• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Monthly Variations of Atmospheric Circulations Associated with Haze Pollution in the Yangtze River Delta and North China

    2021-04-07 10:20:54XinyuZHANGZhicongYINHuijunWANGandMingkengDUAN
    Advances in Atmospheric Sciences 2021年4期

    Xinyu ZHANG,Zhicong YIN*,2,3,Huijun WANG,2,3,and Mingkeng DUAN

    1Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology, Nanjing 210044, China

    2Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519080, China

    3Nansen-Zhu International Research Centre, Institute of Atmospheric Physics,Chinese Academy of Sciences, Beijing 100029, China

    ABSTRACT Haze pollution in early winter (December and January) in the Yangtze River Delta (YRD) and in North China (NC)are both severe;however,their monthly variations are significantly different.In this study,the dominant large-scale atmospheric circulations and local meteorological conditions were investigated and compared over the YRD and NC in each month.Results showed that the YRD (NC) is dominated by the so-called Scandinavia (East Atlantic/West Russia)pattern in December,and these circulations weaken in January.The East Asian December and January monsoons over the YRD and NC have negative correlations with the number of haze days.The local descending motion facilitates less removal of haze pollution over the YRD,while the local ascending motion facilitates less removal of haze pollution over NC in January,despite a weaker relationship in December.Additionally,the monthly variations of atmospheric circulations showed that adverse meteorological conditions restrict the vertical (horizontal) dispersion of haze pollution in December(January) over the YRD,while the associated local weather conditions are similar in these two months over NC.

    Key words:monthly haze pollution,atmospheric circulations,Yangtze River Delta,North China

    1.Introduction

    Heavy haze pollution often occurs in winter (December—February) in North China (NC) and the Yangtze River Delta (YRD) (Ding and Liu,2014).Haze pollution is mainly characterized by high concentrations of fine particulate matter and reduced visibility,causing serious socioeconomic problems (Wang and Chen,2016).Thus,haze pollution has aroused widespread concern in government and among the public.Early studies showed that haze pollution is not only affected by anthropogenic emissions (mainly the long-term trend of haze),but also by climate variability(mainly the interannual variations) (Wang et al.,2013;Yang et al.,2016;Zhang et al.,2016).

    Several researchers have investigated the pollution situation over the YRD from monthly,seasonal and annual mean perspectives (Yu et al.,2011;Zhao et al.,2017;Sun et al.,2019).Affected by urbanization,large cities in the YRD have higher aerosol optical depths than remote areas (Sun et al.,2019),as well as high anthropogenic heat release (Wang et al.,2015),as verified by high-resolution Weather Research and Forecasting model results.In addition to impacts of anthropogenic emissions on the long-term trend of haze pollution in the YRD,a few studies have investigated the roles of weather—climate conditions in the YRD.He et al.(2019b) pointed out that PMthroughout the Yangtze River Basin is negatively correlated with surface wind speed,precipitation and planetary boundary layer height (PBLH) but positively correlated with temperature.High wind speed,more precipitation and a well-developed boundary layer could facilitate the dispersion of aerosols and lead to a decrease in PM(He et al.,2019b).The positive relationship between temperature and PMis possibly due to the enhancement in oxidation of aerosol precursors at high temperatures (He et al.,2019b).Compared to the conditions in NC,He et al.(2019a) also indicated that wet removal of haze brought by precipitation over southern China (south of 30°N) is important.Furthermore,winter haze extremes in India at lower latitudes are even affected by El Ni?o sea surface temperature and signals from the Southern Hemisphere (Gao et al.,2019).

    NC is the most haze-polluted area in China,and the associated atmospheric circulations have already been examined in previous studies.The number of winter haze days (HDs)in NC (WHD) has been found to be directly dominated by local anticyclonic circulations (Chen and Wang,2015;Yin and Wang,2016),connected by two Rossby wave trains [i.e.,the East Atlantic/West Russia (EA/WR) and Eurasia patterns]over the continent and one Rossby wave train (i.e.,the West Pacific pattern) over the ocean (Wallace and Gutzler,1981;Barnston and Livezey,1987).These wave trains provide the favorable atmospheric conditions associated with haze pollution,such as a lower planetary boundary layer,lower wind speed,anomalous southerlies,and higher relative humidity (RH),which restrict the horizontal and vertical ventilation of haze particles (Yin et al.,2017).

    The number of HDs in December over the YRD(DHD),as well as those in January (JHD),slowly increased from 1981 to 2017,while those over NC (DHDand JHD) slightly decreased from 1981 to 2010 but increased from 2011 to 2017 (Fig.1).In this study,we pay more attention to the interannual variations of monthly haze pollution.The correlation coefficient (CC) between DHDand JHDis 0.71;however it decreases to 0.33 in the YRD,indicating significant differences in haze variations in December and January over the YRD.The time series of DHDand DHD(JHDand JHD) during 1981—2017 has a CC of 0.49 (0.2),which are not high for two adjacent economically developed regions (Figs.1a and b).Furthermore,we also compared the variations in emissions (i.e.,the difference of emissions in different months and regions) with the associated differences in HDs and found the CCs between them were all lower than 0.2 [non-significant;Fig.S1 in electronic supplementary material(ESM) ].The above statistical results illustrate the need for an analysis of the monthly variations of atmospheric circulations associated with haze pollution (i.e.,the impacts of meteorology) in the YRD and NC.

