scholarly journals Black carbon record based on a shallow Himalayan ice core and its climatic implications

2008 ◽  
Vol 8 (5) ◽  
pp. 1343-1352 ◽  
Author(s):  
J. Ming ◽  
H. Cachier ◽  
C. Xiao ◽  
D. Qin ◽  
S. Kang ◽  
...  
Keyword(s):  
Black Carbon ◽  
Radiative Forcing ◽  
Trajectory Analysis ◽  
Ice Core ◽  
Historical Record ◽  
The Tibetan Plateau ◽  
Hysplit Model ◽  
The Past ◽  
Glacier Melting ◽  
Increasing Trend

Abstract. A continuous measurement for black carbon (hereafter "BC") in a 40 m shallow ice core retrieved from the East Rongbuk Glacier (hereafter "ERG") in the northeast saddle of Mt. Qomolangma (Everest) provided the first historical record of BC deposition during the past ~50 yrs in the high Himalyas. Apparent increasing trend (smooth average) of BC concentrations was revealed since the mid-1990s. Seasonal variability of BC concentrations in the ice core indicated higher concentrations in monsoon seasons than those in non-monsoon seasons. Backward air trajectory analysis by the HYSPLIT model indicated that South Asia's BC emissions had significant impacts on the BC deposition in the Mt. Qomolangma (Everest) region. The estimated average atmospheric BC concentration in the region was about 80 ng m−3 during 1951–2001. And it was suggested BC emitted from South Asia could penetrate into the Tibetan Plateau by climbing over the elevated Himalayas. A significant increasing trend of the radiative forcing simulated by the SNICAR model appeared since 1990, which even exceeded 4.5 W m−2 in the summer of 2001. It was suggested that this amplitudes of BC concentrations in the atmosphere over the Himalayas and consequently in the ice in the glaciers could not be neglected when assessing the dual warming effects on glacier melting in the Himalayas.

scholarly journals Black carbon record based on a shallow Himalayan ice core and its climatic implications

2007 ◽  
Vol 7 (5) ◽  
pp. 14413-14432 ◽  
Author(s):  
J. Ming ◽  
H. Cachier ◽  
C. Xiao ◽  
D. Qin ◽  
S. Kang ◽  
...  
Keyword(s):  
Black Carbon ◽  
Trajectory Analysis ◽  
Continuous Measurement ◽  
Ice Core ◽  
Historical Record ◽  
The Tibetan Plateau ◽  
The Past ◽  
Increasing Trend ◽  
Radiative Absorption ◽  
Air Trajectory

Abstract. A continuous measurement for black carbon conducted on a shallow ice core extracted from the East Rongbuk glacier beside Mt. Qomolangma recovers the first historical record of black carbon 13 deposition in the past ~50 years in the high Asian cryosphere. Fast increasing trend of BC concentration is revealed since the mid-1990s. Backward air trajectory analysis indicates that South Asia's emission has significant impacts on the BC deposition in the East Rongbuk glacier. The estimated atmospheric BC concentration over the East Rongbuk glacier is about 80 ngC m−3. This suggests black carbon from South Asia's emission might penetrate into the Tibetan Plateau by 18 climbing over the elevated Himalayas. Considering the consequent extra solar radiative absorption over the glacier, it is suggested that this amplitude of BC concentration in the atmosphere over the Himalayas could not be neglected when assessing the warming effect on the surface of the glaciers on the Himalayas.

scholarly journals Impacts of black carbon and mineral dust on radiative forcing and glacier melting during summer in the Qilian Mountains, northeastern Tibetan Plateau

2016 ◽  
Author(s):  
Yang Li ◽  
Jizu Chen ◽  
Shichang Kang ◽  
Chaoliu Li ◽  
Bin Qu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Mineral Dust ◽  
Qilian Mountains ◽  
Radiation Balance ◽  
In Situ Observation ◽  
Observation Data ◽  
The Tibetan Plateau ◽  
Glacier Melting

