Asia-Pacific Journal of Atmospheric Sciences最新文献_第9页

Analysis of Rain Drop Size Distribution to Elucidate the Precipitation Process using a Cloud Microphysics Conceptual Model and In Situ Measurement 利用云微物理概念模型和现场测量分析降水过程中的雨滴大小分布

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-12-20 DOI: 10.1007/s13143-022-00299-w

Joo Wan Cha, Hae Jung Koo, Bu-Yo Kim, Belorid Miloslav, Hyun Jun Hwang, Min Hoo Kim, Ki-Ho Chang, Yong Hee Lee

{"title":"Analysis of Rain Drop Size Distribution to Elucidate the Precipitation Process using a Cloud Microphysics Conceptual Model and In Situ Measurement","authors":"Joo Wan Cha, Hae Jung Koo, Bu-Yo Kim, Belorid Miloslav, Hyun Jun Hwang, Min Hoo Kim, Ki-Ho Chang, Yong Hee Lee","doi":"10.1007/s13143-022-00299-w","DOIUrl":"10.1007/s13143-022-00299-w","url":null,"abstract":"<div><p>\u0000Raindrop size distribution (DSD) is an important parameter in rainfall research and can be used for quantitative precipitation estimation (QPE) in meteorology and hydrology. DSD also improves the understanding of the uncertainty of cloud microphysical processes (CMPs) such as ice-based and warm rain growth during climate change. Changes in CMPs impact the generation of precipitation. However, the estimation of CMPs based on in situ observation is difficult because of the complexity of microphysics processes, and most previous studies on the CMP involved approximations to predict the types of microphysical processes affecting precipitation generation based on in situ observations performed in real-time. Therefore, we developed a simple method for understanding the CMPs of precipitation generation using a conceptual model of CMPs and in situ observation DSD data. We employed previously observed DSD parameters and a CMP conceptual model of the DSD observation-based microphysical process. As case studies, we applied DSD observation data obtained in Korea and East Asia to estimate the CMPs. For example, the major CMP of megacities was vapor deposition in Beijing (< 1 mm h<sup>−1</sup>) and Seoul (< 5 mm h<sup>−1</sup>), as the strong updraft of the urban heat island effect in megacities results in increased liquid water content, leading to the formation of large number of supersaturated clouds at higher altitudes.</p></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 2","pages":"257 - 269"},"PeriodicalIF":2.3,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13143-022-00299-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41708595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Challenges in Attributing the 2022 Australian Rain Bomb to Climate Change 将2022年澳大利亚雨弹归因于气候变化的挑战

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-12-20 DOI: 10.1007/s13143-022-00305-1

Camille Cadiou, Robin Noyelle, Nemo Malhomme, Davide Faranda

{"title":"Challenges in Attributing the 2022 Australian Rain Bomb to Climate Change","authors":"Camille Cadiou, Robin Noyelle, Nemo Malhomme, Davide Faranda","doi":"10.1007/s13143-022-00305-1","DOIUrl":"10.1007/s13143-022-00305-1","url":null,"abstract":"<div><p>In February and March 2022, the eastern coast of Australia recorded an unprecedented amount of precipitation with extended floods and damages to properties amounting at least to AUD 2.3 billions. In this paper we use both reanalysis and observations to perform a statistical and dynamical attribution of this precipitation event to climate change. We define 1948-1977 as the counterfactual period and 1990-2019 as the factual one. The statistical attribution is based on fitting the generalized extreme value distribution for 3-days averaged precipitation annual maxima for the two periods, while the dynamical attribution aims at looking at the recurrence properties of sea-level pressure and geopotential height patterns in both periods. We find that the dynamics of the event consists in an unprecedented combination of several factors: a tropical atmospheric river, the presence of the Coral low pressure system and a blocking anticyclone offshore Eastern Australia. Our main finding is that no clear attribution statements can be made, both because of the unprecedented nature of this event, the lack of long high quality available data and the dependence of the results on the La Nina phase of El Nino Southern Oscillation.</p></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 1","pages":"83 - 94"},"PeriodicalIF":2.3,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47771217","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}

引用次数: 2

Evaluation of Deep-Learning-Based Very Short-Term Rainfall Forecasts in South Korea 基于深度学习的韩国极短期降雨预报评估

