Modeling dust sources, transport, and radiative effects at different altitudes over the Tibetan Plateau

2020 ◽  
Author(s):  
Zhiyuan Hu ◽  
Jianping Huang ◽  
Chun Zhao ◽  
Qinjian Jin ◽  
Yuanyuan Ma ◽  
...  
Keyword(s):  
Middle East ◽  
Tibetan Plateau ◽  
Mass Flux ◽  
Radiation Budget ◽  
Dust Particles ◽  
The Tibetan Plateau ◽  
North African ◽  
The North ◽  
Dust Mass ◽  
Different Altitudes

<p>Mineral dust plays an important role in the climate of the Tibetan Plateau (TP) by modifying the radiation budget, cloud macro- and microphysics, precipitation, and snow albedo. Meanwhile, the TP with the highest topography in the word can affect intercontinental transport of dust plumes and induce typical distribution characteristics of dust at different altitudes. In this study, we conduct a quasi-global simulation to investigate the characteristics of dust source contribution and transport over the TP at different altitude by using a fully coupled meteorology-chemistry model (WRF-Chem) with a tracer-tagging technique. Generally, the simulation reasonably captures the spatial distribution of satellite retrieved dust aerosol optical depth (AOD) at different altitudes. Model results show that dust particles are emitted into atmosphere through updrafts over major desert regions, and then transported to the TP. The East Asian dust (mainly from Gobi and Taklamakan deserts) transports southward and is lifted up to the TP, contributing a mass loading of 50 mg/m<sup>2</sup> at 3 km height and 5 mg/m<sup>2</sup> at 12 km height over the northern slop of the TP. Dust from North Africa and Middle East are concentrated over both northern and southern slopes below 6 km, where mass loadings range from 10 to 100mg/m<sup>2</sup> and 1 to 10 mg/m<sup>2</sup> below 3 km and above 9 km, respectively. As the dust is transported to the north and over the TP, mass loadings are 5-10 mg/m<sup>2</sup> above 6 km.</p><p>The imported dust mass flux from East Asia to the TP is 7.9 Tg/year mostly occuring at the heights of 3–6 km. The North African and Middle East dust particles are transported eastward following the westerly jet, and then imported into the TP at West side with the dust mass flux of 7.8 and 26.6 Tg/year, respectively. The maximum mass flux of the North African dust mainly occurs in 0–3 km (3.9 Tg/year), while the Middle East within 6–9 km (12.3 Tg/year). The dust outflow occurs at East side (–17.89 Tg/year) and South side (–11.22 Tg/year) of the TP with a peak value (8.7 Tg/year) in 6–9 km . Moreover, the dust mass is within the size range of 1.25~5.0</p>

scholarly journals Modeling dust sources, transport, and radiative effects at different altitudes over the Tibetan Plateau

2019 ◽  
Author(s):  
Zhiyuan Hu ◽  
Jianping Huang ◽  
Chun Zhao ◽  
Qinjian Jin ◽  
Yuanyuan Ma ◽  
...  
Keyword(s):  
Middle East ◽  
Mass Flux ◽  
Radiative Forcing ◽  
Size Range ◽  
Dust Particles ◽  
The Tibetan Plateau ◽  
North African ◽  
The North ◽  
Dust Mass ◽  
Different Altitudes

