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Yue Ying and Fuqing Zhang

1. Introduction The tropical atmosphere consists of weather systems spanning a wide range of spatial and temporal scales. At the planetary scale, the Madden–Julian oscillation (MJO) is found to be the dominant mode of intraseasonal variability with typical periods of 20–100 days ( Madden and Julian 1971 , 1972 ; Zhang 2005 ). The active phase of an MJO is characterized by enhanced deep convection and intense precipitation that propagates eastward at a speed around 5 m s −1 . Within the MJO

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

systems and associated boundary layer modification and recovery. Maps in Fig. 9 show where these two convective modes (diurnal and quasi-2-day) were most active during MJO1. The quasi-2-day convective disturbances ( Fig. 9a ) preferentially occurred over open ocean and were mostly confined to near the equator between 10°N and 10°S, similar to that observed over the WPAC during TOGA COARE (Fig. 7 in Haertel and Johnson 1998 ), and the disturbances were present throughout the DYNAMO ESA maximizing

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Angela K. Rowe, Robert A. Houze Jr, Stacy Brodzik, and Manuel D. Zuluaga

indicate vigorous (generally young) convective cells with strong updrafts, defined by 30-dB Z echo reaching 8 km in height. WCCs are often parts of intensifying stages of MCS development where active cells merge together, defined by a contiguous 30-dB Z echo extending horizontally over 800 km 2 , and DWCCs are intense echoes that meet both the DCC and WCC criteria. BSRs are contiguous stratiform echoes exceeding 30 000 km 2 in the horizontal dimension. These echo definitions are modifications of

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Richard H. Johnson and Paul E. Ciesielski

1. Introduction A major challenge in numerical weather and climate prediction is the realistic treatment of the atmospheric boundary layer (ABL) ( Teixeira et al. 2008 ). Complicating factors include the coupling of the boundary layer with the underlying surface, stratification effects, surface inhomogeneities, complex turbulent structures, intermittency, and nonlocal mixing. An additional difficulty, particularly in the tropics, is the coupling of the ABL with the cloud layer, including

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Elizabeth J. Thompson, Steven A. Rutledge, Brenda Dolan, and Merhala Thurai

intense convection and more intense stratiform precipitation by these metrics, respectively. The log 10 = 3.85 line separating C and S rain was a modification of the BR09 partitioning method based on 372 paired dual-polarization radar–2DVD case studies and a quantitative C/S R ( z ) self-consistency test. While a separation line may not appear physically satisfying at first, evaluation of radar echo and DSD evolution from all 372 case studies, previous observational studies, and theoretical

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

Maldivian islands are contained within the domain, the simulations were run as ocean only using weekly (8 day) observed Moderate Resolution Imaging Spectroradiometer (MODIS) SSTs ( Esaias et al. 1998 ). SSTs were therefore updated every 8 days. Between the 8-day MODIS SST updates, SSTs were linearly interpolated between the previous and next MODIS SST files. The control simulations were initialized using 0.25° × 0.25° European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA

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