    2.Datasets and methods

    The monthly geopotential height,horizontal wind(UV),vertical wind (omega),temperature,and RH at different levels for the winters of 1981—2018,as well as surface RH,surface UV,surface air temperature,and sea surface level,are from the NCEP—NCAR reanalyses with a horizontal resolution of 2.5° × 2.5° (Kalnay et al.,1996).The precipitation data are from Climate Prediction Center Merged Analysis of Precipitation (CMAP),with a horizontal resolution of 2.5° × 2.5°,in winters from 1981 to 2018 (Xie and Arkin,1997).Other precipitation data,including the 1° × 1°Precipitation Reconstruction over Land of the National Oceanic and Atmospheric Administration,as well as a station dataset of the China Meteorological Administration(Chen et al.,2002),were used to verify the results.Monthly PBLH data are also used here (resolution:1° × 1°),but were derived from the ERA-Interim dataset with the same time period as the above datasets (Dee et al.,2011).In addition,the EA/WR and Scandinavia patterns are two of three prominent teleconnection patterns that affect Eurasia,and have been referred to as the Eurasia-2 and Eurasia-1 pattern,respectively (Barnston and Livezey,1987).The EA/WR pattern is composed of two positive height anomaly centers over Europe and northern China,and two negative height anomaly centers over the central North Atlantic and north of the Caspian Sea,when in positive phase.The Scandinavia pattern has four centers in Eurasia (i.e.,Spain and the adjacent Mediterranean and Atlantic area,Scandinavia,Northwest China or western Mongolia,and Japan),and sometimes some centers do not show up.The calculation procedures for these two indices are available at https://www.cpc.ncep.noaa.gov/data/teledoc/teleindcalc.shtml,and numerical values were downloaded from https://www.cpc.ncep.noaa.gov/data/teledoc/telecontents.shtml.The emissions inventory data are from http://inventory.pku.edu.cn/.The calculations for atmospheric circulations,including the anomalous anticyclone (AAC),surface air temperature (SAT),surface temperature difference between the north and south (SAT diff.),RH,PBLH,surface wind speed (UV speed),and precipitation,are as follows.The areas calculated as AAC indices are shown in Figs.2a and b for December and Figs.2c and d for January.The areas calculated as SAT diff.indices are[R1 (38°—70°N,85°—130°E) ? R2 (8°—23°N,95°—120°E)]and [R1 (36°—53°N,83°—115°E) ? R2 (15°—19°N,110°—115°E)]in December and January,respectively.Other variables’ indices are defined as area-averaged values of the studied areas (the YRD and NC).

    Fig.1.(a) Variation of December haze days (HDs) in the Yangtze River Delta (YRD) and in North China (NC) from 1981 to 2017.(b) Variation of January HDs in the YRD and in NC from 1982 to 2018.Solid (dotted) lines represent detrended (original) data.The correlation coefficients (CCs) of two solid lines are shown in the spaces.

    As for haze pollution,the number of HDs in each month in the winters of 1981—2017 were adopted owing to the lack of long-term PMdata.Haze was calculated by defining visibility less than a certain threshold,which was 10 km before 1 January 2014 for most stations and 7.5 km after because of the switch in visibility observation means(i.e.,from manual observation to automatic observation)according to a report of the China Meteorological Administration in 2014 (Yin et al.,2017) and RH less than 90% (Chen and Wang,2015;Yin and Wang,2016).One HD at a station was defined as a day with haze at any time,after excluding other weather phenomena that affected visibility.All the HDs of a month at all stations in the region were accumulated,and then the average value of all stations in the region was calculated as the HDs in the region.HDs over the YRD(27.05°—33.77°N,118.15°—121.95°E) and NC (34°—42°N,114°—120°E) were computed as the HD average value in these two areas,respectively.For more detail,readers are referred to Chen and Wang (2015),Yin and Wang (2016),and Yin et al.(2017).

    Fig.2.(a) Regressions of December geopotential height (contours;units:m) and the associated wave activity flux(WAF;arrows;units:m2 s?2) at 500 hPa on the December HDs in the YRD during 1981—2017.(b) As in (a) but in NC.(c) Regressions of the January geopotential height (contours;units:m) and the associated WAF (arrows;units:m2 s?2) at 500 hPa on the January HDs in the YRD during 1982—2018.(d) As in (c) but in NC.Solid lines and dotted lines represent positive and negative values of regression,respectively.Shaded regions indicate that the 500-hPa geopotential height anomalies are significant at the 95% confidence level,and yellow (green) color represents positive (negative) regression coefficients passing the Student’s t-test.The linear trend of the data was removed.The purple (gray) solid-line box indicates the location of the YRD (NC).The orange dotted-line boxes in (a,b)respectively indicate the regions of the AAC indices of the YRD (38°—60°N,90°—123°E) and NC (30°—49°N,100°—135°E) in December.The orange dotted-line boxes in (c,d) respectively indicate the regions of the AAC indices of the YRD (30°—49°N,85°—115°E) and NC (35°—40°N,115°—135°E) in January.

    3.Results

    3.1.Atmospheric circulations drive the monthly variations in haze

    The atmospheric circulations associated with December and January haze pollution in the YRD were investigated.As illustrated in Fig.2a,a Rossby wave—like train at middle and high latitudes of continental Eurasia strongly contributes to the variations in DHD.In comparison,in January,the Rossby wave train becomes non-significant,and the only significant centers are the local AAC located in the northwest of the YRD (Fig.2c).That is,the large-scale atmospheric circulation affecting HDs degenerate to the local anticyclone from December to January.Lower PBLH (Fig.3c)in December is apparent because of anomalous descending motions (Fig.3a) over the YRD.Weak surface wind speed,induced by anomalous southerly wind,is apparent in January over the YRD (Fig.3d).Thus,the vertical movement(Figs.3a and c) is restricted in December and the horizontal movement (Figs.3b and d) is restricted in January,over the YRD,leading to high contemporaneous HDs.Furthermore,the anomalous precipitation plays a critical role in the removal of haze particles over the YRD (Figs.4a and b).Precipitation and HDs over the YRD show a significant outof-phase relationship in both December (CC=?0.34) and January (CC=?0.46) (Figs.4a and b).

    Fig.3.(a) Cross-section (115°—125°E mean) CCs between December HDs in the YRD and December air temperature (shading),RH (contours),and wind (arrows).(b) As in (a) but in January.(c) The CCs between December HDs in the YRD and December PBLH (shading) and surface wind (arrows) from 1981 to 2017.(d) The CCs between January HDs in the YRD and January surface wind speed (shading) and surface wind (arrows) from 1982 to 2018.All the above CCs share the same colorbar at the bottom of the figure.The south wind component in the meridional direction (a—d),the east wind component in the latitudinal direction (c,d),and the ascending movement in the vertical direction (a,b;owing to omega multiplied by ?1) are positive,and vice versa.White slanted lines indicate that the CCs represented by the shading exceed the 95% confidence level.The linear trends of all data were removed.The purple box or purple line indicates the location of the YRD.

