Xiuhong Chen, Xianglei Huang, Yifan Cai, Haomin Shen, Jiayue Lu
Accurate forecast of global horizontal irradiance (GHI) is one of the key issues for power grid managements with large penetration of solar energy. A challenge for solar forecasting is to forecast the solar irradiance with a lead time of 1 – 8 hours, here termed as intra-day forecast. This study investigated an algorithm using a long short-term memory (LSTM) model to predict the GHI in 1 – 8 hours. The LSTM model has been applied before for inter-day (> 24 hours) solar forecast but never for the intra-day forecast. Four years (2010 – 2013) of observations by the National Renewable Energy Laboratory (NREL) at Golden, Colorado were used to train the model. Observations in 2014 at the same site were used to test the model performance. According to the results, for a 1 – 4 hour lead time, the LSTM-based model can make predictions of GHIs with root-mean-square-errors (RMSE) ranging from 77 to 143 W m, and normalized RMSEs around 18.4 – 33.0 %. With five-minute inputs, the forecast skill of LSTM with respect to smart persistence model is 0.34 – 0.42, better than random forest forecast (0.27) and the numerical weather forecast (−0.40) made by the Weather Research and Forecasting (WRF) model. The performance levels off beyond 4-hour lead time. The model performs better in fall and winter than in spring and summer, and better under clear-sky conditions than under cloudy conditions. Using adjacent information from the reanalysis as extra inputs can further improve the forecast performance.
准确预测全球水平辐照度（GHI）是太阳能大面积渗透的电网管理的关键问题之一。太阳预报的一个挑战是预测1–8小时的太阳辐照度，这里称为日内预报。本研究研究了一种使用长短期记忆（LSTM）模型预测1-8小时内GHI的算法。LSTM模型以前曾用于日间（>24小时）太阳预报，但从未用于日内预报。科罗拉多州戈尔登的国家可再生能源实验室（NREL）进行了四年（2010-2013年）的观测，用于训练该模型。2014年在同一地点的观测结果用于测试模型性能。根据结果，在1–4小时的交付周期内，基于LSTM的模型可以预测GHI，均方根误差（RMSE）范围为77至143 W m，归一化均方根误差约为18.4–33.0%。在5分钟的输入下，LSTM相对于智能持久性模型的预测技巧为0.34–0.42，优于天气研究与预测（WRF）模型的随机森林预测（0.27）和数值天气预测（−0.40）。性能在4小时交付周期后趋于平稳。该模型在秋季和冬季比春季和夏季表现更好，在晴朗的天空条件下比在多云的条件下表现更好。使用来自再分析的相邻信息作为额外输入可以进一步提高预测性能。
{"title":"Intra-day Forecast of Ground Horizontal Irradiance Using Long Short-term Memory Network (LSTM)","authors":"Xiuhong Chen, Xianglei Huang, Yifan Cai, Haomin Shen, Jiayue Lu","doi":"10.2151/jmsj.2020-048","DOIUrl":"https://doi.org/10.2151/jmsj.2020-048","url":null,"abstract":"Accurate forecast of global horizontal irradiance (GHI) is one of the key issues for power grid managements with large penetration of solar energy. A challenge for solar forecasting is to forecast the solar irradiance with a lead time of 1 – 8 hours, here termed as intra-day forecast. This study investigated an algorithm using a long short-term memory (LSTM) model to predict the GHI in 1 – 8 hours. The LSTM model has been applied before for inter-day (> 24 hours) solar forecast but never for the intra-day forecast. Four years (2010 – 2013) of observations by the National Renewable Energy Laboratory (NREL) at Golden, Colorado were used to train the model. Observations in 2014 at the same site were used to test the model performance. According to the results, for a 1 – 4 hour lead time, the LSTM-based model can make predictions of GHIs with root-mean-square-errors (RMSE) ranging from 77 to 143 W m, and normalized RMSEs around 18.4 – 33.0 %. With five-minute inputs, the forecast skill of LSTM with respect to smart persistence model is 0.34 – 0.42, better than random forest forecast (0.27) and the numerical weather forecast (−0.40) made by the Weather Research and Forecasting (WRF) model. The performance levels off beyond 4-hour lead time. The model performs better in fall and winter than in spring and summer, and better under clear-sky conditions than under cloudy conditions. Using adjacent information from the reanalysis as extra inputs can further improve the forecast performance.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"945-957"},"PeriodicalIF":3.1,"publicationDate":"2020-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42181736","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}
Moeka Yamaji, H. Takahashi, T. Kubota, R. Oki, A. Hamada, Y. Takayabu
