scholarly journals Biomass Burning and Gas Flares Create the Extreme West African Aerosol Plume Which Perturbs the Hadley Circulation and Thereby Changes Europe’s Winter Climate

2021 ◽  
Author(s):  
Keith A. Potts
Keyword(s):  
High Pressure ◽  
Biomass Burning ◽  
Hadley Circulation ◽  
West African ◽  
Natural State ◽  
Circulation System ◽  
Winter Climate ◽  
Gas Flaring ◽  
The Uk ◽  
Aerosol Plume

Three significant changes have occurred in the winter climate in Europe recently: increased UK flooding; Iberian drought; and warmer temperatures north of the Alps. The literature links all three to a persistent, significant increase in sea level pressure over Southern Europe, the Medi-terranean, Iberia and the Eastern Atlantic (SEMIEA) which changes the atmospheric circulation system: forcing cold fronts to the north away from Iberia; and creating a south westerly flow around the northern perimeter of the high-pressure region bringing warmer, moist air from the subtropical Atlantic to the UK and Europe which increases precipitation in the UK and raises the temperature in Europe. I use the Last Millennium Ensemble, MERRA-2 and Terra-NCEP data to demonstrate that the extreme, anthropogenic, West African aerosol Plume (WAP) which only exists from December to April perturbs the northern, regional Hadley Circulation creating the high pressure in the SEMIEA. I also show that the anthropogenic WAP has only existed in its extreme form in recent decades as the two major sources of the WAP aerosols: biomass burning; and gas flaring have both increased significantly since 1950 due to: a four-fold increase in population; and gas flaring rising from zero to 7.4 billion m3/annum and note that this time span coincides with the changes in the three elements of the winter climate of Europe. I also suggest that it may be possible to eliminate the WAP and return the winter climate of Europe to its natural state after the crucial first step of recognising the cause of the changes is taken.

scholarly journals Biomass Burning and Gas Flares create the extreme West African Aerosol Plume Which Perturbs the Hadley Circulation and thereby Changes Europe’s Winter Climate

2021 ◽  
Author(s):  
Keith A. Potts
Keyword(s):  
High Pressure ◽  
Biomass Burning ◽  
Hadley Circulation ◽  
West African ◽  
Natural State ◽  
Circulation System ◽  
Winter Climate ◽  
Gas Flaring ◽  
The Uk ◽  
Aerosol Plume

Three significant changes have occurred in the winter climate in Europe recently: increased UK flooding; Iberian drought; and warmer temperatures north of the Alps. The literature links all three to a persistent, significant increase in sea level pressure over Southern Europe, the Mediterranean, Iberia and the Eastern Atlantic (SEMIEA) which changes the atmospheric circulation system: forcing cold fronts to the north away from Iberia; and creating a south westerly flow around the northern perimeter of the high-pressure region bringing warmer, moist air from the subtropical Atlantic to the UK and Europe which increases precipitation in the UK and raises the temperature in Europe. I use the Last Millennium Ensemble, MERRA-2 and Terra-NCEP data to demonstrate that the extreme, anthropogenic, West African aerosol Plume (WAP) which only exists from December to April perturbs the northern, regional Hadley Circulation creating the high pressure in the SEMIEA. I also show that the anthropogenic WAP has only existed in its extreme form in recent decades as the two major sources of the WAP aerosols: biomass burning; and gas flaring have both increased significantly since 1950 due to: a four-fold increase in population; and gas flaring rising from zero to 7.4 billion m3/annum and note that this time span coincides with the changes in the three elements of the winter climate of Europe. I also suggest that it may be possible to eliminate the WAP and return the winter climate of Europe to its natural state after the crucial first step of recognising the cause of the changes is taken.

scholarly journals Biomass Burning and Gas Flares create the extreme West African Aerosol Plume which perturbs the Hadley Circulation and thereby changes Europe’s winter climate

2021 ◽  
Author(s):  
Keith A. Potts
Keyword(s):  
High Pressure ◽  
Biomass Burning ◽  
Hadley Circulation ◽  
West African ◽  
Natural State ◽  
Winter Climate ◽  
Gas Flaring ◽  
Pressure Region ◽  
Aerosol Plume ◽  
High Pressure Region

