1. Introduction The banded organization of clouds and zonal winds in the atmospheres of the outer planets has long fascinated atmosphere and ocean dynamicists and planetologists, especially with regard to the stability and persistence of these patterns. This banded organization, mainly apparent in clouds thought to be of ammonia and NH 4 SH ice, is one of the most striking features of the atmosphere of Jupiter. The cloud bands are associated with multiple zonal jets of alternating sign with
1. Introduction The banded organization of clouds and zonal winds in the atmospheres of the outer planets has long fascinated atmosphere and ocean dynamicists and planetologists, especially with regard to the stability and persistence of these patterns. This banded organization, mainly apparent in clouds thought to be of ammonia and NH 4 SH ice, is one of the most striking features of the atmosphere of Jupiter. The cloud bands are associated with multiple zonal jets of alternating sign with
light winds (less than 2 m s −1 ) and fast-traveling swells, namely upward momentum transfer from the ocean to the atmosphere ( Grachev and Fairall 2001 ) and the occurrence of low-level wind jets ( Smedman et al. 1999 ). Such features are thought to be characteristic of a wave-driven wind regime. This regime was first reported by Harris (1966) , who found that in laboratory wave tank experiments, a progressive water wave led to airflow directly above the waves with a mean component in the
light winds (less than 2 m s −1 ) and fast-traveling swells, namely upward momentum transfer from the ocean to the atmosphere ( Grachev and Fairall 2001 ) and the occurrence of low-level wind jets ( Smedman et al. 1999 ). Such features are thought to be characteristic of a wave-driven wind regime. This regime was first reported by Harris (1966) , who found that in laboratory wave tank experiments, a progressive water wave led to airflow directly above the waves with a mean component in the
Rapid Update Cycle (RUC) wind analyses. In a 20-yr climatology of warm season nocturnal CI over the central and southern Great Plains, Reif and Bluestein (2017) found that 24% of the nocturnal CI episodes occurred without a nearby surface boundary. Nearly one-half of these no-boundary (NB) CI episodes were of a linear storm type, the majority of which had a preferred north–south orientation, the same preference exhibited by nocturnal low-level jets (LLJs) over the Great Plains (e.g., Hoecker 1963
Rapid Update Cycle (RUC) wind analyses. In a 20-yr climatology of warm season nocturnal CI over the central and southern Great Plains, Reif and Bluestein (2017) found that 24% of the nocturnal CI episodes occurred without a nearby surface boundary. Nearly one-half of these no-boundary (NB) CI episodes were of a linear storm type, the majority of which had a preferred north–south orientation, the same preference exhibited by nocturnal low-level jets (LLJs) over the Great Plains (e.g., Hoecker 1963
1. Introduction Recent studies related to the South America Low-Level Jet (SALLJ) have been focused on describing its mean features using gridded analyses ( Marengo et al. 2004 ; Salio et al. 2002 , and references therein), with an emphasis on the assessment of how this low-level wind flow affects the moisture balance of one of the richest agricultural basins in the world—the La Plata basin. Also, dynamical downscaling has been the choice to document the smaller-scale characteristics of this
1. Introduction Recent studies related to the South America Low-Level Jet (SALLJ) have been focused on describing its mean features using gridded analyses ( Marengo et al. 2004 ; Salio et al. 2002 , and references therein), with an emphasis on the assessment of how this low-level wind flow affects the moisture balance of one of the richest agricultural basins in the world—the La Plata basin. Also, dynamical downscaling has been the choice to document the smaller-scale characteristics of this
and organize convection (e.g., Zhang et al. 2001 ), and they are identified as a possible source of clear-air turbulence (e.g., Koch et al. 2005 ). Mountains, convection, wind shear, and adjustment of unbalanced flows related to jet streams and frontal systems are the most important sources of gravity waves ( Hooke 1986 ). Uccellini and Koch (1987) conceptualized the synoptic pattern of gravity wave generation and found that mesoscale waves with amplitudes of 1–15 hPa, horizontal wavelengths of
and organize convection (e.g., Zhang et al. 2001 ), and they are identified as a possible source of clear-air turbulence (e.g., Koch et al. 2005 ). Mountains, convection, wind shear, and adjustment of unbalanced flows related to jet streams and frontal systems are the most important sources of gravity waves ( Hooke 1986 ). Uccellini and Koch (1987) conceptualized the synoptic pattern of gravity wave generation and found that mesoscale waves with amplitudes of 1–15 hPa, horizontal wavelengths of
