Pronounced changes in atmospheric circulation and dust source area during the mid-Pleistocene as indicated by the Caotan loess-soil sequence in North China

2015 ◽  
Vol 372 ◽  
pp. 97-107 ◽  
Author(s):  
Shasha Peng ◽  
Junyi Ge ◽  
Chaozhu Li ◽  
Zongxiu Liu ◽  
Lin Qi ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
North China ◽  
Source Area ◽  
Loess Soil ◽  
Dust Source

scholarly journals Why super sandstorm 2021 in North China

2021 ◽  
Author(s):  
Zhicong Yin ◽  
Yu Wan ◽  
Yijia Zhang ◽  
Huijun Wang
Keyword(s):  
North China ◽  
Source Area ◽  
Recent Decade ◽  
Reanalysis Data ◽  
Late Winter ◽  
Snow Melt ◽  
Dust Source ◽  
Climate Anomalies ◽  
Dry Soil ◽  
Strong Evaporation

Abstract Severe sandstorms reoccurred in the spring of 2021 after absence for more than 10 years in North China. The dust source area, located in Mongolia, suffered destructive cooling and warming in early and late winter which loosened the land. Lacked precipitation, excessive snow melt, and strong evaporation resulted in dry soil and exiguous spring vegetation. A super-strong Mongolian cyclone developed on the bare and loose ground, and easily blew and transported large amounts of sand particles into North China. Furthermore, the top-ranking anomalies of sea ice shift in the Barents and Kara Sea and the sea surface temperatures in east Pacific and northwest Atlantic were identified to induce the aforementioned tremendous climate anomalies in dust source area. Analyses, based on large-ensemble CMIP6, yield identical results as the reanalysis data. Thus, the climate variabilities at different latitudes and synoptic disturbances jointly facilitated the strongest spring sandstorm over the recent decade.

scholarly journals New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2

2016 ◽  
Vol 9 (2) ◽  
pp. 765-777 ◽  
Author(s):  
Bernd Heinold ◽  
Ina Tegen ◽  
Kerstin Schepanski ◽  
Jamie R. Banks
Keyword(s):  
Climate Model ◽  
Dust Emission ◽  
Source Area ◽  
Saharan Dust ◽  
Moist Convection ◽  
Dust Source ◽  
New Developments ◽  
Infrared Imager ◽  
Dust Sources ◽  
Dust Events

Abstract. In the aerosol–climate model ECHAM6-HAM2, dust source activation (DSA) observations from Meteosat Second Generation (MSG) satellite are proposed to replace the original source area parameterization over the Sahara Desert. The new setup is tested in nudged simulations for the period 2007 to 2008. The evaluation is based on comparisons to dust emission events inferred from MSG dust index imagery, Aerosol Robotic Network (AERONET) sun photometer observations, and satellite retrievals of aerosol optical thickness (AOT).The model results agree well with AERONET measurements especially in terms of seasonal variability, and a good spatial correlation was found between model results and MSG-SEVIRI (Spinning-Enhanced Visible and InfraRed Imager) dust AOT as well as Multi-angle Imaging SpectroRadiometer (MISR) AOT. ECHAM6-HAM2 computes a more realistic geographical distribution and up to 20 % higher annual Saharan dust emissions, using the MSG-based source map. The representation of dust AOT is partly improved in the southern Sahara and Sahel. In addition, the spatial variability is increased towards a better agreement with observations depending on the season. Thus, using the MSG DSA map can help to circumvent the issue of uncertain soil input parameters.An important issue remains the need to improve the model representation of moist convection and stable nighttime conditions. Compared to sub-daily DSA information from MSG-SEVIRI and results from a regional model, ECHAM6-HAM2 notably underestimates the important fraction of morning dust events by the breakdown of the nocturnal low-level jet, while a major contribution is from afternoon-to-evening emissions.

scholarly journals Spring Extreme Precipitation Days in North China and Their Reliance on Atmospheric Circulation Patterns During 1979–2019

