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(1950) , one of the greatest meteorologists of the era. He presented the cross-section analysis of Thunderstorm Project radiosonde data collected in Ohio in Fig. 17-2 in which he drew isotherms according to the rules of standard synoptic frontal analysis, with first-order discontinuities defining the boundaries of a frontal zone (indicated by heavy lines). Reliance on synoptic surface meteorological observations and polar-front thinking also led Tepper (1950) to try to explain the pressure rise
(1950) , one of the greatest meteorologists of the era. He presented the cross-section analysis of Thunderstorm Project radiosonde data collected in Ohio in Fig. 17-2 in which he drew isotherms according to the rules of standard synoptic frontal analysis, with first-order discontinuities defining the boundaries of a frontal zone (indicated by heavy lines). Reliance on synoptic surface meteorological observations and polar-front thinking also led Tepper (1950) to try to explain the pressure rise
stepped” as the model integrates forward from its initial conditions. These so-called prognostic variables have special importance because they are the only things that a model remembers from one time step to the next; everything else is recreated on each time step by starting from the prognostic variables and the boundary conditions. The prognostic variables typically include information about the mass of dry air, the temperature, the wind components, water vapor, various condensed-water species, and
stepped” as the model integrates forward from its initial conditions. These so-called prognostic variables have special importance because they are the only things that a model remembers from one time step to the next; everything else is recreated on each time step by starting from the prognostic variables and the boundary conditions. The prognostic variables typically include information about the mass of dry air, the temperature, the wind components, water vapor, various condensed-water species, and
have differing strengths and weaknesses that have been explored in follow-up studies (e.g., McComiskey et al. 2009 ; Kim et al. 2008 ; Berg et al. 2011 ). Primary lessons are the sensitivity of b to binning data by LWP; the positive correlation between b and adiabaticity (i.e., how close the LWP is to the adiabatic value; Kim et al. 2008 ); use of subcloud aerosol as a more relevant CCN proxy to surface aerosol in decoupled boundary layers; the sensitivity of b to updraft w ( Feingold
have differing strengths and weaknesses that have been explored in follow-up studies (e.g., McComiskey et al. 2009 ; Kim et al. 2008 ; Berg et al. 2011 ). Primary lessons are the sensitivity of b to binning data by LWP; the positive correlation between b and adiabaticity (i.e., how close the LWP is to the adiabatic value; Kim et al. 2008 ); use of subcloud aerosol as a more relevant CCN proxy to surface aerosol in decoupled boundary layers; the sensitivity of b to updraft w ( Feingold
these disturbances is around 3000 km, so a box was selected around these disturbances with a comparable lateral and meridional scale. The generation and energy conversion term for each case were computed and are illustrated in these panels. Boundary flux terms were not computed, so these results only confirm the internal processes. The following results stand out in all cases: There is a substantial generation of eddy available potential energy from convective heating. There is significant
these disturbances is around 3000 km, so a box was selected around these disturbances with a comparable lateral and meridional scale. The generation and energy conversion term for each case were computed and are illustrated in these panels. Boundary flux terms were not computed, so these results only confirm the internal processes. The following results stand out in all cases: There is a substantial generation of eddy available potential energy from convective heating. There is significant
is a horizontal view of the distribution of air masses at the ground. The broken line is the boundary (polar front) at the ground between a warm current from the west-southwest (white arrows), displacing to the east a wedge of cold air (black arrows) returning northward from a brief sojourn in southern latitudes. Along the boundary of the receding cold air (warm front) the warm air rises, and its moisture condenses and produces a broad area of rain or snow (shaded area). The upper part of the
is a horizontal view of the distribution of air masses at the ground. The broken line is the boundary (polar front) at the ground between a warm current from the west-southwest (white arrows), displacing to the east a wedge of cold air (black arrows) returning northward from a brief sojourn in southern latitudes. Along the boundary of the receding cold air (warm front) the warm air rises, and its moisture condenses and produces a broad area of rain or snow (shaded area). The upper part of the