This study investigates the global drop size distribution (DSD) of rainfall and its relationship to large-scale precipitation characteristics using the Dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) Core Observatory. This study focuses on seasonal variations in the dominant precipitation systems regarding variations in DSD. A mass-weighted mean diameter (Dm), which is estimated based on the dualfrequency information derived from the GPM/DPR, is statistically analyzed as a typical parameter of the DSD. Values of the annual mean Dm, in general, are larger over land than over the oceans, and the relationship between Dm and precipitation rate (R) is not a simple one-to-one relationship. Furthermore, Dm exhibits statistically significant seasonal variations, specifically over the northwest Pacific Ocean, whereas R shows insignificant variations, indicating the variations in R cannot explain the distinct seasonal changes in Dm. Focusing on the seasonal variation in Dm over the northwest Pacific Ocean, the results indicate that the variation in Dm is related to the seasonal change in the dominant precipitation systems. In the summer over the northwest Pacific Ocean, Dm is related to the organized precipitation systems associated with the Baiu front over the mid-latitudes and tropical disturbances over the subtropical region, with relatively higher precipitation top heights, composed of both stratiform and convective precipitations. Contrary to the summer, larger Dm over the mid-latitudes in winter is related to extraCorresponding author: Moeka Yamaji, Earth Observation Research Center, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki, 305-8505, Japan E-mail: yamaji.moeka@jaxa.jp J-stage Advance Published Date: 27 May 2020 Journal of the Meteorological Society of Japan Vol. 98, No. 4 756
{"title":"4-year Climatology of Global Drop Size Distribution and its Seasonal Variability Observed by Spaceborne Dual-frequency Precipitation Radar","authors":"Moeka Yamaji, H. Takahashi, T. Kubota, R. Oki, A. Hamada, Y. Takayabu","doi":"10.2151/jmsj.2020-038","DOIUrl":"https://doi.org/10.2151/jmsj.2020-038","url":null,"abstract":"This study investigates the global drop size distribution (DSD) of rainfall and its relationship to large-scale precipitation characteristics using the Dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) Core Observatory. This study focuses on seasonal variations in the dominant precipitation systems regarding variations in DSD. A mass-weighted mean diameter (Dm), which is estimated based on the dualfrequency information derived from the GPM/DPR, is statistically analyzed as a typical parameter of the DSD. Values of the annual mean Dm, in general, are larger over land than over the oceans, and the relationship between Dm and precipitation rate (R) is not a simple one-to-one relationship. Furthermore, Dm exhibits statistically significant seasonal variations, specifically over the northwest Pacific Ocean, whereas R shows insignificant variations, indicating the variations in R cannot explain the distinct seasonal changes in Dm. Focusing on the seasonal variation in Dm over the northwest Pacific Ocean, the results indicate that the variation in Dm is related to the seasonal change in the dominant precipitation systems. In the summer over the northwest Pacific Ocean, Dm is related to the organized precipitation systems associated with the Baiu front over the mid-latitudes and tropical disturbances over the subtropical region, with relatively higher precipitation top heights, composed of both stratiform and convective precipitations. Contrary to the summer, larger Dm over the mid-latitudes in winter is related to extraCorresponding author: Moeka Yamaji, Earth Observation Research Center, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki, 305-8505, Japan E-mail: yamaji.moeka@jaxa.jp J-stage Advance Published Date: 27 May 2020 Journal of the Meteorological Society of Japan Vol. 98, No. 4 756","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"755-773"},"PeriodicalIF":3.1,"publicationDate":"2020-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49074246","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}
Yasutaka Hirockawa, T. Kato, Hiroshige Tsuguti, N. Seino
We propose a new procedure for the objective identification and classification of heavy rainfall areas (HRAs) to advance the understanding of mesoscale convective systems (MCSs) in Japan. The distributions of accumulated precipitation amounts are evaluated from the radar/raingauge-analyzed precipitation amounts and characteristic features of HRAs are examined. The HRAs extracted during the warm seasons (April–November) in 2009 – 2018 are classified into four types (e.g., linear-stationary, linear, stationary, and others) based on their morphological features and temporal variations. HRAs are frequently observed on the Pacific sides of eastern and western Japan; 80 % of HRAs appeared from June to September and 60 % of the HRAs were observed in association with stationary fronts and tropical cyclones. Approximately 80 % of those HRAs of the linear-stationary type corresponded to typical elongated and stagnated MCSs, as suggested in previous studies.
