Journal of the Meteorological Society of Japan最新文献

{"title":"Summertime Convective Initiation Nowcasting over Southeastern China Based on Advanced Himawari Imager Observations","authors":"X. Zhuge, X. Zou","doi":"10.2151/JMSJ.2018-041","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-041","url":null,"abstract":"12 Convective initiation (CI) nowcasting often has a low probability of detection (POD) and 13 a high false-alarm ratio (FAR) at sub-tropical regions where the warm-rain processes often 14 occur. Using the high spatial- and temporal-resolution and multi-spectral data from the 15 Advanced Himawari Imager (AHI) on board Japanese new-generation geostationary satellite 16 Himawari-8, a stand-alone CI nowcasting algorithm is developed in this study. The 17 AHI-based CI algorithm utilizes the reflectance observations from channels 1 (0.47 μm ) and 7 18 (3.9 μm ), brightness temperature observations from infrared window channel 13 (10.4 μm ), the 19 dual-spectral differences between channels 10 (7.3 μm ) and 13, 13 and 15 (12.4 μm ), as well as 20 a tri-spectral combination of channels 11, 15 and 13, as CI predictors without relying on any 21 dynamic ancillary data (e.g., cloud type and atmospheric motion vector products). The 22 proposed AHI-based algorithm is applied to CI cases over Fujian province in the 23 Southeastern China. When validated by S-band radar observations, the CI algorithm 24 produced a POD as high as 93.33%, and a FAR as low as 33.33% for a CI case day that 25 occurred on 1 August 2015 over Northern Fujian. For over 216 CI events that occurred in a 26 three-month period from July to September 2015, the CI nowcasting lead time has a mean 27 value of ~64 minutes, with a longest lead time over 120 minutes. It is suggested that 28 false-alarm nowcasts that occur in the presence of capping inversion require further 29 investigation and algorithm enhancements.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43364563","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":"Validation of MODIS and AHI Observed Water Cloud Properties Using Surface Radiation Data","authors":"P. Khatri, T. Hayasaka, H. Iwabuchi, T. Takamura, H. Irie, T. Nakajima","doi":"10.2151/JMSJ.2018-036","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-036","url":null,"abstract":"The present study implements long-term surface observed radiation data (pyranometer observed global flux and sky radiometer observed spectral zenith transmittance data) of multiple SKYNET sites to validate water cloud optical properties (cloud optical depth COD and effective radius Re) observed from space by MODIS onboard TERRA and AQUA satellites and AHI onboard Himawari-8 satellite. Despite some degrees of differences in COD and Re between MODIS and AHI, they both showed common features when validated using surface based global flux data as well as cloud properties retrieved from sky radiometer observed zenith transmittance data. In general, CODs from both satellite sensors are found to overestimated when clouds are optically thin. Among a number of factors (spatial and temporal variations of cloud, sensor and solar zenith angles), the solar zenith angle (SZA) is found to have an impact on COD difference between reflectance based satellite sensor and transmittance based sky radiometer. The Re values from the sky radiometer and satellite sensor are generally poorly correlated. The difference in Re between the sky radiometer and satellite sensor is negatively correlated with COD difference between them, which is likely due to the inherent influence of Re retrieval precision on COD retrieval and vice versa in transmittance based sky radiometer.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42737573","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":"Assimilation and Forecasting Experiment for Heavy Siberian Wildfire Smoke in May 2016 with Himawari-8 Aerosol Optical Thickness","authors":"K. Yumimoto, T. Tanaka, Mayumi Yoshida, M. Kikuchi, T. Nagao, H. Murakami, T. Maki","doi":"10.2151/JMSJ.2018-035","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-035","url":null,"abstract":"The Japan Meteorological Agency (JMA) launched a next-generation geostationary meteorological satellite (GMS), Himawari-8, on October 7, 2014, which began its operation on July 7, 2015. The Advanced Himawari Imager (AHI) onboard Himawari-8 has 16 observational bands that enable the retrieval of full-disk maps of aerosol optical properties (AOPs), including aerosol optical thickness (AOT) and the Ångström exponent (AE), with unprecedented spatial and temporal resolutions. In this study, we combined an aerosol transport model with the Himawari-8 AOT using the data assimilation method and performed aerosol assimilation and forecasting experiments on smoke from an intensive wildfire that occurred over Siberia between May 15 and 18, 2016. To effectively utilize the high observational frequency of Himawari-8, we assimilated 1-h merged AOTs generated through the combination of six AOT snapshots taken over 10-min intervals, three times per day. The heavy smoke originating from the wildfire was transported eastward behind a low-pressure trough and covered northern Japan from May 19 to 20. The southern part of the smoke plume then traveled westward, in a clockwise flow associated with high pressure. The forecast without assimilation reproduced the transport