coincident CARL and Doppler lidar measurements, and characterizing entrainment in cumulus clouds using Raman lidar, AERI, cloud radar, microwave radiometer, and surface measurements ( Wagner et al. 2013 ). e. Current status and future outlook The primary goal of the Raman lidar within the ARM Program was to provide routine measurements of water vapor through the boundary layer across the diurnal cycle. The original programmatic dream was that water vapor and temperature profile be remotely sensed and
coincident CARL and Doppler lidar measurements, and characterizing entrainment in cumulus clouds using Raman lidar, AERI, cloud radar, microwave radiometer, and surface measurements ( Wagner et al. 2013 ). e. Current status and future outlook The primary goal of the Raman lidar within the ARM Program was to provide routine measurements of water vapor through the boundary layer across the diurnal cycle. The original programmatic dream was that water vapor and temperature profile be remotely sensed and
during the next century. However, this decade of research has also revealed that considerable uncertainties in model estimates remain. For example, although the 1980s have been especially warm, the extent of global warming over the past century may have been 2 to 3 times less than that estimated by current models. Further, when the results of different models are compared, there are substantial differences among their estimates of temperature and precipitation changes in response to doubled carbon
during the next century. However, this decade of research has also revealed that considerable uncertainties in model estimates remain. For example, although the 1980s have been especially warm, the extent of global warming over the past century may have been 2 to 3 times less than that estimated by current models. Further, when the results of different models are compared, there are substantial differences among their estimates of temperature and precipitation changes in response to doubled carbon
radiation ( Curry and Ebert 1990 ), and the formation of ice crystals serves to remove water vapor from the lower troposphere ( Curry 1983 ; Blanchet and Girard 1994 , 1995 ). Girard and Blanchet (2001a , b ) estimate that diamond dust (freely falling larger ice crystals) may increase the downward flux of infrared radiation at the surface by as much as 60 W m −2 during the wintertime. The actual magnitude of ice fog’s climate effect remains largely unknown because current climate models still do not
radiation ( Curry and Ebert 1990 ), and the formation of ice crystals serves to remove water vapor from the lower troposphere ( Curry 1983 ; Blanchet and Girard 1994 , 1995 ). Girard and Blanchet (2001a , b ) estimate that diamond dust (freely falling larger ice crystals) may increase the downward flux of infrared radiation at the surface by as much as 60 W m −2 during the wintertime. The actual magnitude of ice fog’s climate effect remains largely unknown because current climate models still do not
Asia. The proposal that ultimately led to the launch of the National Aeronautics and Space Administration (NASA) CloudSat radar relied heavily on results obtained by the ARM Program. The goal of this chapter is to describe the evolution and current status of the ARM Program millimeter-wavelength radar effort. Fig . 17-1. Timeline of the key developments in the 20-yr history of the ARM cloud radar. 2. A brief primer on cloud radar terminology and parameters As the operating wavelength of radar
Asia. The proposal that ultimately led to the launch of the National Aeronautics and Space Administration (NASA) CloudSat radar relied heavily on results obtained by the ARM Program. The goal of this chapter is to describe the evolution and current status of the ARM Program millimeter-wavelength radar effort. Fig . 17-1. Timeline of the key developments in the 20-yr history of the ARM cloud radar. 2. A brief primer on cloud radar terminology and parameters As the operating wavelength of radar
of wind and buoyancy forcing over the North Atlantic (1948–2003) and quantified the relative roles of Ekman transport, geostrophic adjustment, and buoyancy forcing in the spatiotemporal evolution of the circulation in the subpolar gyre (see also Eden and Willebrand 2001 ; Eden and Jung 2001 ). Deshayes and Frankignoul (2008) showed that the time-integrated NAO also governs the strength of the deep western boundary current along the western boundary of the Labrador Sea, and hence affects the
of wind and buoyancy forcing over the North Atlantic (1948–2003) and quantified the relative roles of Ekman transport, geostrophic adjustment, and buoyancy forcing in the spatiotemporal evolution of the circulation in the subpolar gyre (see also Eden and Willebrand 2001 ; Eden and Jung 2001 ). Deshayes and Frankignoul (2008) showed that the time-integrated NAO also governs the strength of the deep western boundary current along the western boundary of the Labrador Sea, and hence affects the