Europe’s winter climate has experienced three significant changes recently: increased UK flooding; Iberian drought; and warmer temperatures north of the Alps. The literature links all three to a persistent, significant increase in sea level pressure over the Mediterranean and Iberia which changes the atmospheric circulation system by: forcing cold fronts north away from Iberia; and creating a south westerly flow around the high-pressure region bringing warmer, moist air from the subtropical Atlantic to Europe which increases UK precipitation and European temperatures. Here I show, using modelled, reanalysis and measured data, that: the extreme, anthropogenic, West African aerosol Plume (WAP) which exists from late December to early April perturbs the northern, regional Hadley Circulation creating the high-pressure region; and that the WAP has only existed in its extreme form in recent decades as the major sources of the aerosols: biomass burning; and gas flaring have both increased significantly since 1950 due to: a four-fold increase in population (United Nations); and gas flaring rising from zero to 7.4 billion m3/annum (Global Gas Flaring Reduction Partnership). I also suggest that the WAP can be eliminated and Europe’s winter climate returned to its natural state after the crucial first step of recognising the cause of the changes is taken.

scholarly journals Saharan dust and biomass burning aerosols during ex-hurricane Ophelia: observations from the new UK lidar and sun-photometer network

2019 ◽  
Vol 19 (6) ◽  
pp. 3557-3578 ◽  
Author(s):  
Martin Osborne ◽  
Florent F. Malavelle ◽  
Mariana Adam ◽  
Joelle Buxmann ◽  
Jaqueline Sugier ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Forest Fires ◽  
Complex Structure ◽  
Atmospheric Dispersion ◽  
Saharan Dust ◽  
Atmospheric Concentration ◽  
Back Trajectories ◽  
Sun Photometer ◽  
The Uk ◽  
Aerosol Types

Abstract. On 15–16 October 2017, ex-hurricane Ophelia passed to the west of the British Isles, bringing dust from the Sahara and smoke from Portuguese forest fires that was observable to the naked eye and reported in the UK's national press. We report here detailed observations of this event using the UK operational lidar and sun-photometer network, established for the early detection of aviation hazards, including volcanic ash. We also use ECMWF ERA5 wind field data and MODIS imagery to examine the aerosol transport. The observations, taken continuously over a period of 30 h, show a complex picture, dominated by several different aerosol layers at different times and clearly correlated with the passage of different air masses associated with the intense cyclonic system. A similar evolution was observed at several sites, with a time delay between them explained by their different location with respect to the storm and associated meteorological features. The event commenced with a shallow dust layer at 1–2 km in altitude and culminated in a deep and complex structure that lasted ∼12 h at each site over the UK, correlated with the storm's warm sector. For most of the time, the aerosol detected was dominated by mineral dust mixtures, as highlighted by depolarisation measurements, but an intense biomass burning aerosol (BBA) layer was observed towards the end of the event, lasting around 3 h at each site. The aerosol optical depth at 355 nm (AOD355) during the whole event ranged from 0.2 to 2.9, with the larger AOD correlated to the intense BBA layer. Such a large AOD is unprecedented in the UK according to AERONET records for the last 20 years. The Raman lidars permitted the measurement of the aerosol extinction coefficient at 355 nm, the particle linear depolarisation ratio (PLDR), and the lidar ratio (LR) and made the separation of the dust (depolarising) aerosol from other aerosol types possible. A specific extinction has also been computed to provide an estimate of the atmospheric concentration of both aerosol types separately, which peaked at 420±200 µg m−3 for the dust and 558±232 µg m−3 for the biomass burning aerosols. Back trajectories computed using the Numerical Atmospheric-dispersion Modelling Environment (NAME) were used to identify the sources and strengthen the conclusions drawn from the observations. The UK network represents a significant expansion of the observing capability in northern Europe, with instruments evenly distributed across Great Britain, from Camborne in Cornwall to Lerwick in the Shetland Islands, and this study represents the first attempt to demonstrate its capability and validate the methods in use. Its ultimate purpose will be the detection and quantification of volcanic plumes, but the present study clearly demonstrates the advanced capabilities of the network.