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-12-08 DOI: 10.1007/s13143-022-00310-4

Seok-Geun Oh, Chanil Park, Seok-Woo Son, Jihoon Ko, Kijung Shin, Sunyoung Kim, Junsang Park

{"title":"Evaluation of Deep-Learning-Based Very Short-Term Rainfall Forecasts in South Korea","authors":"Seok-Geun Oh, Chanil Park, Seok-Woo Son, Jihoon Ko, Kijung Shin, Sunyoung Kim, Junsang Park","doi":"10.1007/s13143-022-00310-4","DOIUrl":"10.1007/s13143-022-00310-4","url":null,"abstract":"<div><p>This study evaluates the performance of a deep learning model, Deep-learning-based Rain Nowcasting and Estimation (DEEPRANE), for very short-term (1–6 h) rainfall forecasts in South Korea. Rainfall forecasts and in-situ observations from June–September 2020, when record-breaking summer rainfall was observed in South Korea, are particularly considered. It is found that DEEPRANE adequately predicts moderate rainfall events (MREs; ≥ 1 mm h<sup>−1</sup>) and strong rainfall events (SREs; ≥ 10 mm h<sup>−1</sup>) with critical success indices of 0.6 and 0.4 at the 1-h lead time, respectively. The probability of detection scores of MRE forecasting is higher than the false alarm rates at all lead times, suggesting that DEEPRANE MRE forecast can be useful even at a long lead time. However, for SRE forecasting, the probability of detection scores becomes smaller than the false alarm rates at a lead time of 2 h. Localized heavy rainfall events (LHREs, ≥ 30 mm h<sup>−1</sup>) are also reasonably well predicted only at a lead time of 2 h. Irrespective of their patterns, the forecast scores systematically decrease with lead time. This result indicates that DEEPRANE SRE forecast is useful only for nowcasting. DEEPRANE generally shows better performance in the early morning hours when rainfall events are more frequent than in other hours. When considering synoptic conditions, better performance is found when rainfall events are organized by monsoon rainband rather than caused by extratropical or tropical cyclones. These results suggest that DEEPRANE is especially useful for nowcasting early-morning rainfall events which are embedded in the monsoon rainband.</p></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 2","pages":"239 - 255"},"PeriodicalIF":2.3,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49542992","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}

引用次数: 1

A Comparative Assessment of Changes in Heat-Related Mortality Risk Under the RCP2.6 and RCP8.5 Scenarios Based on the CORDEX-CORE Ensembles 基于CORDEX-CORE集合的RCP2.6和RCP8.5情景下热相关死亡风险变化的比较评估

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-12-05 DOI: 10.1007/s13143-022-00304-2

Yuwen Fan, Eun-Soon Im

{"title":"A Comparative Assessment of Changes in Heat-Related Mortality Risk Under the RCP2.6 and RCP8.5 Scenarios Based on the CORDEX-CORE Ensembles","authors":"Yuwen Fan, Eun-Soon Im","doi":"10.1007/s13143-022-00304-2","DOIUrl":"10.1007/s13143-022-00304-2","url":null,"abstract":"<div><p>This study assesses the future heat-related mortality risk under varying levels of warming specified by the RCP2.6 and RCP8.5 scenarios using dynamically downscaled ensemble projections across six different domains. The excess mortality risk due to heat is estimated by the empirical relationship between daily maximum temperature (Tmax) and mortality. The changes in heat-related mortality based on three empirical formulas derived from different countries’ data are compared to examine the sensitivity of change patterns to the empirical formula. The ensemble projections reveal a drastic increase in heat-related mortality risk under the RCP8.5 scenario. However, a significant reduction is expected by limiting greenhouse gas emissions to the RCP2.6 level. While mitigation’s possible benefit is clearly exemplified by comparing the mortality risk derived from RCP2.6 and RCP8.5 projections, this study also provides valuable insights into regional hotspots by comparing the results from multi-domains. Regardless of the emission scenario (RCP2.6 vs. RCP8.5) and empirical formulas that represent the relationship between temperature and mortality, the most vulnerable regions to heat-related mortality risk are identified in the low-latitude near the equator where the adaptation capacities to avoid serious consequences are found to be poor. The higher risk of heat-related mortality in the future is largely attributable to a significant increase in frequency exceeding the optimum temperature where the mortality risk is minimum during the historical period.</p></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 2","pages":"207 - 218"},"PeriodicalIF":2.3,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13143-022-00304-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45028942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Diagnostic Relations for the Intercept Parameter of Exponential Raindrop Size Distribution According to Rain Types Derived from Disdrometer Data and Their Impacts on Precipitation Prediction 指数型雨滴大小分布截距参数的诊断关系及其对降水预报的影响

