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Previous Issue

JMSJ, 2021, Vol. 99, No. 1 (February)

Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Aoki and Shige (2021)

Aoki, S., and S. Shige, 2021: Large precipitation gradients along the south coast of Alaska revealed by spaceborne radars. J. Meteor. Soc. Japan, 99, 5-25.
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary
https://doi.org/10.2151/jmsj.2021-001Graphical Abstract

Plain Language Summary: At high latitudes, discriminating the phase of precipitation, as well as amount, is crucial in grasping the hydrological cycle. This study investigates the horizontal and vertical distribution of precipitation along the south coast of Alaska, using two spaceborne radars: the Dual-frequency Precipitation Radar (DPR) KuPR onboard the Global Precipitation Measurement (GPM) Core Observatory and the Cloud Profiling Radar (CPR) onboard CloudSat. It reveals that the precipitation phase and amount considerably change with the distance from the coastline.

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Articles:

Suzuki et al. (2021)

Suzuki, K., T. Iwasaki, and T. Yamazaki, 2021: Analysis of systematic error in numerical weather prediction of coastal fronts in Japan’s Kanto Plain. J. Meteor. Soc. Japan, 99, 27-47.
https://doi.org/10.2151/jmsj.2021-002Graphical Abstract

Plain Language Summary: Coastal fronts tend to be forecast on the inland side of their actual positions by the operational Numerical Weather Prediction (NWP with a horizontal grid spacing of 5 km) model at the Japan Meteorological Agency. This study confirms a systematic NWP error through statistical validations of coastal fronts, and the numerical experiments reveal that the systematic error may be caused primarily by an underestimation of the mountain barrier surrounding the Kanto Plain in the model.

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Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Le and Chandrasekar (2021)

Le, M. and V. Chandrasekar, 2021: Graupel and hail identification algorithm for the Dual-Frequency Precipitation Radar (DPR) on the GPM core satellite. J. Meteor. Soc. Japan, 99, 49-65.
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary
https://doi.org/10.2151/jmsj.2021-003Graphical Abstract

Plain Language Summary: This paper aims to develop a graupel and hail identification algorithm for GPM DPR. This algorithm is constructed using a precipitation type index (PTI) defined for DPR. The PTI is effective in separating hydrometeor types and is calculated using measurements of reflectivity, dual-frequency ratio, and storm top height data. The output of the algorithm is a Boolean product representing the existence of graupel or hail along with the vertical profile for each Ku- and Ka-band matched footprint. Cross validation is performed with the Weather Service Radar (WSR-88D) network over continental United States as well as during the Remote sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observations (RELAMPAGO) experiment. Evaluation of this identification algorithm is performed on a global basis, which illustrates promising comparisons with the global lightning and hail precipitation maps generated using radar and radiometer.

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Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Yu et al. (2021)

Yu, T., V. Chandrasekar, H. Xiao, and S. S. Joshil, 2021: Snowfall estimation using dual-wavelength radar during the PyeongChang 2018 Olympics and Paralympic winter games. J. Meteor. Soc. Japan, 99, 67-77.
https://doi.org/10.2151/jmsj.2021-004Graphical Abstract

Plain Language Summary: This paper aims to develop S-Z and S-Z-DFR relationships for snow estimation using D3R radar in a coastal area. The velocity and diameter measured by the disdrometer is used to derive the snow density directly. Evaluation of the two snow estimation methods is performed at three sites (YPO, CPO, and DGW), and the results show that the radar snowfall estimation agrees well with the ground observations at the three sites and S-Z-DFR algorithm performs better compared with S-Z algorithm.

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Articles:

Kusunoki and Mizuta (2021)

Kusunoki, S. and R. Mizuta, 2021: Future changes in rainy season over East Asia projected by massive ensemble simulations with a high-resolution global atmospheric model. J. Meteor. Soc. Japan, 99, 79-100.
https://doi.org/10.2151/jmsj.2021-005Graphical Abstract

Plain Language Summary: Future changes in the rainy season in East Asia are projected based on massive ensemble simulations of about 100 members with a 60-km mesh global atmospheric model called the “Database for Policy Decision-Making for Future Climate Change (d4PDF)”. Summer precipitation will generally increase in most regions of East Asia, but will decrease over western Japan, where the onset of rainy season will delay and the retreat will occur earlier, resulting in a shorter rainy season.