Abstract. Mineral dust plays an important role in the climate of the Tibetan Plateau (TP) by modifying the radiation budget, cloud macro- and microphysics, precipitation, and snow albedo. Meanwhile, the TP with the highest topography in the word can affect intercontinental transport of dust plumes and induce typical distribution characteristics of dust at different altitudes. In this study, we conduct a quasi-global simulation to investigate the characteristics of dust source contribution and transport over the TP at different altitude by using a fully coupled meteorology–chemistry model (WRF–Chem) with a tracer-tagging technique. Generally, the simulation reasonably captures the spatial distribution of satellite retrieved dust aerosol optical depth (AOD) at different altitudes. Model results show that dust particles are emitted into atmosphere through updrafts over major desert regions, and then transported to the TP. The East Asian dust is transported and lifted up to the TP, contributing a mass loading of 50 mg/m2 at 3 km height and 5 mg/m2 at 12 km height over the northern slop of the TP. Dust from North Africa and Middle East are concentrated over both northern and southern slopes below 6 km, where mass loadings range from 10 to 100 mg/m2 and 1 to 10 mg/m2 below 3 km and above 9 km, respectively. As the dust is transported to the north and over the TP, mass loadings are 5–10 mg/m2 above 6 km. The imported dust mass flux from East Asia to the TP is 7.9 Tg/year mostly occuring at the heights of 3–6 km. The North African and Middle East dust particles are transported eastward following the westerly jet, and then imported into the TP at West side with the dust mass flux of 7.8 and 26.6 Tg/year, respectively. The maximum mass flux of the North African dust mainly occurs in 0–3 km (3.9 Tg/year), while the Middle East within 6–9 km (12.3 Tg/year). The dust outflow occurs at East side (−17.89 Tg/year) and South side (−11.22 Tg/year) of the TP with a peak value (8.7 Tg/year) in 6–9 km. Moreover, the dust mass is within the size range of 1.25~5.0 μm and dust number is concentrated in the size range of 0.156~1.25 μm. Compared with other aerosols, the dust contributes more than 50 % to the total AOD over the TP. The direct radiative forcing induced by the dust is −1.28 W/m2 at the top of the atmosphere (cooling), 0.41 W/m2 in the atmosphere (warming) and −1.68 W/m2 at the surface (cooling). Our quantitative analyses of the dust contribution from different source regions and the associated radiative forcing can help better understand the role of dust on the climate over the TP and surrounding regions.

scholarly journals Modeling dust sources, transport, and radiative effects at different altitudes over the Tibetan Plateau

2020 ◽  
Vol 20 (3) ◽  
pp. 1507-1529 ◽  
Author(s):  
Zhiyuan Hu ◽  
Jianping Huang ◽  
Chun Zhao ◽  
Qinjian Jin ◽  
Yuanyuan Ma ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
North Africa ◽  
Mass Flux ◽  
Radiative Forcing ◽  
Size Range ◽  
Dust Particles ◽  
The Tibetan Plateau ◽  
The North ◽  
Dust Mass ◽  
Different Altitudes

Abstract. Mineral dust plays an important role in the climate of the Tibetan Plateau (TP) by modifying the radiation budget, cloud macro- and microphysics, precipitation, and snow albedo. Meanwhile, the TP, with the highest topography in the world, can affect intercontinental transport of dust plumes and induce typical distribution characteristics of dust at different altitudes. In this study, we conduct a quasi-global simulation to investigate the characteristics of dust source contribution and transport over the TP at different altitudes by using a fully coupled meteorology–chemistry model, the Weather Research and Forecasting model with chemistry (WRF-Chem), with a tracer-tagging technique. Generally, the simulation reasonably captures the spatial distribution of satellite-retrieved dust aerosol optical depth (AOD) at different altitudes. Model results show that dust particles are emitted into atmosphere through updrafts over major desert regions and then transported to the TP. The East Asian dust (mainly from the Gobi and Taklamakan deserts) is transported southward and is lifted up to the TP, contributing a mass loading of 50 mg m−2 at a height of 3 km and 5 mg m−2 at a height of 12 km over the northern slope of the TP. Dust from North Africa and the Middle East are concentrated over both of the northern and southern slopes below 6 km, where mass loadings range from 10 to 100 and 1 to 10 mg m−2 below 3 km and above 9 km, respectively. As the dust is transported to the north and over the TP, mass loadings are 5–10 mg m−2 above a height of 6 km. The dust mass flux carried from East Asia to the TP is 7.9 Tg yr−1, mostly occurring at heights of 3–6 km. The dust particles from North Africa and the Middle East are transported eastward following the westerly jet and then are carried into the TP at the west side with dust mass fluxes of 7.8 and 26.6 Tg yr−1, respectively. The maximum mass flux of the North African dust mainly occurs at 0–3 km (3.9 Tg yr−1), while the Middle Eastern dust occurs at 6–9 km (12.3 Tg yr−1). The dust outflow occurs on the east side (−17.89 Tg yr−1) and south side (−11.22 Tg yr−1) of the TP, with a peak value (8.7 Tg yr−1) at 6–9 km. Moreover, the dust (by mass) is concentrated within the size range of 1.25–5.0 µm and the dust (by particle number) is concentrated in the size range of 0.156–1.25 µm. Compared with other aerosols, the dust contributes to more than 50 % of the total AOD over the TP. The direct radiative forcing induced by the dust is −1.28 W m−2 at the top of the atmosphere (cooling), 0.41 W m−2 in the atmosphere (warming), and −1.68 W m−2 at the surface (cooling). Our quantitative analyses of the dust contributions from different source regions and the associated radiative forcing can help us to better understand the role of dust on the climate over the TP and surrounding regions.

