JMSJ Highlights

Each year, a range of material is derived from JMSJ's articles - from Editors' Highlights to press releases and more. We present them here.

JMSJ Editor's Highlight (7 Mar. 2022)

• Ishioka, K., N. Yamamoto, and M. Fujita, 2022: A formulation of a three-dimensional spectral model for the primitive equations. J. Meteor. Soc. Japan, 100,
  https://doi.org/10.2151/jmsj.2022-022
  Early Online Release   Graphical Abstract
  

  

  A formulation of a three-dimensional spectral model based on the primitive equations is proposed. In this formulation, the Legendre polynomial expansion is used for the vertical discretization. By performing several calculations with different vertical degrees of freedom, a characteristic property of the spectral method is observed in which the error of the numerical solution decreases rapidly when the number of vertical degrees of freedom is increased. [click here]

  
  

Author's Article Summary (6 Dec. 2021)   The document at NOTE Homepage (in Japanese)

• Ito, K., 2022: Bias in near-real-time global sea surface temperature analysis of Japan Meteorological Agency associated with tropical cyclone passages in western North Pacific. J. Meteor. Soc. Japan, 100,
  https://doi.org/10.2151/jmsj.2022-016.
  Early Online Release   Graphical Abstract

  

  The near-real-time merged satellite and in-situ data global sea surface temperature (SST) of the Japan Meteorological Agency (hereafter, R-MGD) is subjected to the exceeding filtering of short-time-scale fluctuations. Therefore, the rapid SST change due to the passage of tropical cyclones (TCs) causes biases. The issue can be alleviated by putting more weight on the observations within 72 h.

Author's Article Summary (18 Apr. 2021)   The document at NIES Homepage (in Japanese)

• 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, 287-308.
  https://doi.org/10.2151/jmsj.2021-014
  Graphical Abstract
  

  

  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.

Author's Article Summary (19 Feb. 2021)   The document at The University of Tokyo/AORI Homepage (in Japanese)

• Oizumi, T., K. Saito, L. Duc, and J. Ito, 2020: Ultra-high resolution numerical weather prediction with a large domain using the K computer. Part 2: The case of the Hiroshima heavy rainfall event on August 2014 and dependency of simulated convective cells on model resolutions. J. Meteor. Soc. Japan, 98, 1163-1182.
  https://doi.org/10.2151/jmsj.2020-060
  Graphical Abstract
  

  

  This study conducts the Ultra-high-resolution (5-km to 250-m grid spacing) numerical weather prediction (NWP) experiments and investigates the impacts of model resolutions on the Hiroshima heavy rain event in August 2014. The results show that the finer resolution model well reproduces the torrential rain event and the simulated convective cores (CCs) tend to converge when the resolution goes beyond 500 m.

JMSJ Editor's Highlight (19 Jan. 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, 309-337.
  https://doi.org/10.2151/jmsj.2021-015
  Graphical Abstract
  

  

  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.

JMSJ Editor's Highlight (12 Jan. 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, 205-237.
  https://doi.org/10.2151/jmsj.2021-011
  Graphical Abstract
  

  

  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).

  [click here]
  

Author's Article Summary (23 Sep. 2020)   The document at JAXA/EORC Homepage (in Japanese)

• Yamaji, M., H. G. Takahashi, T. Kubota, R. Oki, A. Hamada, and Y. N. Takayabu, 2020: 4-year climatology of global drop size distribution and its seasonal variability observed by spaceborne Dual-frequency Precipitation Radar. J. Meteor. Soc. Japan, 98, 755-773.
  https://doi.org/10.2151/jmsj.2020-038
  Graphical Abstract
  

  

  Plain Language Summary: Global-scale spatial distributions of rainfall drop size (mean diameter; Dm) are newly obtained by using 4-year accumulated products from the spaceborne precipitation radar. Relationship between Dm and precipitation rate is not a simple one-to-one relationship. 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 of the dominant precipitation systems.

Press Release (25 Aug. 2020)   The press release document from MRI/JMA (in Japanese)

• Yamaguchi, M., and S. Maeda, 2020: Increase in the number of tropical cyclones approaching Tokyo since 1980. J. Meteor. Soc. Japan, 98, 775-786.
  https://doi.org/10.2151/jmsj.2020-039 Graphical Abstract
  

  

  This study investigated whether tropical cyclones (TCs) approaching Tokyo have changed in terms of number and environmental conditions using observational and reanalysis data during the geostationary satellite era (1980-2019). The number of TCs approaching the southern coast of Japan, including Tokyo, has increased over the last 40 years. The environmental conditions for TC development have become more favorable, with warmer sea surface temperature, less vertical wind shear, and more moisture in the atmosphere. In addition, the translation speed of TCs has decreased, which indicates a longer influence time.