    Fig.4.(a) Variation of December HDs in the YRD and the December area-averaged precipitation from CMAP datasets,with their CC in the top-right corner.(b) Variation of January HDs in the YRD and January area-averaged precipitation from CMAP datasets,with their CC in the top-right corner.(c,d) As in (a,b) but in NC.The linear trends of all data were removed.

    Atmospheric circulations associated with haze pollution in NC in December and January were also examined.In the mid-troposphere,a Rossby wave—like train clearly affects the haze pollution over NC in December (Fig.2b).However,in January,the associated atmospheric circulations become relatively local (Fig.2d),which is different from the results revealed in many previous studies for the whole winter season (Chen and Wang,2015;Yin and Wang,2016).Anomalous ascending motion (Figs.5a and b),warming near the surface (Figs.5a and b),southerly wind (Figs.5c and d),weak surface wind speed (Figs.S2a in the ESM and 5d),low PBLH (Figs.5c and S3a),high potential of thermal inversion,i.e.,the air temperature at 925 hPa minus the air temperature at 1000 hPa (Figs.S2b and S3b),and high RH (Figs.5a and b,Figs.S2c and S3c),are favorable for both DHDand JHD.That is,the monthly variations of associated local weather conditions are similar.However,precipitation makes different contributions to DHDand JHD.December precipitation is almost unrelated to DHD(Fig.4c),while January precipitation has a significantly positive relationship with DHD(CC=0.33,exceeding the 95% confidence level;Fig.4d).

    From the data in Table 1,we can see that the AAC index is crucial for both DHDand DHD,while the SAT diff.index and precipitation index (SAT index,RH index,PBLH index and UV speed index) play important roles in the YRD (NC).To quantify the contributions of atmospheric circulations to haze pollution,the highly correlated variables (≥ 95% confidence level) were selected to regress on the number of HDs.In other words,the AAC,SAT diff.and precipitation indices (ACC,SAT,RH,PBLH and UV speed indices) in December were selected as regression factors of DHD(DHD).The predicted DHDand DHDdid not include the observed trend here,and in the last calculation step we added the trend as fitted values,shown in Fig.6.The fitted and observed DHDand DHDhad a CC of 0.77 and 0.67 for the YRD and NC,respectively (Figs.6a and b).That is,atmospheric circulations made variance contributions of 59% and 45%,respectively (Figs.6a and b),confirming that these circulation variables have large influences on DHDand DHD.DHDhad the same sign as the AAC (SAT difference between the north and the south of the YRD) in 33 (31) of 37 years,while it had opposite signs to precipitation in 25 of 37 years (Fig.7a).DHDshared the same mathematical sign as the AAC,local SAT and RH in 24,28 and 28 of 37 years,respectively,while it had opposite mathematical signs to the PBLH and surface wind in 26 and 25 of 37 years,respectively (Fig.7b).As can be seen from Fig.7a,three variables correspond to DHDin the minimum year of 2010,while it is two variables in the maximum year of 2013.In contrast,as shown in Fig.7b,all five variables correspond to DHDin the minimum (maximum) year of 2010 (2015),which highlights the importance of meteorological and climate conditions.

    Fig.5.(a) The cross-section (110°—120°E mean) CCs between December HDs in NC and December air temperature(shading),RH (contours),and wind (arrows).(b) As in (a) but in January.(c) The CCs between December HDs in NC and December PBLH (shading) and surface wind (arrows) from 1981 to 2017.(d) The CCs between January HDs in NC and January surface wind speed (shading) and surface wind (arrows) from 1982 to 2018.All the above CCs share the same colorbar at the bottom of the figure.The south wind component in the meridional direction(a—d),the east wind component in the latitudinal direction (c,d),and the ascending movement in the vertical direction (a,b;owing to omega multiplied by ?1) are positive,and vice versa.White slanted lines indicate that the CCs represented by the shading exceed the 95% confidence level.The linear trends of all the data were removed.The white box or gray line indicates the location of NC.

    Table 1.The correlation coefficients (CCs) between atmospheric circulation indices and haze days (HDs) of two regions (the YRD and NC) in early winter (December and January).The linear trends in all data were removed.Double asterisks (**) and triple asterisks (***)indicate the results pass the 95% and 99% confidence level,respectively.A forward-slash (/) indicates the significance level is below 95%.

    Fig.6.Variation in the standardized observed HDs (black bars) and fitted HDs (red solid line) in the YRD in (a)December from 1981 to 2017 and (b) January from 1982 to 2018.Fitted detrended HDs plus the observed HDs’trend are fitted HDs,represented here by the red solid line.Red dotted lines represent their same trend line.The number on the right is the CC of the observed HDs and fitted HDs plus the trend (i.e.,the CC between the black bars and the red solid line).(c,d) As in (a,b) but in NC.

    Similarly,CCs were calculated between circulation indices in January and JHD(JHD),as shown in Table 1,and the significant indices (exceeding the 95% confidence level) were selected to fit JHD(JHD).Three (five) circulation indices,including the AAC,SAT diff.and precipitation indices (the ACC,RH,PBLH,UV speed and precipitation indices),were demonstrated to be useful for the formation of JHD(JHD).The fitted circulation indices explain 56% (42%) of the variance of JHD(JHD)with the trend,indicating large contributions of these atmospheric circulations (Figs.6c and d).In Fig.7c,the AAC,SAT and precipitation all show corresponding results with JHDin the minimum (maximum) year of 1993 (2015).Meanwhile,in Fig.7d,five meteorological variables show corresponding results with JHDin the minimum year of 2011;however,only RH shows corresponding results with JHDin the maximum year of 2016.Regardless,meteorological and climate conditions play important roles in the interannual variabilities of HDs rather than other elements.

    3.2.Comparison of atmospheric circulations associated with DHDNCand DHDYRD

    The wave activity flux (WAF) demonstrates the wave energy propagation paths (Takaya and Nakamura,2001;Hsu and Lin,2007;Honda et al.,2009).A quasi-stationary planetary wave route (i.e.,the Scandinavia pattern) is apparent,with an anomalous negative center over Scandinavia and an anomalous positive center over Mongolia (Fig.2a).The CC between the Scandinavia pattern and DHDis?0.48 (significant at the 99% confidence level).In contrast,the WAF associated with DHD(Fig.2b) shows a positive EA/WR phase (CC=0.56).These results demonstrate that the Scandinavia and EA/WR patterns contribute to the variations of DHDand DHD,respectively.The AAC near Northeast Asia is located in the crossover regions of the Scandinavia and EA/WR patterns and might explain the close relationship between DHDand DHD.

