scholarly journals Phylogenetic analysis of bacterial species compositions in sand dunes and dust aerosol in an Asian dust source area, the Taklimakan Desert

2015 ◽  
Vol 9 (6) ◽  
pp. 631-644 ◽  
Author(s):  
Findya Puspitasari ◽  
Teruya Maki ◽  
Guangyu Shi ◽  
Chen Bin ◽  
Fumihisa Kobayashi ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Sand Dunes ◽  
Bacterial Species ◽  
Source Area ◽  
Asian Dust ◽  
Dust Aerosol ◽  
Taklimakan Desert ◽  
Dust Source ◽  
The Taklimakan Desert

scholarly journals Estimating radiative forcing efficiency of dust aerosol based on direct satellite observations: case studies over the Sahara and Taklimakan Desert

2021 ◽  
Vol 21 (15) ◽  
pp. 11669-11687
Author(s):  
Lin Tian ◽  
Lin Chen ◽  
Peng Zhang ◽  
Lei Bi
Keyword(s):  
Radiative Forcing ◽  
Complex Refractive Index ◽  
Satellite Observations ◽  
Dust Aerosol ◽  
Taklimakan Desert ◽  
Dust Source ◽  
Dust Aerosols ◽  
Microphysical Properties ◽  
Source Regions ◽  
The Taklimakan Desert

Abstract. The direct radiative forcing efficiency of dust aerosol (DRFEdust) is an important indicator to measure the climate effect of dust. The DRFEdust is determined by the microphysical properties of dust, which vary with dust source regions. However, there are only sparse in situ measurements of them, such as the distribution of the dust aerosol particle size and the complex refractive index in the main dust source regions. Furthermore, recent studies have shown that the non-spherical effect of the dust particle is not negligible. The DRFEdust is often evaluated by estimating given microphysical properties of the dust aerosols in the radiative transfer model (RTM). However, considerable uncertainties exist due to the complex and variable dust properties, including the complex refractive index and the shape of the dust. The DRFEdust over the Taklimakan Desert and Sahara is derived from the satellite observations in this paper. The advantage of the proposed satellite-based method is that there is no need to consider the microphysical properties of the dust aerosols in estimating the DRFEdust. For comparison, the observed DRFEdust is compared with that simulated by the RTM. The differences in the dust microphysical properties in these two regions and their impacts on DRFEdust are analyzed. The DRFEdust derived from the satellite observation is -39.6±10.0 W m-2τ-1 in March 2019 over Tamanrasset in the Sahara and -48.6±13.7 W m-2τ-1 in April 2019 over Kashi in the Taklimakan Desert. According to the analyses of their microphysical properties and optical properties, the dust aerosols from the Taklimakan Desert (Kashi) scatter strongly. The RTM-simulated results (−41.5 to −47.4 W m-2τ-1 over Kashi and −32.2 to −44.3 W m-2τ-1 over Tamanrasset) are in good agreement with the results estimated by satellite observations. According to previous studies, the results in this paper are proven to be reasonable and reliable. The results also show that the microphysical properties of the dust can significantly influence the DRFEdust. The satellite-derived results can represent the influence of the dust microphysical properties on the DRFEdust, which can also validate the direct radiative effect of the dust aerosol and the DRFEdust derived from the numerical model more directly.

scholarly journals Solar radiative forcing of aerosol particles near the Taklimakan desert during the Dust Aerosol Observation-Kashi campaign in Spring 2019

2020 ◽  
Author(s):  
Li Li ◽  
Zhengqiang Li ◽  
Wenyuan Chang ◽  
Yang Ou ◽  
Philippe Goloub ◽  
...  
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Surface Albedo ◽  
Dust Aerosol ◽  
Dust Particles ◽  
Taklimakan Desert ◽  
Aerosol Radiative Forcing ◽  
Microphysical Properties ◽  
The Taklimakan Desert ◽  
Cooling Effects

Abstract. The Taklimakan desert is a main and continuous source of Asian dust particles causing a significant direct aerosol solar radiative forcing (ASRF). In order to improve the accuracy of the estimation of dust radiative forcing effects, the Dust Aerosol Observation-Kashi (DAO-K) campaign was carried out near the Taklimakan desert in April 2019. The objective of the campaign is to provide comprehensive parameters such as: dust optical and microphysical properties, vertical distribution and surface albedo, for the calculation of ASRF. The measurements were employed in radiative transfer (RT) simulations and the estimations are improved by considering the actual measured atmospheric profiles and diurnal variations of land surface albedo in addition to reliable aerosol parameters. The RT model estimates the ASRF results in average daily mean cooling effects of −19 W m−2 at the top of atmosphere and −36 W m−2 at the bottom of atmosphere during the DAO-K campaign. The Weather Research and Forecasting model with Chemistry (WRF-Chem) with assimilations of the aerosol optical depth and PM2.5 and PM10 concentrations measurements is prone to overestimate the radiative forcing effects of dust aerosols. The percent difference of daily mean ASRF between the two simulations are greater than 50 % in heavy dust episode. Ground-based observations of downward irradiances have validated that the RT simulations are in good agreement with simultaneous observations, whereas the WRF-Chem estimations exhibit obvious discrepancy with these independent measurements. Data assimilations can partly reduce the discrepancy, but there is still room for improving the WRF-Chem simulation of dust aerosol radiative forcing.

scholarly journals Variability in Dust Observed over China Using A-Train CALIOP Instrument