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Notes and Correspondence

Ohigashi et al. (2021)

Ohigashi, T., T. Maesaka, S. Suzuki, Y. Shusse, N. Sakurai, and K. Iwanami, 2021: Clear-air echoes observed by Ka-band polarimetric cloud radar: A case study on insect echoes in the Tokyo metropolitan area, Japan. J. Meteor. Soc. Japan, 99, 101-112.
https://doi.org/10.2151/jmsj.2021-006Graphical Abstract

Plain Language Summary: The clear-air echoes (CAEs), that appeared on May 21, 2016 in the Tokyo metropolitan area, Japan, were investigated to establish the potential for distinguishing CAEs and hydrometeor echoes in the initial stage of cloud formation using Ka-band polarimetric cloud radar. The polarimetric variables obtained by Ka-band polarimetric cloud radar are useful in distinguishing between clear-air echoes and hydrometeor echoes.

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Articles: Special Edition on Years of the Maritime Continent (YMC)

Seiki et al. (2021)

Seiki, A., S. Yokoi, and M. Katsumata, 2021: The impact of diurnal precipitation over Sumatra Island, Indonesia, on synoptic disturbances and its relation to the Madden-Julian Oscillation. J. Meteor. Soc. Japan, 99, 113-137.
Special Edition on Years of the Maritime Continent (YMC)
https://doi.org/10.2151/jmsj.2021-007Graphical Abstract

Plain Language Summary: Summary: Upscale effects of diurnal precipitation over Sumatra on synoptic disturbances are examined. The strong diurnal cycle is followed by the development of synoptic disturbances over the eastern Indian Ocean for several days, and apparent twin synoptic disturbances straddling the equator develop only when the convective center of the Madden–Julian Oscillation (MJO) lies over the Indian Ocean. Furthermore, the MJO events with the strong diurnal cycle tend to have continuing eastward propagation of active convection across the Maritime Continent, suggesting that the strong diurnal cycle facilitate the smooth eastward propagation of the MJO.

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Huang et al. (2021)

Huang, X.-G., X.-D. Peng, J.-F. Fei, X.-P. Cheng, J.-L. Ding, and D.-D. Yu, 2021: Evaluation and error analysis of official tropical cyclone intensity forecasts during 2005-2008 for the western North Pacific. J. Meteor. Soc. Japan, 99, 139-163.
https://doi.org/10.2151/jmsj.2021-008Graphical Abstract

Plain Language Summary: This study systematically evaluates the accuracy, trends, and error sources of three centers as the China Meteorological Administration (CMA), Joint Typhoon Warning Center (JTWC), and Regional Specialized Meteorological Center Tokyo-Typhoon Center (RSMC-Tokyo) for western North Pacific tropical cyclone (TCs) intensity forecasts between 2005 and 2018. The results of the study confirm the steady progress of the intensity forecast in the three centers in recent years. Meanwhile, the intensity forecast skill still needs to be greatly improved for the rapidly intensification (RI) TCs.

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Articles: Special Edition on Extreme Rainfall Events in 2017 and 2018

Unuma and Takemi (2021)

Unuma, T., and T. Takemi, 2021: Rainfall characteristics and their environmental conditions during the heavy rainfall events over Japan in July of 2017 and 2018. J. Meteor. Soc. Japan, 99, 165-180.
Special Edition on Extreme Rainfall Events in 2017 and 2018
https://doi.org/10.2151/jmsj.2021-009Graphical Abstract

Plain Language Summary: Precipitating cloud systems during the heavy rainfall events in July of 2017 and 2018 were categorized into five types, based on the intensity, area, and lifetime of rainfall. Organized convective systems having larger rainfall areas and longer lifetimes play a major role in generating the heavy rainfalls. Column moisture content and tropospheric relative humidity characterize the environmental conditions for the occurrence of the present heavy rainfall events.

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Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Meneghini et al. (2021)

Meneghini, R., H. Kim, L. Liao, J. Kwiatkowski, and T. Iguchi, 2021: Path attenuation estimates for the GPM Dual-Frequency Precipitation Radar (DPR). J. Meteor. Soc. Japan, 99, 181-200.
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary
https://doi.org/10.2151/jmsj.2021-010Graphical Abstract

Plain Language Summary: Estimation of the path-integrated attenuation (PIA) is a critical part of retrieving precipitation parameters using measurements from the Dual-Frequency Precipitation Radar (DPR) on board the Global Precipitation Measurement Mission (GPM) satellite. In this paper, we describe and evaluate different techniques used to estimate the PIA using both single- and dual-frequency DPR radar data. The resulting algorithm forms part of the present operational system used to process the DPR data.

