Aerosol direct radiative forcing in desert and semi-desert regions of northwestern China

Xin, Jinyuan; Gong, Chongshui; Wang, Shigong; Wang, Yuesi

doi:10.1016/j.atmosres.2015.12.004

Cited by 52 publications

(19 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dependences between radiative efficiency and SSA are approximately linear, but the dependences between radiative efficiency and imaginary refractive index become less apparent with increasing imaginary refractive index. The strong dependence between aerosol radiative efficiency and SSA has also been shown over central China and desert and semi-desert regions of northwestern China (Xin et al, 2016;Zhang et al, 2017).…”

Section: Discussionmentioning

confidence: 97%

Radiative absorption enhancement of dust mixed with anthropogenic pollution over East Asia

Tian

Zhang

et al. 2018

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. The particle mixing state plays a significant yet poorly quantified role in aerosol radiative forcing, especially for the mixing of dust (mineral absorbing) and anthropogenic pollution (black carbon absorbing) over East Asia. We have investigated the absorption enhancement of mixed-type aerosols over East Asia by using the Aerosol Robotic Network observations and radiative transfer model calculations. The mixed-type aerosols exhibit significantly enhanced absorbing ability than the corresponding unmixed dust and anthropogenic aerosols, as revealed in the spectral behavior of absorbing aerosol optical depth, single scattering albedo, and imaginary refractive index. The aerosol radiative efficiencies for the dust, mixed-type, and anthropogenic aerosols are −101.0, −112.9, and −98.3 Wm −2 τ −1 at the bottom of the atmosphere (BOA); −42.3, −22.5, and −39.8 Wm −2 τ −1 at the top of the atmosphere (TOA); and 58.7, 90.3, and 58.5 Wm −2 τ −1 in the atmosphere (ATM), respectively. The BOA cooling and ATM heating efficiencies of the mixed-type aerosols are significantly higher than those of the unmixed aerosol types over the East Asia region, resulting in atmospheric stabilization. In addition, the mixed-type aerosols correspond to a lower TOA cooling efficiency, indicating that the cooling effect by the corresponding individual aerosol components is partially counteracted. We conclude that the interaction between dust and anthropogenic pollution not only represents a viable aerosol formation pathway but also results in unfavorable dispersion conditions, both exacerbating the regional air pollution in East Asia. Our results highlight the necessity to accurately account for the mixing state of aerosols in atmospheric models over East Asia in order to better understand the formation mechanism for regional air pollution and to assess its impacts on human health, weather, and climate.

show abstract

Section: Discussionmentioning

confidence: 97%

Radiative absorption enhancement of dust mixed with anthropogenic pollution over East Asia

Tian

Zhang

et al. 2018

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…This suggests that there is a non-negligible atmospheric absorption of solar radiation that induces a significant warming of the atmosphere. Few studies have investigated the longwave radiative effects associated with desert dust intrusions [28][29][30][31][32]. These works note that, on the daily timescale, the longwave effect may compensate for a large fraction (up to 50%) of the substantial decrease of shortwave irradiance recorded at the surface during desert dust episodes.…”

Section: Introductionmentioning

confidence: 99%

Estimation of Downwelling Surface Longwave Radiation under Heavy Dust Aerosol Sky

Wang

Tang

et al. 2017

Remote Sensing

View full text Add to dashboard Cite

Abstract:The variation of aerosols, especially dust aerosol, in time and space plays an important role in climate forcing studies. Aerosols can effectively reduce land surface longwave emission and re-emit energy at a colder temperature, which makes it difficult to estimate downwelling surface longwave radiation (DSLR) with satellite data. Using the latest atmospheric radiative transfer code (MODTRAN 5.0), we have simulated the outgoing longwave radiation (OLR) and DSLR under different land surface types and atmospheric profile conditions. The results show that dust aerosol has an obvious "warming" effect to longwave radiation compared with other aerosols; that aerosol longwave radiative forcing (ALRF) increased with the increasing of aerosol optical depth (AOD); and that the atmospheric water vapor content (WVC) is critical to the understanding of ALRF. A method is proposed to improve the accuracy of DSLR estimation from satellite data for the skies under heavy dust aerosols. The AOD and atmospheric WVC under cloud-free conditions with a relatively simple satellite-based radiation model yielding the high accurate DSLR under heavy dust aerosol are used explicitly as model input to reduce the effects of dust aerosol on the estimation of DSLR. Validations of the proposed model with satellites data and field measurements show that it can estimate the DSLR accurately under heavy dust aerosol skies. The root mean square errors (RMSEs) are 20.4 W/m 2 and 24.2 W/m 2 for Terra and Aqua satellites, respectively, at the Yingke site, and the biases are 2.7 W/m 2 and 9.6 W/m 2 , respectively. For the Arvaikheer site, the RMSEs are 23.2 W/m 2 and 19.8 W/m 2 for Terra and Aqua, respectively, and the biases are 7.8 W/m 2 and 10.5 W/m 2 , respectively. The proposed method is especially applicable to acquire relatively high accurate DSLR under heavy dust aerosol using MODIS data with available WVC and AOD data.