Spring Dust Mass Flux over the Tibetan Plateau during 2007–19 and Connections with North Atlantic SST Variability

2020 ◽  
Vol 33 (22) ◽  
pp. 9691-9703
Author(s):  
Chao Xu ◽  
Yaoming Ma ◽  
Jiehua Ma ◽  
Chao You ◽  
Huijun Wang
Keyword(s):  
Tibetan Plateau ◽  
North Atlantic ◽  
Tarim Basin ◽  
Mass Flux ◽  
The Tibetan Plateau ◽  
Indian Peninsula ◽  
The North ◽  
Dust Mass ◽  
The North Atlantic ◽  
Spring Dust

AbstractDust is the major aerosol type over the Tibetan Plateau (TP), and the TP plays an important role in forming the spring dust belt across the Northern Hemisphere in the upper troposphere. Estimated spring dust mass flux (DMF) showed a significant declining trend over the TP during 2007–19. The total spring DMF across the TP (TDMFTP) was mainly affected by DMFs over the Tarim Basin, while the spring DMF across the TP in the midtroposphere was also connected with DMFs over the northwest Indian Peninsula and central Asia. Interannual variability of spring TDMFTP was strongly correlated with the North Atlantic winter sea surface temperature (SST) tripole. A cold preceding winter induced by the North Atlantic winter SST tripole over midlatitude Eurasia promotes dust activities in the subsequent spring. The North Atlantic winter SST tripole anomalies persist into the subsequent spring and induce a corresponding atmosphere response. Enhanced atmospheric baroclinicity develops over northwest China and the northern Indian Peninsula during spring, which is attributed to surface thermal forcing induced by the positive winter SST tripole phase. A strong positive North Atlantic winter SST tripole anomaly strengthens the upper-level westerly jets, enhancing airflow toward the TP midtroposphere; together, these circulation patterns cause anomalous cyclonic conditions in the lower troposphere, especially over the Tarim Basin, via the eastward propagation of a Rossby wave train. These atmospheric circulation conditions are likely to increase the frequency of dust occurrence and promote the transport of dust onto the TP.

scholarly journals Airborne dust distributions over the Tibetan Plateau and surrounding areas derived from the first year of CALIPSO lidar observations

2008 ◽  
Vol 8 (16) ◽  
pp. 5045-5060 ◽  
Author(s):  
Z. Liu ◽  
D. Liu ◽  
J. Huang ◽  
M. Vaughan ◽  
I. Uno ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Time History ◽  
Dust Particles ◽  
The Tibetan Plateau ◽  
Airborne Dust ◽  
Dust Transport ◽  
Desert Dust ◽  
The North ◽  
Surrounding Areas ◽  
Lidar Observations

Abstract. Using an analysis of the first full year of CALIPSO lidar measurements, this paper derives unprecedented, altitude-resolved seasonal distributions of desert dust transported over the Tibetan Plateau (TP) and the surrounding areas. The CALIPSO lidar observations include numerous large dust plumes over the northern slope and eastern part of the TP, with the largest number of dust events occurring in the spring of 2007, and some layers being lofted to altitudes of 11–12 km. Generation of the Tibetan airborne dusts appears to be largely associated with source regions to the north and on the eastern part of the plateau. Examination of the CALIPSO time history reveals an "airborne dust corridor" due to the eastward transport of dusts originating primarily in these source areas. This corridor extends from west to east and shows a seasonality largely modulated by the TP through its dynamical and thermal forcing on the atmospheric flows. On the southern side, desert dust particles originate predominately in Northwest India and Pakistan. The dust transport occurs primarily in dry seasons around the TP western and southern slopes and dust particles become mixed with local polluted aerosols. No significant amount of dust appears to be transported over the Himalayas. Extensive forward trajectory simulations are also conducted to confirm the dust transport pattern from the nearby sources observed by the CALIPSO lidar. Comparisons with the OMI and MODIS measurements show the unique capability of the CALIPSO lidar to provide unambiguous, altitude-resolved dust measurements.