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-12-05 DOI: 10.1007/s13143-022-00306-0

Joohyun Lee, Han-Gyul Jin, Jong-Jin Baik

{"title":"Diagnostic Relations for the Intercept Parameter of Exponential Raindrop Size Distribution According to Rain Types Derived from Disdrometer Data and Their Impacts on Precipitation Prediction","authors":"Joohyun Lee, Han-Gyul Jin, Jong-Jin Baik","doi":"10.1007/s13143-022-00306-0","DOIUrl":"10.1007/s13143-022-00306-0","url":null,"abstract":"<div><p>The raindrop size distribution observed from ground-based or airborne disdrometers has been widely used to understand the characteristics of clouds and precipitation. However, its variability needs to be studied further and properly considered for improving precipitation prediction. In this study, using disdrometer data, the diagnostic relations for the intercept parameter of the exponential raindrop size distribution <i>N</i><sub>0</sub> are derived for different rain types and the impacts of the diagnostic relations on precipitation prediction are examined. The disdrometer data observed at four sites in South Korea show spatiotemporal variations of <i>N</i><sub>0</sub>. Three different derivation methods proposed by previous studies are used to derive the diagnostic relations, and the diagnostic relation that best reproduces the observed <i>N</i><sub>0</sub> is selected. The diagnostic relation is implemented into the WRF single-moment 6-class microphysics (WSM6) scheme, and its impacts are investigated through the simulations of summertime precipitation events in South Korea. Compared to the simulation using the original WSM6 scheme (WSM6-O) where a constant <i>N</i><sub>0</sub> is used, the simulation where <i>N</i><sub>0</sub> is diagnosed by the diagnostic relation using the rainwater content at the lowest level (WSM6-L) yields better precipitation prediction. The WSM6-L simulation represents the variability of <i>N</i><sub>0</sub>. Also, the WSM6-L simulation predicts <i>N</i><sub>0</sub> that is on average smaller than the prescribed value in the WSM6-O simulation, agreeing with the observation to some extent. The smaller <i>N</i><sub>0</sub> in the WSM6-L simulation decreases the rainwater production by the accretion of cloud water and the melting of ice hydrometeors, decreasing the rainwater mixing ratio.</p></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 2","pages":"219 - 238"},"PeriodicalIF":2.3,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13143-022-00306-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44369285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sub-Seasonal Experiment (SubX) Model-based Assessment of the Prediction Skill of Recent Multi-Year South Korea Droughts 基于亚季节试验(SubX)模式的韩国近年多年干旱预测能力评估

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-12-02 DOI: 10.1007/s13143-022-00307-z

Chang-Kyun Park, Jonghun Kam

{"title":"Sub-Seasonal Experiment (SubX) Model-based Assessment of the Prediction Skill of Recent Multi-Year South Korea Droughts","authors":"Chang-Kyun Park, Jonghun Kam","doi":"10.1007/s13143-022-00307-z","DOIUrl":"10.1007/s13143-022-00307-z","url":null,"abstract":"<div><h2>Abstract\u0000</h2><div><p>Reliable sub-seasonal forecast of precipitation is essential to manage the risk of multi-year droughts in a timely manner. However, comprehensive assessments of sub-seasonal prediction skill of precipitation remain limited, particularly during multi-year droughts. This study used various verification metrics to assess the sub-seasonal prediction skill of hindcasts of five Sub-seasonal Experiment (SubX) models for precipitation during two recent multi-year South Korea droughts (2007 − 10 and 2013 − 16). Results show that the sub-seasonal prediction skill of the SubX models were stage-, event-, and model-dependent over the recent multi-year droughts. According to the Brier skill scores, SubX models show a more skillful in one to four lead weeks during the drought onset and persistence stages, than the recovery stage. While the prediction skill of the SubX models in the first two initial weeks show more skillful prediction during the 2007–10 drought, the impact of the forecast initial time on the prediction skill is relatively weak during the 2013–16 drought. Overall, the EMC-GEFSv12 model with the 11 ensemble members (the largest among the five SubX models) show the most skillful forecasting skill. According to the sensitivity test to the ensemble member size, the EMC-GEFSv12 model had no gain for biweekly precipitation forecast with the nine ensemble members or more. This study highlights the importance of a robust evaluation of the predictive performance of sub-seasonal climate forecasts via multiple verification metrics.</p></div></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 1","pages":"69 - 82"},"PeriodicalIF":2.3,"publicationDate":"2022-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13143-022-00307-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42990204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Analysis of the Interdecadal and Interannual Variability of Autumn Extreme Rainfall in Taiwan Using a Deep-Learning-Based Weather Typing Approach 基于深度学习的天气分型方法分析台湾秋季极端降雨的年代际和年际变化