Abstract. Black carbon (BC) and mineral dust (MD), the most important compositions of light absorbing particles (LAPs), significantly reduce the albedo of glaciers and thus accelerate their melting. In order to investigate the impacts of BC and MD on the glacier radiation balance and ablation, a total of 92 surface snow/ice samples were collected along different elevations from 4300–4950 m a.s.l. on Laohugou glacier No. 12 (LHG, 39°10'–35' N, 96°10'–35' E), located at Qilian Mountains, northeastern margin of the Tibetan Plateau (TP), during summer of 2013 and 2014. A thermal-optical method was employed to detect the BC (EC – element carbon) concentrations in snow/ice samples. The results showed that BC and MD concentrations were much lower in snow than those in ice, and gradually declined with increasing elevation. The effects of BC and MD on albedo reduction at different melting conditions were identified with the SNow ICe Aerosol Radiative (SNICAR) model initiated by in-situ observation data. The sensitivity analysis showed that BC had a stronger impact on albedo reduction than MD on this glacier. The impacts of BC represented around 45 % of albedo reduction while the contribution of MD was 35 % when the glacier surface presented as superimposed ice and experienced intensive melting. During summer, when the surface was covered by snow, BC and MD contributed for 15 % and 9 % respectively. On average, the radiative forcing (RF) caused by BC in the snow/ice, more than MD, was 41.6 ± 37.0 W m−2. Meanwhile, compared to glacier melting in summer of 2013 and 2014 (409 mm w.e. and 366 mm w.e., respectively) calculated using the surface energy-mass balance model, contributions of BC and MD were less than 37 % and 32 % respectively of summer melting, while MD and BC together contributed a maximum of 61 %. This study provided the baseline information on BC and MD concentrations in glaciers of the northeastern TP and their contributions in glacier melting during summer.

scholarly journals Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere

2021 ◽  
Vol 7 (22) ◽  
pp. eabc1379
Author(s):  
Pengfei Liu ◽  
Jed O. Kaplan ◽  
Loretta J. Mickley ◽  
Yang Li ◽  
Nathan J. Chellman ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Radiative Forcing ◽  
Ice Core ◽  
Ice Cores ◽  
Terrestrial Ecosystems ◽  
Rapid Expansion ◽  
Past Century ◽  
Fire Emissions ◽  
The Past ◽  
Fire Activity

Fire plays a pivotal role in shaping terrestrial ecosystems and the chemical composition of the atmosphere and thus influences Earth’s climate. The trend and magnitude of fire activity over the past few centuries are controversial, which hinders understanding of preindustrial to present-day aerosol radiative forcing. Here, we present evidence from records of 14 Antarctic ice cores and 1 central Andean ice core, suggesting that historical fire activity in the Southern Hemisphere (SH) exceeded present-day levels. To understand this observation, we use a global fire model to show that overall SH fire emissions could have declined by 30% over the 20th century, possibly because of the rapid expansion of land use for agriculture and animal production in middle to high latitudes. Radiative forcing calculations suggest that the decreasing trend in SH fire emissions over the past century largely compensates for the cooling effect of increasing aerosols from fossil fuel and biofuel sources.

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

2020 ◽  
Vol 20 (10) ◽  
pp. 5923-5943 ◽  
Author(s):  
Meixin Zhang ◽  
Chun Zhao ◽  
Zhiyuan Cong ◽  
Qiuyan Du ◽  
Mingyue Xu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Monsoon Season ◽  
Radiative Heating ◽  
The Tibetan Plateau ◽  
Complex Topography ◽  
Meridional Transport ◽  
Near Surface ◽  
Mass Volume

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.

scholarly journals History of desert dust deposition recorded in the Elbrus ice core

2019 ◽  
Author(s):  
Stanislav Kutuzov ◽  
Michel Legrand ◽  
Suzanne Preunkert ◽  
Patrick Ginot ◽  
Vladimir Mikhalenko ◽  
...  
Keyword(s):  
North Africa ◽  
Drought Index ◽  
Decadal Variability ◽  
Ice Core ◽  
Ice Cores ◽  
Dust Deposition ◽  
The Past ◽  
Dust Sources ◽  
Increasing Trend ◽  
History Of