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JMSJ, 2021, Vol. 99, No. 2 (April)

Seto et al. (2021)

Seto, S., T. Iguchi, R. Meneghini, J. Awaka, T. Kubota, T. Masaki, and N. Takahashi, 2021: The Precipitation rate retrieval algorithms for the GPM Dual-frequency Precipitation Radar. J. Meteor. Soc. Japan, 99,
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary,
https://doi.org/10.2151/jmsj.2021-011.Early Online ReleaseGraphical Abstract

Plain Language Summary: New precipitation rate retrieval algorithms (version 06A) for the GPM Dual-frequency Precipitation Radar are developed. Major changes from the previous algorithms (version 03B) include the introduction of the relation between precipitation rate and mass-weighted mean diameter (R−Dm relation), non-uniform beam filling correction, DSD database (single-frequency algorithms only), and the ZfKa method (dual-frequency algorithm only).

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Review Articles:

Hitchman et al. (2021)

Hitchman, M. H., S. Yoden, P. H. Haynes, V. Kumar, and S. Tegtmeier, 2021: An observational history of the direct influence of the stratospheric Quasi-biennial Oscillation on the tropical and subtropical upper troposphere and lower stratosphere. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-012.Early Online ReleaseGraphical Abstract

Plain Language Summary: The history of observational studies regarding the influence of the quasi-biennial oscillation (QBO) on the tropical and subtropical upper troposphere and lower stratosphere (UTLS) is described. The seasonal and geographical variation of QBO westerly (W) minus easterly (E) differences in UTLS temperature, pressure, and zonal wind is presented. Results from the periods 1958-1978 and 1978-2000 using National Centers for Environmental Prediction (NCEP) reanalyses are compared with modern updates using Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA2) data for 1980-2017, and European Centre for Medium Range Weather Forecasting Reanalysis – Interim (ERA-Interim) data for 1979-2018.

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Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Jian et al. (2021)

Jian, H.-W., W.-T. Chen, P.-J. Chen, C.-M. Wu, and K. I. Rasmussen, 2021: The synoptically- influenced extreme precipitation systems over Asian-Australian monsoon region observed by TRMM Precipitation Radar. J. Meteor. Soc. Japan, 99,
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary
https://doi.org/10.2151/jmsj.2021-013.Early Online ReleaseGraphical Abstract

Plain Language Summary: This study investigates the synoptic-scale flows associated with extreme rainfall systems over the Asian-Australian monsoon region observed by precipitation radar onboard TRMM satellite. The extreme rainfall systems are classified into four categories based on the synoptic flow patterns and the vicinity to coastlines. The spatial-temporal variation of the four categories and their internal structures are examined.

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Articles

Yamashita et al. (2021)

Yamashita, Y., M. Takigawa, D. Goto, H. Yashiro, M. Satoh, Y. Kanaya, F. Taketani, and T. Miyakawa, 2021: Effect of model resolution on black Carbon transport from Siberia to the Arctic associated with the well-developed low-pressure systems in September. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-014.Early Online ReleaseGraphical Abstract

Plain Language Summary: Atmospheric transport of black carbon (BC) affects the absorption/scattering of solar radiation, precipitation, and snow/ice cover, especially in areas of low human activity such as the Arctic. The resolution dependency of simulated BC transport from Siberia to the Arctic, related to the well-developed low-pressure systems in September, was evaluated using the Nonhydrostatic Icosahedral Atmospheric Model–Spectral Radiation Transport Model for Aerosol Species (NICAM-SPRINTARS) with fine (∼ 56 km) and coarse (∼ 220 km) horizontal resolutions.

