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Jian Ling, Peter Bauer, Peter Bechtold, Anton Beljaars, Richard Forbes, Frederic Vitart, Marcela Ulate, and Chidong Zhang

operational analysis using a relaxation time scale of 6 h. There are 91 vertical levels in the humidity relaxation experiment in order to better match the humidity profiles in the operational analysis. Humidity relaxation or nudging has been shown to be an effective way to make numerical simulations of the MJO closer to observations in regional models (e.g., Hagos et al. 2011 ), but relaxation (of a single field) may have a detrimental effect on the overall dynamical and thermodynamical balance of the

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Tim Li, Chongbo Zhao, Pang-chi Hsu, and Tomoe Nasuno

, H.-H. , and M. Lee , 2005 : Topographic effects on the eastward propagation and initiation of the Madden–Julian oscillation . J. Climate , 18 , 795 – 809 , doi: 10.1175/JCLI-3292.1 . Hsu , H.-H. , B. J. Hoskins , and F.-F. Jin , 1990 : The 1985/86 intraseasonal oscillation and the role of the extratropics . J. Atmos. Sci. , 47 , 823 – 839 , doi: 10.1175/1520-0469(1990)047<0823:TIOATR>2.0.CO;2 . Hsu , P.-C. , and T. Li , 2011 : Interactions between boreal summer

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H. Bellenger, R. Wilson, J. L. Davison, J. P. Duvel, W. Xu, F. Lott, and M. Katsumata

) that formed during the different experiments are indicated by the correspondingly colored dotted paths (see section 2d for details). Details on the number and frequencies of launches together with the type of radiosondes are given in Table 1 . In the cloud-free free atmosphere, turbulence occurs intermittently in the form of isolated and horizontally elongated patches (e.g., Wilson et al. 2005 ). The resulting effects of these intense and localized mixing events are difficult to evaluate

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Simon P. de Szoeke, James B. Edson, June R. Marion, Christopher W. Fairall, and Ludovic Bariteau

weaker variability than OLR on shorter time scales. The NCEP SST used by ERA-I in 1992/93 is only weekly, so for a fairer comparison to the daily SST in DYNAMO, we use NOAA Optimally Interpolated version 2 daily SST ( Reynolds et al. 2007 ) at the TOGA COARE location in Fig. 4d . Local time series show the local effects of daily and intraseasonal variability on OLR and SST ( Fig. 4 ). The magnitude of the vector formed from the first two PCs is about 1.5 standard deviations for most of DYNAMO as

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Kunio Yoneyama, Chidong Zhang, and Charles N. Long

a 0.25-m vertical resolution and extremely high frequency (10 Hz). Vertically profiling wire walkers ( Pinkel et al. 2011 ), each equipped with temperature–pressure or CTD sensors, were deployed during leg 4 to measure the upper-ocean structure without ship effects in the top 20 m every 5 min and in the top 200 m every 20 min. Surface and subsurface moorings ( Fig. 5 ) were deployed along 78.5°E. Surface and subsurface moorings were deployed at 9.75°S, 1.5°S, and 0° during the IOP by R

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George N. Kiladis, Juliana Dias, Katherine H. Straub, Matthew C. Wheeler, Stefan N. Tulich, Kazuyoshi Kikuchi, Klaus M. Weickmann, and Michael J. Ventrice

, which are present despite the lack of accompanying coherent eastward-propagating signals in the unfiltered fields. This is likely due in part due to the spectral ringing effects of the intraseasonal filtering with the imprint of the large amplitude March MJO4 event extending back in time. In all cases these signals would lead to the classification of MJO4 as a successive event, also inferring that late January event should be classified as an MJO. The indices all capture the timing of the onset of

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Weixin Xu and Steven A. Rutledge

or nonlinear, MCS or sub-MCS) have not been quantified. Convective organization has important effects on heating distributions, momentum transport, and surface fluxes. For example, squall lines accompanied by extensive stratiform precipitation have very different heating profiles from convective-only systems, as the corresponding latent heating profiles for the convective and stratiform components are distinctly different ( Johnson 1984 ; Houze 1989 ; Tao et al. 1993 ). Previous studies have

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Xiouhua Fu, Wanqiu Wang, June-Yi Lee, Bin Wang, Kazuyoshi Kikuchi, Jingwei Xu, Juan Li, and Scott Weaver

with enhanced convection (minus OLR anomaly >30 W m −2 ) scattered around ( Fig. 5a ). Regional SLP is also systematically reduced ( Fig. 6a ). On day 15, the convective anomaly over the positive SST anomaly continues to enhance and become organized ( Fig. 5b ). A Kelvin–Rossby wave couplet is excited with two cyclonic Rossby wave–like disturbances straddling the equatorial western Indian Ocean along with the Kelvin wave response manifesting as an eastward-extended tongue of low SLP and easterly

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Jun-Ichi Yano and Joseph J. Tribbia

manifestation of modon dynamics. A preliminary but positive result is already found by the scale analysis presented in appendix A . The analysis in the Hough-function space (cf. Žagar and Franzke 2015 ) would likely to be helpful for further elucidating the nonlinear balance in a more lucid manner. For a lucid theoretical demonstration, various higher-order effects are neglected in the present study. An obvious next step is to move to higher-order analyses in asymptotic expansion in the MJO problem. Such

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Weixin Xu, Steven A. Rutledge, Courtney Schumacher, and Masaki Katsumata

entrainment of cooler subsurface water to the ocean surface owing to shear driven mixing, and enhanced heat fluxes out of the ocean ( Moum et al. 2014 ). On the regional scale, Gan and Revelle experienced higher SSTs (especially during phases 8, 1, and 2) and experienced greater SST variability due to MJO passage compared to the trends at the Mirai . Fig . 5. Satellite-estimated daily mean SST (°C; TMI/AMSR-E) composited by WH MJO phase (phases 1–8) during October–December 2011. 4. Observations from

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