Recent Dust Outbreaks in the Taklimakan Desert and their Relation to Surface Wind and Land Surface Condition

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.

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Simulation and Analysis of Land-Surface Processes in the Taklimakan Desert Based on Noah LSM

Advances in Meteorology ◽

10.1155/2019/1750102 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Huoqing Li ◽

Ali Mamtimin ◽

Chenxiang Ju

Keyword(s):

Heat Flux ◽

Soil Moisture ◽

Land Surface ◽

Exchange Process ◽

Model Performance ◽

Surface Model ◽

Taklimakan Desert ◽

Observation Data ◽

Net Radiation ◽

The Taklimakan Desert

This study evaluated the Noah land-surface model performance to simulate the land-surface process during different weather conditions in the hinterland of the Taklimakan Desert. This study is based on observation data from the Taklimakan Desert Meteorology Field Experiment Station in 2014. The results illustrated that the energy-exchange process between the land surface and the atmosphere in the drifting desert can be simulated by Noah effectively. However, the effects of soil moisture and latent heat flux were very poor. For sunny days, the soil temperature and heat flux were underestimated significantly in the nighttime and overestimated in the daytime. The simulation results are very good in sand-dust weather. The simulation of heat flux and net radiation is very consistent with the observation during cloudy days. For rainy days, the model can successfully model the diurnal variation of soil moisture, but it has obvious deviations in the net radiation, heat flux, and soil heat flux.

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Comparison of Surface Wind Speed and Wind Speed Profiles in the Taklimakan Desert

10.21203/rs.3.rs-723326/v2 ◽

2021 ◽

Author(s):

Liu Xinchun ◽

kang yongde ◽

Chen Hongna ◽

Lu Hui

Keyword(s):

Wind Speed ◽

Hydrological Cycle ◽

Similarity Theory ◽

Surface Wind ◽

Taklimakan Desert ◽

Diurnal Changes ◽

Wind Speed Profile ◽

Near Surface ◽

The Taklimakan Desert ◽

Neutral Stratification

Abstract Near-surface (10 m) wind speed (NWS) plays a crucial role in many areas, including the hydrological cycle, wind energy production, and the dispersion of air pollution. Based on wind speed data from Tazhong and the northern margins of the Taklimakan Desert in Xiaotang in spring, summer, autumn, and winter of 2014 and 2015, statistical methods were applied to determine the characteristics of the diurnal changes in wind speed near the ground and the differences in the wind speed profiles between the two sites. The average wind speed on a sunny day increased slowly with height during the day and rapidly at night. At heights below 4 m the wind speed during the day was higher than at night, whereas at 10 m the wind speed was lower during the day than at night. The semi-empirical theory and Monin-Obukhov (M-O) similarity theory were used to fit the NWS profile in the hinterland of the Tazhong Desert. A logarithmic law was applied to the neutral stratification wind speed profile, and an exponential fitting correlation was used for non-neutral stratification. The more unstable the stratification, the smaller the n. Using M-O similarity theory, the “linear to tens of” law was applied to the near-neutral stratification. According to the measured data, the distribution of φM with stability was obtained. The γm was obtained when the near-surface stratum was stable in the hinterland of Tazhong Desert and the βm was obtained when it was unstable. In summer, γm and βm were 5.84 and 15.1, respectively, while in winter, γm and βm were 1.9 and 27.1, respectively.

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Coefficients optimization of the GLASS broadband emissivity based on FTIR and MODIS data over the Taklimakan Desert

Scientific Reports ◽

10.1038/s41598-019-54982-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Aynigar Yalkun ◽

Ali Mamtimin ◽

Suhong Liu ◽

Fan Yang ◽

Qing He ◽

...

Keyword(s):

Land Surface ◽

Taklimakan Desert ◽

Sparse Vegetation ◽

Land Surface Emissivity ◽

The Taklimakan Desert ◽

Before And After ◽

Moderate Resolution ◽

Resolution Imaging ◽

Moderate Resolution Imaging Spectroradiometer ◽

Thermal Infrared Spectroscopy

AbstractIn this paper, the Taklimakan Desert land surface emissivity measured by portable Fourier Transform thermal InfraRed spectroscopy (FTIR) was used to re-estimate Global LAnd Surface Satellite (GLASS) BroadBand Emissivity (BBE) and Moderate Resolution Imaging Spectroradiometer (MODIS) BBE optimal coefficients equations. In addition, the revised BBE equations of both GLASS and MODIS with the optimized coefficients were obtained. Comparing the FTIR and MODIS BBE data with the values retrieved before and after the revised GLASS BBE equation, it was found that the revised GLASS BBE equation is more accurate than the original one. First, according to the error analysis with FTIR data, the value of R2 is increased from 0.4 to 0.9, and the Root Mean Square Error (RMSE) and Bias are reduced by 1 and 3 magnitude orders, respectively. Second, with MODIS BBE data, the value of R2 is increased from 0.6 to 0.9, the RMSE and Bias are reduced by 1 and 2 magnitude orders, respectively. Finally, the Taklimakan Desert BBE was calculated using the revised GLASS BBE equation. The results showed that the BBE values are between 0.890 and 0.920 in the desert center, between 0.920 and 0.950 in the sparse vegetation areas, and between 0.950 and 0.980 in the oasis edges.

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Controlling blown sand along the highway crossing the Taklimakan Desert

Journal of Arid Environments ◽

10.1016/j.jaridenv.2002.02.001 ◽

2004 ◽

Vol 57 (3) ◽

pp. 329-344 ◽

Cited By ~ 46

Author(s):

Zhibao Dong ◽

Guangting Chen ◽

Xingdong He ◽

Zhiwen Han ◽

Xunming Wang

Keyword(s):

Taklimakan Desert ◽

The Taklimakan Desert

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Intercomparison of Mesoscale Model Simulations of the Daytime Valley Wind System

Monthly Weather Review ◽

10.1175/2010mwr3523.1 ◽

2011 ◽

Vol 139 (5) ◽

pp. 1389-1409 ◽

Cited By ~ 42

Author(s):

Juerg Schmidli ◽

Brian Billings ◽

Fotini K. Chow ◽

Stephan F. J. de Wekker ◽

James Doyle ◽

...

Keyword(s):

Land Surface ◽

Mesoscale Model ◽

Numerical Models ◽

Surface Wind ◽

Sensible Heat Flux ◽

Surface Wind Speed ◽

Time Shift ◽

Wind System ◽

Valley Wind ◽

The Mean

Three-dimensional simulations of the daytime thermally induced valley wind system for an idealized valley–plain configuration, obtained from nine nonhydrostatic mesoscale models, are compared with special emphasis on the evolution of the along-valley wind. The models use the same initial and lateral boundary conditions, and standard parameterizations for turbulence, radiation, and land surface processes. The evolution of the mean along-valley wind (averaged over the valley cross section) is similar for all models, except for a time shift between individual models of up to 2 h and slight differences in the speed of the evolution. The analysis suggests that these differences are primarily due to differences in the simulated surface energy balance such as the dependence of the sensible heat flux on surface wind speed. Additional sensitivity experiments indicate that the evolution of the mean along-valley flow is largely independent of the choice of the dynamical core and of the turbulence parameterization scheme. The latter does, however, have a significant influence on the vertical structure of the boundary layer and of the along-valley wind. Thus, this ideal case may be useful for testing and evaluation of mesoscale numerical models with respect to land surface–atmosphere interactions and turbulence parameterizations.

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