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Chandra et al. (2021)

Chandra, N., P. K. Patra, J. S. H. Bisht, A. Ito, T. Umezawa, N. Saigusa, S. Morimoto, S. Aoki, G. Janssens-Menhout, and R. Fujita, M. Takigawa, S. Watanabe, N. Saitoh, and J. G. Canadell, 2021: Emissions from the oil and gas sectors, coal mining and ruminant farming drive methane growth over the past three decades. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-015.Early Online ReleaseGraphical Abstract

Plain Language Summary: Methane (CH4) is an important greenhouse gas and plays a significant role in tropospheric and stratospheric chemistry. CH4 growth rate (i.e., year to year change) in atmosphere varied in three distinct phases in the past three decades (1988-2016); namely, the periods of slowed (1988-1998), quasi-stationary (1999-2006) and renewed (2007-2016) growth phases. These distinct growth rate phases are explained by the anomalies in global and regional emissions that are estimated with an atmospheric chemistry-transport model (ACTM) based inverse modelling framework and observations from 19 sites worldwide. The anomalies in global and regional emissions are further attributed into different sectorial categories with the help of emission inventory.

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Articles:

Takemura et al. (2021)

Takemura, K., T. Enomoto, and H. Mukougawa, 2021: Predictability of enhanced monsoon trough related to the meandered Asian jet and consequent Rossby wave breaking in late August 2016. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-016.Early Online ReleaseGraphical Abstract

Plain Language Summary: Predictability of an enhanced monsoon trough south of Japan seen in late August 2016 is diagnosed. The monsoon trough is found to be enhanced by a meandering of the Asian jet and by a subsequent Rossby wave breaking east of Japan (Fig. 1). Japan Meteorological Agency (JMA)’s operational one-month ensemble forecast from 12 UTC 16 August 2016 fails to predict the enhanced monsoon trough. The main findings obtained from the predictability assessment are summarized as follows.

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Articles:

Chandra et al. (2021)

Chandra, N., P. K. Patra, J. S. H. Bisht, A. Ito, T. Umezawa, N. Saigusa, S. Morimoto, S. Aoki, G. Janssens-Menhout, and R. Fujita, M. Takigawa, S. Watanabe, N. Saitoh, and J. G. Canadell, 2021: Emissions from the oil and gas sectors, coal mining and ruminant farming drive methane growth over the past three decades. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-017.Early Online ReleaseGraphical Abstract

Plain Language Summary: Methane (CH4) is an important greenhouse gas and plays a significant role in tropospheric and stratospheric chemistry. CH4 growth rate (i.e., year to year change) in atmosphere varied in three distinct phases in the past three decades (1988-2016); namely, the periods of slowed (1988-1998), quasi-stationary (1999-2006) and renewed (2007-2016) growth phases. These distinct growth rate phases are explained by the anomalies in global and regional emissions that are estimated with an atmospheric chemistry-transport model (ACTM) based inverse modelling framework and observations from 19 sites worldwide. The anomalies in global and regional emissions are further attributed into different sectorial categories with the help of emission inventory.

Highlights:

 

Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Seiki (2021)

Seiki, T., 2021: Near-global three-dimensional hail signals detected by using GPM-DPR observations. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-018.Early Online ReleaseGraphical Abstract

Plain Language Summary: Hail is a large dense ice particle and its particle size often reaches more than 1 cm. Hail is known to be associated with intense storms and causes severe damage to cars, buildings, and croplands. In general, hail has been observed by weather radar systems or reported from visual check on the ground. Such the observations are limited to developed countries and populated regions and, hence, global three-dimensional structure of hail has not been analyzed yet. This study proposed a method to detect hail signals using space-borne radar observations and successfully illustrated a near-global three-dimensional hail map. This new dataset for hail is to be utilized for improving weather forecasting and risk management of hail disasters in the global scale.

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Articles:

Shibata and Sai (2021)

Shibata, K., and A. Sai, 2021: Long-term trends and variations in surface humidity and temperature in the Japanese archipelago over 100 years from 1880s. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-019.Early Online ReleaseGraphical Abstract

Plain Language Summary: The surface observation data in Japan, beginning around the 1880s, are analyzed focusing on the long–term trends and variations in humidity and temperature. It is found that the annual–mean temperature trend exhibits statistically significant warming of 1.0°C–2.5°C century¬1, while the annual–mean relative humidity shows significantly decreasing trend of −2% to −12% century-1. On the other hand, the annual–mean mixing ratio trend displays a different spatial distribution compared to the temperature or relative humidity trend. In this study, three types of trends exist: significantly positive and negative values, and virtually zero. Significantly negative trends of about −0.2 to −0.3 g kg−1 century−1 are located approximately in the Pacific side of Honshu from the middle Tohoku through Shikoku to the eastern Kyushu. Significantly positive trends of about 0.2 to 0.4 g kg−1 century−1 are observed over Hokkaido, the western Japan along Sea of Japan, the western Kyushu, and the remote islands including Okinawa.

