Search Results 1-20 of 218

  • Impact of Latent Heat Flux Modifications on the Reproduction of a Madden–Julian Oscillation Event during the 2015 Pre-YMC Campaign Using a Global Cloud-System-Resolving Model

    Matsugishi Shuhei , Miura Hiroaki , Nasuno Tomoe , Satoh Masaki

    … <p>We show that a modification to the latent heat flux (LHF) formulation in Non-hydrostatic Icosahedral Atmospheric Model (NICAM) impacts the representation of a Madden–Julian oscillation (MJO) event during the Pre-Years of the Maritime Continent (Pre-YMC) field campaign in 2015. … Consequently, the MJO signal weakens when it passes over the Maritime Continent (MC). …

    SOLA 16A(Special_Edition), 12-18, 2020


  • Revisiting the Impact of Stochastic Multicloud Model on the MJO Using Low-Resolution ECHAM6.3 Atmosphere Model

    MA Libin , PETERS Karsten , WANG Bin , LI Juan

    … <p> Based on the preceding work, the influence of the stochastic multicloud model (SMCM) on the Madden–Julian oscillation (MJO) in the state-of-the-art ECHAM6.3 atmospheric general circulation model (AGCM) is further evaluated. … Lag–longitude correlation maps of surface precipitation in the eastern Indian Ocean and West Pacific Ocean confirm the previously discovered improved representation of the MJO in the modified ECHAM6.3 model compared with the standard configuration. …

    Journal of the Meteorological Society of Japan. Ser. II 97(5), 977-993, 2019


  • Resolution Dependencies of Tropical Convection in a Global Cloud/Cloud-System Resolving Model

    MIYAKAWA Tomoki , MIURA Hiroaki

    … The simulations are targeted on the 2nd Madden-Julian oscillation (MJO) event observed in the CINDY2011/DYNAMO field campaign. … However, the amplitude of the anomalous MJO circulation was considerably smaller in the 3.5-km simulation. …

    Journal of the Meteorological Society of Japan. Ser. II 97(3), 745-756, 2019


  • The evolution and intensification of Cyclone Pam (2015) and resulting strong winds over the southern Pacific islands

    Takemi Tetsuya

    … Cyclone Pam was originated from an active convective region in the Madden-Julian oscillation (MJO) and evolved from convective clouds into a tropical cyclone. … The numerical simulations successfully reproduced the eastward propagation of the MJO and the aggregation of convective clouds that transformed to a tropical cyclone. …

    Journal of Wind Engineering & Industrial Aerodynamics (182), 27-36, 2018-11


  • New Observational Metrics of Convective Self-Aggregation: Methodology and a Case Study

    KADOYA Toshiki , MASUNAGA Hirohiko

    … The proposed index is applied to infrared imagery from the Meteosat-7 satellite and is assessed with sounding-array measurements in the tropics from Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011)/Dynamics of the Madden Julian Oscillation (MJO) (DYNAMO)/Atmospheric Radiation Measurement (ARM) MJO Investigation Experiment (AMIE). …

    Journal of the Meteorological Society of Japan. Ser. II 96(6), 535-548, 2018


  • Evolution of Mesoscale Convective System Properties as Derived from Himawari-8 High Resolution Data Analyses

    PUTRI Nurfiena Sagita , IWABUCHI Hironobu , HAYASAKA Tadahiro

    … The first case over Java Island showed a land-originating MCS in the boreal winter, which coincided with a wet phase of Madden-Julian Oscillation (MJO) over the Maritime Continent. …

    Journal of the Meteorological Society of Japan. Ser. II 96B(0), 239-250, 2018


  • Outcomes and challenges of global high-resolution non-hydrostatic atmospheric simulations using the K computer

    Satoh Masaki , Tomita Hirofumi , Yashiro Hisashi , Kajikawa Yoshiyuki , Miyamoto Yoshiaki , Yamaura Tsuyoshi , Miyakawa Tomoki , Nakano Masuo , Kodama Chihiro , Noda Akira T. , Nasuno Tomoe , Yamada Yohei , Fukutomi Yoshiki