{"title":"Identification and Classification of Heavy Rainfall Areas and their Characteristic Features in Japan","authors":"Yasutaka Hirockawa, T. Kato, Hiroshige Tsuguti, N. Seino","doi":"10.2151/jmsj.2020-043","DOIUrl":"https://doi.org/10.2151/jmsj.2020-043","url":null,"abstract":"We propose a new procedure for the objective identification and classification of heavy rainfall areas (HRAs) to advance the understanding of mesoscale convective systems (MCSs) in Japan. The distributions of accumulated precipitation amounts are evaluated from the radar/raingauge-analyzed precipitation amounts and characteristic features of HRAs are examined. The HRAs extracted during the warm seasons (April–November) in 2009 – 2018 are classified into four types (e.g., linear-stationary, linear, stationary, and others) based on their morphological features and temporal variations. HRAs are frequently observed on the Pacific sides of eastern and western Japan; 80 % of HRAs appeared from June to September and 60 % of the HRAs were observed in association with stationary fronts and tropical cyclones. Approximately 80 % of those HRAs of the linear-stationary type corresponded to typical elongated and stagnated MCSs, as suggested in previous studies.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"835-857"},"PeriodicalIF":3.1,"publicationDate":"2020-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42760560","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}
Through a set of ensemble experiments with an atmospheric general circulation model (AGCM), potential influence of sea-surface temperature (SST) anomalies is assessed on large-scale atmospheric circulation anomalies that induced two extreme events observed over Japan in July 2018. One is a heavy rainfall event in early July mainly over western Japan, which was primarily caused by extreme moisture inflow associated with a cyclonic anomaly to the southwest of Japan and an anticyclonic anomaly to the east of Japan. An AGCM experiment with prescribed global SST anomalies cannot reproduce the anticyclonic anomaly, leading to the failure to simulate the enhancement of the moisture inflow and thereby precipitation over western Japan. The other extreme event is heat wave in midand late July almost over the entire Japan, which was caused by a strong anticyclonic anomaly around Japan. The AGCM experiment with global SST anomalies can well reproduce the warm anticyclonic anomalies. The additional experiments have confirmed that SST anomalies in both the tropics and midlatitude North Pacific have potential for forcing the leading mode of the atmospheric variability over the western North Pacific that brought the heat wave. Both the tropical and extratropical SST anomalies are also found to force a poleward shift of the subtropical jet axis over the western Pacific and anomalous tropospheric warming in the midlatitude Northern Hemisphere, both of which persisted in June and July.