Abstract. Ice cores are one of the most valuable paleo-archives. Records from the ice cores can provide information not only about the amount of dust in the atmosphere but also about dust sources and its changes in the past. A 182 m long ice core has been recovered at the western plateau of Mt. Elbrus (5115 m elevation) in 2009. This record was extended with the shallow ice core drilling in 2013. Here we present analysis of the concentrations of Ca2+, a commonly used proxy of dust, recorded in Elbrus ice core over the period 1774–2013. The calcium record reveals a quasi decadal variability with a general increasing trend. Using multiple regression analysis we found a statistically significant spatial correlation of the Elbrus Ca2+ summer concentrations and precipitation and soil moisture content in Levant region (specifically Syria and Iraq). The Ca2+ record also correlates with drought index in North Africa (r = 0.69 p 

scholarly journals Temperature variations over the past millennium on the Tibetan Plateau revealed by four ice cores

2007 ◽  
Vol 46 ◽  
pp. 362-366 ◽  
Author(s):  
Tandong Yao ◽  
Keqin Duan ◽  
L.G. Thompson ◽  
Ninglian Wang ◽  
Lide Tian ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
19Th Century ◽  
Northern Hemisphere ◽  
Ice Core ◽  
Ice Cores ◽  
Ice Age ◽  
The Tibetan Plateau ◽  
Late 19Th Century ◽  
The Past ◽  
Northern Tibetan Plateau

AbstractTemperature variation on the Tibetan Plateau over the last 1000 years has been inferred using a composite δ18O record from four ice cores. Data from a new ice core recovered from the Puruogangri ice field in the central Tibetan Plateau are combined with those from three other cores (Dunde, Guliya and Dasuopu) recovered previously. The ice-core δ18O composite record indicates that the temperature change on the whole Tibetan Plateau is similar to that in the Northern Hemisphere on multi-decadal timescales except that there is no decreasing trend from AD 1000 to the late 19th century. The δ18O composite record from the northern Tibetan Plateau, however, indicates a cooling trend from AD 1000 to the late 19th century, which is more consistent with the Northern Hemisphere temperature reconstruction. The δ18O composite record reveals the existence of the Medieval Warm Period and the Little Ice Age (LIA) on the Tibetan Plateau. However, on the Tibetan Plateau the LIA is not the coldest period during the last millennium as in other regions in the Northern Hemisphere. The present study indicates that the 20th-century warming on the Tibetan Plateau is abrupt, and is warmer than at any time during the past 1000 years.

Integration of Tibetan Plateau ice-core temperature records and the influence of atmospheric circulation on isotopic signals in the past century

2014 ◽  
Vol 81 (3) ◽  
pp. 520-530 ◽  
Author(s):  
Xiaoxin Yang ◽  
Tandong Yao ◽  
Daniel Joswiak ◽  
Ping Yao
Keyword(s):  
Tibetan Plateau ◽  
Atmospheric Circulation ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Ice Core ◽  
Past Century ◽  
The Tibetan Plateau ◽  
The Past ◽  
Increasing Trends

AbstractTemperature signals in ice-core δ18O on the Tibetan Plateau (TP), particularly in the central and southern parts, continue to be debated because of the large scale of atmospheric circulation. This study presents ten ice-core δ18O records at an annual resolution, with four (Malan, Muztagata, Guliya, and Dunde) in the northern, three (Puruogangri, Geladaindong, Tanggula) in the central and three (Noijin Kangsang, Dasuopu, East Rongbuk) in the southern TP. Integration shows commonly increasing trends in δ18O in the past century, featuring the largest one in the northern, a moderate one in the central and the smallest one in the southern TP, which are all consistent with ground-based measurements of temperature. The influence of atmospheric circulation on isotopic signals in the past century was discussed through the analysis of El Niño/Southern Oscillation (ENSO), and of possible connections between sea surface temperature (SST) and the different increasing trends in both ice-core δ18O and temperature. Particularly, El Niño and the corresponding warm Bay of Bengal (BOB) SST enhance the TP ice-core isotopic enrichment, while La Niña, or corresponding cold BOB SST, causes depletion. This thus suggests a potential for reconstructing the ENSO history from the TP ice-core δ18O.