    … Before the K computer era, NICAM was used to demonstrate realistic simulations of intra-seasonal oscillations including the Madden-Julian oscillation (MJO), merely as a case study approach. … Thanks to the big leap in computational performance of the K computer, we could greatly increase the number of cases of MJO events for numerical simulations, in addition to integrating time and horizontal resolution. …

    Progress in Earth and Planetary Science (4), 13, 2017-04-28


  • Stratospheric tropical warming event and its impact on the polar and tropical troposphere

    Kodera Kunihiko , Eguchi Nawo , Mukougawa Hitoshi , Nasuno Tomoe , Hirooka Toshihiko

    … In the troposphere, an abrupt termination of a Madden–Julian Oscillation (MJO) event occurred following the static stability increase in the TTL. …

    Atmospheric Chemistry and Physics 17(1), 615-625, 2017-01-12


  • Why Torrential Rain Occurs on the Western Coast of Sumatra Island at the Leading Edge of the MJO Westerly Wind Bursts

    Wu Peiming , Ardiansyah Dodi , Yokoi Satoru , Mori Shuichi , Syamsudin Fadli , Yoneyama Kunio

    … <p>This study examined the impact of an active phase of the Madden–Julian Oscillation (MJO) on a torrential rain event that occurred on the western coast of Sumatra Island on 12 December 2015, using surface meteorological observations, meteorological radar observations, and balloon sounding data obtained from the pre-Years of the Maritime Continent field campaign. … Strong MJO activity took place in mid-December 2015 into January 2016. …

    SOLA 13(0), 36-40, 2017


  • Evaluation of the Near Real-Time Forecasts Using a Global Nonhydrostatic Model during the CINDY2011/DYNAMO

    NASUNO Tomoe , KIKUCHI Kazuyoshi , NAKANO Masuo , YAMADA Yohei , IKEDA Mikiko , TANIGUCHI Hiroshi

    … </p><p> The simulated precipitation time series fairly represented the evolution and propagation of the observed Madden-Julian Oscillation (MJO) events, although a 30 % overprediction of precipitation over the IO domain (60–90°E, 10°S–10°N) was found on average. … Despite these mean biases, temporal variations of the moisture and zonal wind profiles including the MJO events were reasonably simulated.</p><p> Using the forecast data the moisture and energy budgets during the IOP were investigated. …

    Journal of the Meteorological Society of Japan. Ser. II 95(6), 345-368, 2017


  • Seasonal environmental characteristics for the tropical cyclone genesis in the Indian Ocean during the CINDY2011/DYNAMO field experiment

    Tsuboi Aya , Takemi Tetsuya , Yoneyama Kunio

    … This study investigated the seasonal environmental characteristics for tropical cyclone genesis (TCG) over the Indian Ocean during the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 and the Dynamics of the Madden-Julian Oscillation (MJO) (CINDY2011/DYNAMO) field experiment and compare them with long-term climatological features. …

    Atmosphere 7(5), 2016-05-12


  • Precipitation microstructure in different Madden-Julian Oscillation phases over Sumatra

    Marzuki , Hashiguchi Hiroyuki , Kozu Toshiaki , Shimomai Toyoshi , Shibagaki Yoshiaki , Takahashi Yukihiro

    … Precipitation types are classified using 1.3-GHz wind profiler observation, and are partitioned according to active and inactive convective phases of Madden-Julian Oscillation (MJO). … Assessment of cloud effective radius of the Moderate Resolution Imaging Spectroradiometer (MODIS) data also shows a slight difference in the cloud droplet between the active and the inactive MJO phases. … Different convective storms in different MJO phases lead to different DSD characteristics and Z- R relationships. …

    Atmospheric Research (168), 121-138, 2016-02-01


  • Intraseasonal Variability of δ<sup>18</sup>O of Precipitation over the Indonesian Maritime Continent Related to the Madden–Julian Oscillation

    Belgaman Halda A. , Ichiyanagi Kimpei , Tanoue Masahiro , Suwarman Rusmawan , Yoshimura Kei , Mori Shuichi , Kurita Naoyuki , Yamanaka Manabu D. , Syamsudin Fadli