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-11-22 DOI: 10.1007/s13143-022-00303-3

Li-Huan Hsu, Yi-chao Wu, Chou-Chun Chiang, Jung-Lien Chu, Yi-Chiang Yu, An-Hsiang Wang, Ben Jong-Dao Jou

{"title":"Analysis of the Interdecadal and Interannual Variability of Autumn Extreme Rainfall in Taiwan Using a Deep-Learning-Based Weather Typing Approach","authors":"Li-Huan Hsu, Yi-chao Wu, Chou-Chun Chiang, Jung-Lien Chu, Yi-Chiang Yu, An-Hsiang Wang, Ben Jong-Dao Jou","doi":"10.1007/s13143-022-00303-3","DOIUrl":"10.1007/s13143-022-00303-3","url":null,"abstract":"<div><h2>Abstract\u0000</h2><div><p>This study sought to assess the interdecadal and interannual variability of autumn extreme rainfall (ER) in Taiwan from 1979 to 2019. Three types of ER events were identified based on a clustering analysis augmented by a deep autoencoder-based neural network model. This method outperforms other methods in obtaining the optimal number of clusters by extracting the synoptic features in advance. The patterns associated with these three types include a tropical cyclone covering Taiwan (TC), a TC-like circulation in the South China Sea (SCS) accompanied by northeasterly near northern Taiwan (TC-NE), and northeasterly near northern Taiwan (NE). The differences in the rainfall pattern caused by the three types were discernable over Taiwan. How the PDO or ENSO modulates the regional large-scale environment to favor the occurrence of these ER events was investigated. The occurrence of TC-NE events was simultaneously correlated with the negative phases of PDO/ENSO in the interdecadal/interannual scale. In the negative phases of PDO/ENSO, a low-level anomalous cyclone over SCS accompanied by background northeasterly favored the regional TC activities and may cause more TC-NE events. The occurrence of NE events is simultaneously correlated with the cold phase of ENSO. An anomalous low-level anticyclone in Northeast Asia strengthened the northeasterly toward northern Taiwan, and with the seasonal background moisture, provided favorable conditions for the occurrence of the NE events. Overall, the occurrence of the TC events did not correlate with the PDO or ENSO signals; the reasons for the lack of correlation were discussed herein.</p></div></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 2","pages":"185 - 205"},"PeriodicalIF":2.3,"publicationDate":"2022-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46613940","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}

引用次数: 1

Improvement of Rainfall Measurements by Using a Dual Tipping Bucket Rain Gauge 双翻斗雨量计测雨方法的改进

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-10-31 DOI: 10.1007/s13143-022-00295-0

Jeong Hwan Choi, Ki-Ho Chang, Kyung-Eak Kim, Ki Seok Bang

引用次数: 2

Outbreak of a Tornado with Tropical Cyclone Yaas (2021) Formed over the Bay of Bengal 热带气旋Yaas(2021)在孟加拉湾形成的龙卷风爆发

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-10-27 DOI: 10.1007/s13143-022-00302-4

