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Le Van Thien, William A. Gallus Jr., Mark A. Olsen, and Nathaniel Livesey

1. Introduction Satellites have become an important source of atmospheric data in recent decades. They have been particularly useful in providing information in the upper troposphere and stratosphere, where measurements from other instruments are rare (e.g., Hegglin et al. 2008 ). Although the amount of water vapor in the upper troposphere and lower stratosphere (UTLS) is small, water vapor in this region is important to the earth’s climate system. In addition to its role as one of the most

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Donald E. Wroblewski, Owen R. Coté, Jorg M. Hacker, and Ronald J. Dobosy

1. Introduction Turbulence in the upper troposphere and lower stratosphere (UTLS) can adversely impact the performance of a range of aerospace systems. Optical turbulence (OpT) from fluctuations in temperature and humidity can affect electromagnetic propagation, disrupting communications, radar, high-energy laser systems, and space imaging. Similarly, clear-air turbulence (CAT) can lead to aircraft upset, a problem particularly acute for stratospheric vehicles that often must fly within a

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Kevin M. Grise, David W. J. Thompson, and Thomas Birner

stratospheric residual circulation may also play an important role in forcing the TIL at midlatitudes during winter ( Birner 2010 ). In this paper, we present the first global survey of static stability in the stratosphere and upper troposphere as a function of latitude, longitude, and season using high vertical resolution temperature data. We also document for the first time the relationship between stratospheric processes and the magnitude of near-tropopause static stability (i.e., the TIL) at tropical

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Donald E. Wroblewski, Owen R. Coté, Jorg M. Hacker, and Ron J. Dobosy

order is reversed for the ramp–cliff (RC) structures, with a gradual increase in temperature followed by a steep decrease. For atmospheric flows with primary gradients in the vertical direction, for example, boundary layer and jet stream, CR patterns will be observed when the product of the vertical gradients of velocity and temperature is positive, while RC patterns will be seen if the product is negative. The present research deals with CR/RC structures identified in the upper troposphere from

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Jung-Hee Ryu, M. Joan Alexander, and David A. Ortland

equatorial waves in the upper troposphere and lower stratosphere (UTLS). As mentioned in previous studies ( Wheeler and Kiladis 1999 ; Kiladis et al. 2009 ), it is implicitly expected that the stratiform-type heating will be associated with shallower vertical wavelength equatorial waves than those forced by the convective-type heating. Thus, we also examine whether/how the stratiform-type heating can contribute to a realization of the equatorial waves with vertical wavelengths comparable to those of the

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Francesco d’Ovidio, Emily Shuckburgh, and Bernard Legras

1. Introduction It is now well established that the distribution of tracers in the upper troposphere and the lower stratosphere (UTLS) strongly depends on the transport and mixing properties of the flow. It is also well established that the dominant isentropic motion induces a chaotic type of tracer advection, giving rise to strongly inhomogeneous stirring (and thus, in the presence of diffusion, inhomogeneous mixing). 1 This segregates tracers into distinct well-mixed reservoirs separated by

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Ryo Mizuta, Mio Matsueda, Hirokazu Endo, and Seiji Yukimoto

remain insufficiently understood, especially with regard to extreme cyclones ( Solomon et al. 2007 ). According to the results of climate models that contributed to the Coupled Model Intercomparison Project phase 3 (CMIP3; Meehl et al. 2007 ), synoptic-scale activity (so-called storm-track activity) increases in the middle–upper troposphere in future climate experiments compared with present-day experiments. Yin (2005) reported that the zonal-mean eddy kinetic energy at a synoptic time scale shows

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Qiang Li and Erik Lindborg

from general circulation models (GCMs) show quite different results. Hamilton et al. (2008) found that rotational energy was about 4 times larger than divergent energy at mesoscales near the tropopause, while Skamarock et al. (2014) obtained rotational and divergent energy of the same order in the upper troposphere (8.5–10.5 km). Divergent energy was more than 5 times larger in the stratosphere (16–18 km). Brune and Becker (2013) found that divergent energy was greater than rotational energy

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Jean-Luc Baray, Yves Pointin, Joël Van Baelen, Marie Lothon, Bernard Campistron, Jean-Pierre Cammas, Olivier Masson, Aurélie Colomb, Claude Hervier, Yannick Bezombes, Sandra Banson, Christophe Duroure, Dany Hadad, and Frédéric Tridon

1. Introduction Jet streams are strong zonal winds in the upper troposphere, identified in the first half of the twentieth century by observing the motions of clouds ( Schaefer 1953 ). The jet streams are caused by the combination of Earth’s rotation on its axis and atmospheric heating by solar radiation. Palmin and Newton (1948) showed the coincidence between the jet stream’s maximum wind and tropopause discontinuities, paving the way to numerous studies of dynamical coupling and exchanges

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Chi-Hua Wu and Ming-Dah Chou

investigated the convection evolution over the mid North Pacific Ocean and its relation to the large-scale circulation in the upper troposphere. In section 4 , we investigated changes of the monsoon circulation in South and Southeast Asia and its relation to the Asian high variation during the late July EA-WNP monsoon transition. Conclusions are given in section 5 . 2. Data and identification of abrupt monsoon transition Data used in this study include (i) the outgoing longwave radiation (OLR) at the top

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