Shengping He , Tore Furevik , Huijun Wang , Fei Li , Mingkeng Duan
{"title":"Impacts of the extratropical North Pacific on boreal summer Arctic circulation","authors":"Shengping He , Tore Furevik , Huijun Wang , Fei Li , Mingkeng Duan","doi":"10.1016/j.aosl.2023.100405","DOIUrl":"10.1016/j.aosl.2023.100405","url":null,"abstract":"<div><p>A distinct characteristic of the Arctic summer atmospheric circulation is the anomalous anticyclonic circulation centered over the Arctic Ocean associated with significant Arctic warming. Previous studies have related the underlying mechanisms to the earlier spring Eurasian snowmelt and the tropical Pacific forcing. Here, the authors show that the Arctic summer anomalous anticyclonic circulation is significantly related to the extratropical North Pacific sea surface temperature anomalies (SSTAs) in spring, indicating a teleconnection from the extratropical North Pacific to the Arctic. The SSTA pattern is characterized by warm anomalies in the midlatitudes of the extratropical North Pacific surrounded by significant cold anomalies, resembling the negative phase of the Pacific Decadal Oscillation (PDO) but without significant signals in the tropics (referred to as the negative PDO-like pattern). This negative PDO-like pattern in May can stimulate a Rossby wave propagating from the Bering Sea to the Arctic and lead to an anomalous Arctic anticyclone which can be sustained during summer. Meanwhile, the negative PDO-like pattern can persist to summer and induce an anomalous surface low pressure over the Bering Sea in summer. This anomalous surface low causes anomalous rising motions and induces upper-level divergence anomalies which further intensify the summer Arctic anticyclone. The upper-level tropospheric Arctic anticyclone can force anomalous adiabatic descent over the Arctic and sub-Arctic, leading to significant adiabatic heating in the Arctic. As a result, a significant warming emerges over the Arctic with the center located in the middle troposphere. The connection between the negative PDO-like SSTAs and the summer Arctic anticyclone has been confirmed by numerical experiments.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46979342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research progress on inter-monthly winter temperature variation in East Asia and climate prediction","authors":"Ke Fan , Hongqing Yang , Haixia Dai","doi":"10.1016/j.aosl.2023.100372","DOIUrl":"10.1016/j.aosl.2023.100372","url":null,"abstract":"<div><p>Inter-monthly winter temperature variation in East Asia has been remarkable in recent years, showing reversed or alternating extreme cold and extreme warm events in different months or in different stages of the winter. There are many challenges in climate prediction in the winter months because the inter-monthly climate variation is often within the seasonal mean variation. It is therefore urgent to understand the variation of inter-monthly winter temperatures in East Asia, to identify their predictability and predictive sources, and to propose effective prediction methods and prediction models for the inter-monthly winter climate. This paper reviews progress in research during the last five years on the main characteristics, physical processes, mechanisms, predictability, and prediction of inter-monthly winter temperatures in East Asia, considering several related systems including the winter monsoon, Siberian high, and stratospheric polar vortex. The authors also discuss future research prospects.</p><p>摘要</p><p>近年来, 东亚冬季气温的月际间变化十分显著, 冬季不同月份或不同阶段之间极端冷暖事件的转折或交替频发. 由于月际间变化常常被季节平均掩盖, 东亚冬季气候预测面临众多的挑战. 因此, 亟需研究东亚冬季气温月际间变化的特征和机理, 明确其可预测性和预测来源, 进而研制考虑月际变化的东亚冬季气温的有效预测方法和预测模型. 本文回顾了过去5年对东亚冬季气温月际间变化的主要特征, 物理过程, 机制, 可预测性和预测的研究进展, 同时考虑了多个与气温相联系统的变化, 包括冬季风, 西伯利亚高压, 平流层极涡. 本文也进一步讨论了未来的研究前景.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47411668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Corrigendum to “Effects of solar radiation modification on the ocean carbon cycle: An earth system modeling study” Atmospheric and Oceanic Science Letter 15 (2022) 100187","authors":"Xiaoyu Jin, Long Cao, Jingyu Zhang","doi":"10.1016/j.aosl.2023.100418","DOIUrl":"https://doi.org/10.1016/j.aosl.2023.100418","url":null,"abstract":"","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135433888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Precursory atmospheric teleconnection patterns for strong Siberian High events","authors":"Jian Song , Ning Shi , Qilei