IF 1.9 4区地球科学

Sola Pub Date : 2024-04-09 DOI: 10.2151/sola.2024-020

Satoru Yokoi, Yoshiyuki Kajikawa

{"title":"Precipitation diurnal cycle over tropical coastal regions represented in climate experiments with a global cloud-system resolving model","authors":"Satoru Yokoi, Yoshiyuki Kajikawa","doi":"10.2151/sola.2024-020","DOIUrl":"https://doi.org/10.2151/sola.2024-020","url":null,"abstract":"Climate experiments using global cloud-system resolving models (GCRMs) are expected to realistically simulate precipitation diurnal cycle (PDC) in the tropics, which is important for better representation of influences of cumulus convection on the climate system. This study examines how three series of decade-long climate experiments with Nonhydrostatic ICosahedral Atmospheric Model (NICAM), one of the GCRMs, realistically simulate the PDC over tropical coastal regions. Analyses reveal that it is more difficult to reproduce the PDC over coastal waters than that over coastal land, the former of which is characterized by nighttime offshore migration of precipitation areas. A comparison with in situ shipborne observations further reveals that biases in the offshore migration feature are associated with poor representation of convective cold pools; experiments with poor reproducibility of the offshore migration underestimate overall intensity of cold pools. The underestimation of the intensity may be associated with overestimation of environmental moisture in the lower free troposphere. As reproducing the environmental field is a difficult task particularly for climate experiments with global models, it seems more challenging for the climate experiments to realistically simulate the PDC over the coastal waters than for short-term experiments and regional climate experiments.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"51 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584411","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: 0

Verification of wind prediction in the upper troposphere in the north Pacific via flight observation 通过飞行观测验证北太平洋对流层上层的风力预测

IF 1.9 4区地球科学

Sola Pub Date : 2024-04-04 DOI: 10.2151/sola.2024-019

Takuaki Hirayama, Yoshiaki Miyamoto, Kozo Okamoto, Izumi Okabe

引用次数: 0

A Deep Learning Nowcasting Model for Convective Cell Occurrence in Taiwan 针对台湾对流性小区发生率的深度学习即时预报模型

IF 1.9 4区地球科学

Sola Pub Date : 2024-03-30 DOI: 10.2151/sola.2024-018

Yu-Tai Pan, Buo-Fu Chen, Dian-You Chen, Chia-Tung Chang, Treng-Shi Huang

{"title":"A Deep Learning Nowcasting Model for Convective Cell Occurrence in Taiwan","authors":"Yu-Tai Pan, Buo-Fu Chen, Dian-You Chen, Chia-Tung Chang, Treng-Shi Huang","doi":"10.2151/sola.2024-018","DOIUrl":"https://doi.org/10.2151/sola.2024-018","url":null,"abstract":"Afternoon thunderstorms, mesoscale convective systems, and other short-duration rainfall events threaten property and transportation. Recent deep learning techniques have been proven effective in nowcasting for rainfall accumulation (rain maps), but predicting occurrences of intense convective cells can add additional value to decision-making procedures. This study develops a deep-learning model that predicts the locations of cell occurrences in the next 60 minutes. The training data include reflectivities from the Taiwanese radar network and convective cell trajectories from the System for Convection Analysis and Nowcasting (SCAN). The label is the SCAN cell occurrence (1 or 0) within a 7.5 × 7.5 km2 area in the next hour. In addition to providing occurrence probabilities, the post-analysis procedure deploys a threshold mask to convert the probabilistic forecast into deterministic forecasts; it achieves a ∼40% improvement in the critical success index compared with the baseline method. Furthermore, the new model informs users about the risks under the chosen threshold selected based on their risk tolerance. This study provides proof of concept that replacing the predicting objectives (“cell occurrence” instead of “rainfall”) of the model may help forecasters' decisions and the integration of deep learning into operational forecasting.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"36 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584313","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: 0

Recent decelerating trends of urban warming in Japan 日本城市变暖的最新减速趋势

IF 1.9 4区地球科学

Sola Pub Date : 2024-03-12 DOI: 10.2151/sola.2024-016

Fumiaki Fujibe

引用次数: 0

Emergent constraints on future changes in several climate variables and extreme indices from global to regional scales 从全球到区域尺度对若干气候变量和极端指数未来变化的新制约因素