    Local meteorological conditions associated with DHDand DHDwere also compared (Figs.3—5).The climate-mean vertical motion is weak in the downward direction over the YRD (not shown),and the AAC enhances the anomalous descending movement (Fig.3a).Besides,anomalous reversion of the north—south temperature is favorable for DHD(Fig.3a),which restricts the invasion of the East Asian winter monsoon (EAWM) into the YRD.Low PBLH also restricts the vertical dispersion (Fig.3c).Against the background of intensive descending motion over the YRD,dry air is carried from the top to the ground,causing the weak negative RH anomaly (Fig.3a) and less precipitation.As we know,some pollutants can be removed via wet removal,i.e.,precipitation,especially in southern areas with large precipitation.In Fig.4a,precipitation has a negative CC with DHD(CC=?0.34,≥ 95% confidence level).Local meteorological conditions related to DHDare correspondingly discussed (Figs.5a and c).Different from DHD,anomalous upward movement (Fig.5a),southerly wind near the surface (Fig.5a),high RH (Figs.5a and S2c),high surface temperature (Fig.5a),high potential of temperature inversion (Fig.S2b),and low surface wind speed(Fig.S2a),are favorable for DHD.In addition,precipitation has little influence on the elimination of haze pollution over NC (Fig.4c),as compared to that over the YRD (Fig.4a).As shown in Figs.3c and 5c,the PBLH shows negative anomalies over both NC and the YRD,indicating a negative contribution to the elimination of haze pollution.

    Fig.7.(a) Variation of December HDs (line) and associated significant meteorological variables (histogram) in the YRD from 1981 to 2017.(b) As in (a) but in NC.(c) Variation of January HDs (line) and associated significant meteorological variables (histogram) in the YRD from 1982 to 2018.(d) As in (c) but in NC.Dark green,pink,cyan,brown,blue,gray,and purple solid circles at the top indicate the same or opposite signs between HDs and meteorological variables (AAC,SAT,SAT diff.,RH,PBLH,UV speed,precipitation) according to the CCs in Table 1.The linear trends of all data were removed.

    It is common knowledge that the wintertime weather and climate of East Asia is affected by the EAWM,so the monthly EAWM [i.e.,the East Asian December (January)monsoon,abbreviated as EADM (EAJM)]was separately analyzed to study the effects on DHDand DHD.Here,the definitions of the EADM and EAJM refer to previous studies (Wang and Jiang,2004;He and Wang,2012) and are shown in Table S1 (in the ESM),including the sub-indices and synthetic index.The CCs of the EADM and DHD(DHD) show that specific members,such as the East Asian deep trough,westerly jet,as well as the synthetic index,have an influence on DHD,while all members of the EADM have a significant impact on DHD(Table 2).The question,then,is how does the EADM affect DHDand DHD? A strong EADM may weaken the temperature difference between the north and south of the YRD (Fig.8a)and bring cold air from the mid—high latitudes to China.Meanwhile,there is sufficient water vapor in the YRD,so the intrusion of cold air may enhance the precipitation over the YRD (Fig.8b).When precipitation increases,haze pollution in the YRD will be removed.In addition,a strong EADM may also increase the surface wind speed in theYRD (not shown),strengthening the conditions of horizontal dispersion.As for DHD,a strong EADM may lead to favorable local ventilation conditions and unfavorable growth conditions for haze particles,such as low SAT (Fig.8c),low RH (Fig.8d),high PBLH (Fig.8e),and high surface wind speed (Fig.8f).

    Table 2.The CCs between East Asian early winter (December and January) monsoon indices and HDs of two areas (the YRD and NC) in December and January,respectively.Double asterisks(**) and triple asterisks (***) indicate the results pass the 95% and 99% confidence level,respectively.

    Fig.8.Scatterplot of (a) December East Asian jet index and December SAT diff.index between the north and south of the YRD,and (b) the December SAT diff.index between the north and south of the YRD and the December precipitation index of the YRD.Scatterplot of the East Asian December monsoon synthetic index and December (c)SAT index,(d) RH index,(e) PBLH index,and (f) UV speed index of NC.The linear trends in all data were removed.The straight lines are the lines of best fit,and the CCs indicate the CCs between two variables.

    3.3.Comparison of atmospheric circulations associated with JHDNCand JHDYRD

    The CCs of JHDand JHDbecome non-significant (Fig.1b),indicating weak synergistic variations of JHDand JHD.The associated wave-like train is significantly weakened (Figs.2c and d) in January rather than that in December.Consequently,the influence of Eurasian wave trains on local HDs is weakened.Local anticyclones affect local HDs in both areas,with CCs of 0.40 and 0.37(Table 1),significant at the 95% confidence level.Additionally,the AAC in January is also relatively weaker than that in December (Fig.2,Table 1).

    It was shown in Zhong et al.(2019) that the directions of vertical motion vary according to the locations of the AAC.Because the YRD is located in the east of the bottom of the AAC (Fig.2c),descending motion was delivered to the region (Fig.3b).Although the descending motion only exists in the south of the YRD,other local meteorological conditions induced by the AAC,such as the SAT diff.(Fig.3b),weak UV speed (Fig.3d),anomalous southerly wind (Fig.3d),and less precipitation (Fig.4b),are crucial for high JHD.By contrast,for JHD,anomalous ascending motion(Fig.5b),high SAT (Fig.5b),high RH (Figs.5b and S3c in the ESM),anomalous southerly wind (Figs.5b and d),weak UV speed (Fig.5d),low PBLH (Fig.S3a),and high potential of temperature inversion (Fig.S3b),provide adverse conditions for the dispersion of haze particles.Besides,in January,precipitation makes different contributions to HDs over NC and the YRD,i.e.,more precipitation brings more JHD(Fig.4d).Light rain is dominant when precipitation happens over NC,which is conducive to the hygroscopic growth of haze particles.