JMSJ Editor's Highlight (13 Jul. 2020)

• Kawabata, Y., and M. Yamaguchi, 2020: Probability ellipse for tropical cyclone track forecasts with multiple ensembles. J. Meteor. Soc. Japan, 98,821-833.
  https://doi.org/10.2151/jmsj.2020-042   Graphical Abstract
  

  

  The effectiveness of the probability ellipse for tropical cyclone (TC) track forecasts is investigated with multiple ensembles from the Japan Meteorological Agency (JMA), the European Centre for Medium-Range Weather Forecasts (ECMWF), the U.S. National Centers for Environmental Prediction (NCEP), and the Met Office in the United Kingdom (UKMO), for all TCs from 2016 to 2018. The multiple ensembles composed of these four global ensembles are capable of predicting the situation-dependent uncertainties of TC track forecasts appropriately in both the along-track and cross-track directions. [click here]

JMSJ Editor's Highlight (5 Mar. 2020)

• Stevens, B., C. Acquistapace, A. Hansen, R. Heinze, C. Klinger, D. Klocke, H. Rybka, W. Schubotz, J. Windmiller, P. Adamidis, I. Arka, V. Barlakas, J. Biercamp, M. Brueck, S. Brune, S. A. Buehler, U. Burkhardt, G. Cioni, M. Costa-Surós, S. Crewell, T. Crüger, H. Deneke, P. Friederichs, C. C. Henken, C. Hohenegger, M. Jacob, F. Jakub, N. Kalthoff, M. Köhler, T. W. van Laar, P. Li, U. Löhnert, A. Macke, N. Madenach, B. Mayer, C. Nam, A. K. Naumann, K. Peters, S. Poll, J. Quaas, N. Röber, N. Rochetin, L. Scheck, V. Schemann, S. Schnitt, A. Seifert, F. Senf, M. Shapkalijevski, C. Simmer, S. Singh, O. Sourdeval, D. Spickermann, J. Strandgren, O. Tessiot, N. Vercauteren, J. Vial, A. Voigt, and G. Zängl, 2020: The added value of large-eddy and storm-resolving models for simulating clouds and precipitation. J. Meteor. Soc. Japan, 98, 395-435.
  Special Edition on DYAMOND: The DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains
  https://doi.org/10.2151/jmsj.2020-021  Graphical Abstract
  

  

  This study investigates, if atmospheric models with horizontal resolutions of 100 m to 2 km are able to better simulate key features, like clouds and precipitation, of the climate system than currently used models employing much coarser resolution and parameterized convection. Precipitation characteristics are much more realistic in the simulations with explicitly convection, already at kilometer resolutions. Increasing resolution to hectometer scales improves the simulation of precipitation only modestly, but substantially improves the simulation of clouds. The results suggest that new climate models, which explicitly resolve convection and the interaction with its environment, offer exciting opportunities to learn about the climate system. [click here]

JMSJ Editor's Highlight (4 Jan. 2020)

• Takemura, K., and H. Mukougawa, 2020: Dynamical relationship between quasi-stationary Rossby wave propagation along the Asian jet and Pacific-Japan pattern in boreal summer. J. Meteor. Soc. Japan, 98, 169-187.
  https://doi.org/10.2151/jmsj.2020-010   Graphical Abstract
  

  

  To reveal a new possible process linking the quasi-stationary Rossby wave propagation over Eurasia along the Asian jet and the Pacific-Japan (PJ) pattern through the Rossby wave breaking (RWB) east of Japan during boreal summer, this study conducts a lag composite analysis of the past 44 RWB events. The results of this paper show that the quasi-stationary Rossby wave propagation along the Asian jet can excite the PJ pattern, through high potential vorticity (PV) intrusion toward the subtropical western North Pacific associated with the RWB and the consequent enhanced convection over the region. [click here]

JMSJ Editor's Highlight (11 Dec. 2019)

• Tsuyuki, T., 2019: Ensemble Kalman filtering based on potential vorticity for atmospheric multi-scale data assimilation. J. Meteor. Soc. Japan, 97, 1191-1210.
  https://doi.org/10.2151/jmsj.2019-067   Graphical Abstract
  

  

