scholarly journals Global source attribution of sulfate concentration, direct and indirect radiative forcing

2017 ◽  
Author(s):  
Yang Yang ◽  
Hailong Wang ◽  
Steven J. Smith ◽  
Richard Easter ◽  
Po-Lun Ma ◽  
...  
Keyword(s):  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
Central Asia ◽  
Southern Hemisphere ◽  
North Africa ◽  
Radiative Forcing ◽  
Sulfate Concentration ◽  
Near Surface ◽  
Indirect Radiative Forcing

Abstract. The global source-receptor relationships of sulfate concentration, direct and indirect radiative forcing (DRF and IRF) from sixteen regions/sectors for years 2010–2014 are examined in this study through utilizing a sulfur source-tagging capability implemented in the Community Earth System Model (CESM) with winds nudged to reanalysis data. Sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate concentrations are primarily attributed to non-local sources from long-range transport. The export of SO2 and sulfate from Europe contributes 16–20 % of near-surface sulfate concentrations over North Africa, Russia/Belarus/Ukraine (RBU) region and Central Asia. Sources from the Middle East account for 15–24 % of sulfate over North Africa, Southern Africa and Central Asia in winter and autumn, and 19 % over South Asia in spring. Sources in RBU account for 21–42 % of sulfate concentrations over Central Asia. East Asia accounts for about 50 % of sulfate over Southeast Asia in winter and autumn, 15 % over RBU in summer, and 11 % over North America in spring. South Asia contributes to 11–24 % of sulfate over Southeast Asia in winter and spring. Regional source efficiencies of sulfate concentrations are higher over regions with dry atmospheric conditions and less export, suggesting that lifetime of aerosols, together with regional export, is important in determining regional air quality. The simulated global total sulfate DRF is −0.42 W m−2, with  0.31 W m−2 contributed by anthropogenic sulfate and −0.11 W m−2 contributed by natural sulfate, relative to a state with no sulfur emissions. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes 17–84 % to the total DRF. East Asia has the largest contribution of 20–30 % over the Northern Hemisphere mid- and high-latitudes. A 20 % perturbation of sulfate and its precursor emissions gives a sulfate incremental IRF of −0.44 W m−2. DMS has the largest contribution, explaining −0.23 W m−2 of the global sulfate incremental IRF. Incremental IRF over regions in the Southern Hemisphere with low background aerosols is more sensitive to emission perturbation than those over the polluted Northern Hemisphere.

scholarly journals Global source attribution of sulfate concentration and direct and indirect radiative forcing

2017 ◽  
Vol 17 (14) ◽  
pp. 8903-8922 ◽  
Author(s):  
Yang Yang ◽  
Hailong Wang ◽  
Steven J. Smith ◽  
Richard Easter ◽  
Po-Lun Ma ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Radiative Forcing ◽  
Dimethyl Sulfide ◽  
Sulfur Source ◽  
Atmospheric Conditions ◽  
So2 Emissions ◽  
Near Surface ◽  
Indirect Radiative Forcing ◽  
Global Source

Abstract. The global source–receptor relationships of sulfate concentrations, and direct and indirect radiative forcing (DRF and IRF) from 16 regions/sectors for years 2010–2014 are examined in this study through utilizing a sulfur source-tagging capability implemented in the Community Earth System Model (CESM) with winds nudged to reanalysis data. Sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate concentrations are primarily attributed to non-local sources from long-range transport. Regional source efficiencies of sulfate concentrations are higher over regions with dry atmospheric conditions and less export, suggesting that lifetime of aerosols, together with regional export, is important in determining regional air quality. The simulated global total sulfate DRF is −0.42 W m−2, with −0.31 W m−2 contributed by anthropogenic sulfate and −0.11 W m−2 contributed by natural sulfate, relative to a state with no sulfur emissions. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes 17–84 % to the total DRF. East Asia has the largest contribution of 20–30 % over the Northern Hemisphere mid- and high latitudes. A 20 % perturbation of sulfate and its precursor emissions gives a sulfate incremental IRF of −0.44 W m−2. DMS has the largest contribution, explaining −0.23 W m−2 of the global sulfate incremental IRF. Incremental IRF over regions in the Southern Hemisphere with low background aerosols is more sensitive to emission perturbation than that over the polluted Northern Hemisphere.