    As for the EAJM,the significant impact factors are the Siberian high index and synthetic index (Siberian high index,Aleutian low index and meridional wind at 850 hPa index) for JHD(JHD).Additionally,the influential process of the EAJM is as follows.A strong EAJM can reduce the temperature difference between the north and south of the YRD and enhance the precipitation over the YRD(Figs.9a and b).Meanwhile,for JHD,the Siberian high can affect local meteorological conditions (Figs.9c—e),including RH (Fig.9c),PBLH (Fig.9d),and UV speed (Fig.9e).In other words,a strong EAJM,represented by the Siberian high,creates an unstable environment for high JHD.

    Fig.9.Scatterplot of (a) the East Asian January monsoon synthetic index and January SAT diff.index between the north and south of the YRD,and (b) the January SAT diff.index between the north and south of the YRD and the January precipitation index of the YRD.Scatterplot of the January Siberian high index and the January (c) RH index,(d) PBLH index,and (e) UV speed index of NC.The linear trends of all data were removed.The straight lines are the lines of best fit,and the CCs indicate the CCs between two variables.

    4.Conclusions and discussion

    Monthly haze pollution over the YRD and NC was investigated in early winter (i.e.,December and January),as well as the associated large-scale atmospheric circulations and local meteorological conditions (Fig.10).The DHD(DHD) is dominated by the Scandinavia (EA/WR) pattern in December,and these two wave trains degenerate into local AACs in January.In December,the DHD(DHD) is dominated by descending motion,the large temperature difference between the north and south,and less precipitation (ascending motion,high SAT,high RH,low PBLH,and weak UV speed).The precipitation is more important in January,and it makes a negative (positive) contribution to JHD(JHD).Most members of the EAWM make negative contributions to DHD and JHD over the two areas by affecting the local meteorological conditions.In fact,the locations of the study areas relative to the AAC might affect local circulations,according to Zhong et al.(2019).Because the YRD is located in the front of the AAC and NC at the back,it stimulates the descending (ascending)motion in the vertical direction for the YRD (NC) in both December and January,which results in the differences of local meteorological conditions,especially for the precipitation.

    Fig.10.Schematic diagram of the subseasonal variation of the atmospheric circulation associated with haze pollution in the YRD and NC.The schematic of the YRD and NC in December (January) is on the left (right).Ellipses represent anomalous cyclones and anticyclones at high levels.Black (purple) curves on the left indicate the EA/WR(Scandinavia) pattern.Vertical arrows indicate the directions of vertical movement.Warm (cold) colors at the surface indicate warm (cold) anomalous surface air temperature.Green (red) clouds indicate positive (negative)anomalies of precipitation.Yellow crescents indicate a low boundary layer height.The purple (gray) box indicates the location of the YRD (NC).

    Utilizing these significant circulation indices to establish regression models of HDs,results showed that these circulation indices make large contributions and can explained more than 40% of the variance of DHD,JHD,DHDand JHD.Owing to the switch in the observation methods of visibility in January 2014,the reliability of HDs after January 2014 has been tested.It was found that the conclusions are still robust if the data after January 2014 are removed.The collinearity of the indices can be ignored because the variance inflation factors of most selected factors are lower than five in the four regression equations(Fig.6).In Fig.11 in Zhang et al.(2019),the adverse weather conditions in autumn and winter might reduce the effect of emissions reduction in the Beijing—Tianjin—Hebei region in 2014 and 2015.Yin and Zhang (2020) investigated the pollution situation in the winters of 2017 and 2018 under almost the same emission conditions,finding that haze pollution rebounded in 2018 compared with that in 2017,indicating the important effect of climate and weather conditions.

    Acknowledgements

    .This research was supported by the National Key Research and Development Plan (Grant No.2016YFA0600703),the National Natural Science Foundation of China (Grant Nos.91744311,41991283 and 41705058),and the funding of the Jiangsu Innovation &Entrepreneurship Team.

    Electronic supplementary material:

    Supplementary material is available in the online version of this article at https://doi.org/10.1007/s00376-020-0227-z.