{"title":"An Atmospheric General Circulation Model Assessment of Oceanic Impacts on Extreme Climatic Events over Japan in July 2018","authors":"K. Nishii, B. Taguchi, H. Nakamura","doi":"10.2151/jmsj.2020-041","DOIUrl":"https://doi.org/10.2151/jmsj.2020-041","url":null,"abstract":"Through a set of ensemble experiments with an atmospheric general circulation model (AGCM), potential influence of sea-surface temperature (SST) anomalies is assessed on large-scale atmospheric circulation anomalies that induced two extreme events observed over Japan in July 2018. One is a heavy rainfall event in early July mainly over western Japan, which was primarily caused by extreme moisture inflow associated with a cyclonic anomaly to the southwest of Japan and an anticyclonic anomaly to the east of Japan. An AGCM experiment with prescribed global SST anomalies cannot reproduce the anticyclonic anomaly, leading to the failure to simulate the enhancement of the moisture inflow and thereby precipitation over western Japan. The other extreme event is heat wave in midand late July almost over the entire Japan, which was caused by a strong anticyclonic anomaly around Japan. The AGCM experiment with global SST anomalies can well reproduce the warm anticyclonic anomalies. The additional experiments have confirmed that SST anomalies in both the tropics and midlatitude North Pacific have potential for forcing the leading mode of the atmospheric variability over the western North Pacific that brought the heat wave. Both the tropical and extratropical SST anomalies are also found to force a poleward shift of the subtropical jet axis over the western Pacific and anomalous tropospheric warming in the midlatitude Northern Hemisphere, both of which persisted in June and July.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"801-820"},"PeriodicalIF":3.1,"publicationDate":"2020-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44239728","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":"Location of the Preferred Region for Tropical Cyclogenesis in Strong Monsoon Trough Pattern over the Western North Pacific","authors":"Xi Cao, R. Wu, N. Wei, Yifeng Dai","doi":"10.2151/jmsj.2020-034","DOIUrl":"https://doi.org/10.2151/jmsj.2020-034","url":null,"abstract":"","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"637-654"},"PeriodicalIF":3.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46095744","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}
Ozone loss pathways and their rates in the ozone quasi-biennial oscillation (QBO), which is simulated by a chemistry-climate model developed by the Meteorological Research Institute of Japan, are evaluated using an ob- jective pathway analysis program (PAP). The analyzed chemical system contains catalytic cycles caused by NOx , HOx , ClOx , Ox , and BrOx . PAP quantified the rates of all significant catalytic ozone loss cycles, and evaluated the partitioning among these cycles. The QBO amplitude of the sum of all cycles amounts to about 4 and 14 % of the annual mean of the total ozone loss rate at 10 and 20 hPa, respectively. The contribution of catalytic cycles to the QBO of the ozone loss rate is found to be as follows: NOx cycles contribute the largest fraction (50 – 85 %) of the QBO amplitude of the total ozone loss rate; HOx cycles are the second-largest (20 – 30 %) below 30 hPa and the third-largest (about 10 %) above 20 hPa; Ox cycles rank third (5 – 20 %) below 30 hPa and second (about 20 %) above 20 hPa; ClOx cycles rank fourth (5 – 10 %); and BrOx cycles are almost negligible. The relative contribution of the NOx and Ox cycles to the QBO amplitude of ozone loss differs by up to 10 % and 20 %, respectively, from their contribution to the annual mean ozone loss rate. The ozone QBO at 20 hPa is mainly driven by ozone transport, which then alters the ozone loss rate. In contrast, the ozone QBO at 10 hPa is driven chemically by NOx and the temperature dependence of [O]/[O3], which results from the temperature dependence of the reaction O + O2 + M → O3 + M. In addition, the ozone QBO at 10 hPa is influenced by the overhead ozone column, which affects [O]/[O3] (through ozone photolysis) and the ozone production rate (through oxygen photolysis).