The Design of Mitred Bends—A Background to BS 806 : 1975 Amendment No 3

1986 ◽  
Vol 200 (1) ◽  
pp. 51-58 ◽  
Author(s):  
K Battle ◽  
G D T Carmichael ◽  
E Cresswell ◽  
D Morse ◽  
H Porter ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Working Party ◽  
The Uk ◽  
Design And Application

To satisfy a requirement within the high pressure pipework industry in the UK, PVE/10 of the British Standards Institution established a Working Party to produce recommendations on the design and application of gusseted or mitred bends. The ultimate conclusions of the Working Party were eventually published within Amendment AMD 3545 to BS 806 ‘Ferrous pipes and piping installations for and in connection with land boilers’. Prior to this amendment BS 806 provided only limited guidance on the design of such bends, based on rules derived from custom and practice. AMD 3545 provides more extensive guidance than previously, based on experimental data and analysis and provides guidance on pipework design. This paper describes the background to the amendment and provides most of the reasoning behind the conclusions drawn by the Working Party.

scholarly journals Sources of Springtime Surface Black Carbon in the Arctic: An Adjoint Analysis

2017 ◽  
Author(s):  
Ling Qi ◽  
Qinbin Li ◽  
Daven K. Henze ◽  
Hsien-Liang Tseng ◽  
Cenlin He
Keyword(s):  
Natural Gas ◽  
Black Carbon ◽  
Biomass Burning ◽  
Transport Model ◽  
Lower Troposphere ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Anthropogenic Source ◽  
Gas Flaring ◽  
Arctic Front

Abstract. We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC at Barrow, Alert, and Zeppelin are dominated by Asian anthropogenic sources (40–43 %) before April 18 and by Siberian open biomass burning emissions (29–41 %) afterward. In contrast, Summit, a mostly free tropospheric site, has predominantly an Asian anthropogenic source contribution (24–68 %, with an average of 45 %). We compute the adjoint sensitivity of BC concentrations at the five sites during a pollution episode (April 20–25) to global emissions from March 1 to April 25. The associated contributions are the combined results of these sensitivities and BC emissions. Local and regional anthropogenic sources in Alaska are the largest anthropogenic sources of BC at Denali (63 %), and natural gas flaring emissions in the Western Extreme North of Russia (WENR) are the largest anthropogenic sources of BC at Zeppelin (26 %) and Alert (13 %). We find that long-range transport of emissions from Beijing-Tianjin-Hebei (also known as Jing-Jin-Ji), the biggest urbanized region in Northern China, contribute significantly (~ 10 %) to surface BC across the Arctic. On average it takes ~ 12 days for Asian anthropogenic emissions and Siberian biomass burning emissions to reach Arctic lower troposphere, supporting earlier studies. Natural gas flaring emissions from the WENR reach Zeppelin in about a week. We find that episodic, direct transport events dominate BC at Denali (87 %), a site outside the Arctic front, a strong transport barrier. The relative contribution of direct transport to surface BC within the Arctic front is much smaller (~ 50 % at Barrow and Zeppelin and ~ 10 % at Alert). The large contributions from Asian anthropogenic sources are predominately in the form of ‘chronic’ pollution (~ 40 % at Barrow and 65 % at Alert and 57 % at Zeppelin) on 1–2 month timescales. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. Both finer temporal resolution of biomass burning emissions and accounting for the Wegener-Bergeron-Findeisen (WBF) process in wet scavenging improve the source attribution estimates.

Occurrence and prediction of high-pressure sediment along the West African margin

2011 ◽  
Vol 30 (6) ◽  
pp. 682-687 ◽  
Author(s):  
Richard Swarbrick ◽  
Stephen O'Connor ◽  
Richard Lahann
Keyword(s):  
High Pressure ◽  
West African ◽  
The West

scholarly journals Aerosol influences on low-level clouds in the West African monsoon