  A multi-scale data assimilation method for the ensemble Kalman filter (EnKF) is proposed and its performance is demonstrated using a shallow water model. The method is based on the conservation and invertibility of potential vorticity. It suppresses spurious error correlations between the balanced and unbalanced parts of dynamical state variables and makes it possible to appropriately address the balance issue of covariance localization. [click here]

JMSJ Editor's Highlight (09 Aug. 2019)

• Yukimoto, S., H. Kawai, T. Koshiro, N. Oshima, K. Yoshida, S. Urakawa, H. Tsujino, M. Deushi, T. Tanaka, M. Hosaka, S. Yabu, H. Yoshimura, E. Shindo, R. Mizuta, A. Obata, Y. Adachi, and M. Ishii, 2019: The Meteorological Research Institute Earth System Model version 2.0, MRI-ESM2.0: Description and basic evaluation of the physical component. J. Meteor. Soc. Japan, 97,931-965.
  https://doi.org/10.2151/jmsj.2019-051   Graphical Abstract
  

  

  A new earth system model MRI-ESM 2.0 was developed at the Meteorological Research Institute. As a result of enhancement of the atmospheric vertical resolution and various improvements for the cloud scheme, the aerosol model, and the ocean model, the performance in present-day climate reproduction has significantly improved in many aspects compared to the former model MRI-CGCM3. Root-meansquare- error (RMSE) of the shortwave radiation distribution at the top of the atmosphere reduced by about 42% compared to MRI-CGCM3 (Figure 1). Performance is also improved in expressing climate change and variability. For example, the observed global mean surface temperature change from the mid-19th century to the present is reproduced quite well. The stratospheric quasi biennial oscillation is now represented realistically. [click here]

JMSJ Editor's Highlight (10 Jun. 2019)

• Liu, B., C. Zhu, J. Su, S. Ma, and K. Xu, 2019: Record-breaking northward shift of the western North Pacific Subtropical High in July 2018. J. Meteor. Soc. Japan, 97, 913-925.
  Special Edition on Extreme Rainfall Events in 2017 and 2018
  https://doi.org/10.2151/jmsj.2019-047   Graphical Abstract
  

  

  The northward shift of the western North Pacific Subtropical High (WNPSH) in July 2018 broke the historical record since 1958. The present work attributes the extreme WNPSH anomaly to the strongest positive tri-pole pattern of sea surface temperature anomaly (SSTA) in the North Atlantic. This SSTA could induce an eastward propagating wave-train over the Eurasian Continent and enhance the atmospheric diabatic heating over the eastern Tibetan Plateau to cause the extreme northward shift of the WNPSH, finally leading to the extreme heat waves and casualties across Northeast Asia (NEA), especially over the southern Japan. [click here]

Press Release (13 Mar. 2019)

• Watanabe, S., M. Fujita, S. Kawazoe, S. Sugimoto, Y. Okada, R. Mizuta, and M. Ishii, 2019: Frequency change of clear-air turbulence over the North Pacific under 2 K global warming - Ensemble projections using a 60-km atmospheric general circulation model. J. Meteor. Soc. Japan, 97, 757-771.
  https://doi.org/10.2151/jmsj.2019-038   Graphical Abstract
  

  

  Global warming may influence geographical distributions of clear-air turbulence (CAT) hazardous for aircrafts. This study addresses frequency change of CAT over the North Pacific under 2 K global warming based on the database for Policy Decision making for Future climate change (d4PDF; http://www.miroc-gcm.jp/~pub/d4PDF/index_en.html). The CAT broadly decreases in the midlatitude central to western North Pacific along with the south side of its present-day high-frequency band extending from Japan to the eastern North Pacific. Meanwhile, large relative increases are found outside the band, implying an increased risk of CAT encounters. These changes depend on season, CAT indices, and uncertainties in future warming patterns of sea surface temperature projected by climate models. [click here for the press release from JAMSTEC (in Japanese)]

JMSJ Editor's Highlight (1 Feb. 2019)

• Ose, T., 2019: Characteristics of future changes in summertime East Asian monthly precipitation in MRI-AGCM global warming experiments. J. Meteor. Soc. Japan, 97, 317-335.
  https://doi.org/10.2151/jmsj.2019-018   Graphical Abstract
  

  

  Future changes in monthly June-to-August precipitation over East Asia are interpreted through the analysis based on a theoretical concept of the Baiu rain-band formation (Figure 1). The analysis is performed on the global warming experiments during the end period of 21st century under the RCP8.5 scenario using the high-resolution Meteorological Research Institute Atmospheric Global Circulation Models (MRI-AGCM3.2H with 60 km mesh). The results are potentially valuable for interpreting the output of other global warming simulations. [click here]