of the smoke to northern Japan; however, it underestimated AOT and the extinction coefficient compared with observed values mainly because of errors in the emission inventory. Data assimilation with the Himawari-8 AOT compensated for the underestimation and successfully forecasted the unique C-shaped distribution of the smoke. In particular, the assimilation of the Himawari-8 AOT in May 18 greatly improved the forecast of the southern part of the smoke flow. Our results indicate that the inheritance of assimilation cycles and the assimilation of more recent observations led to better forecasting in this case of a continental smoke outflow. ©The Author(s) 2018. This is an open access article published by the Meteorological Society of Japan under a Creative Commons Attribution 4.0 International (CC BY 4.0) license (http://creativecommons.org/license/by/4.0). Corresponding author: Keiya Yumimoto, Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasugakoen, Kasuga-city, Fukuoka 816-8580, Japan E-mail: yumimoto@riam.kyushu-u.ac.jp J-stage Advance Published Date: 8 April 2018 Journal of the Meteorological Society of Japan, Vol. 96B, pp. 133−149, DOI:10.2151/jmsj.2018-035, 2018 Special Issue on Meteorology and Climate Change Studies by Using the Geostationary Meteorological Satellite Himawari-8 Journal of the Meteorological Society of Japan Vol. 96B 134","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42305599","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":"Assimilation of Himawari-8 Clear Sky Radiance Data in JMA's Global and Mesoscale NWP Systems","authors":"M. Kazumori","doi":"10.2151/JMSJ.2018-037","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-037","url":null,"abstract":"This article reports on the impacts of Himawari-8 Clear Sky Radiance (CSR) data assimilation in the global and mesoscale numerical weather prediction (NWP) systems of the Japan Meteorological Agency (JMA). Adoption of the Advanced Himawari Imager (AHI) on board JMA’s Himawari-8 and -9 satellites has enhanced observational capabilities in terms of spectral, horizontal, and temporal resolution. Improvements brought by the switchover from the Multi-functional Transport Satellite-2 (MTSAT-2) to the new-generation Himawari-8 satellite include an upgrade to the horizontal resolution of CSR data from 64 to 32 km and an increase in the number of available water vapor bands from one to three. CSR products are obtained every hour and distributed to the NWP community. The improved horizontal and spectral resolution of Himawari-8 CSR data provides new information on horizontal water vapor distribution and vertical profiles in data assimilation. In data assimilation experiments using JMA’s global NWP system, the assimilation of Himawari-8’s three water vapor bands significantly improved the tropospheric humidity field in analysis, especially in the lower troposphere, as compared to assimilation of the single MTSAT-2 water vapor channel. First-guess (FG) departure statistics for microwave humidity sounders indicated an improvement in the water vapor field, especially over Himawari-8 observation areas. Improved forecasting of tropospheric temperature, humidity, and wind fields for Himawari-8 observation areas was also seen. In data assimilation experiments using JMA’s mesoscale NWP system, a disastrous heavy precipitation event that took place in Japan’s Kanto-Tohoku region in 2015 was investigated. A single water vapor band of Himawari-8 CSR corresponding to MTSAT-2 was assimilated, resulting in enhanced contrast of the water vapor field between moist and dry areas, as well as a realistic representation of moist air flows from the ocean in analysis. The changes also improved mesoscale model heavy precipitation forecasts.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42631884","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":"Impact of ENSO on the Thermal Condition over the Tibetan Plateau","authors":"Yafei Wang, Xiaoyu Xu","doi":"10.2151/JMSJ.2018-032","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-032","url":null,"abstract":"The proposed study aims to examine the relation between the Tibetan Plateau (TP) thermal condition and El Niño and Southern Oscillation (ENSO). There were significant positive correlations between the snow water equivalent (SWE) over the TP from November to next April and sea surface temperature (SST) in the Eastern Equatorial Pacific (EEP) in November from 1987 to 2005. SST in EEP in November is most significantly cor related with the TP-SWE in next April, which suggests an accumulative effect of the ENSO on the TP snow cover. Although El Niño conditions could bring anomalous snowfall over the TP by generating a wave train en tering the North African-Asian jet, it is questionable if this impact could change the thermal condition over the TP. There was almost no significant negative correlation between the SWE and TP surface temperature (representing the TP thermal condition) in winter. This suggests that the TP thermal condition hardly varies with the anomalous snowfall caused by this ENSO impact, despite some cooling effect of snowfall during the El Niño phase. On the contrary, preceding El Niño conditions tended to be associated with increasing TP surface temperature in May and there were significant positive correlations between SWE in April and TP surface temperature in May and June. ENSO might play a part in affecting TP thermal condition in a way that is quite different from the previ ous research. A plausible mechanism based on the relation of ENSO-TP thermal condition has been proposed. The mechanism explained the direct and indirect effects of ENSO on the TP thermal condition and role that the seasonal progress can play in this relation. The issues about snow cover aging and the impact of global warming, among others, were also included in the mechanism.