2019 ◽  
Vol 19 (13) ◽  
pp. 8503-8522 ◽  
Author(s):  
Jonathan W. Taylor ◽  
Sophie L. Haslett ◽  
Keith Bower ◽  
Michael Flynn ◽  
Ian Crawford ◽  
...  
Keyword(s):  
West Africa ◽  
Southern Hemisphere ◽  
Biomass Burning ◽  
Cloud Cover ◽  
Number Concentration ◽  
West African ◽  
The West ◽  
Cloud Drop ◽  
Drop Number ◽  
Local Emissions

Abstract. Low-level clouds (LLCs) cover a wide area of southern West Africa (SWA) during the summer monsoon months and have an important cooling effect on the regional climate. Previous studies of these clouds have focused on modelling and remote sensing via satellite. We present the first comprehensive set of in situ measurements of cloud microphysics from the region, taken during June–July 2016, as part of the DACCIWA (Dynamics–aerosol–chemistry–cloud interactions in West Africa) campaign. This novel dataset allows us to assess spatial, diurnal, and day-to-day variation in the properties of these clouds over the region. LLCs developed overnight and mean cloud cover peaked a few hundred kilometres inland around 10:00 local solar time (LST), before clouds began to dissipate and convection intensified in the afternoon. Regional variation in LLC cover was largely orographic, and no lasting impacts in cloud cover related to pollution plumes were observed downwind of major population centres. The boundary layer cloud drop number concentration (CDNC) was locally variable inland, ranging from 200 to 840 cm−3 (10th and 90th percentiles at standard temperature and pressure), but showed no systematic regional variations. Enhancements were seen in pollution plumes from the coastal cities but were not statistically significant across the region. A significant fraction of accumulation mode aerosols, and therefore cloud condensation nuclei, were from ubiquitous biomass burning smoke transported from the Southern Hemisphere. To assess the relative importance of local and transported aerosol on the cloud field, we isolated the local contribution to the aerosol population by comparing inland and offshore size and composition measurements. A parcel model sensitivity analysis showed that doubling or halving local emissions only changed the calculated cloud drop number concentration by 13 %–22 %, as the high background meant local emissions were a small fraction of total aerosol. As the population of SWA grows, local emissions are expected to rise. Biomass burning smoke transported from the Southern Hemisphere is likely to dampen any effect of these increased local emissions on cloud–aerosol interactions. An integrative analysis between local pollution and Central African biomass burning emissions must be considered when predicting anthropogenic impacts on the regional cloud field during the West African summer monsoon.

Fitness-for-Purpose Assessment of Encirclement Split-Tees

2002 ◽  
Author(s):  
S. Wheat ◽  
C. S. Jandu ◽  
D. N. Bramley ◽  
J. H. Liu
Keyword(s):  
High Pressure ◽  
Design Criteria ◽  
Plastic Collapse ◽  
Fitness For Purpose ◽  
Design Code ◽  
Gas Industry ◽  
Fatigue Design ◽  
The Uk ◽  
Transmission Pipelines

Hot tap tees of the full encirclement split tee design are currently used in the UK gas industry to provide connections onto existing high pressure gas transmission pipelines and above ground installations. The fitness-for-purpose of this type of tee is not covered by the UK design code for above ground gas installations, IGE/TD/9. A fitness-for-purpose methodology has been developed by Advantica Technologies to determine the integrity of the fitting and attachment welds. The fitness-for-purpose assessment addresses the following: • The compliance of the fitting to plastic collapse, shakedown and fatigue design criteria. • The integrity of the attachment welds onto the carrier pipe. • The use of Engineering Critical Assessments in conjunction with existing procedures to ensure overall integrity.

The Quest in the United Kingdom for African Unity, 1945-48

1970 ◽  
Vol 5 (1) ◽  
pp. 61-86
Author(s):  
Marika Sherwood
Keyword(s):  
Cold War ◽  
West African ◽  
Gold Coast ◽  
Afrique De L’Ouest ◽  
The United Kingdom ◽  
The Uk ◽  
The Cold War ◽  
Afrique De L'ouest ◽  
Political Groups ◽  
Groupes Ethniques