IF 1.9 4区地球科学

Sola Pub Date : 2024-03-12 DOI: 10.2151/sola.2024-017

Hideo Shiogama, Michiya Hayashi, Nagio Hirota, Tomoo Ogura

{"title":"Emergent constraints on future changes in several climate variables and extreme indices from global to regional scales","authors":"Hideo Shiogama, Michiya Hayashi, Nagio Hirota, Tomoo Ogura","doi":"10.2151/sola.2024-017","DOIUrl":"https://doi.org/10.2151/sola.2024-017","url":null,"abstract":"Climate change impact modelling studies often require not only mean temperature and precipitation but also other climate variables (e.g., solar radiation and wind speed) and extreme indices as input data. However, studies on observational constraints (emergent constraints) about these variables and indices are limited. Based on linearities of future climate change as functions of global warming levels and biases in recent global mean temperature trends in the simulations of 40 Earth system models (ESMs), the upper bounds of uncertainties in future changes of various variables (annual mean temperature, annual maximum daily maximum temperature, mean specific humidity, mean downward longwave radiation and specific humidity on days when annual maximum daily precipitation (Rx1day) events occur) are successfully lowered in most regions of the world. We can also reduce inter-model variances of regional changes in mean precipitation, Rx1day, mean downward shortwave radiation, mean sea level pressure and mean surface wind speed in some areas. These results would be useful for climate change impact studies to consider whether they should weight ESMs or exclude some ESMs to prevent possible biases in impact assessments.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"67 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140107114","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: 0

Heavy Rainfall on the North Side of Western Japan Induced by Typhoon Lan (2023): Roles of High Sea Surface Temperature over the Sea of Japan and a Terrain-Induced Mesoscale Low 台风 "兰"（2023 年）诱发的西日本北侧暴雨：日本海海面温度高和地形诱发的中尺度低气压的作用

IF 1.9 4区地球科学

Sola Pub Date : 2024-03-05 DOI: 10.2151/sola.2024-015

Satoki Tsujino, Akiyoshi Wada, Teruyuki Kato

{"title":"Heavy Rainfall on the North Side of Western Japan Induced by Typhoon Lan (2023): Roles of High Sea Surface Temperature over the Sea of Japan and a Terrain-Induced Mesoscale Low","authors":"Satoki Tsujino, Akiyoshi Wada, Teruyuki Kato","doi":"10.2151/sola.2024-015","DOIUrl":"https://doi.org/10.2151/sola.2024-015","url":null,"abstract":"An extreme rainfall event with 48-h accumulated precipitation amounts exceeding 500 mm on the north (Japan Sea) side of western Japan occurred when Typhoon Lan (2023) approached and passed over Japan in a weak baroclinic environment. The rainfall event included two local heavy precipitation peaks. In the present study, we perform numerical simulations with a cloud-system-resolving model to investigate the potential roles of two factors in the first event peak: (1) an abnormally high sea surface temperature (AHSST) anomaly (∼ +4°C) and (2) a mesoscale low formed over the Sea of Japan. The results of sensitivity experiments showed that the AHSST increased the total rainfall amount by about 100 mm. The mesoscale low, which was generated by southeasterly flows over the mountain ranges of central Japan, determined the location of the heavy rainfall by controlling the direction and intensity of low-level flows. The role of this terrain-induced mesoscale low provided new insight into the mechanisms producing heavy rainfall in association with typhoons approaching Japan in a weak baroclinic environment.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"1 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140037245","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: 0

Vertical development speed of shallow radiation fog 浅层辐射雾的垂直发展速度

IF 1.9 4区地球科学

Sola Pub Date : 2024-03-02 DOI: 10.2151/sola.2024-014

Rieko Y. Tanahashi, Ryota Misawa, Hirofumi Sugawara

引用次数: 0

Seasonal prediction system using CFES and comparison with SINTEX-F2 使用 CFES 的季节预测系统以及与 SINTEX-F2 的比较

