Search Results
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
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
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
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
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
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
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
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
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
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
Using Radio Occultation to Detect Clouds in the Middle and Upper Tropospheremicrowave refractivity in the middle to upper troposphere is ~100 N units. While RO measurements have little direct sensitivity to clouds, they may have an indirect sensitivity to thin, high-altitude clouds such as cirrus, as first noted in Kursinski et al. (1999) , that are difficult to detect using conventional passive space-based cloud sensors. Peng et al. (2006 , hereafter P06 ) explored the signatures caused by upper-tropospheric clouds in Challenging Minisatellite Payload (CHAMP) RO profiles
microwave refractivity in the middle to upper troposphere is ~100 N units. While RO measurements have little direct sensitivity to clouds, they may have an indirect sensitivity to thin, high-altitude clouds such as cirrus, as first noted in Kursinski et al. (1999) , that are difficult to detect using conventional passive space-based cloud sensors. Peng et al. (2006 , hereafter P06 ) explored the signatures caused by upper-tropospheric clouds in Challenging Minisatellite Payload (CHAMP) RO profiles
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
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
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
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
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
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
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
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