Huang","doi":"10.1016/j.aosl.2023.100376","DOIUrl":"10.1016/j.aosl.2023.100376","url":null,"abstract":"<div><p>Based on Japanese 55-year daily reanalysis data, the present study reveals that a strong Siberian high (SH) is preceded by three teleconnection patterns—namely, the Scandinavian (SCA) pattern, western Pacific (WP) pattern, and Polar/Eurasian (POL) pattern. Accordingly, strong SH events are classified into three types. Composite results show that there are evident differences among the three types in their typical circulation characteristics and impacts on surface air temperature (SAT) in East Asia. The SCA type is characterized by a wave-train anomaly over mid- and high-latitude Eurasia, while the WP type is characterized by a western expansion of circulation anomalies from the downstream western North Pacific/Far East. The significant signal of the POL type is a gradual southward movement of anticyclonic anomalies from the North Pole. In terms of the impact on SAT in East Asia, the SCA type and POL type are similar since they can cause a wide range of cold anomalies in East Asia. However, the cold anomalies caused by the POL type in northern China show significant signals earlier. The WP type causes only modest cold anomalies over northern and eastern China, but the persistence of SAT anomalies is obvious.</p><p>摘要</p><p>本文利用日本55年逐日再分析资料, 发现在SH异常增强前, 有三种不同的大气遥相关型前兆信号, 即斯堪的纳维亚 (SCA) 型, 西太平洋 (WP) 型, 极地-欧亚 (POL) 型. 据此, 本文将异常增强的SH分为对应的三类事件. 合成结果表明, 三类事件在典型环流特征和对东亚气温的影响上存在着明显的不同. 具体而言, SCA类事件主要表现为在欧亚中高纬度上自西向东的波列异常, WP类事件表现为环流异常自下游太平洋/俄罗斯远东地区向西发展的特征, POL型事件的显著信号则来源于自极区向南移动的反气旋式环流异常. 在对东亚地表气温的影响上, SCA类与POL类事件类似, 它们均可造成大范围的低温异常. 而WP类仅在我国北方和东部地区造成强度较弱的地表气温异常, 但该异常的持续性特征较明显.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46503197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ting Lei , Jingjing Min , Chao Han , Chen Qi , Chenxi Jin , Shuanglin Li
{"title":"Multi-model ensemble forecasting of 10-m wind speed over eastern China based on machine learning optimization","authors":"Ting Lei , Jingjing Min , Chao Han , Chen Qi , Chenxi Jin , Shuanglin Li","doi":"10.1016/j.aosl.2023.100402","DOIUrl":"10.1016/j.aosl.2023.100402","url":null,"abstract":"<div><p>Wind substantially impacts human activity and electricity generation. Thus, accurately forecasting the short-term wind speed is of profound societal and economic significance. Based on 100 weather stations in eastern China, the authors first evaluate the performance of the 10-m wind forecast products from five operational forecast models. Among them, the Japan Meteorological Agency (JMA) model performs best in reducing the forecasting errors. Then, the authors establish a 10-m wind speed multimodel ensemble forecast based on the five numerical models’ outputs and machine learning methods, combining dynamic and statistical methods. Feature engineering and machine learning algorithm optimization are conducted for each site separately. The forecast performance of this method is compared to the JMA model and multimodel ensemble forecast by ridge regression at lead times of 24–96 h. The results demonstrate that the multimodel ensemble method based on machine learning optimization can reduce the forecast error of JMA by more than 39%, and the improvement in forecast skill is most evident in November. In addition, it performs better than the ensemble forecast by ridge regression.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45531162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vertical structure of variabilities in the tropical easterly jet and associated factors","authors":"Ye Yao , Yuanyuan Guo , Zhiping Wen , Sihua Huang","doi":"10.1016/j.aosl.2023.100400","DOIUrl":"10.1016/j.aosl.2023.100400","url":null,"abstract":"<div><p>The tropical easterly jet (TEJ) is an easterly jet stream that occurs from the upper troposphere to lower stratosphere in boreal summer. Owing to its wide vertical extension from 300 to 70 hPa, the TEJ may exhibit distinct characteristics at different levels, the details of which remain thus far unclear. In this study, two empirical orthogonal function (EOF) modes of the year-to-year variability in the vertical structure of the TEJ were investigated. The leading EOF mode represents a consistent strengthening or weakening of the TEJ's main body in the vertical direction and varies on both interannual and interdecadal time scales. It has been suggested that ENSO can modulate this vertically consistent mode interannually, whereas the Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation can influence its interdecadal variability. In contrast, the second EOF mode exhibits an out-of-phase relationship between the zonal wind anomalies of the upper troposphere and lower stratosphere, linked with the changes in the TEJ's vertical movement and dominating on the quasi-biennial time scale. The Quasi-Biennial Oscillation could contribute to variations in the TEJ's vertical movement by changing the tropopause winds as a direct pathway and inducing anomalous convection over the tropical Indian Ocean and Maritime Continent as an indirect pathway.