IF 1.9 4区地球科学

Sola Pub Date : 2024-02-23 DOI: 10.2151/sola.2024-013

Tomomichi Ogata, Nobumasa Komori, Takeshi Doi, Ayako Yamamoto, Masami Nonaka

{"title":"Seasonal prediction system using CFES and comparison with SINTEX-F2","authors":"Tomomichi Ogata, Nobumasa Komori, Takeshi Doi, Ayako Yamamoto, Masami Nonaka","doi":"10.2151/sola.2024-013","DOIUrl":"https://doi.org/10.2151/sola.2024-013","url":null,"abstract":"In this study, we introduce a new seasonal prediction system using an atmosphere–ocean-coupled general circulation model called CFES (hereafter referred to as CFES ESPreSSO). We compare its prediction skill of the interannual variability of the surface air temperature (SAT) and precipitation anomalies with that of the SINTEX-F2 seasonal prediction system. We find that CFES ESPreSSO has a higher skill in predicting the SAT variability in January-February-March over East Asia and northeastern North America than SINTEX-F2, while the following season (April-May-June), SINTEX-F2 provides better predictions of the SAT variability over the Maritime Continent and subtropical North Pacific. Meanwhile, CFES better predicts the SAT variability in July-August-September over Eurasia and Arctic, and it continues to be so over the following season (October-November-December) over Eurasia. However, the prediction skill of SINTEX-F2 is generally better in the tropics (e.g., SAT in the subtropical North Pacific, SAT and precipitation in the Maritime Continent). Regarding climate indices, CFES shows a better prediction skill for the Atlantic Niño and Ningaloo Niño indices, whereas SINTEX-F2 is generally better for El Niño and the Indian Ocean dipole mode. These results suggest that for improved seasonal forecasting, it is beneficial to consider a multi-model approach, leveraging the respective strengths of each model.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"2013 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139955394","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: 0

Typhoon Intensity Forecasts using TIFS with Pseudo Ocean Coupling 使用带有伪海洋耦合的 TIFS 预测台风强度

IF 1.9 4区地球科学

Sola Pub Date : 2024-02-23 DOI: 10.2151/sola.2024-012

Munehiko Yamaguchi, Norihisa Usui, Nariaki Hirose

{"title":"Typhoon Intensity Forecasts using TIFS with Pseudo Ocean Coupling","authors":"Munehiko Yamaguchi, Norihisa Usui, Nariaki Hirose","doi":"10.2151/sola.2024-012","DOIUrl":"https://doi.org/10.2151/sola.2024-012","url":null,"abstract":"Typhoon HAISHEN, Typhoon No. 10 in 2020, was weaker than forecasts as it moved north over the western coast of Kyushu. The typhoon intensity forecasting scheme called TIFS operated at the Japan Meteorological Agency (JMA) tended to predict HAISHEN's intensity more strongly than the observed one, resulting in large errors in JMA's operational forecasts. One possible reason for the large errors is that TIFS does not include the effect of ocean cooling associated with tropical cyclones. Here, we investigated whether the accuracy of the typhoon intensity predictions can be improved by replacing static sea surface temperature and ocean heat content used in the conventional TIFS by those predicted by an ocean model. The results of prediction experiments using the pseudo-ocean-coupled TIFS show that the over-intensification of HAISHEN was suppressed and that the prediction errors were significantly reduced. We also extended the evaluation to all typhoons in 2020 and found that the pseudo-ocean-coupled TIFS reduced the prediction errors by about 10% compared to the conventional TIFS for prediction times of 3 to 5 days. This indicates that pseudo-ocean coupling of the conventional TIFS can improve the accuracy of typhoon intensity forecasts.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"50 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139955396","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: 0

Recent Global Distribution of Aridity Index and Land Use in Arid Regions 近期干旱地区干旱指数和土地利用的全球分布情况

IF 1.9 4区地球科学

Sola Pub Date : 2024-02-15 DOI: 10.2151/sola.2024-011

Reiji Kimura, Masao Moriyama

{"title":"Recent Global Distribution of Aridity Index and Land Use in Arid Regions","authors":"Reiji Kimura, Masao Moriyama","doi":"10.2151/sola.2024-011","DOIUrl":"https://doi.org/10.2151/sola.2024-011","url":null,"abstract":"Drylands, which occupy 41% of Earth's land area, have large effects on Earth's climate via land-atmosphere interactions, and simulations of future climate indicate that drylands will be very sensitive to climate changes associated with global warming. Monitoring of drylands is therefore necessary to help guide sustainable development in drylands and to protect the global environment. This study examined changes of the global distribution of the aridity index from 2000 to 2020 and compared them to changes from 1951 to 1980. The regions with relatively wet climates, that is, semi-arid and dry sub-humid regions, became drier from 2000 to 2020. The largest use of land in drylands was grassland, followed by open shrubland, cropland, savanna, and woody savanna. More than 50% of dry land was accounted for by grasslands (18,651,109 km2) and dryland forests including shrubland and savanna (13,331,231 km2). The relationship between the aridity index and the normalized difference vegetation index indicated that the value of the aridity index of dryland forests and grasslands equaled the threshold for climatically stable existence, although the range of the aridity index was wide in both cases. We also made rough assessments of soil organic carbon sequestration in dryland forests and grasslands.\u0000","PeriodicalId":49501,"journal":{"name":"Sola","volume":"16 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139770173","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: 0

Sola最新文献