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hui Xu ◽  
Fengjie Zheng ◽  
Wenhao Zhang
Keyword(s):  
Soil Moisture ◽  
Correlation Coefficients ◽  
Dust Aerosol ◽  
Vegetation Coverage ◽  
Taklimakan Desert ◽  
Vertical Column ◽  
Dust Source ◽  
Dust Layer ◽  
Source Regions ◽  
Vertical Variations

Patterns of dust aerosol variation over China are analyzed using A-Train CALIOP and precipitation, soil moisture, and vegetation coverage datasets during the period of 2007 and 2014. Spatially, dust is mostly prominent over northwestern China, with the highest and most widespread dust activities being in Taklimakan Desert. Dust is generally distributed across the atmosphere up to 5 km altitude, with a peak of DAFOD around 3 km. The dust layer has a significant geographical and seasonal drifting, with higher altitude in spring and summer and dust source regions (between 3 km and 5 km). Additionally, single dust layer is more often observed in a vertical column. Temporally, high amounts of dust aerosol (C-DAFOD as high as 0.08) experienced in spring subsequently continuous decrease until the spring of next year. The correlation coefficients between the latitude averaged column integrated dust aerosol feature optical depth (C-DAFOD) and precipitation, soil moisture, and vegetation coverage are −0.65, −0.81, and −0.77, respectively. The correlation coefficients of seasonal mean C-DAFOD with the three factors are −0.15, −0.67, and −0.35, respectively. The analysis showed dust and the other three factors are negatively correlated. Overall, dust over China shows considerable spatial, temporal, and vertical variations.

scholarly journals Trans-pacific dust transport: integrated analysis of NASA/CALIPSO and a global aerosol transport model

2009 ◽  
Vol 9 (9) ◽  
pp. 3137-3145 ◽  
Author(s):  
K. Eguchi ◽  
I. Uno ◽  
K. Yumimoto ◽  
T. Takemura ◽  
A. Shimizu ◽  
...  
Keyword(s):  
North America ◽  
Dust Storm ◽  
Air Pollutants ◽  
Asian Dust ◽  
Integrated Analysis ◽  
Gobi Desert ◽  
Taklimakan Desert ◽  
Dust Layer ◽  
Dust Transport ◽  
The Taklimakan Desert

Abstract. Detailed 3-D structures of Trans-Pacific Asian dust transport occurring during 5–15 May 2007 were investigated using the NASA/CALIOP vertical-resolved measurements and a three-dimensional aerosol model (SPRINTARS). Both CALIOP and SPRINTARS dust extinctions showed a good agreement along the way of the transport from the dust source regions across North Pacific into North America. A vertically two-layered dust distribution was observed over the northeastern Pacific and North America. The lower dust layer originated from a dust storm generated in the Gobi Desert on 5 May. It was transported at an altitude of around 4 km MSL and has mixed with Asian anthropogenic air pollutants during the course of transport. The upper dust layer mainly originated from a dust storm that occurred in the Taklimakan Desert 2–3 days after the Gobi dust storm generation. The upper dust cloud was transported in higher altitudes above the major clouds layer during the Trans-Pacific transport. It therefore has remained unmixed with the Asian air pollutants and almost unaffected by wet removal. The decay of its concentration level was small (only one-half after its long-distance transport crossing the Pacific). Our dust budget analysis revealed that the Asian dust flux passing through the longitude plane of 140° E was 2.1 Tg, and one third of that arrived North America. The cases analyzed in this study revealed that, while the Gobi Desert is an important source that can contribute to the long-range dust transport, the Taklimakan Desert appears to be another important source that can contribute to the dust transport occurring particularly at high altitudes.

scholarly journals Trans-Pacific dust transport: integrated analysis of NASA/CALIPSO and a global aerosol transport model

2009 ◽  
Vol 9 (1) ◽  
pp. 4013-4034 ◽  
Author(s):  
K. Eguchi ◽  
I. Uno ◽  
K. Yumimoto ◽  
T. Takemura ◽  
A. Shimizu ◽  
...  
Keyword(s):  
North America ◽  
Dust Storm ◽  
Air Pollutants ◽  
Asian Dust ◽  
Integrated Analysis ◽  
Gobi Desert ◽  
Taklimakan Desert ◽  
Dust Layer ◽  
Dust Transport ◽  
The Taklimakan Desert

Abstract. Detailed 3-D structures of Trans-Pacific Asian dust transport occurring during 5–15 May 2007 were investigated using the NASA/CALIOP vertical-resolved measurements and a three-dimensional aerosol model (SPRINTARS). Both CALIOP and SPRINTARS dust extinctions showed a good agreement along the way of the transport from the dust source regions across North Pacific into North America. A vertically two-layered dust distribution was observed over the northeastern Pacific and North America. The lower dust layer originated from a dust storm generated in the Gobi Desert on 5 May. It was transported at an altitude of around 4 km MSL and has mixed with Asian anthropogenic air pollutants during the course of transport. The upper dust layer mainly originated from a dust storm that occurred in the Taklimakan Desert 2–3 days after the Gobi dust storm generation. The upper dust cloud was transported in higher altitudes above the major clouds layer during the Trans-Pacific transport. It therefore has remained unmixed with the Asian air pollutants and almost unaffected by wet removal. The decay of its concentration level was small (only one-half after its long-distance transport crossing the Pacific). Our dust budget analysis revealed that the Asian dust flux passing through the longitude plane of 140° E was 2.1 Tg, and one third of that arrived North America. The cases analyzed in this study revealed that, while the Gobi Desert is an important source that can contribute to the long-range dust transport, the Taklimakan Desert appears to be another important source that can contribute to the dust transport occurring particularly at high altitudes.

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