Dust aerosols substantially impinge on the Earth’s climate by altering its energy balance, particularly over Northwest China, where dust storms occur frequently. However, the quantitative contributions of dust aerosols to direct radiative forcing (DRF) are not fully understood and warrant in-depth investigations. Taking a typical dust storm that happened during 9–12 April 2020 over Northwest China as an example, four simulation experiments based on the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) were designed, including a real scenario with dust emissions and three hypothetical scenarios without dust emissions, with dust emissions doubled, and with dust emissions reduced by half, to quantitatively evaluate the contributions of dust aerosols to DRF and then to surface temperature, with particular attention to the differences between daytime and nighttime. Moreover, multi-satellite observations were used to reveal the behavior of dust events and to evaluate the model performance. During the daytime, the net dust radiative forcing induced by dust aerosols was −3.76 W/m² at the surface (SFC), 3.00 W/m² in the atmosphere (ATM), and −0.76 W/m² at the top of the atmosphere (TOA), and thus led to surface air temperature cooling by an average of −0.023 °C over Northwest China. During the nighttime, the net dust radiative forcing was 2.20 W/m² at the SFC, −2.65 W/m² in the ATM, and −0.45 W/m² at the TOA, which then resulted in surface temperature warming by an average of 0.093 °C over Northwest China. These results highlight that the contribution of dust aerosols to DRF is greater during the daytime than that during the nighttime, while exhibiting the opposite impact on surface temperature, as dust can slow down the rate of surface temperature increases (decreases) by reducing (increasing) the surface energy during the daytime (nighttime). Our findings are critical to improving the understanding of the climate effects related to dust aerosols and provide scientific insights for coping with the corresponding disasters induced by dust storms in Northwest China.

Every spring, the dust weather in the northwest and northern regions of China comes into a frequent period, which seriously affects people’s lives and capacity for production. When the direct radiative effect of dust aerosol changes the energy distribution of the Earth-atmosphere system, the temperature field and boundary layer in the dust-affected area respond quickly. Therefore, it is of great scientific significance to study the direct radiative effect of dust aerosol on the temperature field and boundary layer. In this case study of a typical dust storm event during 5–8 May 2021, we use ground-based observations, satellite data, reanalysis products, and numerical model simulations to quantitatively evaluate the influence of the direct radiative effect of dust aerosols on the daytime and nighttime temperature field. We also focus on the impact of dust weather on the boundary layer and the interaction mechanisms among dust aerosols, the temperature field, and the boundary layer. The results showed the following: (1) Dust aerosols tend to make atmospheric stratification more stable during the day and less stable at night. Dust aerosols decreased the planetary boundary layer height (PBLH) by 109 m in the daytime, but increased it by 215 m at night. (2) The most significant daytime cooling effect is −0.26 °C at an altitude of 0–1 km, while the most significant nighttime warming effect is 0.07 °C at an altitude of 2–3 km. (3) In this event, warm advection was present prior to dust arrival. When dust weather occurs at night, the warming effect of dust aerosol is superimposed on the influence of warm advection, resulting in a temperature increase range near the surface caused by dust aerosol up to 1.55 °C. This results in enhanced thermal instability in the middle and lower layers, further sustaining the development of the ongoing dust weather.

PM_2.5 pollution poses significant risks to human health and the environment, underscoring the importance of accurate PM_2.5 simulation. This study simulated a representative PM_2.5 pollution event using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem), incorporating the assimilation of infrared atmospheric motion vector (AMV) data from the Fengyun-4A (FY-4A) satellite. A comprehensive analysis was conducted to examine the meteorological characteristics of the event and their influence on PM_2.5 concentration simulations. The results demonstrate that the assimilation of FY-4A infrared AMV data significantly enhanced the simulation performance of meteorological variables, particularly improving the wind field and capturing local and small-scale wind variations. Moreover, PM_2.5 concentrations simulated with AMV assimilation showed improved spatial and temporal agreement with ground-based observations, reducing the root mean square error (RMSE) by 8.2% and the mean bias (MB) by 15.2 µg/m³ relative to the control (CTL) experiment. In addition to regional improvements, the assimilation notably enhanced PM_2.5 simulation accuracy in severely polluted cities, such as Tangshan and Tianjin. Mechanistic analysis revealed that low wind speeds and weak atmospheric divergence restricted pollutant dispersion, resulting in higher near-surface concentrations. This was exacerbated by cooler nighttime temperatures and a lower planetary boundary layer height (PBLH). These findings underscore the utility of assimilating satellite-derived wind products to enhance regional air quality modeling and forecasting accuracy. This study highlights the potential of FY-4A infrared AMV data in improving regional pollution simulations, offering scientific support for the application of next-generation Chinese geostationary satellite data in numerical air quality forecasting.