{"title":"Partitioning of Ozone Loss Pathways in the Ozone Quasi-biennial Oscillation Simulated by a Chemistry-Climate Model","authors":"K. Shibata, R. Lehmann","doi":"10.2151/jmsj.2020-032","DOIUrl":"https://doi.org/10.2151/jmsj.2020-032","url":null,"abstract":"Ozone loss pathways and their rates in the ozone quasi-biennial oscillation (QBO), which is simulated by a \u0000chemistry-climate model developed by the Meteorological Research Institute of Japan, are evaluated using an ob- \u0000jective pathway analysis program (PAP). The analyzed chemical system contains catalytic cycles caused by NOx , \u0000HOx , ClOx , Ox , and BrOx . PAP quantified the rates of all significant catalytic ozone loss cycles, and evaluated the \u0000partitioning among these cycles. The QBO amplitude of the sum of all cycles amounts to about 4 and 14 % of \u0000the annual mean of the total ozone loss rate at 10 and 20 hPa, respectively. The contribution of catalytic cycles \u0000to the QBO of the ozone loss rate is found to be as follows: NOx cycles contribute the largest fraction (50 – 85 %) \u0000of the QBO amplitude of the total ozone loss rate; HOx cycles are the second-largest (20 – 30 %) below 30 hPa \u0000and the third-largest (about 10 %) above 20 hPa; Ox cycles rank third (5 – 20 %) below 30 hPa and second (about \u000020 %) above 20 hPa; ClOx cycles rank fourth (5 – 10 %); and BrOx cycles are almost negligible. The relative \u0000contribution of the NOx and Ox cycles to the QBO amplitude of ozone loss differs by up to 10 % and 20 %, \u0000respectively, from their contribution to the annual mean ozone loss rate. The ozone QBO at 20 hPa is mainly \u0000driven by ozone transport, which then alters the ozone loss rate. In contrast, the ozone QBO at 10 hPa is driven \u0000chemically by NOx and the temperature dependence of [O]/[O3], which results from the temperature dependence \u0000of the reaction O + O2 + M → O3 + M. In addition, the ozone QBO at 10 hPa is influenced by the overhead \u0000ozone column, which affects [O]/[O3] (through ozone photolysis) and the ozone production rate (through oxygen \u0000photolysis).","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"615-636"},"PeriodicalIF":3.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47681579","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}
C. Hohenegger, L. Kornblueh, D. Klocke, T. Becker, G. Cioni, J. F. Engels, Uwe Schulzweida, B. Stevens
Basic climate statistics, such as water and energy budgets, location and width of the Intertropical Convergence Zone (ITCZ), trimodal tropical cloud distribution, position of the polar jet, and land sea contrast, remain either biased in coarse-resolution general circulation models or are tuned. Here, we examine the horizontal resolution dependency of such statistics in a set of global convection-permitting simulations integrated with the ICOsahedral Non-hydrostatic (ICON) model, explicit convection, and grid spacings ranging from 80 km down to 2.5 km. The impact of resolution is quantified by comparing the resolution-induced differences to the spread obtained in an ensemble of eight distinct global storm-resolving models. Using this metric, we find that, at least by 5 km, the resolution-induced differences become smaller than the spread in 26 out of the 27 investigated statistics. Even for nine (18) of these statistics, a grid spacing of 80 (10) km does not lead to significant differences. Resolution down to 5 km matters especially for net shortwave radiation, which systematically increases with the resolution because of reductions in the low cloud amount over the subtropical oceans. Further resolution dependencies can be found in the land-to-ocean precipitation ratio, in the latitudinal position and width of the Pacific ITCZ, and in the longitudinal position of the Atlantic ITCZ. In addition, in the tropics, the deep convective cloud population systematically increases at the expense of the shallow one, whereas the partition of congestus clouds remains fairly constant. Finally, refining the grid spacing systematically moves the simulations closer to observations, but climate statistics exhibiting weaker resolution dependencies are not necessarily associated with smaller biases. Corresponding author: Cathy Hohenegger, Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany E-mail: cathy.hohenegger@mpimet.mpg.de J-stage Advance Published Date: 10 November 2019 Journal of the Meteorological Society of Japan Vol. 98, No. 1 74