2022 ◽  
pp. 1-41
Keyword(s):  
Climate Variability ◽  
Atmospheric Circulation ◽  
Extreme Precipitation ◽  
Interannual Variation ◽  
North China ◽  
Circulation Pattern ◽  
Southerly Wind ◽  
Atmospheric Circulation Patterns ◽  
Rain Gauges ◽  
Circulation Patterns

Abstract The interannual variation of springtime extreme precipitation (SEP) days in North China (NC) and their reliance on atmospheric circulation patterns are studied by using the continuous daily record of 396 rain gauges and the fifth generation of the European Centre for Medium-Range Weather Forecasts atmospheric reanalysis during 1979–2019. The SEP days are defined as the days when at least 10% of rain gauges in NC record daily precipitation no less than 10.5 mm. Results show that the number of SEP days shows large interannual variability but no significant trend in the study period. Using the objective classification method of the obliquely rotated principal analysis in T-mode, we classify the atmospheric circulation into five different patterns based on the geopotential height at 700 hPa. Three circulation patterns all have fronts and are associated with strong southerly wind, leading to 88% of SEP days in NC. The strong southerly wind may provide moisture and dynamic forcing for the frontal precipitation. The interannual variation of SEP days is related with the number of the three above-mentioned dominant circulation patterns. Further analysis shows that the West Pacific pattern could be one of the possible climate variability modes related to SEP days. This study reveals that the daily circulation pattern may be the linkage between SEP days and climate variability modes in NC.

scholarly journals Vertical Distribution of Wind-eroded Dust within 50m High at Minqin Dust Source Area in North-Western China

2017 ◽  
Author(s):  
Duo-Qing Man ◽  
Shi-Zeng Liu ◽  
De-Lu Li ◽  
Zi-Zhu Yan ◽  
Qing-Zhong Zheng ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Source Area ◽  
Western China ◽  
Dust Source ◽  
North Western

Changes in prevailing surface-paleowinds reveal the atmospheric circulation transition during Early Cretaceous in North China

2022 ◽  
Vol 586 ◽  
pp. 110784
Author(s):  
Dawei Qiao ◽  
Nan Peng ◽  
Hongwei Kuang ◽  
Yongqing Liu ◽  
Yanxue Liu ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Early Cretaceous ◽  
North China

scholarly journals North African dust transport toward the western Mediterranean basin: Atmospheric controls on dust source activation and transport pathways during June–July 2013

2016 ◽  
Author(s):  
Kerstin Schepanski ◽  
Marc Mallet ◽  
Bernd Heinold ◽  
Max Ulrich
Keyword(s):  
Atmospheric Circulation ◽  
Mediterranean Basin ◽  
Dust Emission ◽  
Western Mediterranean ◽  
North African ◽  
Atmospheric Dust ◽  
Dust Source ◽  
Dust Transport ◽  
The Mediterranean ◽  
Heat Low

