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Emily M. Riley Dellaripa, Eric Maloney, and Susan C. van den Heever

simulation was initialized on 1200 UTC 30 October 2011 and run with 36 h of domainwide nudging to ERA-I. This second 4-km control simulation is referred to as “4Ctrl12” ( Table 1 ). For all of the control simulations, the time period with domainwide nudging is considered model spinup and not included in analysis. Starting on 0000 UTC 1 November (i.e., after domainwide nudging has ceased in all control simulations), lateral boundary nudging was applied to the seven outermost grid points with a 30-min time

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Simon P. de Szoeke, Eric D. Skyllingstad, Paquita Zuidema, and Arunchandra S. Chandra

capable of accelerating the air downward, forming a downdraft. Continued evaporative cooling and moistening by rain keeps the downdraft nearly saturated when it reaches the planetary boundary layer (BL), where it spreads horizontally along the surface in a cold pool ( Zipser 1977 ). Cold pools have become a topic of renewed fascination because of their potential role in assisting the shallow-to-deep convective transition (e.g., Rowe and Houze 2015 ) and to correct erroneous convective diurnal cycles

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Nick Guy and David P. Jorgensen

phenomena (e.g., El Niño–Southern Oscillation, North Atlantic Oscillation, Indian Ocean dipole); discussed further in Lau and Waliser (2005) and Zhang (2005) . Given the extensive impact of the MJO on global circulations, it is important to correctly simulate the MJO in forecast and climate models. However, current model simulations do not represent the MJO well ( Lin et al. 2006 ; Benedict and Randall 2009 ). This is due in part to an incomplete understanding of convective dynamics and

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Aurélie J. Moulin, James N. Moum, and Emily L. Shroyer

current profiler and the Chameleon turbulence profiler ( Moum et al. 1995 ). Table 1. Details of T -chain instruments. Fig . 2. Thermistor chain deployed from the bow of R/V Revelle during DYNAMO. The chain was outfitted with two CTDs and eight thermistors as listed in Table 1 . The ship maintained position and was oriented into a strong and relatively steady surface flow that brought undisturbed fluid past the bow-mounted sensor suite. Profilers tethered to the fantail are not well suited to

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Sue Chen, Maria Flatau, Tommy G. Jensen, Toshiaki Shinoda, Jerome Schmidt, Paul May, James Cummings, Ming Liu, Paul E. Ciesielski, Christopher W. Fairall, Ren-Chieh Lien, Dariusz B. Baranowski, Nan-Hsun Chi, Simon de Szoeke, and James Edson

increase in the boundary layer moisture near the central and eastern axis of the MJO convection and the development of westerly wind anomalies along the equator ( Wang and Xie 1998 ; Kemball-Cook and Wang 2001 ; Weare 2003 ; Maloney and Hartmann 2000 ; Sperber 2003 ; Seo and Kim 2003 ). More recent studies ( Tian et al. 2010 ; Benedict and Randall 2007 ) have shown the moisture distribution during the MJO cycle consists of large-scale alternating dry and moist anomalies. Results from Benedict

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Kunio Yoneyama, Chidong Zhang, and Charles N. Long

is the only large tropical ocean that is bounded by land in three directions. It is therefore the ocean that experiences the strongest influence of the monsoons. The monsoon circulation and the trade winds over the Indian Ocean induce unusually shallow thermocline in the middle of the basin, known as the Seychelles–Chagos thermocline ridge ( Vialard et al. 2009 ), and strong eastward surface current along the equator, the Wyrtki jet, which appears semiannually during the monsoon transition

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Hungjui Yu, Richard H. Johnson, Paul E. Ciesielski, and Hung-Chi Kuo

conceptual mesoscale process was proposed involving the nonlinear interaction between clouds, radiation, and surface processes, the so-called “diurnal dancing” of convective systems, to explain the near 2-day periodicity. In their scenario, despite diurnal radiative forcing, boundary layer (BL) recovery extends to a second day, likely due to the expanded stratiform clouds of MCSs, which impacts the timing of the next round of convection. The BL recovery for a future convective event over a given region

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

truncation of T1279, a reduced Gaussian grid (equivalent to 16-km global grid spacing), and 91 vertical levels (denoted as T1279L91). Persisted SST anomalies are used as the lower boundary condition. Forecasts from 12 to 240 h with an interval of 12 h initialized at 0000 and 1200 UTC from 1 October 2011 to 31 January 2012 were evaluated in this study. Table 2. List of operational forecast products. All forecasts were initialized daily at 0000 and 1200 UTC. The other ECMWF forecast component is the

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Simon P. de Szoeke and Eric D. Maloney

, https://doi.org/10.1175/JCLI-D-12-00074.1 . 10.1175/JCLI-D-12-00074.1 Sverdrup , H. U. , 1947 : Wind-driven currents in a baroclinic ocean; with application to the equatorial currents of the eastern Pacific . Proc. Natl. Acad. Sci. USA , 33 , 318 – 326 , https://doi.org/10.1073/pnas.33.11.318 . 10.1073/pnas.33.11.318 Wang , B. , and T. Li , 1994 : Convective interaction with boundary-layer dynamics in the development of a tropical intraseasonal system . J. Atmos. Sci. , 51 , 1386

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Samson M. Hagos, Zhe Feng, Casey D. Burleyson, Chun Zhao, Matus N. Martini, and Larry K. Berg

, rendering the intraseasonal modes unstable. This study aims to bridge the gap between current theoretical understanding of MJO processes on the one hand and evaluation and improvement of cumulus parameterizations on the other using data collected during the 2011 Atmospheric Radiation Measurement Program (ARM) MJO Investigation Experiment–Dynamics of the MJO (AMIE/DYNAMO) field campaign ( Yoneyama et al. 2013 ). We examine the contributions of model biases associated with the processes discussed above to

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