English in Asia, Asian Englishes, and the issue of proficiency

English Today ◽  
2008 ◽  
Vol 24 (2) ◽  
pp. 3-12 ◽  
Author(s):  
Kingsley Bolton
Keyword(s):  
Middle East ◽  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
Central Asia ◽  
English Learning ◽  
Outer Circle ◽  
Asian Region ◽  
The World ◽  
Basic Issue

ABSTRACTThe contemporary visibility and importance of English throughout the Asian region coupled with the emergence and development of distinct varieties of Asian Englishes have played an important part in the global story of English in recent years. Across Asia, the numbers of people having at least a functional command of the language have grown exponentially over the last four decades, and current changes in the sociolinguistic realities of the region are often so rapid that it is difficult for academic commentators to keep pace. One basic issue in the telling of this story is the question of what it is we mean by the term ‘Asia’, itself a word of contested etymology, whose geographical reference has ranged in application from the Middle East to Central Asia, and from the Indian sub-continent to Japan and Korea. In this article, my discussion will focus on the countries of South Asia, Southeast Asia, and East Asia, as it is in these regions that we find not only the greatest concentration of ‘outer-circle’ English-using societies but also a number of the most populous English-learning and English-knowing nations in the world.

Asian Development Outlook Supplement July 2021

2021 ◽  
Keyword(s):  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
Central Asia ◽  
Regional Growth ◽  
Asian Development ◽  
The Pacific ◽  
Growth Projection ◽  
Development Outlook

This publication provides updated economic projections for developing Asia and the Pacific. It notes that recovery is underway but that regional growth in 2021 is expected to be 7.2%, which is 0.1% lower than was projected in April. Forecast upgrades for Central Asia and East Asia in 2021 partly offset downgrades for South Asia, Southeast Asia, and the Pacific. The regional growth projection for 2022 is upgraded from 5.3% to 5.4%.

Introduction

2016 ◽  
Author(s):  
Michael Jerryson
Keyword(s):  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
Central Asia ◽  
Cultural Context ◽  
Beliefs And Practices

This Handbook examines the transformations to Buddhists, their beliefs, and practices throughout the nineteenth, twentieth, and twenty-first centuries. Over the centuries, Buddhism changed with modernity. These changes accelerated in diverse manners during the colonial and postcolonial periods. As each tradition offers its own distinctive historical and cultural context, Part I in the Handbook reviews the development of specific traditions. There are seven subsections that demarcate the regions from which various traditions emerged: South Asia, East Asia, Central Asia, Southeast Asia, Europe/Americas, Southern, and Global. Part II tracks patterns and themes that relate to the diverse Buddhist traditions. In this section, chapters address the modes or manners in which Buddhist traditions manifest in the contemporary age.

scholarly journals Quantifying sources, transport, deposition, and radiative forcing of black carbon over the Himalayas and Tibetan Plateau

2015 ◽  
Vol 15 (11) ◽  
pp. 6205-6223 ◽  
Author(s):  
R. Zhang ◽  
H. Wang ◽  
Y. Qian ◽  
P. J. Rasch ◽  
R. C. Easter ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
East Asia ◽  
South Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Glacier Retreat ◽  
Modeling Framework ◽  
Near Surface ◽  
Geographical Regions ◽  
Source Receptor Relationships