    久久国产精品人妻蜜桃| 久久ye,这里只有精品| 欧美午夜高清在线| 成年人午夜在线观看视频| 国产97色在线日韩免费| 亚洲人成77777在线视频| 中文字幕制服av| 精品少妇内射三级| 亚洲欧美成人综合另类久久久| 久久精品人人爽人人爽视色| 亚洲精品国产av蜜桃| 亚洲av片天天在线观看| 女人精品久久久久毛片| 性色av乱码一区二区三区2| 日本欧美视频一区| 欧美精品亚洲一区二区| 国产精品亚洲av一区麻豆| 久久香蕉激情| 午夜福利免费观看在线| 久久久精品免费免费高清| 欧美日韩av久久| 精品国产国语对白av| 人人澡人人妻人| 亚洲性夜色夜夜综合| 日韩电影二区| 波多野结衣av一区二区av| 乱人伦中国视频| 老司机影院成人| 国产激情久久老熟女| 性色av乱码一区二区三区2| 久久精品aⅴ一区二区三区四区| 一边摸一边做爽爽视频免费| 淫妇啪啪啪对白视频 | 精品久久久久久电影网| 肉色欧美久久久久久久蜜桃| 国产欧美日韩一区二区三 | 99久久综合免费| 国产精品 欧美亚洲| 啪啪无遮挡十八禁网站| 亚洲国产毛片av蜜桃av| 国产成人av教育| 中文字幕另类日韩欧美亚洲嫩草| 男女无遮挡免费网站观看| 久久久精品区二区三区| 男男h啪啪无遮挡| 老司机午夜福利在线观看视频 | 免费在线观看视频国产中文字幕亚洲 | 国产一区二区三区av在线| 亚洲av电影在线进入| 国产精品麻豆人妻色哟哟久久| 国产亚洲精品一区二区www | 天天躁日日躁夜夜躁夜夜| 久久ye,这里只有精品| 亚洲欧洲日产国产| 日韩有码中文字幕| 丝袜人妻中文字幕| 中亚洲国语对白在线视频| 女人高潮潮喷娇喘18禁视频| 国产99久久九九免费精品| 中文字幕最新亚洲高清| av网站在线播放免费| 亚洲av男天堂| 久久精品成人免费网站| 国产精品偷伦视频观看了| 午夜福利在线观看吧| 亚洲精品久久久久久婷婷小说| 国产精品二区激情视频| 午夜免费成人在线视频| 丝袜脚勾引网站| 天堂8中文在线网| 国产一区二区在线观看av| 国产成人精品无人区| 欧美黄色片欧美黄色片| 日本91视频免费播放| 亚洲欧美日韩另类电影网站| 啦啦啦视频在线资源免费观看| √禁漫天堂资源中文www| 国产av又大| 国产精品偷伦视频观看了| 亚洲一区二区三区欧美精品| 99精国产麻豆久久婷婷| 一区二区三区激情视频| 国产成人av激情在线播放| 国产国语露脸激情在线看| 国产精品 国内视频| 岛国毛片在线播放| 国产又色又爽无遮挡免| 韩国精品一区二区三区| 欧美成人午夜精品| 色播在线永久视频| 亚洲色图综合在线观看| 亚洲精品乱久久久久久| 国产av又大| 天天操日日干夜夜撸| 在线永久观看黄色视频| 国产日韩欧美亚洲二区| 纯流量卡能插随身wifi吗| a 毛片基地| 手机成人av网站| 手机成人av网站| 热99国产精品久久久久久7| 亚洲色图综合在线观看| 极品人妻少妇av视频| 亚洲人成电影观看| 国产精品久久久久久人妻精品电影 | 三级毛片av免费| a在线观看视频网站| 久久人妻熟女aⅴ| 在线精品无人区一区二区三| 久久国产精品男人的天堂亚洲| 女人被躁到高潮嗷嗷叫费观| 黄色视频在线播放观看不卡| 99国产精品99久久久久| 精品少妇久久久久久888优播| 亚洲av男天堂| 人人妻人人澡人人看| 国产欧美日韩综合在线一区二区| 精品国产一区二区久久| 亚洲天堂av无毛| 高清黄色对白视频在线免费看| www.999成人在线观看| 欧美变态另类bdsm刘玥| 亚洲第一av免费看| 久久精品国产a三级三级三级| 日韩一区二区三区影片| 手机成人av网站| 国产精品久久久久久精品电影小说| 久久精品国产综合久久久| av电影中文网址| 中文字幕精品免费在线观看视频| 欧美激情久久久久久爽电影 | 欧美日韩精品网址| 一本综合久久免费| 亚洲一区中文字幕在线| 欧美 亚洲 国产 日韩一| 亚洲欧美清纯卡通| 老司机影院成人| 老司机亚洲免费影院| 秋霞在线观看毛片| 午夜激情av网站| 黄网站色视频无遮挡免费观看| 国产亚洲一区二区精品| 老汉色∧v一级毛片| 欧美日韩亚洲高清精品| 韩国高清视频一区二区三区| 成人18禁高潮啪啪吃奶动态图| 成人国产av品久久久| av欧美777| 欧美97在线视频| 国产真人三级小视频在线观看| 18禁国产床啪视频网站| 久久久欧美国产精品| 精品一区二区三卡| 91成人精品电影| 久久亚洲精品不卡| 十八禁网站网址无遮挡| 宅男免费午夜| 好男人电影高清在线观看| 国产成人欧美| 欧美日韩黄片免| 亚洲精品第二区| 97人妻天天添夜夜摸| 午夜激情av网站| 亚洲精品一卡2卡三卡4卡5卡 | 亚洲国产欧美日韩在线播放| 久久久久久久大尺度免费视频| 国产在线一区二区三区精| 亚洲伊人色综图| 免费黄频网站在线观看国产| 日韩制服丝袜自拍偷拍| 飞空精品影院首页| 一边摸一边做爽爽视频免费| 国产在视频线精品| 女人爽到高潮嗷嗷叫在线视频| 久久 成人 亚洲| 色视频在线一区二区三区| 亚洲欧洲精品一区二区精品久久久| 日本猛色少妇xxxxx猛交久久| 人妻久久中文字幕网| 久久久久视频综合| 性少妇av在线| 亚洲成国产人片在线观看| 精品熟女少妇八av免费久了| 欧美黄色淫秽网站| 制服人妻中文乱码| 午夜福利视频精品| 日韩免费高清中文字幕av| 中文字幕av电影在线播放| 久久久精品94久久精品| 青春草亚洲视频在线观看| 青春草亚洲视频在线观看| 国产1区2区3区精品| 精品少妇久久久久久888优播| 国产精品一区二区免费欧美 | av天堂在线播放| 亚洲少妇的诱惑av| 乱人伦中国视频| 丁香六月天网| 国产野战对白在线观看| 国产野战对白在线观看| 国产精品香港三级国产av潘金莲| 精品亚洲成a人片在线观看| 欧美变态另类bdsm刘玥| 美女高潮到喷水免费观看| 伊人亚洲综合成人网| 视频区图区小说| 国产精品秋霞免费鲁丝片| 国产欧美日韩一区二区精品| 久久国产精品大桥未久av| 高清视频免费观看一区二区| 老熟妇仑乱视频hdxx| 亚洲精品国产av蜜桃| www.