scholarly journals Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau

2010 ◽  
Vol 10 (9) ◽  
pp. 21615-21651 ◽  
Author(s):  
M. Kopacz ◽  
D. L. Mauzerall ◽  
J. Wang ◽  
E. M. Leibensperger ◽  
D. K. Henze ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Tibetan Plateau ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Middle Eastern ◽  
Central China ◽  
The Tibetan Plateau ◽  
Adjoint Sensitivity ◽  
Snow Albedo ◽  
Northern Tibetan Plateau

Abstract. The remote and high elevation regions of central Asia are influenced by black carbon (BC) emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and estimate the forcing due to the BC induced snow-albedo effect at about 5–15 W m−2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo accelerates glacier melting. Our analysis can help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.

scholarly journals Reevaluating the black carbon in the Himalayan and Tibetan Plateau: concentration and deposition

2017 ◽  
Author(s):  
Chaoliu Li ◽  
Fangping Yan ◽  
Shichang Kang ◽  
Pengfei Chen ◽  
Xiaowen Han ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Atmospheric Deposition ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Ice Core ◽  
River Sediments ◽  
Ice Cores ◽  
Lake Basin ◽  
Arid Environments ◽  
Lake Cores

Abstract. Black carbon (BC) is the second most important warming component in the atmosphere after CO2. The BC in the Himalayan and Tibetan Plateau (HTP) has shaped the evolution of the Indian Monsoon and accelerated the retreat of glaciers, thereby resulting in serious consequences for billions of Asian residents. Although a number of related studies of this region have been conducted, the BC concentration and deposition indexes remain poorly understood. Because of the presence of arid environments and the potential influence of carbonates from mineral dust (MD), the reported concentrations of BC from the HTP are overestimated. In addition, large discrepancies in the deposition of BC have been reported from lake cores, ice cores, snowpits and models. Therefore, the actual BC concentration and deposition values in this sensitive region must be determined. A comparison between the BC values of acid (HCl) fumigated and original aerosol samples from the HTP showed that the BC concentrations previously reported for the Namco station (central part of the HTP) and the Everest station (northern slope of the central Himalayas) were overestimated by approximately 47 ± 37 % and 35 ± 26 %, respectively, because of the influence of carbonates from MD. Additionally, the organic carbon (OC) levels were overestimated by roughly 22 ± 10 % and 22 ± 12 % for the same reason. Based on previously reported values from these two areas, we propose that the actual BC concentrations at the Namco and Everest stations are 44 ng m−3 and 164 ng m−3, respectively. Second, a comprehensive comparison of the BC deposition levels obtained via different methods indicated that the BC deposits derived from lake cores of the HTP were mainly caused by river sediments transported from the lake basin as a result of climate change (e.g., increases in temperature and precipitation), and fewer BC deposits were related to atmospheric deposition. Therefore, previously reported BC deposition levels from lake cores overestimated the atmospheric deposition of BC in the HTP. Correspondingly, BC deposition derived from snowpit, ice core and model from the HTP were not only agree very well with each other, but also were close to those of other remote areas (e.g., Arctic), implying that the BC deposits calculated from these three methods reflect the actual values. Therefore, based on reported values of snowpits and ice cores, we propose that the BC deposits of the HTP range from 10 mg m−2 a−1 to 25 mg m−2 a−1, with high and low values appearing along the fringes and central areas of the HTP, respectively. The adjusted BC concentration and deposition values in the HTP observed here are critical for performing accurate evaluations of other indexes of BC such as atmospheric distribution, radiative forcing and chemical transport in the HTP.

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