Atmospheric Aerosol Elements over the Inland Tibetan Plateau: Concentration, Seasonality, and Transport

Ghimire, Prakriti Sharma

doi:10.4209/aaqr.2015.02.0307

Cited by 3 publications

(4 citation statements)

References 25 publications

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“…MD mass was simply derived from one single metallic element mass with a weighting factor (e.g., Al/0.07 and Fe/0.04) in some studies (Sciare et al., 2005; Zhao et al., 2013). However, the proportions of metallic elements in MD vary greatly for different regions and particle sizes (Kang et al., 2016; Wang et al., 2016; Zhang et al., 2003). Thus, the MD mass calculation by a single metallic element suffers from large uncertainty.…”

Section: Atmospheric Aerosol Chemical Compositionsmentioning

confidence: 99%

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Unexpected High Absorption of Atmospheric Aerosols Over a Western Tibetan Plateau Site in Summer

et al. 2021

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The assessment of atmospheric aerosol radiative effects in the Tibetan Plateau (TP) suffers from large uncertainties due to limited understanding of aerosol physicochemical properties. To quantify aerosol optical properties, size distributions, and chemical compositions in the western TP, an intensive field campaign was carried out at Shiquanhe National Reference Climatological Station from July 8 to August 2, 2019. Unexpected low single scattering albedo (SSA) at 870 nm was found for the fine aerosols with an average value of 0.73 ± 0.18. SSA was even lower than 0.60 in the morning when fine aerosols peaked, indicating high absorption of the fine aerosols induced by anthropogenic activities. Coarse mode aerosols accounted for 70.58% ± 14.98% of the total volume concentration and mineral dust was the most abundant species in total suspended particles with a mass fraction of 48.7%. Fine mode aerosol concentrations showed little dependence on wind speed while coarse mode aerosols and metallic element concentrations exhibited strong positive correlations with wind speed, indicating the importance of wind‐blown dust particles. The present study for the first time quantified key aerosol parameters in the western TP and unexpected high absorption of atmospheric aerosols were found over the site in summer. Our results suggest the need to carefully consider the radiative effects caused by aerosol absorption in the TP region.

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Section: Atmospheric Aerosol Chemical Compositionsmentioning

confidence: 99%

“…Waliguan, Gongga, Lhasa, and Mt. Yulong (Cong et al., 2015; Kang et al., 2016; Wan et al., 2016; Xu et al., 2020; Zhang et al., 2001, 2012; Zhao et al., 2013). Chemical characterization of submicron aerosols has also been carried out by using aerosol mass spectrometer at a few sites such as Menyuan (Du et al., 2015), Mt.…”

Section: Introductionmentioning

confidence: 99%

Unexpected High Absorption of Atmospheric Aerosols Over a Western Tibetan Plateau Site in Summer

et al. 2021

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“…The TP is surrounded by various sources of pollutants. Over the south of the TP, previous studies have suggested that southern Asia was the main source of pollutants transported to the plateau (e.g., Cong et al, 2009Cong et al, , 2015aKopacz et al, 2011;Lu et al, 2012;Zhao et al, 2013;Wang et al, 2015;Zhang et al, 2015;Kang et al, 2016Kang et al, , 2019Chen et al, 2018). A huge blanket or layer of "haze" is composed of light-absorbing carbonaceous aerosol particles that often erupts in the pre-monsoon season over southern Asia and has a significant influence on the plateau (e.g., Prasad and Singh, 2007;Engling and Gelencser, 2010).…”

Section: Introductionmentioning

confidence: 99%

Impact of topography on black carbon transport to the southern Tibetan Plateau during the pre-monsoon season and its climatic implication