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68294417","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":"Validation of Himawari-8/AHI Radiometric Calibration Based on Two Years of In-Orbit Data","authors":"A. Okuyama, Masaya Takahashi, K. Date, K. Hosaka, Hidehiko Murata, T. Tabata, Ryoko Yoshino","doi":"10.2151/JMSJ.2018-033","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-033","url":null,"abstract":"The new geostationary (GEO) meteorological satellite of the Japan Meteorological Agency (JMA), Himawari-8, entered operation on 7 July 2015. Himawari-8 features the new 16-band Advanced Himawari Imager (AHI), whose spatial resolution and observation frequency are improved over those of its predecessor MTSAT-series satellites. These improvements will bring about unprecedented levels of performance in nowcasting services and short-range weather forecasting systems. In view of the essential nature of navigation and radiometric calibration in fully leveraging the imager’s potential, this study reports on the current status of calibration for the AHI. Image navigation is accurate to within 1 km, and band-to-band coregistration has also been validated. Infrared (IR) band calibration is accurate to within 0.2 K with no significant diurnal variation and is being validated using an approach developed under the Global Space-based Inter-Calibration System (GSICS) framework. Validation approaches are currently being tested for the visible and near-IR (NIR) bands. Two such approaches were compared and found to produce largely consistent results.","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42975710","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":"Characteristics of Himawari-8 Rapid Scan Atmospheric Motion Vectors Utilized in Mesoscale Data Assimilation","authors":"Michiko Otsuka, H. Seko, Kazuki Shimoji, K. Yamashita","doi":"10.2151/JMSJ.2018-034","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-034","url":null,"abstract":"Rapid scan atmospheric motion vectors (RS-AMVs) were derived using an algorithm developed by the Meteorological Satellite Center of the Japan Meteorological Agency (JMA) from Himawari-8 rapid scan imagery over the area around Japan. They were computed every 10 min for seven different channels, namely, the visible channel (VIS), near infrared and infrared channels (IR), three water vapor absorption channels (WV), and CO2 absorption channel (CO2), from image triplets with time intervals of 2.5 min for VIS and 5 min for the other six channels. In June 2016, the amount of data was increased by more than 20 times compared to the number of routinely used AMVs. To exploit these high-resolution data in mesoscale data assimilation for the improvement of short-range forecasts, data verification, and assimilation experiments were conducted. The RS-AMVs were of sufficiently good quality for assimilation and consistent overall with winds from JMA’s mesoscale analyses, radiosonde, and wind profiler observations. Errors were slightly larger in WV than in VIS and IR channels. Significant negative biases relative to sonde winds were seen at high levels in VIS, IR, and CO2, whereas slightly positive biases were noticeable in WV at midto high levels. Data assimilation experiments with the JMA’s nonhydrostatic model based Variational Data Assimilation System (JNoVA) on a cold vortex event in June 2016 were conducted using RS-AMVs from seven channels. The wind forecasts improved slightly in early forecast hours before 12 hours in northern Japan, over which the vortex passed during the assimilation period. They also showed small improvements at low levels when averaged over the whole forecast period. The results varied slightly depending on the channels used for assimilation, which might be caused by different error characteristics of RS-AMVs in different channels. ©The Author(s) 2018. This is an open access article published by the Meteorological Society of Japan under a Creative Commons Attribution 4.0 International (CC BY 4.0) license (http://creativecommons.org/license/by/4.0). Corresponding author: Michiko Otsuka, Forecast Department, Meteorological Research Institute, 1-1 Nagamine, Tsukuba, Ibaraki 305-0052, Japan E-mail: motsuka@mri-jma.go.jp 1 Present affiliation: Numerical Prediction Division, Japan Meteorological Agency, Tokyo, Japan 2 Present affiliation: Meteorological Satellite Center, Japan Meteorological Agency, Kiyose, Japan J-stage Advance Published Date: 23 March 2018 Journal of the Meteorological Society of Japan, Vol. 96B, pp. 111−131, DOI:10.2151/jmsj.2018-034, 2018 Special Issue on Meteorology and Climate Change Studies by Using the Geostationary Meteorological Satellite Himawari-8 Journal of the Meteorological Society of Japan Vol. 96B 112","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41572142","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":"Comparison of Different