly used models to replicate these releases, and statistical analysis of how well these models were able to predict the plume concentrations is presented. The experiment was designed to generate a dataset to describe the behavior of gaseous plumes under low-wind conditions and the ability of current, commonly used models to predict these movements. The dataset documents the release and transport of three gases: ammonia (buoyant), ethylene (neutral), and propylene (dense) in low–wind speed (diffusion) conditions. Release rates ranged from 1 to 20 kg h−1. Ammonia and ethylene had five 5-min releases each to represent puff releases and five 20-min releases each to represent plume releases. Propylene had five 5-min puffs, six 20-min plumes, and a single 30-min plume. Thirty-two separate releases ranging from 6 to 47 min were conducted, of which only 30 releases generated useful data. The data collected included release rates, atmospheric concentrations to 100 m from the release point, and local meteorological conditions. The diagnostics included nine meteorological stations on 100-m centers and 36 photoionization detectors in a radial pattern. Three current state-of-the-practice models, Aerial Locations of Hazardous Atmospheres (ALOHA), Emergency Prediction Information code (EPIcode), and Second-Order Closure Integrated Puff (SCIPUFF), were used to try to duplicate the measured field results. Low wind speeds are difficult to model, and all of the models had difficulty replicating the field measurements. However, the work does show that these models, if used correctly, are conservative (overpredict concentrations) and can be used for safety and emergency planning.

New Spatio-Temporal Wind Exergy Maps

2006 ◽  
Vol 128 (3) ◽  
pp. 194-202 ◽  
Author(s):  
Ahmet Duran Şahin ◽  
Ibrahim Dincer ◽  
Marc A. Rosen
Keyword(s):  
Wind Energy ◽  
Wind Speeds ◽  
Common Basis ◽  
Energy And Exergy ◽  
New Energy ◽  
Temperature And Pressure ◽  
Spatio Temporal ◽  
Low Wind Speeds ◽  
Generating System

In this paper, energy and exergy characteristics of wind energy are investigated. The effects of wind speed and air temperature and pressure at the inlet of a wind turbine on windchill temperature are examined. We also investigate energy and exergy efficiencies of the wind energy generating system and verify the models through a case study on a 100 kW wind generating system for 21 climatic stations in the province of Ontario, Canada. New energy and exergy efficiency maps of the wind energy generating system are introduced to provide a common basis for regional assessments and interpretations. These efficiency maps are plotted for 4 months of the year (January, April, July, October), which are taken to be representative months of the seasons. The results show that aerial differences between energy and exergy efficiencies are approximately 20%–24% at low wind speeds and approximately 10%–15% at high wind speeds.

Development of New Spatio-Temporal Wind Exergy Maps

2006 ◽  
Author(s):  
Ahmet Duran Sahin ◽  
Ibrahim Dincer ◽  
Marc A. Rosen
Keyword(s):  
Wind Energy ◽  
Wind Speeds ◽  
Common Basis ◽  
Energy And Exergy ◽  
New Energy ◽  
Temperature And Pressure ◽  
Spatio Temporal ◽  
Low Wind Speeds ◽  
Generating System

In this paper, energy and exergy characteristics of wind energy are investigated. The effects of wind speed and air temperature and pressure at the inlet of a wind turbine on wind chill temperature are examined. We also investigate energy and exergy efficiencies of the wind energy generating system and verify the models through a case study on a 100-kW wind generating system for 21 climatic stations in the province of Ontario, Canada. New energy and exergy efficiency maps of the wind energy generating system are introduced to provide a common basis for regional assessments and interpretations. These efficiency maps are plotted for two months of the year (January and July), which are taken to be representative months of the winter and summer seasons. The results show that aerial differences between energy and exergy efficiencies are approximately to 20-24% at low wind speeds and approximately to 10-15% at high wind speeds.

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