Two Types of Heat Wave in Korea Associated With Atmospheric Circulation Pattern

2019 ◽  
Vol 124 (14) ◽  
pp. 7498-7511 ◽  
Author(s):  
Sae‐Rim Yeo ◽  
Sang‐Wook Yeh ◽  
Woo‐Seop Lee
2012 ◽  
Vol 25 (20) ◽  
pp. 7248-7265 ◽  
Author(s):  
XiaoJing Jia ◽  
Hai Lin ◽  
June-Yi Lee ◽  
Bin Wang

Abstract Multimodel ensemble (MME) seasonal forecasts are analyzed to evaluate numerical model performance in predicting the leading forced atmospheric circulation pattern over the extratropical Northern Hemisphere (NH). Results show that the time evolution of the leading tropical Pacific sea surface temperature (SST)-coupled atmospheric pattern (MCA1), which is obtained by applying a maximum covariance analysis (MCA) between 500-hPa geopotential height (Z500) in the extratropical NH and SST in the tropical Pacific Ocean, can be predicted with a significant skill in March–May (MAM), June–August (JJA), and December–February (DJF) one month ahead. However, most models perform poorly in capturing the time variation of MCA1 in September–November (SON) with 1 August initial condition. Two possible reasons for the models’ low skill in SON are identified. First, the models have the most pronounced errors in the mean state of SST and precipitation along the central equatorial Pacific. Because of the link between the divergent circulation forced by tropical heating and the midlatitude atmospheric circulation, errors in the mean state of tropical SST and precipitation may lead to a degradation of midlatitude forecast skill. Second, examination of the potential predictability of the atmosphere, estimated by the ratio of the total variance to the variance of the model forecasts due to internal dynamics, shows that the atmospheric potential predictability over the North Pacific–North American (NPNA) region is the lowest in SON compared to the other three seasons. The low ratio in SON is due to a low variance associated with external forcing and a high variance related to atmospheric internal processes over this area.


2013 ◽  
Vol 26 (10) ◽  
pp. 3377-3393 ◽  
Author(s):  
Shengping He ◽  
Huijun Wang ◽  
Jiping Liu

Abstract Interdecadal changes in the relationship between El Niño–Southern Oscillation (ENSO) and midlatitude atmospheric circulation are investigated in this study. Comparison of associations between ENSO and midlatitude atmospheric circulation anomalies between 1958–76 and 1977–2010 suggest that during 1958–76, ENSO exerted a strong impact on the East Asian winter monsoon (EAWM) and the associated atmospheric circulation pattern was similar to the positive North Pacific Oscillation (NPO). In contrast, during 1977–2010, the NPO-like atmospheric pattern disappeared. Instead, ENSO exerted a strong impact on the eastern North Pacific Ocean (NP) and North America, and the associated atmospheric circulation pattern resembled the Pacific–North America (PNA) teleconnection. Also, significant correlations between ENSO and sea surface temperature anomalies (SSTAs) over the western subtropical NP during 1958–76 became insignificant during 1977–2010, whereas negative correlations between ENSO and SSTAs in the central and northeastern subtropical NP became more significant since the mid-1970s. Further analyses suggest that the interdecadal shift of the Aleutian low, which occurred around the mid-1970s, might be responsible for the identified changes. Before the mid-1970s, warm ENSO events generated an anomalous anticyclone over the western NP, which is a key system bridging ENSO and EAWM-related atmospheric circulation. After the mid-1970s, the Aleutian low intensified and shifted eastward, leading to the impact of ENSO prevailing over the eastern NP. In addition, the weakened (strengthened) ENSO–NPO/EAWM (ENSO–PNA) relationship likely contributed to the weakened (strengthened) relationship between ENSO and SSTAs over the western (central and eastern) subtropical NP.


2019 ◽  
Vol 230 ◽  
pp. 104630 ◽  
Author(s):  
Antonio Manzano ◽  
Miguel A. Clemente ◽  
Ana Morata ◽  
M. Yolanda Luna ◽  
Santiago Beguería ◽  
...  

2019 ◽  
Vol 99 ◽  
pp. 02015
Author(s):  
Karim Shukurov ◽  
Lyudmila Shukurova

Array of 7-day backward trajectories of air particles for Moscow were simulated for days of measurement of volume concentrations of aerosols with particle sizes of 0.1-1.0, 1.0-2.5 and 2.5-5.0 μm at the AERONET site in Moscow in 2001-2018. The CWT (concentration weighted trajectory) method, modified for the atmosphere column, was used to determine the potential sources of aerosols of these three fractions for Moscow region. Potential sources of extreme concentrations of these aerosols in the Moscow atmosphere and the atmospheric circulation pattern favored of their transport to Moscow have been identified.


2012 ◽  
Vol 13 (1) ◽  
pp. 172-188 ◽  
Author(s):  
Monica Ionita ◽  
Gerrit Lohmann ◽  
Norel Rimbu ◽  
Silvia Chelcea

Abstract Interannual-to-decadal variability of Rhine River streamflow and their relationship with large-scale climate anomaly patterns for spring [March–May (MAM)] and autumn [September–November (SON)] are investigated through a statistical analysis of observed streamflow data and global climate anomaly fields. A wavelet analysis reveals that spring streamflow variability is nonstationary with enhanced variability in the 8–16-yr band from 1860 to 1900 and in the 2–8 and 16–30 yr after 1960. A composite analysis reveals that streamflow anomalies during spring are related to a sea surface temperature (SST) pattern that resembles the corresponding El Niño–Southern Oscillation (ENSO) SST pattern. The corresponding atmospheric circulation pattern favors enhanced moisture advection over the Rhine catchment area during positive streamflow anomalies. During autumn, the streamflow variability follows a distribution similar to spring streamflow, but with a strong peak in the 30–60-yr band. Autumn streamflow anomalies are significantly related only with the North Atlantic SST anomalies. The atmospheric circulation pattern associated with high streamflow during autumn, which is more regional than the corresponding spring pattern, shows a deep low pressure system over the British Isles and the northwestern part of Europe and a shift southward of the Atlantic jet axis. The orientation of the axis of the Atlantic and African jets, as well as the advection of the moist air from the ocean, plays a crucial role in the variability of Rhine streamflow both in spring and autumn.


2015 ◽  
Vol 380-381 ◽  
pp. 14-21 ◽  
Author(s):  
Buda Su ◽  
Mingjin Zhan ◽  
Jianqing Zhai ◽  
Yanjun Wang ◽  
Thomas Fischer

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