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Paul E. Roundy and William M. Frank

1. Introduction a. Linear and nonlinear interactions Intraseasonal oscillations (ISOs), including the Southern Hemisphere summer Madden–Julian oscillation (MJO; Madden and Julian 1994 ), are 20–60-day fluctuations of tropical winds and convection that are largely characterized by zonal wavenumbers 1–4. Studies of these low-frequency variations have improved our understanding of the tropical atmosphere and may enhance intraseasonal weather predictability. Since the discovery of the MJO in 1971

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Feimin Zhang and Zhaoxia Pu

a great challenge and a key scientific issue for numerical weather prediction (NWP) ( Marks and Shay 1998 ; Pu et al. 2009 ; Wu et al. 2016 ). Understanding the evolution of landfalling hurricanes is very important for improving their forecasts. When a hurricane moves from ocean to land, the environmental conditions change significantly. Interaction between the hurricane and the environment over land becomes very important for the evolution of the hurricane. In the early 1980s, the Hurricane

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Edward G. Patton, Peter P. Sullivan, and Chin-Hoh Moeng

interpretation of observations. This paper examines the interactions between the atmosphere and the land surface using an LES model of the PBL coupled to a land surface model (LSM). Fine grids and large computational domains are used to examine the impact of a range of soil heterogeneity scales ( λ = 2 to 30 km) on PBL turbulence. We use phase averaging to investigate the influence of the heterogeneity scale on the organized motions that develop. The coupling between the PBL and the land surface is found to

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Simon P. Alexander, Kaoru Sato, Shingo Watanabe, Yoshio Kawatani, and Damian J. Murphy

land regions is visible in Fig. 9a throughout the middle atmosphere. Fig . 9. Mean MF as a function of pressure level for each region for (a) January and (b) July. Solid lines indicate oceanic regions while dashed lines indicate land regions. The vertical profile of the mean intermittency (expressed as the Gini coefficient) in each region is presented in Fig. 10 . The intermittency is essentially constant with altitude during January for all regions (~0.5). In contrast, the intermittency during

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Martin L. M. Wong and Johnny C. L. Chan

considers a sea surface over the entire domain, and is therefore regarded as the control (CTRL). All the experiments begin with a very intense TC (minimum sea level pressure ∼888 hPa) embedded in an atmosphere that is at rest. The TC is placed over the center of the domains and the north–south-oriented coast is 150 km west of the TC. The surface temperature over land and sea is fixed at 28.5°C in all the experiments. 3. Results a. Track and intensity The position of the minimum pressure is used to

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Jeffrey M. Forbes and Saburo Miyahara

migrating in Mars's atmosphere and its interaction with the zonal mean flow ( Hamilton 1982 ; Zurek 1986 ; Zurek and Haberle 1988 ) under similar conditions, but with emphasis on the atmosphere below about 40–60 km. These works used classical atmospheric tidal theory ( Chapman and Lindzen 1970 ) to estimate tidal amplitudes that resulted from realistic thermal forcing, that is, heating rates that yielded tidal variations in surface pressure consistent with those measured by the Viking 1 and Viking

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Yevgeniy Frenkel, Boualem Khouider, and Andrew J. Majda

) . However, the latter is used to confirm that all the corresponding solutions are Floquet asymptotically stable, although the results are not reported here. c. The physical mechanism of diurnal cycle of precipitation over land The underlying physical mechanism and dynamical behavior associated with the solutions in Fig. 2 is explained here in terms of the interactions of the three cloud types with the periodically forced boundary layer dynamics. It is evident from the plots in Fig. 2 that the sudden

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David A. Randall, Harshvardhan, and Donald A. Dazlich

vertically integrated atmospheric cloud radiative forcing.ima, while the land points in the tropics and the summer hemisphere tend to experience afternoon or evening precipitation maxima.4. Why is there a diurnal cycle of precipitation over the oceans?a. Background Three mechanisms that have been suggested forproducing daily oscillations of precipitation over theoceans are considered: 1) Direct radiation-convection interactions. According to this simple hypothesis, atmospheric solarabsorption

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Linda Schlemmer, Cathy Hohenegger, Jürg Schmidli, Christopher S. Bretherton, and Christoph Schär

altitudes. Second, as we include the full sequence of model parameterizations in our framework, we do not merely address the role of convection in some atmospheric environment, but rather the full interaction between the soil and the atmosphere. The relaxation of the lower-tropospheric conditions toward a prescribed profile would thus be difficult to justify, in particular as we allow for a strong diurnal cycle over continental land surfaces. This strong diurnal cycle is in contrast to the diurnal cycle

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Syukuro Manabe and Kirk Bryan

main thermocline. An extensive icepack with a thickness of 1-4 m forms in the northernpart of the ocean. In the final part of the calculation interaction between the atmosphere and the ocean is allowed. Sincedifferent types of fluid motion occur in the atmosphericand ocean models, the atmospheric model requiresapproximately 40 times more computation to integrateover a given time period as the ocean model. Accordingto the stage I results of the numerical integration of theatmospheric model, the

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