著者

YUKIMOTO Seiji KAWAI Hideaki KOSHIRO Tsuyoshi OSHIMA Naga YOSHIDA Kohei URAKAWA Shogo TSUJINO Hiroyuki DEUSHI Makoto TANAKA Taichu HOSAKA Masahiro YABU Shokichi YOSHIMURA Hiromasa SHINDO Eiki MIZUTA Ryo OBATA Atsushi ADACHI Yukimasa ISHII Masayoshi

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

pp.2019-051, (Released:2019-06-18)

被引用文献数

441

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The new Meteorological Research Institute Earth System Model version 2.0 (MRI-ESM2.0) has been developed based on previous models, MRI-CGCM3 and MRI-ESM1, which participated in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). These models underwent numerous improvements meant for highly accurate climate reproducibility. This paper describes model formulation updates and evaluates basic performance of its physical components. The new model has nominal horizontal resolutions of 100 km for atmosphere and ocean components, similar to the previous models. The atmospheric vertical resolution is 80 layers which is enhanced from 48 layers of its predecessor. Accumulation of various improvements concerning clouds, such as a new stratocumulus cloud scheme, led to remarkable reduction in errors in shortwave, longwave, and net radiation at the top of the atmosphere. The resulting errors are sufficiently small compared with those in the CMIP5 models. The improved radiation distribution brings the accurate meridional heat transport required for the ocean and contributes to a reduced surface air temperature (SAT) bias. MRI-ESM2.0 displays realistic reproduction of both mean climate and interannual variability. For instance, the stratospheric quasi-biennial oscillation can now be realistically expressed through the enhanced vertical resolution and introduction of non-orographic gravity wave drag parameterization. For the historical experiment, MRI-ESM2.0 reasonably reproduces global SAT change for recent decades; however, cooling in the 1950s through the 1960s and warming afterward are overestimated compared with observations. MRI-ESM2.0 has been improved in many aspects over the previous models, MRI-CGCM3/MRI-ESM1, and is expected to demonstrate superior performance in many experiments planned for CMIP6.

著者

NAOE Hiroaki MATSUMOTO Takanori UENO Keisuke MAKI Takashi DEUSHI Makoto TAKEUCHI Ayako

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

pp.2020-019, (Released:2020-02-03)

被引用文献数

1

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This study constructs a merged total column ozone (TCO) dataset using 20 available satellite Level 2 TCO (L2SAT) datasets over 40 years from 1978 to 2017. The individual 20 datasets and the merged TCO dataset are corrected against ground-based Dobson and Brewer spectrophotometer TCO (GD) measurements. Two bias correction methods are used: simple linear regression (SLR) as a function of time and multiple linear regression (MLR) as a function of time, solar zenith angle, and effective ozone temperature. All of the satellite datasets are consistent with GD within ±2-3%, except for some degraded data from the Total Ozone Mapping Spectrometer/Earth Probe during a period of degraded calibration and from the Ozone Mapping and Profiling Suite (OMPS) provided from NOAA at an early stage of measurements. OMPS data provided from NASA show fairly stable L2SAT-GD differences. The Global Ozone Monitoring Experiment/MetOp-A and -B datasets show abrupt changes of approximately 8 DU coincident with the change of retrieval algorithm. For the TCO merged datasets created by averaging all coincident data located within a grid cell from the 20 satellite-borne TCO datasets, the differences between corrected and uncorrected TCOs by MLR are generally positive at lower latitudes where the bias correction increases TCO because of low effective ozone temperature. In the trend analysis, the difference between corrected and uncorrected TCO trends by MLR shows clear seasonal and latitudinal dependency, whereas such seasonal and latitudinal dependency is lost by SLR. The root mean square difference of L2SAT-GD for the uncorrected merged datasets, 8.6 DU, is reduced to 8.4 DU after correction using SLR and MLR. Therefore, the empirically corrected merged TCO datasets that are converted into time-series homogenization with high temporal-resolution are suitable as a data source for trend analyses as well as assimilation for long-term reanalysis.