1. Introduction A gap-exiting wind over the ocean is a strong wind blowing from terrestrial gaps such as straits, mountain gaps, and chains of mountainous islands. The low-level strong wind, called a wind jet hereafter, is generally characterized by its short duration, high spatial variability, and highly localized strong wind in the gap exit region, depending on the terrain configurations and atmospheric structures. The wind jets have been an area of investigation for a long time (e
1. Introduction A gap-exiting wind over the ocean is a strong wind blowing from terrestrial gaps such as straits, mountain gaps, and chains of mountainous islands. The low-level strong wind, called a wind jet hereafter, is generally characterized by its short duration, high spatial variability, and highly localized strong wind in the gap exit region, depending on the terrain configurations and atmospheric structures. The wind jets have been an area of investigation for a long time (e
1. Introduction Extratropical atmospheric jets are commonly described as either subtropical or midlatitude (also called eddy driven or polar front) in character ( Hartmann 2007 ). The existence of these jets is attributed to different dynamical processes: the subtropical jet forms as a result of angular momentum transport by the thermally direct Hadley circulation ( Held and Hou 1980 ), while the midlatitude jet forms as a result of eddy momentum flux convergence by atmospheric waves that
1. Introduction Extratropical atmospheric jets are commonly described as either subtropical or midlatitude (also called eddy driven or polar front) in character ( Hartmann 2007 ). The existence of these jets is attributed to different dynamical processes: the subtropical jet forms as a result of angular momentum transport by the thermally direct Hadley circulation ( Held and Hou 1980 ), while the midlatitude jet forms as a result of eddy momentum flux convergence by atmospheric waves that
the region. The thunderstorms are often elevated, in the sense that storm updrafts develop in an elevated region separated from the surface by a nocturnal stable boundary layer ( Colman 1990 ; Wilson and Roberts 2006 ). One feature associated with the initiation and development of these nocturnal thunderstorms is the Great Plains low-level jet (LLJ) ( Pitchford and London 1962 ; Maddox 1983 ; Astling et al. 1985 ; Trier and Parsons 1993 ; Trier et al. 2006 ; Tuttle and Davis 2006 ). LLJs are
the region. The thunderstorms are often elevated, in the sense that storm updrafts develop in an elevated region separated from the surface by a nocturnal stable boundary layer ( Colman 1990 ; Wilson and Roberts 2006 ). One feature associated with the initiation and development of these nocturnal thunderstorms is the Great Plains low-level jet (LLJ) ( Pitchford and London 1962 ; Maddox 1983 ; Astling et al. 1985 ; Trier and Parsons 1993 ; Trier et al. 2006 ; Tuttle and Davis 2006 ). LLJs are
1. Introduction and potential vorticity background Solar radiation bathes the earth, varying smoothly with latitude, and yet the circulations it produces are filled with small-scale transient eddies, jet streams, and boundary currents. Zonal jet stream generation occurs with thermally forced circulations on a simple, smooth globe. Instability of zonally symmetric, baroclinic circulations is often given as a primary reason for these synoptic-scale features, which are amplified or generated ab
1. Introduction and potential vorticity background Solar radiation bathes the earth, varying smoothly with latitude, and yet the circulations it produces are filled with small-scale transient eddies, jet streams, and boundary currents. Zonal jet stream generation occurs with thermally forced circulations on a simple, smooth globe. Instability of zonally symmetric, baroclinic circulations is often given as a primary reason for these synoptic-scale features, which are amplified or generated ab
1. Introduction The maintenance and variability of the zonal mean zonal flow in the midlatitude upper troposphere can be linked to the eddy momentum fluxes of planetary-scale Rossby waves ( Limpasuvan and Hartmann 2000 ). The eddy momentum flux associated with these waves is strongly tied to their meridional propagation through the upper troposphere. The meridional propagation of eddies is highly sensitive to the structure of the background flow—namely, the subtropical and eddy-driven jets
1. Introduction The maintenance and variability of the zonal mean zonal flow in the midlatitude upper troposphere can be linked to the eddy momentum fluxes of planetary-scale Rossby waves ( Limpasuvan and Hartmann 2000 ). The eddy momentum flux associated with these waves is strongly tied to their meridional propagation through the upper troposphere. The meridional propagation of eddies is highly sensitive to the structure of the background flow—namely, the subtropical and eddy-driven jets