自偷自拍.com| 97在线人人人人妻| 日韩视频在线欧美| 日本黄色日本黄色录像| 精品久久久久久久毛片微露脸 | 天天操日日干夜夜撸| 99热国产这里只有精品6| 午夜激情久久久久久久| 午夜免费鲁丝| 精品国内亚洲2022精品成人 | 亚洲精品国产色婷婷电影| 啦啦啦视频在线资源免费观看| 久久久久网色| 中文字幕制服av| 午夜福利一区二区在线看| 99国产综合亚洲精品| 丝袜人妻中文字幕| 精品国产一区二区久久| 午夜免费鲁丝| 18禁黄网站禁片午夜丰满| 最黄视频免费看| 国产亚洲午夜精品一区二区久久| av在线播放精品| 老司机亚洲免费影院| 热re99久久精品国产66热6| 亚洲午夜精品一区,二区,三区| 人妻人人澡人人爽人人| 久久精品国产综合久久久| 国产精品.久久久| 国产欧美亚洲国产| 欧美日韩中文字幕国产精品一区二区三区 | 一级毛片女人18水好多| 亚洲avbb在线观看| 777米奇影视久久| 国产男女内射视频| 91老司机精品| 欧美乱码精品一区二区三区| 欧美性长视频在线观看| 9热在线视频观看99| 在线观看www视频免费| 亚洲精品久久成人aⅴ小说| 亚洲性夜色夜夜综合| 亚洲精品日韩在线中文字幕| 精品国产一区二区久久| 国产精品一区二区免费欧美 | 国产成人系列免费观看| 99精品欧美一区二区三区四区| 久久久久久久久久久久大奶| 操出白浆在线播放| 十分钟在线观看高清视频www| 狂野欧美激情性xxxx| 午夜免费鲁丝| 午夜日韩欧美国产| 亚洲精品成人av观看孕妇| 少妇精品久久久久久久| 免费黄频网站在线观看国产| 久久毛片免费看一区二区三区| 国产三级黄色录像| 天天操日日干夜夜撸| 成人手机av| 国产97色在线日韩免费| 男女高潮啪啪啪动态图| 久久国产亚洲av麻豆专区| 亚洲专区字幕在线| 国产亚洲一区二区精品| 国产日韩欧美亚洲二区| 他把我摸到了高潮在线观看 | 黑人巨大精品欧美一区二区mp4| 国产精品1区2区在线观看. | 美女福利国产在线| 又黄又粗又硬又大视频| 精品国产超薄肉色丝袜足j| 精品人妻1区二区| 久久毛片免费看一区二区三区| av有码第一页| 久久久久久久久久久久大奶| 日本wwww免费看| 黑人欧美特级aaaaaa片| 无限看片的www在线观看| 久久人人爽人人片av| 亚洲国产毛片av蜜桃av| 啦啦啦 在线观看视频| 国产精品 国内视频| 成人三级做爰电影| 两性午夜刺激爽爽歪歪视频在线观看 | 热re99久久国产66热| 欧美人与性动交α欧美软件| 在线亚洲精品国产二区图片欧美| 久久中文看片网| 色精品久久人妻99蜜桃| 国产亚洲欧美精品永久| 欧美 亚洲 国产 日韩一| 亚洲av成人不卡在线观看播放网 | 大片电影免费在线观看免费| 搡老熟女国产l中国老女人| 久久久久久人人人人人| 亚洲国产毛片av蜜桃av| 亚洲,欧美精品.| 91av网站免费观看| 色婷婷av一区二区三区视频| 日日爽夜夜爽网站| 欧美亚洲日本最大视频资源| 美女午夜性视频免费| 久久亚洲国产成人精品v| 久久人妻熟女aⅴ| 精品国产乱码久久久久久小说| 国产精品 欧美亚洲| 咕卡用的链子| 久久久久久免费高清国产稀缺| 国产又爽黄色视频| 日韩熟女老妇一区二区性免费视频| 色婷婷av一区二区三区视频| 欧美日韩国产mv在线观看视频| 亚洲伊人色综图| 黄频高清免费视频| av网站在线播放免费| 美女福利国产在线| 丰满饥渴人妻一区二区三| 青春草视频在线免费观看| 国产精品自产拍在线观看55亚洲 | 美女福利国产在线| 欧美日韩亚洲高清精品| 蜜桃在线观看..| 日本a在线网址| 视频区图区小说| 青青草视频在线视频观看| 蜜桃国产av成人99| 在线观看一区二区三区激情| 亚洲中文av在线| 99热国产这里只有精品6| xxxhd国产人妻xxx| 啦啦啦啦在线视频资源| 美女高潮喷水抽搐中文字幕| 久久精品亚洲av国产电影网| 热99re8久久精品国产| 91麻豆av在线| 久久精品国产综合久久久| 飞空精品影院首页| 亚洲成av片中文字幕在线观看| 中国美女看黄片| 婷婷丁香在线五月| 一区二区三区乱码不卡18| 18禁观看日本| 捣出白浆h1v1| 亚洲人成电影免费在线| 看免费av毛片| 嫩草影视91久久| 国产有黄有色有爽视频| 亚洲精品乱久久久久久| 国精品久久久久久国模美| 国产亚洲av高清不卡| 欧美97在线视频| 免费观看人在逋| 日本vs欧美在线观看视频| 国产成人av激情在线播放| 一级a爱视频在线免费观看| 日韩欧美国产一区二区入口| 亚洲精品美女久久av网站| 国产免费福利视频在线观看| 免费不卡黄色视频| 日日摸夜夜添夜夜添小说| 蜜桃国产av成人99| 免费在线观看完整版高清| 国产黄色免费在线视频| 国产成人啪精品午夜网站| 亚洲精品国产av成人精品| 狠狠精品人妻久久久久久综合| 日本精品一区二区三区蜜桃| 大香蕉久久成人网| 制服人妻中文乱码| 亚洲欧美日韩另类电影网站| h视频一区二区三区| 国产黄色免费在线视频| www.熟女人妻精品国产| 一级a爱视频在线免费观看| 国产又色又爽无遮挡免| 欧美日韩成人在线一区二区| 色视频在线一区二区三区| 久久久久久久国产电影| 十八禁网站免费在线| 青草久久国产| 男女高潮啪啪啪动态图| 欧美成人午夜精品| 热99久久久久精品小说推荐| 丝袜人妻中文字幕| 淫妇啪啪啪对白视频 | 在线亚洲精品国产二区图片欧美| 日本黄色日本黄色录像| 久久久国产成人免费| 日日夜夜操网爽| 黄色 视频免费看| 91成年电影在线观看| 人人妻人人澡人人看| 99久久99久久久精品蜜桃| 午夜福利视频在线观看免费| 久久久久久久久久久久大奶| 久久久久久久久免费视频了| 少妇粗大呻吟视频| 精品人妻熟女毛片av久久网站| 欧美成狂野欧美在线观看| 我的亚洲天堂| 国产精品久久久久久精品古装| 亚洲男人天堂网一区| 波多野结衣一区麻豆| 啦啦啦在线免费观看视频4| 亚洲精品国产av蜜桃| 日韩熟女老妇一区二区性免费视频| 极品人妻少妇av视频| 国产精品熟女久久久久浪| 日韩精品免费视频一区二区三区| 免费看十八禁软件| 人人妻人人添人人爽欧美一区卜| 18禁观看日本| 免费观看人在逋| 久久久精品94久久精品| 欧美日韩av久久| 蜜桃在线观看..