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Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

De Meyer and Roca (2021)

De Meyer, V., and R. Roca, 2021: Thermodynamic scaling of extreme daily precipitation over the tropical ocean from satellite observations. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-020.Early Online ReleaseGraphical Abstract

Plain Language Summary: Extreme precipitation is expected to increase in a warmer climate at the same rate of the surface humidity, that is the Clausius-Clapeyron rate (~6%/K in the tropics). This study investigates the scaling of the extreme precipitation over the tropical ocean using an ensemble of satellite-based precipitation products and SST analysis. The microwave constellation-based products show a very robust positive scaling range between 300K to 302.5K, with an ensemble mean very close to the 6%/K theoretical expectation.

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Articles:

Jain et al. (2021)

Jain, S., R. Chhin, R. M. Doherty, S. K. Mishra, and S. Yoden, 2021: A new graphical method to diagnose the impacts of model changes on climate sensitivity. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-021.Early Online ReleaseGraphical Abstract

Plain Language Summary: Equilibrium climate sensitivity (ECS) is defined as the change in global-mean surface air temperature (ΔT) due to the quadrupling of CO2 in a climate model simulation (Fig.1a). In this paper, we propose a new graphical method, which is based on Gregory’s linear regressions (Fig.1b), to visualize the impact of a model change on ECS, climate forcing (RF), and feedbacks (Rα) in a single diagram (Fig.1c), and demonstrate its usefulness with an example of climate sensitivity simulations with interactive (ACTIVE) and prescribed (FIXED) chemistry model.

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Notes and Correspondence

Maeda et al. (2021)

Maeda, S., K. Takemura and C. Kobayashi, 2021: Planetary wave modulations associated with the Eurasian teleconnection pattern. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-022.Early Online ReleaseGraphical Abstract

Plain Language Summary: This study analyzes the modulation of planetary waves associated with the Eurasian pattern through composite analyses to reveal its dynamic mechanism, including wave-mean flow interaction. In the positive phase of the Eurasian pattern (EU+), corresponding to the enhanced Asian monsoon, the upward and eastward propagation of the planetary wave from the Central Eurasia to the North Pacific in the troposphere is enhanced. The enhanced upward and eastward propagating planetary wave converges in the upper troposphere, thereby causing anomalous extratropical direct circulation and cold outflow toward the mid-latitude lower troposphere.

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Articles:

Takemura and Mukougawa (2021)

Takemura, K., and H. Mukougawa, 2021: Relaxation experiments for predictability assessment of enhanced monsoon trough in late August 2016. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-023.Early Online ReleaseGraphical Abstract

Plain Language Summary: Predictability of an enhanced monsoon trough south of Japan seen in late August 2016 is diagnosed using an atmospheric general circulation model. The trough is found to be enhanced by a Rossby wave propagation over Eurasia and the subsequent Rossby wave breaking east of Japan. Three types of relaxation experiments are conducted, with nudging the model forecast toward reanalysis, for regions of the Rossby wave breaking, Rossby wave propagation, and both the regions. The main findings obtained from the experiments are summarized as follows.

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Articles: Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary

Sawada and Ueno (2021)

Sawada, M., and K. Ueno, 2021: Heavy winter precipitation events with extratropical cyclone diagnosed by GPM products and trajectory analysis. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-024.Early Online ReleaseGraphical Abstract

Plain Language Summary: The mechanisms for producing heavy precipitation regarding the structure of an occluding extratropical cyclone during the cold seasons were analyzed using the products of the Dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) core satellite and trajectory analysis on the European Centre for Medium-range Weather Forecasts atmospheric reanalysis data.

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Articles

Voelger and Dalin (2021)

Voelger, P and P. Dalin, 2021: A case study of a quasi-stationary, very long polar stratospheric cloud layer edge. J. Meteor. Soc. Japan, 98, 511-525.
https://doi.org/10.2151/jmsj.2021-025.Early Online ReleaseGraphical Abstract

Plain Language Summary: A very long (more 600 km) straight edge of a Polar Stratospheric Cloud (PSC), located at 24-26 km altitude, was observed east of the Scandinavian Mountain Range both by an optical camera and by lidar. The cloud edge remained unchanged for several hours. We investigated the atmospheric conditions during observation which led to the unusual feature.