Abstract. Black carbon (BC) particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions and emission sectors, it is essential to quantify the source–receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. In this study, we use the Community Atmosphere Model version 5 (CAM5) with a newly developed source-tagging technique, nudged towards the MERRA meteorological reanalysis, to characterize the fate of BC particles emitted from various geographical regions and sectors. Evaluated against observations over the HTP and surrounding regions, the model simulation shows a good agreement in the seasonal variation in the near-surface airborne BC concentrations, providing confidence to use this modeling framework for characterizing BC source–receptor relationships. Our analysis shows that the relative contributions from different geographical regions and source sectors depend on season and location in the HTP. The largest contribution to annual mean BC burden and surface deposition in the entire HTP region is from biofuel and biomass (BB) emissions in South Asia, followed by fossil fuel (FF) emissions from South Asia, then FF from East Asia. The same roles hold for all the seasonal means except for the summer, when East Asia FF becomes more important. For finer receptor regions of interest, South Asia BB and FF have the largest impact on BC in the Himalayas and central Tibetan Plateau, while East Asia FF and BB contribute the most to the northeast plateau in all seasons and southeast plateau in the summer. Central Asia and Middle East FF emissions have relatively more important contributions to BC reaching the northwest plateau, especially in the summer. Although local emissions only contribute about 10% of BC in the HTP, this contribution is extremely sensitive to local emission changes. Lastly, we show that the annual mean radiative forcing (0.42 W m−2) due to BC in snow outweighs the BC dimming effect (−0.3 W m−2) at the surface over the HTP. We also find strong seasonal and spatial variation with a peak value of 5 W m−2 in the spring over the northwest plateau. Such a large forcing of BC in snow is sufficient to cause earlier snow melting and potentially contribute to the acceleration of glacier retreat.

scholarly journals Quantifying sources, transport, deposition and radiative forcing of black carbon over the Himalayas and Tibetan Plateau

2015 ◽  
Vol 15 (1) ◽  
pp. 77-121 ◽  
Author(s):  
R. Zhang ◽  
H. Wang ◽  
Y. Qian ◽  
P. J. Rasch ◽  
R. C. Easter ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
East Asia ◽  
South Asia ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Glacier Retreat ◽  
Modeling Framework ◽  
Near Surface ◽  
Geographical Regions ◽  
Source Receptor Relationships

Abstract. Black carbon (BC) particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions and emission sectors, it is essential to quantify the source–receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. In this study, we use the Community Atmosphere Model version 5 (CAM5) with a newly developed source tagging technique, nudged towards the MERRA meteorological reanalysis, to characterize the fate of BC particles emitted from various geographical regions and sectors. Evaluated against observations over the HTP and surrounding regions, the model simulation shows a good agreement in the seasonal variation of the near-surface airborne BC concentrations, providing confidence to use this modeling framework for characterizing BC source–receptor relationships. Our analysis shows that the relative contributions from different geographical regions and source sectors depend on seasons and the locations in the HTP. The largest contribution to annual mean BC burden and surface deposition in the entire HTP region is from biofuel and biomass (BB) emissions in South Asia, followed by fossil fuel (FF) emissions from South Asia, then FF from East Asia. The same roles hold for all the seasonal means except for the summer when East Asia FF becomes more important. For finer receptor regions of interest, South Asia BB and FF have the largest impact on BC in Himalayas and Central Tibetan Plateau, while East Asia FF and BB contribute the most to Northeast Plateau in all seasons and Southeast Plateau in the summer. Central Asia and Middle East FF emissions have relatively more important contributions to BC reaching Northwest Plateau, especially in the summer. Although local emissions only contribute about 10% to BC in the HTP, this contribution is extremely sensitive to local emission changes. Lastly, we show that the annual mean radiative forcing (0.42 W m−2) due to BC in snow outweighs the BC dimming effect (−0.3 W m−2) at the surface over the HTP. We also find strong seasonal and spatial variation with a peak value of 5 W m−2 in the spring over Northwest Plateau. Such a large forcing of BC in snow is sufficient to cause earlier snow melting and potentially contribute to the acceleration of glacier retreat.

A new species of the montane lacewing genus Rapisma McLachlan (Neuroptera, Ithonidae) from northwestern Yunnan, China

Zootaxa ◽  
2020 ◽  
Vol 4763 (3) ◽  
pp. 439-443
Author(s):  
XINGYUE LIU
Keyword(s):  
New Species ◽  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
The Family ◽  
A New Species ◽  
Northwestern Yunnan

The genus Rapisma McLachlan, 1866 (montane lacewings) is a rare and little known group of the family Ithonidae (Insecta: Neuroptera). There have been 21 described species of Rapisma, and all of them are distributed from East Asia, South Asia and Southeast Asia. Here I report a new species of Rapisma from northwestern Yunnan, China, namely Rapisma weixiense sp. nov. The new species belongs to a group of Rapisma species with very short antennae. 