| 亚洲人成电影免费在线| 老司机深夜福利视频在线观看 | 色婷婷av一区二区三区视频| 老熟妇乱子伦视频在线观看 | 成人亚洲精品一区在线观看| 波多野结衣一区麻豆| 色播在线永久视频| 亚洲国产看品久久| 又大又爽又粗| 大片免费播放器 马上看| tocl精华| 99久久综合免费| 久久毛片免费看一区二区三区| 亚洲人成电影免费在线| 在线十欧美十亚洲十日本专区| 久久亚洲国产成人精品v| 亚洲国产av新网站| 手机成人av网站| 午夜福利在线免费观看网站| 伦理电影免费视频| 亚洲国产欧美日韩在线播放| 国产一区二区三区在线臀色熟女 | 亚洲人成电影免费在线| 免费在线观看视频国产中文字幕亚洲 | 高清视频免费观看一区二区| 桃花免费在线播放| a 毛片基地| www.999成人在线观看| 亚洲国产av影院在线观看| 五月天丁香电影| 宅男免费午夜| 三级毛片av免费| 老司机影院成人| 精品乱码久久久久久99久播| 日本一区二区免费在线视频| 我要看黄色一级片免费的| 久久亚洲精品不卡| 视频区图区小说| 国产欧美日韩一区二区精品| 国产99久久九九免费精品| av在线app专区| 免费看十八禁软件| 国产av国产精品国产| 国产亚洲精品第一综合不卡| 日韩人妻精品一区2区三区| 欧美精品av麻豆av| 久久人人97超碰香蕉20202| 亚洲av日韩在线播放| 国产精品一区二区在线不卡| 老司机靠b影院| 一个人免费在线观看的高清视频 | av在线播放精品| av在线老鸭窝| 视频在线观看一区二区三区| 国产1区2区3区精品| 精品一区二区三卡| 亚洲熟女精品中文字幕| 9热在线视频观看99| 女人久久www免费人成看片| 大码成人一级视频| 久久久精品区二区三区| 欧美激情高清一区二区三区| 少妇的丰满在线观看| 欧美日韩亚洲高清精品| 色精品久久人妻99蜜桃| 女人爽到高潮嗷嗷叫在线视频| 国产在线视频一区二区| 各种免费的搞黄视频| 在线观看www视频免费| 国产欧美亚洲国产| 桃花免费在线播放| 欧美日韩亚洲高清精品| 狠狠婷婷综合久久久久久88av| 人人澡人人妻人| 美女午夜性视频免费| 久9热在线精品视频| 国产精品久久久久成人av| 亚洲男人天堂网一区| 久久久久视频综合| 丰满饥渴人妻一区二区三| 欧美激情高清一区二区三区| 黄片播放在线免费| 精品亚洲成a人片在线观看| 国产精品偷伦视频观看了| 亚洲精品国产av成人精品| 一本一本久久a久久精品综合妖精| 国产成人欧美在线观看 | 久久中文字幕一级| 中国国产av一级| 亚洲欧美色中文字幕在线| 国产一区二区三区av在线| 99国产精品一区二区三区| 高清视频免费观看一区二区| 一本色道久久久久久精品综合| 久久久精品区二区三区| 99国产精品一区二区蜜桃av | 热99久久久久精品小说推荐| 免费不卡黄色视频| 免费在线观看影片大全网站| 大型av网站在线播放| av在线播放精品| 欧美激情 高清一区二区三区| 婷婷丁香在线五月| 亚洲精品第二区| 日韩,欧美,国产一区二区三区| www.精华液| 国产野战对白在线观看| 操出白浆在线播放| 九色亚洲精品在线播放| 男人添女人高潮全过程视频| 69精品国产乱码久久久| 午夜激情av网站| 国产av一区二区精品久久| 操出白浆在线播放| 午夜两性在线视频| 国产有黄有色有爽视频| 老司机福利观看| 99国产极品粉嫩在线观看| 国产熟女午夜一区二区三区| 国产日韩欧美视频二区| 久久久久久久久久久久大奶| 超碰成人久久| 国产有黄有色有爽视频| 午夜日韩欧美国产| 国产精品九九99| 精品第一国产精品| 国产精品久久久人人做人人爽| 成人国产av品久久久| 亚洲第一欧美日韩一区二区三区 | 亚洲成国产人片在线观看| 国产精品久久久久久精品古装| 久久国产精品大桥未久av| 亚洲 欧美一区二区三区| 亚洲国产精品999| av天堂久久9| 午夜免费观看性视频| av又黄又爽大尺度在线免费看| 嫩草影视91久久| 久9热在线精品视频| 黄网站色视频无遮挡免费观看| 交换朋友夫妻互换小说| 国产成+人综合+亚洲专区| 久久精品人人爽人人爽视色| 99国产精品99久久久久| 91成年电影在线观看| 午夜福利视频精品| videosex国产| 久久青草综合色| 黄片小视频在线播放| 色婷婷av一区二区三区视频| 飞空精品影院首页| 青草久久国产| 国产精品国产三级国产专区5o| 美女大奶头黄色视频| 国产精品熟女久久久久浪| 最近中文字幕2019免费版| 亚洲精品av麻豆狂野| 亚洲精品美女久久久久99蜜臀| 黑人猛操日本美女一级片| 久久狼人影院| 亚洲综合色网址| 亚洲第一av免费看| 日韩中文字幕视频在线看片| 亚洲av成人不卡在线观看播放网 | 五月天丁香电影| 性色av乱码一区二区三区2| 一本久久精品| 美女脱内裤让男人舔精品视频| 王馨瑶露胸无遮挡在线观看| 亚洲av日韩精品久久久久久密| 窝窝影院91人妻| 成年人免费黄色播放视频| 国产一区二区 视频在线| 国产又色又爽无遮挡免| 国产成人啪精品午夜网站| 啦啦啦免费观看视频1| 老司机午夜福利在线观看视频 | 啦啦啦在线免费观看视频4| 欧美日本中文国产一区发布| 亚洲 欧美一区二区三区| 国产精品九九99| 亚洲精品av麻豆狂野| 90打野战视频偷拍视频| 国产成+人综合+亚洲专区| 51午夜福利影视在线观看| 亚洲午夜精品一区,二区,三区|