{"title":"Climate Statistics in Global Simulations of the Atmosphere, from 80 to 2.5 km Grid Spacing","authors":"C. Hohenegger, L. Kornblueh, D. Klocke, T. Becker, G. Cioni, J. F. Engels, Uwe Schulzweida, B. Stevens","doi":"10.2151/JMSJ.2020-005","DOIUrl":"https://doi.org/10.2151/JMSJ.2020-005","url":null,"abstract":"Basic climate statistics, such as water and energy budgets, location and width of the Intertropical Convergence Zone (ITCZ), trimodal tropical cloud distribution, position of the polar jet, and land sea contrast, remain either biased in coarse-resolution general circulation models or are tuned. Here, we examine the horizontal resolution dependency of such statistics in a set of global convection-permitting simulations integrated with the ICOsahedral Non-hydrostatic (ICON) model, explicit convection, and grid spacings ranging from 80 km down to 2.5 km. The impact of resolution is quantified by comparing the resolution-induced differences to the spread obtained in an ensemble of eight distinct global storm-resolving models. Using this metric, we find that, at least by 5 km, the resolution-induced differences become smaller than the spread in 26 out of the 27 investigated statistics. Even for nine (18) of these statistics, a grid spacing of 80 (10) km does not lead to significant differences. Resolution down to 5 km matters especially for net shortwave radiation, which systematically increases with the resolution because of reductions in the low cloud amount over the subtropical oceans. Further resolution dependencies can be found in the land-to-ocean precipitation ratio, in the latitudinal position and width of the Pacific ITCZ, and in the longitudinal position of the Atlantic ITCZ. In addition, in the tropics, the deep convective cloud population systematically increases at the expense of the shallow one, whereas the partition of congestus clouds remains fairly constant. Finally, refining the grid spacing systematically moves the simulations closer to observations, but climate statistics exhibiting weaker resolution dependencies are not necessarily associated with smaller biases. Corresponding author: Cathy Hohenegger, Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany E-mail: cathy.hohenegger@mpimet.mpg.de J-stage Advance Published Date: 10 November 2019 Journal of the Meteorological Society of Japan Vol. 98, No. 1 74","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"73-91"},"PeriodicalIF":3.1,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48385524","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}
Variations in raindrop size distribution (DSD) during the southwest monsoon (SWM) season over different climatic regions in the Indian subcontinent and adjoining seas are studied in this paper using five years (2014 – 2018) of global precipitation measurement dual-frequency precipitation radar derived DSDs. The rain rate (R) stratified DSD measurements show clearly that land, sea, and orography differ in their mass-weighted mean diameter (Dm) values. Irrespective of R, Dm values of deep rain were found to be larger in continental rain than in maritime and orographic rain. However, for shallow storms, the Dm values were smaller for continental rain than for orographic and maritime rain. Based on the Dm values and their variations with R of the deep systems, the regions could be categorized into four groups, within which the Dm values were nearly equal: (1) the northwest India (NWI) and the southeast peninsular India (SEPI); (2) the foothills of the Himalayas (FHH) and the central India (CI); (3) the northeast India (NEI) and the Bay of Bengal (BOB); and (4) the Arabian Sea (AS), the Western Ghats (WG), and the Myanmar coast (MC). Compared to other geographical regions of the Indian subcontinent, the Dm values of the deep systems were the largest over NWI and SEPI and the smallest over the WG, MC, and AS; while for shallow systems, the Dm values were the largest over the BOB and AS and the smallest over the SEPI and NWI regions. Though the cloud drops were smaller over the continental regions, the raindrops were larger than in the maritime and orographic rain regions. The microphysical and dynamical processes that occur during precipitation play a vital role in altering the DSDs of continental rain.
