Abstract

A special topography and ultra-high atmospheric boundary layer conditions in the Tarim Basin (TB) lead to the unique spatial–temporal distribution characteristics of dust aerosols. A typical dust storm with persistent floating dust over the TB from 27 April to 1 May 2015 was used to investigate the characteristics of the dust radiative effect using the Weather Research and Forecasting Model with Chemistry (WRF-Chem). Based on reasonable evaluations involving in situ sounding observations, as well as remotely sensed MODIS observations of meteorology, dust aerosols, and the ultra-high atmospheric boundary layer, the simulation characterized the complete characteristics of the dust direct radiative effect (DDRE) during the dust storm outbreak stage and persistent floating dust stage over the TB. During the daytime, the shortwave (SW) radiative effect heated the atmosphere and cooled the land surface (SUR), whereas the longwave (LW) radiative effect had the opposite effect on the TB. Regarding low-level dust, the LW radiative effect was greater than the SW DDRE in the atmosphere, while for high-level dust the situation was reversed. During the nighttime, the LW DDRE at the top of the atmosphere (TOA), at the SUR, and in the atmosphere was less than that during the daytime, when the DDRE at the SUR was the most significant. In contrast to the daytime, the near-surface dust aerosols exerted an LW warming effect in the atmosphere during the nighttime; however, the dust LW radiative effect had a cooling effect from above a 100 m altitude until the top of the dust layer. In contrast, the DDRE heating rate peaked at the top of the dust layer within the TB. The event-averaged net DDRE was 0.53, −5.90, and 6.43 W m−2 at the TOA, at the SUR, and in the atmosphere over the TB, respectively. The dust SW radiative effect was stronger than the dust L4W radiative effect over the TB at the SUR and in the atmosphere. Moreover, the DDRE at the TOA was weaker than that at the SUR. Overall, the study revealed noteworthy radiative effect features of dust aerosols during typical dust storms with persistent floating dust over the TB.

Highlights

  • IntroductionThe sources, compositions, and contents of atmospheric aerosols and their impacts on the atmospheric environment, ecology, and climate change are prominent topics of research in the fields of environmental science, ecology, meteorology, and geography [1,2]

  • The sources, compositions, and contents of atmospheric aerosols and their impacts on the atmospheric environment, ecology, and climate change are prominent topics of research in the fields of environmental science, ecology, meteorology, and geography [1,2].Approximately 1–3 billion tons of aerosols are being released into the atmosphere each year [3], of which approximately 800 million tons are dust aerosols [4]

  • Dust aerosols contain a high amount of Fe2+, which is necessary for seawater plankton

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Summary

Introduction

The sources, compositions, and contents of atmospheric aerosols and their impacts on the atmospheric environment, ecology, and climate change are prominent topics of research in the fields of environmental science, ecology, meteorology, and geography [1,2]. Given the special topography and ultra-high atmospheric boundary layer in the TB, there is still a scarcity of data on the radiative effect characteristics of dust aerosols during typical dust storms with persistent floating dust within the TB. A complete understanding of the DDRE characteristics in the TB is essential for fully comprehending regional/global climate change and further improving and refining weather prediction models For this purpose, we used WRF-Chem simulations with and without dust particles for comparing and analyzing the average radiative effect characteristics of dust over the TB during the daytime and nighttime. We revealed the DDRE characteristics over the TB during a typical dust storm with persistent floating dust

Climate Characteristic of AOD over the Tarim Basin
WRF-Chem
Observations
Model Validation x FOR PEER REVIEW
Synoptic Variations during the Dust Storm
Daily Variation Characteristics of the Dust Radiative Effect
Direct Radiative Effect Induced by Dust during the Daytime
Vertical
Direct byby
Regional
Findings
Conclusions
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