et al. 2020

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Abstract. Most previous modeling studies about black carbon (BC) transport and its impact over the Tibetan Plateau (TP) conducted simulations with horizontal resolutions coarser than 20 km that may not be able to resolve the complex topography of the Himalayas well. In this study, the two experiments covering all of the Himalayas with the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) at the horizontal resolution of 4 km but with two different topography datasets (4 km complex topography and 20 km smooth topography) are conducted for pre-monsoon season (April 2016) to investigate the impacts of topography on modeling the transport and distribution of BC over the TP. Both experiments show the evident accumulation of aerosols near the southern Himalayas during the pre-monsoon season, consistent with the satellite retrievals. The observed episode of high surface BC concentration at the station near Mt. Everest due to heavy biomass burning near the southern Himalayas is well captured by the simulations. The simulations indicate that the prevailing upflow across the Himalayas driven by the large-scale westerly and small-scale southerly circulations during the daytime is the dominant transport mechanism of southern Asian BC into the TP, and it is much stronger than that during the nighttime. The simulation with the 4 km topography resolves more valleys and mountain ridges and shows that the BC transport across the Himalayas can overcome the majority of mountain ridges, but the valley transport is more efficient. The complex topography results in stronger overall cross-Himalayan transport during the simulation period primarily due to the strengthened efficiency of near-surface meridional transport towards the TP, enhanced wind speed at some valleys and deeper valley channels associated with larger transported BC mass volume. This results in 50 % higher transport flux of BC across the Himalayas and 30 %–50 % stronger BC radiative heating in the atmosphere up to 10 km over the TP from the simulation with the 4 km complex topography than that with the 20 km smoother topography. The different topography also leads to different distributions of snow cover and BC forcing in snow. This study implies that the relatively smooth topography used by the models with resolutions coarser than 20 km may introduce significant negative biases in estimating light-absorbing aerosol radiative forcing over the TP during the pre-monsoon season. Highlights. The black carbon (BC) transport across the Himalayas can overcome the majority of mountain ridges, but the valley transport is much more efficient during the pre-monsoon season. The complex topography results in stronger overall cross-Himalayan transport during the study period primarily due to the strengthened efficiency of near-surface meridional transport towards the TP, enhanced wind speed at some valleys and deeper valley channels associated with larger transported BC mass volume. The complex topography generates 50 % higher transport flux of BC across the Himalayas and 30 %–50 % stronger BC radiative heating in the atmosphere up to 10 km over the Tibetan Plateau (TP) than the smoother topography, which implies that the smooth topography used by the models with relatively coarse resolution may introduce significant negative biases in estimating BC radiative forcing over the TP during the pre-monsoon season. The different topography also leads to different distributions of snow cover and BC forcing in snow over the TP.

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“…Gongga and the crust, respectively. It has been documented that the element with the EF value larger than 10 is considered enriched (Deng et al, 2011;Kang, Chen, et al, 2016). When using the data of the La/Al ratio from UCC, the calculated EF for La in the PM 2.5 samples was 55 ± 12, suggesting a large enrichment of La relative to UCC.…”

Section: 1029/2019jd031327mentioning

confidence: 98%

The Sources and Atmospheric Pathway of Phosphorus to a High Alpine Forest in Eastern Tibetan Plateau, China

Meng

Rui

et al. 2020

JGR Atmospheres

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Atmospheric deposition is considered as an important source of phosphorus (P) to P‐limited ecosystems. The PM2.5 samples were collected from a high alpine P‐limited forest of Gongga Mountain (Mt. Gongga), eastern Tibetan Plateau from May 2015 to May 2016. Total P (TP) exhibited a higher concentration in the dry season (November to April, 96 ± 30 ng/m3) than that in the wet season (May to October, 77 ± 21 ng/m3). Source apportionment exhibited that 22% and 44% of TP in the dry season were contributed by soil dust and biomass burning, respectively. During the wet season, soil dust, biomass burning, and anthropogenic sources were estimated to contribute to 19%, 26%, and 41% of TP, respectively. Dissolved organic P (DOP) was found to be the significant fraction of total dissolved P (TDP), accounting for 65% and 53% of TDP in the dry and wet season, respectively. The significant correlations between DOP and KBB+ suggested that the soluble P originating from biomass burning was possible mainly in the form of DOP. In addition, the acidification of apatite during the transport could explain the dissolved inorganic P level in the wet season. Supposing that all the soluble P was bioavailable, the atmospheric deposition of TDP was estimated to result in a fixation of 0.1394 kg C/m2/yr, accounting for 23% of net primary productivity in a forest of Mt. Gongga. The data showed herein highlighted the importance of atmospheric dry deposition of P to the long‐term fertility of high‐elevation soils.

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Atmospheric Aerosol Elements over the Inland Tibetan Plateau: Concentration, Seasonality, and Transport

Cited by 3 publications

References 25 publications

Unexpected High Absorption of Atmospheric Aerosols Over a Western Tibetan Plateau Site in Summer

Unexpected High Absorption of Atmospheric Aerosols Over a Western Tibetan Plateau Site in Summer

Impact of topography on black carbon transport to the southern Tibetan Plateau during the pre-monsoon season and its climatic implication

The Sources and Atmospheric Pathway of Phosphorus to a High Alpine Forest in Eastern Tibetan Plateau, China

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