    … <p>Intraseasonal variability of precipitation over the Indonesian Maritime Continent (IMC) is related mainly to the Madden–Julian oscillation (MJO). … The MJO enhances and suppresses precipitation around the IMC according to its phase. … This study examined the relationship between the MJO and the stable isotope of the precipitation over the IMC. …

    SOLA 12(0), 192-197, 2016


  • Methods to Evaluate Prediction Skill in the Madden-Julian Oscillation Phase Space

    ICHIKAWA Yuiko , INATSU Masaru

    …  Indices of prediction skill over the Madden-Julian oscillation (MJO) phase space are examined with reanalysis and forecast data provided by the Japan Meteorological Agency (JMA). … Conventionally, the RMSE and ACC have been used, although this approach misses information on the model bias for MJO events. … Moreover, the ACC is not suitable for models in which the MJO signal tends to damp in some phases, because the ACC strongly depends on the MJO amplitude. …

    Journal of the Meteorological Society of Japan. Ser. II 94(3), 257-267, 2016


  • Observational Research on Stable Isotopes in Precipitation over Indonesian Maritime Continent  [in Japanese]

    BELGAMAN Halda A. , ICHIYANAGI Kimpei , TANOUE Masahiro , SUWARMAN Rusmawan

    インドネシア海大陸(IMC)は熱帯地方にあって,多数の島と海から構成されている。この多数の陸と海の配置は,独特の天気や気候特徴を形成している。IMCでは,降水の安定同位体の変動を調べる様々な水文気象学的な研究が行われている。降水の安定同位体比(δ<sup>18</sup>O, δD)は,大気過程(例えば,降水量,気温,水循環)に関する情報を得るために使われる。国際原子力機構 …

    Journal of Japanese Association of Hydrological Sciences 46(1), 7-28, 2016


  • Propagation Processes of the Madden-Julian Oscillation Synchronized with an Extratropical Cyclone Observed in Late October during CINDY2011

    Moteki Qoosaku

    … The eastward propagation processes of the Madden-Julian oscillation (MJO) was examined from a case study of the first MJO generated in late October during CINDY2011. … The eastward propagation of the MJO was found to be synchronized with an extratropical cyclone in the Southern Hemisphere. … The synchronized propagation of the MJO and the extratrpical cyclone was associated with the ridge and trough pair meridionally extending between 30°S∼15°N. …

    SOLA 12(0), 60-64, 2016


  • Ocean Response to CINDY/DYNAMO MJOs in Air-Sea-Coupled COAMPS

    JENSEN Tommy G. , SHINODA Toshiaki , CHEN Sue , FLATAU Maria

    …  The response of the ocean to three Madden-Julian Oscillation (MJO) events during the fall of 2011 is simulated by the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) in a fully coupled mode with high resolution in the atmosphere and ocean. …

    Journal of the Meteorological Society of Japan. Ser. II 93A(0), 157-178, 2015


  • Seasonal Onset of the Madden-Julian Oscillation and its Relation to the Southeastern Indian Ocean Cooling

    SEIKI Ayako , NAGURA Motoki , HASEGAWA Takuya , YONEYAMA Kunio

    …  The relation among sea surface temperature (SST) cooling in the southeastern Indian Ocean (SEIO), oceanic Rossby waves, and the seasonal onset of the Madden-Julian oscillation (MJO) is examined for the period 1993-2012. … Convection related to the MJO events during boreal winter propagates from the Indian Ocean to the Pacific only after SEIO cooling is terminated. … An understanding of SEIO upper-ocean processes can contribute to predict the seasonal onset of an MJO sequence. …

    Journal of the Meteorological Society of Japan. Ser. II 93A(0), 139-156, 2015


  • An Ensemble Hindcast of the Madden-Julian Oscillation during the CINDY2011/DYNAMO Field Campaign and Influence of Seasonal Variation of Sea Surface Temperature

    MIURA Hiroaki , SUEMATSU Tamaki , NASUNO Tomoe

    … When sea surface temperature (SST) with a realistic time evolution is prescribed, not only the first but also the second Madden-Julian oscillation (MJO) event observed during the CINDY2011/DYNAMO period emerges in the ensemble mean, although the signal of the second MJO is unsatisfactory in each member. …

    Journal of the Meteorological Society of Japan. Ser. II 93A(0), 115-137, 2015


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