Size distribution of PM20 observed to the north of the Tibetan Plateau

2021 ◽  
Vol 18 (2) ◽  
pp. 367-376
Author(s):  
Cheng-long Zhou ◽  
Fan Yang ◽  
Wen Huo ◽  
Ali Mamtimin ◽  
Xing-hua Yang
Keyword(s):  
Tibetan Plateau ◽  
Size Distribution ◽  
The Tibetan Plateau ◽  
The North

scholarly journals The North African “Extremistan” of the Islamic State Caliphate

2016 ◽  
Vol 22 (1) ◽  
pp. 10-13
Author(s):  
Adrian Cosmin Basarabă ◽  
Maria-Mihaela Nistor
Keyword(s):  
Middle East ◽  
Real Estate ◽  
North Africa ◽  
Islamic State ◽  
North African ◽  
Boko Haram ◽  
Ongoing Process ◽  
The North ◽  
Terrorist Groups ◽  
Cellular Matrices

Abstract This article aims at presenting ISIS expansion in North Africa in the first quarter of 2016, with its subsequent implication in the wider framework of Jihadist proliferation worldwide. It can be argued that, while losing real estate in the Middle East, ISIS has started a permanent search for extra-cellular matrices or an ongoing process of de- and reterritorialization. The allegiance and support pledged by other African-based terrorist groups or organizations such as Boko Haram, al-I’tisam of the Koran and Sunnah in Sudan, al-Huda Battalion in Maghreb of Islam, The Soldiers of the Caliphate, al-Ghurabaa, Djamaat Houmat ad-Da’wa as-Salafiya and al-Ansar Battalion in Algeria, Islamic Youth Shura Council, Islamic State Libya (Darnah), in Libya, Jamaat Ansar Bait al-Maqdis, Jund al-Khilafah and Mujahideen Shura Council in the Environs of Jerusalem in Egypt, Okba Ibn Nafaa Battalion, Mujahideen of Tunisia of Kairouan and Jund al-Khilafah in Tunisia and al-Shabaab Jubba Region Cell Bashir Abu Numan in Somalia is an alarming hypothesis of Jihadism reaching “the threshold of inevitability”- syntagm existent in the network theories of David Singh Grewal- turning a whole region, continent of even world into what Nassim Nicholas Taleb would call Extremistan.

A new species of Cleistocybe (Agaricales, Basidiomycota) from the Tibetan Plateau, China

Phytotaxa ◽  
2018 ◽  
Vol 336 (3) ◽  
pp. 286 ◽  
Author(s):  
HONG-MEI WU ◽  
JIA-QI LUO ◽  
KE WANG ◽  
RUN-CHAO ZHANG ◽  
YI LI ◽  
...  
Keyword(s):  
New Species ◽  
Tibetan Plateau ◽  
Phylogenetic Analyses ◽  
Morphological Observation ◽  
Morphological Description ◽  
The Tibetan Plateau ◽  
Sequence Analyses ◽  
The North ◽  
Close Relationship ◽  
A New Species

During field expeditions to the Tibetan Plateau, a collection of an undescribed species with several basidiomes was found. Morphological observation and DNA sequence analyses of the collection revealed a close relationship with Cleistocybe vernalis, the type species of the genus Cleistocybe. Therefore, a new species is proposed for the fungus with full morphological description accompanied by phylogenetic analyses. The discovery of the species extends the reported distribution of the genus from the north of America and Europe to Asia.

“Tiny wiggles” in the Late Miocene red clay deposits in the north‐east of the Tibetan Plateau

2021 ◽  
Author(s):  
Rui Zhang ◽  
Xiaohao Wei ◽  
Vadim A. Kravchinsky ◽  
Leping Yue ◽  
Yan Zheng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Miocene ◽  
The Tibetan Plateau ◽  
Red Clay ◽  
North East ◽  
The North ◽  
Clay Deposits
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