Nasreen Akter, M. Rafiuddin

{"title":"Outbreak of a Tornado with Tropical Cyclone Yaas (2021) Formed over the Bay of Bengal","authors":"Nasreen Akter, M. Rafiuddin","doi":"10.1007/s13143-022-00302-4","DOIUrl":"10.1007/s13143-022-00302-4","url":null,"abstract":"<div><p>A tornado outbreak occurred in West Bengal (WB), India, about 15–16 h before the landfall of Cyclone Yaas formed in May 2021 over the Bay of Bengal. High-resolution analysis data have been used to investigate the possible tornadoes in terms of environmental conditions connecting to the cyclone. The WB tornado is found as intense as EF2–3 on the tornado scale and is likely associated with a mini-supercell. The total shear of 37 m s<sup>−1</sup> from 0–6 km above ground level (AGL) with strong clockwise rotation, the moderate instability (1504 J kg<sup>−1</sup>) and the energy helicity index of 2.2 are the substantial convective parameters related to the WB tornado. Moreover, the favorable environment owning intense bulk shear, a larger value of storm-relative environmental helicity in the lowest 1 km AGL and high values of significant tornado parameter (STP) urge the potentiality of multiple tornadoes spawning in multi-days accompanying the landfalling Cyclone Yaas. The right-front quadrant of the cyclone is found to be more vulnerable for developing moderate to severe tornadoes within its rainbands. The positive potential vorticity anomalies evidence the cloud-scale cyclonic circulation from surface to 400 hPa with the maximum in the mid-level.</p></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 1","pages":"59 - 67"},"PeriodicalIF":2.3,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47579279","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}

引用次数: 1

Extremely Strong Western Pacific Subtropical High in May 2021 Following a La Niña Event: Role of the Persistent Convective Forcing over the Indian Ocean La Niña事件后2021年5月的超强西太平洋副热带高压:印度洋持续对流强迫的作用

IF 2.3 4区地球科学

Asia-Pacific Journal of Atmospheric Sciences Pub Date : 2022-10-17 DOI: 10.1007/s13143-022-00300-6

Minling Ke, Ziqian Wang, Weijuan Pan, Haolin Luo, Song Yang, Ruyue Guo

{"title":"Extremely Strong Western Pacific Subtropical High in May 2021 Following a La Niña Event: Role of the Persistent Convective Forcing over the Indian Ocean","authors":"Minling Ke, Ziqian Wang, Weijuan Pan, Haolin Luo, Song Yang, Ruyue Guo","doi":"10.1007/s13143-022-00300-6","DOIUrl":"10.1007/s13143-022-00300-6","url":null,"abstract":"<div><h2>Abstract\u0000</h2><div><p>The variation of the western Pacific subtropical high (WPSH) significantly influences the weather and climate in East Asia. El Niño-Southern Oscillation (ENSO) is considered as one of the most important factors for the abnormal activity of the WPSH. An El Niño event tends to result in an anticyclonic anomaly over the western Pacific in the following spring and summer, leading to a westward-shifted and stronger WPSH. Opposite features can be observed for a La Niña event. Following the typical La Niña event in the winter of 2020/2021, an abnormal cyclonic circulation routinely appeared over the western Pacific in the beginning of 2021, but it was suddenly replaced by an obviously abnormal anticyclone in May. This unanticipated change induced an extremely strong WPSH and posed a challenge for the regional climate prediction. A careful examination of the tropical Indian Ocean revealed a significant abnormal warming process from April to May in 2021, with a peak of positive sea surface temperature anomaly (SSTA) in early May. Consequently, persistent atmospheric convective activity was stimulated by the positive SSTA, accompanied by remarkable and eastward-moving diabatic heating in the tropical Indian Ocean. The convective heating aroused significant easterly anomalies in the form of a Kelvin wave response of the Gill-type mode over the equatorial region from the western Pacific to the eastern Indian Ocean, which induced an abnormal anticyclone through a further positive circulation–convection feedback over the western Pacific. Additional experiments with the LBM model further verify that the persistent convective forcing over the tropical Indian Ocean is responsible for the extremely strong WPSH in May 2021, although during an antecedent La Niña event.</p></div></div>","PeriodicalId":8556,"journal":{"name":"Asia-Pacific Journal of Atmospheric Sciences","volume":"59 1","pages":"47 - 58"},"PeriodicalIF":2.3,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13143-022-00300-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45448461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6