show abstract

“…Furthermore, they also claimed that the global average dust DRF was significantly underestimated as a result of less coarser dust aerosols in these current GCMs, which shows a much larger dust DRF of almost −0.2 W m −2 based on a new size 15 distribution of dust aerosols derived from Kok (2011) (Kok et al, 2017). Due to larger dust loading (Zhang et al, 2012) and dust AOD over East Asia (Che et al, 2015), the average dust DRF over this region is much larger than that for the global mean (Zhang et al, 2009;Sun et al, 2012;Han et al, 2012;Xin et al, 2016), which could further influence the East Asian climate significantly (Lau et al, 2006;Sun et al, 2012Sun et al, , 2017Gu et al, 2016;Tang et al, 2018). A mechanism of Elevated Heat Pump (EHP) from absorbing aerosols, affects the monsoon atmospheric circulation and the summer monsoon precipitation over the 20 South and East Asia in late spring and early summer (Lau et al, 2006).…”

Section: Introductionmentioning

confidence: 82%

Modulation of surface sensible heating over the Tibetan Plateau on the interannual variability of East Asian dust cycle

Xie¹,

Duan²,

Shi³

et al. 2020

Preprint

View full text Add to dashboard Cite

Previous observational evidence and numerical simulations have revealed that the surface sensible heating in MAM (March-April-May) over the Tibetan Plateau (TPSH) can affect the Asian regional hydrological cycle, surface energy balance, and climate through altering atmospheric heat source of the Tibetan Plateau (TP). This study aims to investigate the impacts of MAM TPSH on the interannual variability of East Asian dust cycle by use of CAM4-BAM (version 4 of the Community Atmosphere Model coupled to a bulk aerosol model), the MERRA-2 (version 2 of the Modern Era Retrospective-Analysis for 5Research and Applications) surface dust concentration, and TPSH measurements. Our simulations show that the surface dust concentrations over the East Asian dust source region (EA) and over the northwestern Pacific (NP) in MAM are significantly positively correlated with TPSH, with regionally averaged correlation coefficients of 0.49 for EA and 0.44 for NP. Similar positive correlations are also shown to exist between the MAM TPSH measurements averaged over the 73 observation sites and the surface dust concentration from MERRA-2. Simulation-based comparisons between strongest and weakest TPSH years 10 reveal that, the MAM surface dust concentration in the strongest TPSH years increases with relative differences of 13.1% over EA and 36.9% over NP. These corresponding differences are found in MERRA-2 with 22.9% and 13.3% over EA and NP, respectively. Further simulated results show that the processes of whole dust cycles (e.g., dust loading, emission, and transport, as well as dust depositions) are also significantly enhanced during the strongest TPSH yeas over EA and NP. Through enhancing the TP heat source, stronger TPSH in MAM generates an anticyclonic anomaly in middle and upper troposphere over TP and 15 over the downstream Pacific region, respectively. These atmospheric circulation anomalies induced by the increased TPSH result in increasing the westerly winds over both EA and NP, which in turn increases dust emissions over the dust source, and dust transports over these two regions, as well as the regional dust cycles. These results suggest that addressing the East Asian dust changes in the future climates require considering not only increasing greenhouse gas emissions but also the variations of the TP's heat source under global warming.

show abstract

Aerosol direct radiative forcing in desert and semi-desert regions of northwestern China

Cited by 52 publications

References 55 publications

Radiative absorption enhancement of dust mixed with anthropogenic pollution over East Asia

Radiative absorption enhancement of dust mixed with anthropogenic pollution over East Asia

Estimation of Downwelling Surface Longwave Radiation under Heavy Dust Aerosol Sky

Modulation of surface sensible heating over the Tibetan Plateau on the interannual variability of East Asian dust cycle

Contact Info

Product

Resources

About