著者

KAJINO Mizuo DEUSHI Makoto SEKIYAMA Tsuyoshi Thomas OSHIMA Naga YUMIMOTO Keiya TANAKA Taichu Yasumichi CHING Joseph HASHIMOTO Akihiro YAMAMOTO Tetsuya IKEGAMI Masaaki KAMADA Akane MIYASHITA Makoto INOMATA Yayoi SHIMA Shin-ichiro TAKAMI Akinori SHIMIZU Atsushi HATAKEYAMA Shiro SADANAGA Yasuhiro IRIE Hitoshi ADACHI Kouji ZAIZEN Yuji IGARASHI Yasuhito UEDA Hiromasa MAKI Takashi MIKAMI Masao

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

pp.2019-020, (Released:2018-12-09)

被引用文献数

36

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Model performance of a regional-scale meteorology – chemistry model (NHM-Chem) has been evaluated for the consistent predictions of the chemical, physical, and optical properties of aerosols. These properties are essentially important for the accurate assessment of air quality and health hazards, contamination of land and ocean ecosystems, and regional climate changes due to aerosol-cloud-radiation interaction processes. Currently, three optional methods are available: the 5-category non-equilibrium, 3-category non-equilibrium, and bulk equilibrium methods. These three methods are suitable for the predictions of regional climate, air quality, and operational forecasts, respectively. In this paper, the simulated aerosol chemical, physical, and optical properties and their consistency were evaluated by using various observation data in East Asia. The simulated mass, size, and deposition of SO42- and NH4+ agreed well with the observations, whereas those of NO3-, sea-salt, and dust needed improvement. The simulated surface mass concentration (PM10 and PM2.5) and spherical extinction coefficient agreed well with the observations. The simulated aerosol optical thickness and dust extinction coefficient were significantly underestimated.

著者

KOSAKA Yuki KOBAYASHI Shinya HARADA Yayoi KOBAYASHI Chiaki NAOE Hiroaki YOSHIMOTO Koichi HARADA Masashi GOTO Naochika CHIBA Jotaro MIYAOKA Kengo SEKIGUCHI Ryohei DEUSHI Makoto KAMAHORI Hirotaka NAKAEGAWA Tosiyuki TANAKA Taichu Y. TOKUHIRO Takayuki SATO Yoshiaki MATSUSHITA Yasuhiro ONOGI Kazutoshi

出版者

公益社団法人 日本気象学会

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

pp.2024-004, (Released:2023-11-02)

被引用文献数

4

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The Japan Meteorological Agency (JMA) has developed the third Japanese global atmospheric reanalysis, the Japanese Reanalysis for Three Quarters of a Century (JRA-3Q). The objective of JRA-3Q is to improve quality in terms of issues identified in the previous Japanese 55-year Reanalysis (JRA-55) and to extend the reanalysis period further into the past. JRA-3Q is based on the TL479 version of the JMA global Numerical Weather Prediction (NWP) system as of December 2018 and uses results of developments in the operational NWP system, boundary conditions, and forcing fields achieved at JMA since JRA-55. It covers the period from September 1947, when Typhoon Kathleen brought severe flood damage to Japan, and uses rescued historical observations to extend its analyses backwards in time about 10 years earlier than JRA-55. This paper describes the data assimilation system, forecast model, observations, boundary conditions, and forcing fields used to produce JRA-3Q as well as the basic characteristics of the JRA-3Q product. The initial quality evaluation revealed major improvements from JRA-55 in the global energy budget and representation of tropical cyclones (TCs). One of the major problems in JRA-55—global energy imbalance with excess upward net energy flux at the top of the atmosphere and at the surface—has been significantly reduced in JRA-3Q. Another problem—a trend of artificial weakening of TCs—has been resolved through the use of a method that generates TC bogus based on the JMA operational system. There remain several problems such that volcanic-induced stratospheric warming is smaller than expected. This paper discusses the causes of such problems and possible solutions in future reanalyses.