Abstract. Dust transported from North African source region toward the Mediterranean basin and Europe is an ubiquitous phenomenon in the Mediterranean region. Winds formed by large-scale pressure gradients foster dust entrainment into the atmosphere over North African dust source regions and advection of dust downwind. The constellation of centers of high and low pressure determines wind speed and direction, and thus the chance for dust emission over Northern Africa and transport toward the Mediterranean. Here, we present characteristics of the atmospheric dust life-cycle determining dust transport toward the Mediterranean basin. Using the atmosphere-dust model COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdelling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model), a complementary analysis of dust source activation, emission fluxes, transport pathways, and deposition rates is provided with focus on the ChArMEx (Chemistry-Aerosol Mediterranean Experiment) special observation period in June and July 2013. Modes of atmospheric circulation, identified from empirical orthogonal function (EOF) analysis of the geopotential height at 850 hPa are used for investigating the characteristics of the atmospheric dust life-cycle regarding the atmospheric circulation over the Mediterranean. Two different phases are identified from the first EOF, which in total are explaining 45 % of the variance. They are characterized by the propagation of the subtropical ridge into the Mediterranean basin, the position of the Saharan heat low and the predominance Iberian heat low and discussed illustrating a dipole pattern for enhanced (reduced) dust emission fluxes, stronger (weaker) meridional dust transport, and consequent increased (decreased) atmospheric dust concentrations and deposition fluxes. In case of a predominant high pressure zone over the western and central Mediterranean (positive phase), a hot spot in dust emission flux is evident over the Grand Erg Occidental and reduced level of atmospheric dust loading occurs over the western Mediterranean basin. The meridional transport in northward direction is reduced due to prevailing northerly winds. In case of a predominant heat low trough linking the Iberian and the Sahara heat low (negative phase), meridional dust transport toward the western Mediterranean is increased due to prevailing southerly winds resulting into an enhanced atmospheric dust loading over the western Mediterranean. Altogether, results form this study illustrate the relevance of knowing dust source location in concert with atmospheric circulation. The study elaborates the question on the variability of dust transport toward the Mediterranean and Europe in dependence on the atmospheric circulation as a driver for dust emission and a determinant for dust transport routes, exemplarily for the two-month period June to July 2013. Ultimately, outcomes from this study contribute to the understanding of the variance in dust transport into a populated region.

Tillage system change affects soil organic carbon storage and benefits land restoration on loess soil in North China

2018 ◽  
Vol 29 (9) ◽  
pp. 2880-2887 ◽  
Author(s):  
Hao Wang ◽  
Shulan Wang ◽  
Yujiao Zhang ◽  
Xiaoli Wang ◽  
Rui Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Storage ◽  
North China ◽  
System Change ◽  
Loess Soil ◽  
Land Restoration ◽  
Soil Organic Carbon Storage ◽  
Tillage System ◽  
Organic Carbon Storage

14C and 10Be in Dust Deposited During the Storm of 16–17 April 2006 in Beijing

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1790-1800
Author(s):  
C D Shen ◽  
W X Yi ◽  
P Ding ◽  
K X Liu ◽  
X M Xu
Keyword(s):  
Arid Regions ◽  
Inorganic Carbon ◽  
Fossil Fuel ◽  
Surface Soil ◽  
Source Region ◽  
Source Area ◽  
Total Inorganic Carbon ◽  
Dust Source ◽  
C Value ◽  
Dust Surface

The concentrations of 10Be and 14C and values of δ13C in samples collected during a major dust storm in Beijing on 16–17 April 2006 were studied. The 10Be concentrations ranged from 1.69 × 108 to 2.07 × 108 atom/g, 14C ages for black carbon (BC) ranged from 3001 to 5181 yr BP and for total inorganic carbon (TIC) from 8464 to 9119 yr BP, and δ13C values for BC ranged from -23.15% to -23.80% and for TIC from -5.39% to -5.98%. A comparison of BC content and δ13C value between the dust, surface soil in the dust source region, and aerosols in Beijing indicated that BC in the dust deposited in Beijing is significantly incorporated by aerosol BC during the dust transportation. Based on the 14C ages of BC, the proportion of fossil-fuel-derived BC was 0.35–0.49 of the total. In contrast to BC, the TIC deposited in Beijing can be firmly related to the source area and δ13C was not significantly modified during its transportation. According to the 14C ages of TIC, the proportion of the secondary carbonate in the dust was from 0.63 to 0.70. The results confirm that 14C of TIC is another useful tracer to indicate the source region of dust besides the content and δ13C value of TIC from the arid and semi-arid regions of China.

scholarly journals Relationship between Reduction of Summer Precipitation in North China and Atmospheric Circulation Anomalies

2010 ◽  
Vol 02 (06) ◽  
pp. 569-576 ◽  
Author(s):  
Lisheng Hao ◽  
Jinzhong Min ◽  
Yihui Ding ◽  
Ji Wang
Keyword(s):  
Atmospheric Circulation ◽  
North China ◽  
Summer Precipitation ◽  
Circulation Anomalies ◽  
Atmospheric Circulation Anomalies
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