This article outlines the formation, ideology and activities of the West African National Secretariat (WANS), established in London in 1945-6 by Nkrumah and this colleagues, from both the English and French West African colonies. Their aim was unity, as the only hope of real independence was through unity of all ethnic groups and all social classes, not just the ‘intelligentsia’. Outlined are WANS’ activities, its work with other political groups/activists in the UK and France, and reports in Gold Coast and Nigerian newspapers, which were kept fully informed. Labelled a communist, Nkrumah was under surveillance by MI5 in the UK and on his return home in 1947. Was this the beginning of the Cold War in West Africa? La Quête au Royaume-Uni pour l’Union Africaine, 1945-48  Résumé Cet article présente la formation, l’idéologie et les activités du West African National Secretariat [Secrétariat National de l'Afrique de l'Ouest] (WANS), établi à Londres entre les années 1945 et 1946 par Nkrumah et ses collègues issus des colonies anglophones et francophones en Afrique de l’Ouest dont le but était l’union, le seul espoir pour l’Independence réelle étant réalisable à travers l’union de tous les groupes ethniques et de toutes les classes sociales, et non pas seulement « l’intelligentsia ». Sont présentés dans cet article les activités de WANS, ses opérations avec d’autres groupes/militants politiques au Royaume-Uni et en France, ainsi que les rapports dans les journaux au Gold Coast et au Nigeria qui étaient bien informés. Qualifié de communiste, Nkrumah était sous la surveillance de MI5 au Royaume-Uni et à son retour au pays en 1947. Ce fait marque-t-il le début de la Guerre Froide en Afrique de l’Ouest?

The aging process of ambient black carbon and brown carbon from biomass burning emission during MOYA-2017 aircraft campaign

2020 ◽  
Author(s):  
HuiHui Wu ◽  
Jonathan Taylor ◽  
Justin Langridge ◽  
Chenjie Yu ◽  
Paul Williams ◽  
...  
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
Aging Process ◽  
Atmospheric Dispersion ◽  
Chemical Properties ◽  
Carbonaceous Aerosol ◽  
Brown Carbon ◽  
Research Aircraft ◽  
Flaming Combustion ◽  
The Uk

<p>The biomass burning over West Africa during the dry season (December – February) is a globally significant source of trace gases and carbonaceous aerosol particles in the atmosphere. The MOYA-2017 (Methane Observations Yearly Assessments 2017) campaign were conducted using the UK FAAM Bae-146 airborne research aircraft, to investigate biomass burning emissions in this region. Research sorties were flown out of Senegal, with some flights directly over terrestrial fires and others sampling transported smokes over the Atlantic ocean.</p><p>The aircraft was equipped with a variety of aerosol-related instruments to measure submicron aerosol chemical properties (aerosol mass spectrometer, AMS and single-particle soot photometer, SP2) and absorption at different wavelengths (Photoacoustic spectrometer, PAS, measure at 405, 514 and 658 nm). In this study, we focus on the aging process of ambient black carbon (BC) and brown carbon (BrC) from biomass burning, in time scale from (<0.5) h to (9 – 15) h. The transport age of smokes was estimated using Met Office's Numerical Atmospheric-dispersion Modelling Environment (NAME).</p><p>The sampled smokes during MOYA-2017 were controlled by flaming-phase combustion. The enhancement ratios of BC with respect to CO ranged from 14 to 26 (ng m<sup>–3</sup> / ppbv) at sources. Our measurements show that count and mass median diameters of BC core size were relatively stable, which were around 106 and 190 nm respectively. Average BC coating thickness increased from (1.16 ± 0.03) to (1.71 ± 0.06) after approximately half-day transport. Average absorption angstrom exponents (AAE<sub>405-658</sub>) increased from (1.1 ± 0.1) to (1.8 ± 0.3), suggesting that BrC contributed little in the very freshly emitted aerosols (<0.5 h) and were formed during aging process. In order to investigate the importance of BrC in this area, we also attributed the measured aerosol absorption into BC and BrC separately. By linking AAE<sub>405-658</sub> with organic (OA) composition measured by the AMS, we found that the increasing AAE<sub>405-658</sub> is positively correlated with O/C ratio (oxygenation) of the OA. These data indicate that BrC in smokes controlled by flaming combustion is likely to be from the condensation of semi-volatile OA during cooling stage of smokes, and from the aged primary OA or secondary OA formation.</p>

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