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.

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 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 Analysis of Arctic Spring Ozone Anomaly in the Phases of QBO and 11-year Solar Cycle for 1979–2011

2021 ◽  
Author(s):  
Yousuke Yamashita ◽  
Hideharu Akiyoshi ◽  
Masaaki Takahashi
Keyword(s):  
Solar Cycle ◽  
Climate Model ◽  
Polar Vortex ◽  
Reanalysis Data ◽  
Early Spring ◽  
The Arctic ◽  
Negative Anomaly ◽  
Late Winter ◽  
Quasi Biennial Oscillation ◽  
Biennial Oscillation

Arctic ozone amount in winter to spring shows large year-to-year variation. This study investigates Arctic spring ozone in relation to the phase of quasi-biennial oscillation (QBO)/the 11-year solar cycle, using satellite observations, reanalysis data, and outputs of a chemistry climate model (CCM) during the period of 1979–2011. For this duration, we found that the composite mean of the Northern Hemisphere high-latitude total ozone in the QBO-westerly (QBO-W)/solar minimum (Smin) phase is slightly smaller than those averaged for the QBO-W/Smax and QBO-E/Smax years in March. An analysis of a passive ozone tracer in the CCM simulation indicates that this negative anomaly is primarily caused by transport. The negative anomaly is consistent with a weakening of the residual mean downward motion in the polar lower stratosphere. The contribution of chemical processes estimated using the column amount difference between ozone and the passive ozone tracer is between 10–20% of the total anomaly in March. The lower ozone levels in the Arctic spring during the QBO-W/Smin years are associated with a stronger Arctic polar vortex from late winter to early spring, which is linked to the reduced occurrence of sudden stratospheric warming in the winter during the QBO-W/Smin years.

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

scholarly journals Recent El-Nino classification and associated climate response comparisons for the Atlantic-Eurasian region

2017 ◽  
pp. 94-100
Author(s):  
A.S. Lubkov ◽  
◽  
E.N. Voskresenskaya ◽  
O.V. Marchukova ◽  
◽  
...  
Keyword(s):  
Comparative Study ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Reanalysis Data ◽  
Climate Response ◽  
Sea Level Pressure ◽  
Climate Anomalies ◽  
Spatio Temporal ◽  
Eurasian Region

Comparative study of El Nino classification after different authors results and approaches. The preferences of objective spatio-temporal classification which done earlier by the authors of present paper were shown for climate manifestation study over the Atlanic-Eurasian region. Using of NCEP/NCAR reanalysis data on sea level pressure in 1948-2016 the El-Nino types manifestations were estimated in Azor high, Iceland low and Siberian anticyclone. On this basis, appropriate prognostic estimates of typical climate anomalies in the Atlantic-Eurasian region are made. Next, the previous predictions of typical climate anomalies in the Atlantic-Eurasian region associated with El Nino types were done in the paper.

scholarly journals Influence of Arctic Oscillation on Frequency of Wintertime Fog Days in Eastern China

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 162
Author(s):  
Peng Liu ◽  
Mingyue Tang ◽  
Huaying Yu ◽  
Ying Zhang
Keyword(s):  
Water Vapor ◽  
South China ◽  
Arctic Oscillation ◽  
North China ◽  
Eastern China ◽  
Reanalysis Data ◽  
Positive Phase ◽  
Westerly Jet ◽  
Environmental Prediction ◽  
Fog Days

The influence of Arctic Oscillation (AO) on the frequency of wintertime fog days in eastern China is studied based on the winter AO index, the wintertime fog-day data of national stations in China, and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data from 1954 to 2007. The results show that heavy fog and light fog are more likely to occur during winter in eastern China with the strong interannual variability. During the winter with the positive-phase AO, there are more days of heavy fog in North China but less in South China, while light fog days become more in the whole of eastern China. It is mainly because that when AO is in the positive phase, the pressure in the polar region decreases at 500 hPa; the pressure in East Asia increases anomalously; the East Asian trough decreases; and the low-level westerly jet moves northward, preventing the northwesterly cold air from moving southward. Therefore, the whole eastern China gets warmer and wetter air, and there are more light fog days with the enhanced water vapor. However, the atmosphere merely becomes more towards unstable in South China, where the precipitation increases but the heavy fog days decreases. Nevertheless, heavy fog days increase with the water vapor in North China because of moving towards a stable atmosphere, which is formed by the anomalous downdrafts north of the precipitation center in South China. When AO is in the negative phase, the situation is basically opposite to that in the positive phase, but the variations of the corresponding fog days and circulations are weaker than those in the AO-positive-phase winter, which may be related to the nonlinear effect of AO on climate.

