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Richard H. Johnson and Paul E. Ciesielski

boundary layer modification by convective clouds and precipitation. The challenge extends well beyond individual clouds to organized convective systems across a wide span of time scales, from mesoscale convective systems to equatorial waves to the Madden–Julian oscillation (MJO). The recent Dynamics of the MJO (DYNAMO) 1 field campaign ( Yoneyama et al. 2013 ; Zhang et al. 2013 ) affords a unique opportunity to investigate the multiscale variability of the boundary layer under a wide range of

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Matthew A. Janiga and Chidong Zhang

contributions of different physical processes and cloud types to Q 1 and Q 2 . The total large-scale advective tendencies of potential temperature θ and water vapor q υ are Here, is the vector wind and w is the vertical velocity. Overbars denote horizontal averages over the array. As in Varble et al. (2011) and Fridlind et al. (2012) , model horizontal winds are nudged to observations at a 2-h time scale, which is sufficient to allow for the development of mesoscale circulations ( Xu and

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Walter M. Hannah, Brian E. Mapes, and Gregory S. Elsaesser

column temperature variations. For these reasons, here we confine ourselves to the relatively straightforward business of the moisture budget at 0.25° and 6-hourly scales. 3. Data sources The analysis reported here utilized several data sources. Gridded humidity and wind data for budget calculations are taken from the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis and also from the CSU interpolated analysis of the DYNAMO large-scale sounding array ( Johnson and

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

populations and environmental conditions, which were shown to be consistent with the so-called recharge–discharge process ( Bladé and Hartmann 1993 ; Hu and Randall 1994 ; Kemball-Cook and Weare 2001 ). The precipitating cloud population consists of shallow isolated convective cells in suppressed phases, primarily isolated deep convective cells two phases prior to MJO onset, deep organized mesoscale convective systems (MCSs) in active MJO phases, and stratiform-dominant systems in decaying phases

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Richard H. Johnson, Paul E. Ciesielski, James H. Ruppert Jr., and Masaki Katsumata

on Colombo soundings ( Ciesielski et al. 2014b ). Blockage of the low-level flow by the island terrain frequently disrupts the winds at Colombo below about 2 km. This local effect is aliased onto larger scales and impairs computations of divergence over the NSA. The procedure developed by Ciesielski et al. (2014b) mitigates the impacts of Sri Lanka flow blocking on budgets over the NSA by using European Centre for Medium-Range Weather Forecasts (ECMWF) Operational Analysis (OA) data away from

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Rachel C. Zelinsky, Chidong Zhang, and Chuntao Liu

Houze 2015 ). In the local discharge–recharge process hypothesis, shallow convection begins to moisten and heat the environment during the suppressed phase; eventually the environment becomes sufficiently moist to support deep convection in the active phase of the MJO ( Xu and Rutledge 2015 ). Despite the observed importance of the MJO to the weather–climate system, most global climate models (GCM) are unable to reliably forecast or reproduce the MJO ( Hung et al. 2013 ; Jiang et al. 2015 ). This

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Weixin Xu and Steven A. Rutledge

studies first pointed out the importance of cloud clusters at the scale of hundreds of kilometers [or mesoscale convective systems (MCSs)] in the MJO disturbance. Cloud populations, morphology, precipitation evolution, and heating profiles over the western Pacific Ocean were extensively examined using data collected during the 1992/93 Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE; Godfrey et al. 1998 ). DeMott and Rutledge (1998a) showed that the

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David M. Zermeño-Díaz, Chidong Zhang, Pavlos Kollias, and Heike Kalesse

al. 2000 ). Data from Manus also included observations from a microwave radiometer (MWR), upper-air soundings, a micropulse lidar (MPL), a ceilometer, and optical rain gauges. Other data used are rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM 3B42v7; 0.25° × 0.25°; Kummerow et al. 2000 ); rainfall, specific humidity, and its physical tendency term from the operational analysis (0.56° × 0.56°) of the European Centre for Medium Range Weather Forecasts (ECMWF) prepared for

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Naoko Sakaeda, Scott W. Powell, Juliana Dias, and George N. Kiladis

life cycle of cloud systems that are triggered in the afternoon and develop into mesoscale convective systems (MCSs) that mature in the early morning hours ( Chen and Houze 1997 ). While the climatological diurnal cycle of total rainfall is known to be largely contributed by the MCSs ( Chen and Houze 1997 ; Nesbitt and Zipser 2003 ), the relative roles of the first three suggested mechanisms leading to their overnight development is unclear. By examining the variability in the diurnal cycle of

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

.1175/1520-0469(1996)053<1380:MVODCI>2.0.CO;2 . 10.1175/1520-0469(1996)053<1380:MVODCI>2.0.CO;2 Chen , S. S. , and Coauthors , 2016 : Aircraft observations of dry air, the ITCZ, convective cloud systems, and cold pools in MJO during DYNAMO . Bull. Amer. Meteor. Soc. , 97 , 405 – 423 , doi: 10.1175/BAMS-D-13-00196.1 . 10.1175/BAMS-D-13-00196.1 de Szoeke , S. P. , and J. B. Edson , 2017 : Intraseasonal air–sea interaction and convection observed in DYNAMO/CINDY/AMIE. The Global Monsoon System: Research and Forecast , C

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