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42814245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distinct impacts of two kinds of El Niño on precipitation over the Antarctic Peninsula and West Antarctica in austral spring","authors":"Xueyang Chen , Shuanglin Li , Chao Zhang","doi":"10.1016/j.aosl.2023.100387","DOIUrl":"10.1016/j.aosl.2023.100387","url":null,"abstract":"<div><p>Based on multiple reanalysis data, the authors investigated the distinct impacts of central Pacific (CP) and eastern Pacific (EP) El Niño events on precipitation over West Antarctica and the Antarctic Peninsula in austral spring (September–November). The results demonstrate that EP and CP events have similar impacts on precipitation over the Amundsen–Bellingshausen seas, but opposite impacts on that over the Weddell Sea, especially the Antarctic Peninsula. Mechanistically, the tropical heat sources associated with EP events drive two branches of Rossby wave trains, causing an anomalous anticyclone and cyclone over the Ross–Amundsen–Bellingshausen seas and the Weddell Sea, respectively. Anomalous southerly winds to the east (west) of the anomalous anticyclone (cyclone) advect colder and drier air into the Bellingshausen–Weddell seas and the Antarctic Peninsula, which jointly result in negative precipitation anomalies there. CP events, however, trigger only one weak and westward-shifted Rossby wave train, which induces an anomalous anticyclone and cyclone in the Ross–Amundsen seas and Bellingshausen–Weddell seas, respectively, both 20°–30° west of those generated by EP events. Consequently, anomalous northerly (southerly) winds to the east (west) of the anomalous cyclone cause an increase (a decrease) in precipitation over the Weddell Sea (Amundsen–Bellingshausen seas).</p><p>摘要</p><p>本文基于多种再分析资料, 研究了中部型 (CP) 和东部型 (EP) El Niño事件对南半球春季 (9–11月) 西南极和南极半岛降水的不同影响. 结果显示, EP和CP事件对阿蒙森-别林斯高晋海的降水具有相似影响, 而对威德尔海, 特别是南极半岛的降水影响相反. 由于EP事件激发两支罗斯贝波列, 分别引起罗斯-阿蒙森-别林斯高森海和威德尔海上空的异常反气旋和气旋, 从而导致别林斯高晋-威德尔海和南极半岛受到干冷的异常偏南风影响, 降水减少. 然而, CP事件仅激发一支相对较弱且偏西的罗斯贝波列, 分别引起罗斯-阿蒙森海和别林斯高晋-威德尔海上空的异常反气旋和气旋, 从而导致南极半岛以西 (东) 受异常偏南 (北) 风影响, 降水减少 (增加).</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44497463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xu Zhao , Xu Yue , Chenguang Tian , Hao Zhou , Bin Wang , Yuwen Chen , Yuan Zhao , Weijie Fu , Yihan Hu
{"title":"Multimodel ensemble projection of photovoltaic power potential in China by the 2060s","authors":"Xu Zhao , Xu Yue , Chenguang Tian , Hao Zhou , Bin Wang , Yuwen Chen , Yuan Zhao , Weijie Fu , Yihan Hu","doi":"10.1016/j.aosl.2023.100403","DOIUrl":"10.1016/j.aosl.2023.100403","url":null,"abstract":"<div><p>China's demand for solar energy has been growing rapidly to meet energy transformation targets. However, the potential of solar energy is affected by weather conditions and is expected to change under climate warming. Here, the authors project the photovoltaic (PV) power potential over China under low and high emission scenarios by the 2060s, taking advantage of meteorological variables from 24 CMIP6 models and 4 PV models with varied formats. The ensemble mean of these models yields an average PV power of 277.2 KWh m<sup>−2</sup> yr<sup>−1</sup> during 2004–2014, with a decreasing tendency from the west to east. By 2054–2064, the national average PV power potential is projected to increase by 2.29% under a low emission scenario but decrease by 0.43% under a high emission scenario. The emission control in the former scenario significantly enhances surface solar radiation and promotes PV power in the east. On the contrary, strong warming causes inhibitions to PV power generation under the high emission scenario. Extreme warming events on average decrease the PV power potential by 0.28% under the low emission scenario and 0.44% under the high emission scenario, doubling and tripling the present-day loss, respectively. The projections reveal large benefits of controlling emissions for the future solar energy in China due to both the clean atmosphere and the moderate warming.