Time Scale Contributions to Tropical Cyclone Genesis over the Western North Pacific in 2015 and 2016","authors":"Xi Cao, R. Wu","doi":"10.2151/JMSJ.2018-038","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-038","url":null,"abstract":"","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44137544","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":"ARPS Simulations of Convection during TOMACS","authors":"A. P. Filho, Felipe Vemado, Kazuo Saito, H. Seko, José Luis Flores Rojas, H. Karam","doi":"10.2151/JMSJ.2018-030","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-030","url":null,"abstract":"The Tokyo Metropolitan Area Convection Study (TOMACS) for extreme-weather-resilient cities is a research and development project (RDP) of the World Weather Research Programme (WWRP). TOMACS provided a multiplatform and high spatiotemporal resolution dataset for the present research on three episodes of deep convection in the Tokyo Metropolitan Area (TMA) under its heat island effect and sea breeze circulations. Heavy rainfall episodes of August 26, 2011, and July 23 and August 12, 2013, were simulated with (and without) the tropical town energy budget (T-TEB) model coupled with the advanced regional prediction system (ARPS). The T-TEB/ARPS system used initial and boundary conditions from the Japan Meteorological Agency (JMA) mesoscale analysis data for 24-hour integration runs at 5-km resolution over Japan and at 1-km resolution over TOMACS area. The 1-km resolution hourly rainfall field simulations were verified against the respective automated meteorological data acquisition system (AMeDAS) rain gauge network measurements. Statistics of the Contingency tables were obtained to estimate the critical success index (CSI), probability of detection (POD), and false alarm rate (FAR) as well as the root mean square error (RMSE). The T-TEB/ARPS simulations improved the south and east sea breeze circulations of TMA and its urban heat island effect. The time evolution of CSI scores improved within the advective time scale, whereas dissipation (phase) errors on precipitation RMSE increased with the integration time and were larger than the dispersion (amplitude) errors. The initial and boundary conditions of JMA greatly improved the simulations as compared to the previous ones performed with the outputs of NCEP’s global forecast system as indicated by the TOMACS datasets. Thus, the results represent the ©The Author(s) 2018. This is an open access article published by the Meteorological Society of Japan under a Creative Commons Attribution 4.0 International (CC BY 4.0) license (http://creativecommons.org/license/by/4.0). Corresponding author: Augusto José Pereira Filho, Department of Atmospheric Sciences of the Institute of Astronomy, Geophysics and Atmospheric Sciences IAG, University of São Paulo USP, Rua do Matão, 1226, 05508-090 São Paulo, Brazil E-mail: augusto.pereira@iag.usp.br J-stage Advance Published Date: 9 March 2018 Journal of the Meteorological Society of Japan, Vol. 96A, pp. 247−263, DOI:10.2151/jmsj.2018-030, 2018 Special Issue on Tokyo Metropolitan Area Convection Study for Extreme Weather Resilient Cities (TOMACS) Journal of the Meteorological Society of Japan Vol. 96A 248","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44463150","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":"Relationship between Sea Surface Temperature and Rainfall in the Philippines during the Asian Summer Monsoon","authors":"H. Takahashi, Julie Mae B. Dado","doi":"10.2151/JMSJ.2018-031","DOIUrl":"https://doi.org/10.2151/JMSJ.2018-031","url":null,"abstract":"We offer a new perspective on a relationship between sea surface temper- 2 ature (SST) over the windward region of the Philippines and rainfall in 3 the western Philippines during the Asian summer monsoon season, which 4 has been known as the negative correlation, using observational daily SST, 5 rainfall, and atmospheric circulation datasets. This study focuses on the 6 local SST effect rather than the remote effect. A warmer local SST re- 7 sults in greater rainfall over the western Philippines under similar monsoon 8 westerlies conditions, particularly during moderate and relatively stronger 9 monsoon regimes. This result is obtained after selecting only the moderate 10 or relatively stronger monsoon days, because the positive effect of SST on 11 rainfall is masked by the apparent negative correlation between SST and 12 rainfall. The warmer SSTs being associated with less rainfall correspond 13 to weaker cooling by weaker monsoon westerlies and the cooler SSTs being 14 associated with more rainfall correspond to stronger cooling by stronger 15 monsoon westerlies. The cooler SSTs are the result of stronger monsoon 16 cooling and are not the cause of the greater rainfall, which is the appar- 17 ent statistical relationship. This also implies that the monsoon westerly is 18 the primary driver of the variation in rainfall in this region. We conclude that the local SST makes a positive contribution toward rainfall, although 20 it does not primarily control rainfall. This conclusion can be applicable to 21","PeriodicalId":17476,"journal":{"name":"Journal of the Meteorological Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2151/JMSJ.2018-031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42588873","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}