scholarly journals Simulation of dust aerosol and its regional feedbacks over East Asia using a regional climate model

2008 ◽  
Vol 8 (2) ◽  
pp. 4625-4667 ◽  
Author(s):  
D. F. Zhang ◽  
A. S. Zakey ◽  
X. J. Gao ◽  
F. Giorgi
Keyword(s):  
East Asia ◽  
Regional Climate Model ◽  
Radiative Forcing ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Cooling ◽  
Near Surface ◽  
Dust Aerosols ◽  
Source Regions ◽  
Mass Load

Abstract. The ICTP regional climate model (RegCM3) coupled with a desert dust model is used to simulate the radiative forcing and related climate effects of dust aerosols over East Asia. Two sets of experiments encompassing the main dust producing months, February to May, for 10 years (1997–2006) are conducted and inter-compared, one without (Exp. 1) and one with (Exp. 2) the radiative effects of dust aerosols. The simulation results are evaluated against ground station and satellite data. The model captures the basic observed climatology over the area of interest. The spatial and temporal variations of near surface concentration, mass load, and emission of dust aerosols from the main source regions are reproduced by model, with the main model deficiency being an overestimate of dust amount over the source regions and underestimate downwind of these source areas. Both the top-of-the-atmosphere (TOA) and surface radiative fluxes are decreased by dust and this causes a surface cooling locally up to −1°C. The inclusion of dust radiative forcing leads to a reduction of dust emission in the East Asia source regions, which is mainly caused by an increase in local stability and a corresponding decrease in dust lifting. Our results indicate that dust effects should be included in the assessment of climate change over East Asia.

scholarly journals Modeling sensitivity study of the possible impact of snow and glaciers developing over Tibetan Plateau on Holocene African-Asian summer monsoon climate

2008 ◽  
Vol 4 (6) ◽  
pp. 1265-1287 ◽  
Author(s):  
L. Jin ◽  
Y. Peng ◽  
F. Chen ◽  
A. Ganopolski
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Southeast Asia ◽  
South Asia ◽  
North Africa ◽  
Vegetation Cover ◽  
Asian Monsoon ◽  
The Tibetan Plateau ◽  
Monsoon Region ◽  
Asian Monsoon Region

Abstract. The impacts of various scenarios of snow and glaciers developing over the Tibetan Plateau on climate change in Afro-Asian monsoon region and other regions during the Holocene (9 kyr BP–0 kyr BP) are studied by using the coupled climate model of intermediate complexity, CLIMBER-2. The simulations show that the imposed snow and glaciers over the Tibetan Plateau in the mid-Holocene induce global summer temperature decreases, especially in the northern parts of Europe, Asia, and North America. At the same time, with the imposed snow and glaciers, summer precipitation decreases strongly in North Africa and South Asia as well as northeastern China, while it increases in Southeast Asia and the Mediterranean. For the whole period of Holocene (9 kyr BP–0 kyr BP), the response of vegetation cover to the imposed snow and glaciers cover over the Tibetan Plateau is not synchronous in South Asia and in North Africa, showing an earlier and a more rapid decrease in vegetation cover in North Africa from 9 to 6 kyr BP while it has only minor influence on that in South Asia until 5 kyr BP. Imposed gradually increased snow and glacier cover over the Tibetan Plateau causes temperature increases in South Asia and it decreases in North Africa and Southeast Asia during 6 kyr BP to 0 kyr BP. The precipitation decreases rapidly in North Africa and South Asia while it decreases slowly or unchanged during 6 kyr BP to 0 kyr BP with imposed snow and glacier cover over the Tibetan Plateau. The different scenarios of snow and glacier developing over the Tibetan Plateau would result in differences in variation of temperature, precipitation and vegetation cover in North Africa, South Asia and Southeast Asia. The model results show that the response of climate change in African-Asian monsoon region to snow and glacier cover over the Tibetan Plateau is in the way that the snow and glaciers amplify the effect of vegetation feedback and, hence, further amplify orbital forcing.

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