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42808797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unfavorable environmental conditions for tropical cyclone genesis over the western North Pacific during the Last Interglacial based on PMIP4 simulations","authors":"Dubin Huan , Qing Yan , Ting Wei","doi":"10.1016/j.aosl.2023.100395","DOIUrl":"10.1016/j.aosl.2023.100395","url":null,"abstract":"<div><p>Investigating the variation in tropical cyclone (TC) activity over the western North Pacific (WNP) in past warm periods helps to better understand TC behaviors in a warming future. In this study, the authors analyze the changes in large-scale TC genesis factors and the associated mechanisms over the WNP during the Last Interglacial (LIG), based on multimodel outputs from the Paleoclimate Modelling Intercomparison Project Phase 4. The results show that potential intensity exhibits a general decrease over the WNP during the LIG in the storm season, dominated by a weakened thermodynamic disequilibrium. The moist entropy deficit shows an overall increase over the WNP, arising from the decreased mid-tropospheric moisture and weakened vertical temperature contrast. Vertical wind shear enhances over the central WNP but weakens over the southwestern WNP, which is induced by the changes in the meridional tropospheric temperature gradient and hence high-level zonal winds. The absolute vorticity shows a general decrease over the WNP, partially linked with the decreased SST over the western tropical Pacific. Based on a genesis potential index, the authors suggest a decrease in genesis potential over the WNP during the LIG, indicating unfavorable conditions for TC genesis. The results highlight the important role of Earth's orbit in regulating TC activity, which may shed light on TC behaviors in a warmer climate.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47227226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yihao Peng , Xiaolei Liu , Jingzhi Su , Xinli Liu , Yixu Zhang
{"title":"Skill improvement of the yearly updated reforecasts in ECMWF S2S prediction from 2016 to 2022","authors":"Yihao Peng , Xiaolei Liu , Jingzhi Su , Xinli Liu , Yixu Zhang","doi":"10.1016/j.aosl.2023.100357","DOIUrl":"10.1016/j.aosl.2023.100357","url":null,"abstract":"<div><p>Hazardous weather events are often accompanied by subseasonal processes, but the forecast skills of subseasonal prediction are still limited. To assess the skill improvement of the constantly updated model version in ECMWF subseasonal-seasonal (S2S) prediction from 2016 to 2022, the performance of yearly updated reforecasts was evaluated against ERA5 reanalysis data using the temporal anomaly correlation coefficient (TCC) as a metric. The newly updated reforecasts exhibit stable superiority at the weather scale of the first two weeks, regardless of whether the 2-m temperature or precipitation forecast is being considered. At the subseasonal time scale starting from the third week, some slight improvements in prediction skills are only found in several tropical regions. Generally, the week-3 TCC values averaged over global land grids still reflect an advancement in prediction skills for updated reforecasts. For the Madden–Julian Oscillation (MJO), reforecasts can reproduce the characteristics of eastward propagation, but there are deviations in the intensity and propagation range of convection anomalies for reforecasts of all seven years. Based on an evaluation of MJO prediction skill using the bivariate anomaly correlation coefficient and bivariate root-mean-square error, some differences are apparent in the MJO prediction skills among the updated reforecasts, but the improvements do not increase monotonically year by year. Despite the inherent limitation of S2S prediction, positive progress has already been achieved via the constantly updated S2S prediction in ECMWF, which reinforces the confidence in further collaboratively improving S2S prediction in the future.</p><p>摘要</p><p>在2016年至2022年间, ECMWF次季节预测系统不断升级并逐年完成新的回报试验. 本文考察该预测系统逐年升级带来的预测技巧提升潜力. 从2米气温和降水来看, 在起报之后的前两周内天气尺度上预测技巧表现出逐年稳定提升的趋势; 在从第三周开始的次季节时间尺度上, 预测技巧的提升仅限于热带部分区域. MJO预测技巧并不随着模式升级而逐年单调提升. 尽管目前S2S预测技巧存在局限性, 但目前已有的进展增强了在未来深入合作以提高S2S预测技术的信心.</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46446352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}