Dynamics of the ENSO Teleconnection and NAO Variability in the North Atlantic–European Late Winter

2020 ◽  
Vol 33 (3) ◽  
pp. 907-923 ◽  
Author(s):  
Bianca Mezzina ◽  
Javier García-Serrano ◽  
Ileana Bladé ◽  
Fred Kucharski
Keyword(s):  
North Atlantic ◽  
Southern Oscillation ◽  
Reanalysis Data ◽  
Late Winter ◽  
Sea Level Pressure ◽  
The North ◽  
Nao Index ◽  
Eddy Heat Flux ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

AbstractThe winter extratropical teleconnection of El Niño–Southern Oscillation (ENSO) in the North Atlantic–European (NAE) sector remains controversial, concerning both the amplitude of its impacts and the underlying dynamics. However, a well-established response is a late-winter (January–March) signal in sea level pressure (SLP) consisting of a dipolar pattern that resembles the North Atlantic Oscillation (NAO). Clarifying the relationship between this “NAO-like” ENSO signal and the actual NAO is the focus of this study. The ENSO–NAE teleconnection and NAO signature are diagnosed by means of linear regression onto the sea surface temperature (SST) Niño-3.4 index and an EOF-based NAO index, respectively, using long-term reanalysis data (NOAA-20CR, ERA-20CR). While the similarity in SLP is evident, the analysis of anomalous upper-tropospheric geopotential height, zonal wind, and transient-eddy momentum flux, as well as precipitation and meridional eddy heat flux, suggests that there is no dynamical link between the phenomena. The observational results are further confirmed by analyzing two 10-member ensembles of atmosphere-only simulations (using an intermediate-complexity and a state-of-the-art model) with prescribed SSTs over the twentieth century. The SST-forced variability in the Northern Hemisphere is dominated by the extratropical ENSO teleconnection, which provides modest but significant SLP skill in the NAE midlatitudes. The regional internally generated variability, estimated from residuals around the ensemble mean, corresponds to the NAO pattern. It is concluded that distinct dynamics are at play in the ENSO–NAE teleconnection and NAO variability, and caution is advised when interpreting the former in terms of the latter.

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.

Retrospection of recent 30-year changes in the process of soil wind erosion in the Luanhe River Source Area of North China using Cesium-137

2009 ◽  
Vol 67 (10) ◽  
pp. 1785-1789 ◽  
Author(s):  
Zhi-fan Chen ◽  
Ye Zhao ◽  
Jie-juan Qiao ◽  
Qing Zhang ◽  
Yu-en Zhu ◽  
...  
Keyword(s):  
Wind Erosion ◽  
North China ◽  
Source Area ◽  
Soil Wind Erosion ◽  
Cesium 137

spatial and temporal changes in SO2 over China in the recent decade and the Impacts of emissions and meteorology

2020 ◽  
Author(s):  
Ting Wang ◽  
Pucai Wang ◽  
Nicolas Theys ◽  
Dan Tong ◽  
François Hendrick ◽  
...  
Keyword(s):  
South China ◽  
North China ◽  
Function Analysis ◽  
General Rule ◽  
Recent Decade ◽  
Static Stability ◽  
Temporal Changes ◽  
Driving Mechanism ◽  
The North ◽  
Spatial And Temporal Changes

<p>The spatial and temporal changes of SO<sub>2</sub> regimes over China during 2005 to 2016 and their associated driving mechanism are investigated based on a state-of-the-art retrieval dataset. Climatological SO<sub>2</sub>exhibits pronounced seasonal and regional variations, with higher loadings in wintertime and two prominent maxima centered in the North China Plain and the Cheng-Yu District. In the last decade, overall SO<sub>2</sub> decreasing trends have been reported nationwide, with spatially varying downward rates according to a general rule—the higher the SO<sub>2</sub> loading, the more significant the decrease. However, such decline is in fact not monotonic, but instead four distinct temporal regimes can be identified by empirical orthogonal function analysis. After an initial rise at the beginning, SO<sub>2</sub> in China undergoes two sharp drops in the periods 2007-2008 and 2014-2016, amid which 5-year moderate rebounding is sustained. Despite spatial coherent behaviors, different mechanisms are tied to North China and South China. In North China, the same four regimes are detected in the time series of emission that is expected to drive the regime of atmospheric SO<sub>2</sub>, with a percentage of explained variance amounting to 81%. In contrast to North China, SO<sub>2</sub> emissions in South China exhibit a continuous descending tendency, due to the coordinated cuts of industrial and household emissions. As a result, the role of emissions only makes up about 45% of the SO<sub>2</sub> variation, primarily owing to the decoupled pathways of emission and atmospheric content during 2009 to 2013 when the emissions continue to decline but atmospheric content witnesses a rebound. Unfavorable meteorological conditions, including deficient precipitation, weaker wind speed and increased static stability, outweigh the effect of decreasing emissions and thus give rise to the rebound of SO<sub>2</sub> during 2009 to 2013.</p>

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