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Articles: Special Edition on Years of the Maritime Continent (YMC)

Feng et al. (2021)

Feng, L., T. Zhang, T.-Y. Koh, and E. M. Hill, 2021: Selected years of monsoon variations and extratropical dry-air intrusions compared with the Sumatran GPS array observations in Indonesia. J. Meteor. Soc. Japan, 99,
Special Edition on Years of the Maritime Continent (YMC)
https://doi.org/10.2151/jmsj.2021-026.Early Online ReleaseGraphical Abstract

Plain Language Summary: Although the Global Positioning System (GPS) has been widely used to study long-term trends or diurnal and subdiurnal cycles of precipitable water vapor (PWV), it has been rarely used for the intra-seasonal scale. We used the zenith wet delay (ZWD) data from the Sumatran GPS Array (SuGAr) in Indonesia, with help from reanalysis data, to study the summer intra-seasonal variability of PWV over Sumatra in years without strong inter-annual variability, and to probe the underlying atmospheric processes that control the variability.

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Articles

Li and Wang (2021)

Li, T.-H., and Y. Wang, 2021: The role of boundary layer dynamics in tropical cyclone intensification. Part I: Sensitivity to surface drag coefficient. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-027.Early Online ReleaseGraphical Abstract

Plain Language Summary: Most previous studies have found that the intensification rate of a tropical cyclone (TC) simulated in high resolution numerical models is often insensitive to surface drag coefficient (CD) or surface friction. A new explanation to this finding has been provided in this study based on the hypothesis that although surface friction has dual opposite effects: negative direct frictional dissipation effect and indirect positive effect by strengthening and inwardly shifting eyewall updrafts/convection. We have demonstrated that the increased/reduced positive indirect effect of surface friction is roughly offset by the increased/reduced negative direct dissipation effect due to increased/reduced CD. As result, the intensification rate of the simulated TC is insensitive to CD (Figure 1). However, increased CD can result in earlier onset of the intensification stage through increasing frictional moisture convergence and Ekman pumping and thus moistening of the inner-core column of the TC vortex, but would lead to a weaker storm in the mature stage.

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Articles

Li and Wang (2021)

Li, T.-H., and Y. Wang, 2021: The role of boundary layer dynamics in tropical cyclone intensification. Part II: Sensitivity to initial vortex structure. J. Meteor. Soc. Japan, 99,
Special Edition on DYAMOND: The DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains
https://doi.org/10.2151/jmsj.2021-028.Early Online ReleaseGraphical Abstract

Plain Language Summary: Typhoons and hurricanes (collectively known as tropical cyclones) are one of the most destructive natural phenomena, and their prediction is an important task of weather and climate models. In this study, we evaluated nine global storm-resolving models, that is, models with high enough resolution to explicitly simulate the thunderstorms that make up the cyclone power engine, in their ability to simulate tropical cyclones. We found that the models are able to simulate cyclones more realistically than previous generations of global models. For example, unlike current-generation global models, the tested models are able to capture the cyclone eyewall and its extreme winds. But the models are not perfect, and continued work in improving the models is needed to exploit their full potential in tropical cyclone prediction.

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JMSJ, 2021, Vol. 99, No. 3 (June)

Articles: Special Edition on DYAMOND: The DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains

Judt et al. (2021)

Judt, F., D. Klocke, R. Rios-Berrios, B. Vanniere, F. Ziemen, L. Auger, J. Biercamp, C. Bretherton, X. Chen, P. Düben, C. Hohenegger, M. Khairoutdinov, C. Kodama, L. Kornblueh, S.-J. Lin, M. Nakano, P. Neumann, W. Putman, N. Röber, M. Roberts, M. Satoh, R. Shibuya, B. Stevens, P. L. Vidale, N. Wedi, and L. Zhou, 2021: Tropical cyclones in global storm-resolving models. J. Meteor. Soc. Japan, 99,
Special Edition on DYAMOND: The DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains
https://doi.org/10.2151/jmsj.2021-029.Early Online ReleaseGraphical Abstract

Plain Language Summary: Localized heavy rainfall events with 3-houly accumulated precipitation amounts larger than 200 mm are often observed in Japan. Such events are majorly brought from quasi-stationary band-shaped precipitation systems, named as “senjo-kousuitai” in Japanese. Senjo-kousuitai is defined as a band-shaped heavy rainfall area with the length of 50-300 km and the width of 20-50 km, produced by successively formed and developed convective cells, lining up to organize multi-cell clusters, and passing or stagnating at almost the same place for a few hours.