{"title":"Regional Differences in Raindrop Size Distribution within Indian Subcontinent and Adjoining Seas as Inferred from Global Precipitation Measurement Dual-frequency Precipitation Radar","authors":"B. Radhakrishna, K. Saikranthi, T. N. Rao","doi":"10.2151/jmsj.2020-030","DOIUrl":"https://doi.org/10.2151/jmsj.2020-030","url":null,"abstract":"Variations in raindrop size distribution (DSD) during the southwest monsoon (SWM) season over different climatic regions in the Indian subcontinent and adjoining seas are studied in this paper using five years (2014 – 2018) of global precipitation measurement dual-frequency precipitation radar derived DSDs. The rain rate (R) stratified DSD measurements show clearly that land, sea, and orography differ in their mass-weighted mean diameter (Dm) values. Irrespective of R, Dm values of deep rain were found to be larger in continental rain than in maritime and orographic rain. However, for shallow storms, the Dm values were smaller for continental rain than for orographic and maritime rain. Based on the Dm values and their variations with R of the deep systems, the regions could be categorized into four groups, within which the Dm values were nearly equal: (1) the northwest India (NWI) and the southeast peninsular India (SEPI); (2) the foothills of the Himalayas (FHH) and the central India (CI); (3) the northeast India (NEI) and the Bay of Bengal (BOB); and (4) the Arabian Sea (AS), the Western Ghats (WG), and the Myanmar coast (MC). Compared to other geographical regions of the Indian subcontinent, the Dm values of the deep systems were the largest over NWI and SEPI and the smallest over the WG, MC, and AS; while for shallow systems, the Dm values were the largest over the BOB and AS and the smallest over the SEPI and NWI regions. Though the cloud drops were smaller over the continental regions, the raindrops were larger than in the maritime and orographic rain regions. The microphysical and dynamical processes that occur during precipitation play a vital role in altering the DSDs of continental rain.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"573-584"},"PeriodicalIF":3.1,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68295570","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":"Quasi-stationary Band-Shaped Precipitation Systems, Named “Senjo-Kousuitai”, Causing Localized Heavy Rainfall in Japan","authors":"T. Kato","doi":"10.2151/jmsj.2020-029","DOIUrl":"https://doi.org/10.2151/jmsj.2020-029","url":null,"abstract":"","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"485-509"},"PeriodicalIF":3.1,"publicationDate":"2020-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/jmsj.2020-029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47643577","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}
Precipitation efficiency (PE) is a useful concept for estimating precipitation under a given environmental condition. PE is used in various situations in meteorology such as to evaluate severe precipitation associated with a single storm event, as a parameter of cumulus convective parameterization, and to separate clouds and precipitation in climate projection studies. PE has been defined in several ways. In this review, we first introduce definitions of PE from microscopic and macroscopic perspectives, and provide estimates of PE based on observational and modeling approaches. Then, we review PE in shallow and organized deep convective systems that provide either a conceptual framework or physical constraints on representations of convection in models. Specifically, we focus on the roles of PE in cloud-radiative feedbacks to climate variability. Finally, we argue the usefulness of PE for investigating cloud and precipitation changes in climate projection studies.
{"title":"Precipitation Efficiency and its Role in Cloud-Radiative Feedbacks to Climate Variability","authors":"C. Sui, M. Satoh, Kentaroh Suzuki","doi":"10.2151/jmsj.2020-024","DOIUrl":"https://doi.org/10.2151/jmsj.2020-024","url":null,"abstract":"Precipitation efficiency (PE) is a useful concept for estimating precipitation under a given environmental condition. PE is used in various situations in meteorology such as to evaluate severe precipitation associated with a single storm event, as a parameter of cumulus convective parameterization, and to separate clouds and precipitation in climate projection studies. PE has been defined in several ways. In this review, we first introduce definitions of PE from microscopic and macroscopic perspectives, and provide estimates of PE based on observational and modeling approaches. Then, we review PE in shallow and organized deep convective systems that provide either a conceptual framework or physical constraints on representations of convection in models. Specifically, we focus on the roles of PE in cloud-radiative feedbacks to climate variability. Finally, we argue the usefulness of PE for investigating cloud and precipitation changes in climate projection studies.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":"98 1","pages":"261-282"},"PeriodicalIF":3.1,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42140014","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}
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