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Kobayashi et al. (2021)

Kobayashi T., M. Nomura, A. Adachi, S. Sugimoto, N. Takahashi, and H. Hirakuchi, 2021: Retrieval of attenuation profiles from the GPM dual-frequency radar observations. J. Meteor. Soc. Japan, 99,
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary
https://doi.org/10.2151/jmsj.2021-030.Early Online ReleaseGraphical Abstract

Plain Language Summary: A new method retrieving attenuation profiles using a Dual-Frequency Precipitation Radar equipped on the Global Precipitation Mission (GPM) is proposed. The method utilizes the differential frequency ratio (DFR), which is the difference in the measured reflectivity in the log scale between Ka and Ku bands. The range variations of relative values of differential attenuation between two frequencies are estimated and can be used for identifying hydrometeor types. Simulations indicate that estimated attenuation profiles agree with the shape of theoretical ones for rain, melted snow. The method was applied to identify rain and dry snow regions in the GPM measurements. High and low correlation coefficients between attenuated part of DFR and radar range were observed for rain and dry snow, respectively.

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Cheng and Suzuki (2021)

Cheng, C. T., and K. Suzuki, 2021: Size-resolved aerosol microphysics in a global nonhydrostatic atmospheric model: Model description and validation. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-031.Early Online ReleaseGraphical Abstract

Plain Language Summary: Particle size determines the aerosol transport and removal processes, as well as how aerosol interacts with clouds and climate. In this study, we develop a sectional aerosol scheme for Spectral Radiation-Transport Model for Aerosol Species (SPRINTARS-bin) which explicitly simulates the variations in size distributions due to microphysical processes. SPRINTARS-bin is implemented in NICAM (Nonhydrostatic ICosahedral Atmospheric Model) as an alternative to the original mass-based SPRINTARS-orig aerosol module. Both schemes are evaluated by comparing year-long simulation results to ground-based measurements and satellite observations to find that the sectional scheme with better representations of ultra-fine particles largely alleviates underestimates of the aerosol number concentration in the original scheme.

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Articles

Shibata and Lehmann (2020)

Cui, Y., Z. Ruan, M. Wei, F. Li, R. Ge, and Y. Huang, 2021: Vertical evolution of microphysical properties during snow events in middle latitudes of China observed by a C-band vertically pointing radar. J. Meteor. Soc. Japan, 99,
https://doi.org/10.2151/jmsj.2021-032.Early Online ReleaseGraphical Abstract

Plain Language Summary: The snow clouds were divided into upper generating cell (GC) and lower stratiform (St) regions according to their vertical structure. The growth of particle size and mass mainly occurred in the St regions. The increases of ice particle number concentration (N) were usually observed near −5°C accompanied by bimodal Doppler spectra, which might be caused by ice multiplication. The average ratios of the median N, median mass diameter (Dm), and ice water content (IWC) inside GCs to those outside GCs are 2, 1.3, and 2.5 respectively for shallow events, with 1.7, 1.2, and 2.3 respectively for deep events. These values were basically the same as those for the fall streaks (FSs), implying the importance of GCs to the enhanced ice growth subsequently found in FSs. The larger values of N, Dm, and IWC inside GCs could be related to the upward air motions inside GCs. The first Ze–IWC relationship suitable for snow clouds in the midlatitudes of China was also established.

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Articles

Yamaji et al. (2021)

Yamaji, M., T. Kubota, and M. K. Yamamoto, 2021: An approach to reliability characterization of GSMaP near-real-time precipitation product. J. Meteor. Soc. Japan, 99, Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary,
https://doi.org/10.2151/jmsj.2021-033.
Early Online ReleaseGraphical Abstract

Plain Language Summary: Reliability information of satellite precipitation products is required for various applications, such as agricultural monitoring, public health, and education, as well as weather monitoring and disaster prevention. This study confirms effectiveness for a reliability flag of the Global Satellite Mapping of Precipitation Near-Real-Time precipitation product (GSMaP_NRT), which is developed to characterize the reliability of GSMaP_NRT data “simply” and “qualitatively”.

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