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1. Introduction In 2021, the Colorado River basin snowpack was 80% of average but only delivered around 30% of average flows. This is concerning for the 40 million people who depend on the river ( Fleck and Udall 2021 ). Many are now asking, where did the snow water go? Is snow water likely to disappear like this again in the future? Snow is a vital part of water resources ( Huss et al. 2017 ), but sublimation may remove 10%–90% of snowfall from the hydrologic system ( Strasser et al
1. Introduction In 2021, the Colorado River basin snowpack was 80% of average but only delivered around 30% of average flows. This is concerning for the 40 million people who depend on the river ( Fleck and Udall 2021 ). Many are now asking, where did the snow water go? Is snow water likely to disappear like this again in the future? Snow is a vital part of water resources ( Huss et al. 2017 ), but sublimation may remove 10%–90% of snowfall from the hydrologic system ( Strasser et al
is essentially impossible to follow the growth or sublimation of individual particles in real cirrus as a balloon or aircraft probe is necessarily capturing a single snapshot of a particle at some undefined point in its lifetime. Because of these challenges, some of the most fundamental thermodynamic parameters and physical characteristics of ice particle surfaces are still highly uncertain at cirrus-relevant temperatures and pressures. Specifically, the equilibrium vapor pressure with respect to
is essentially impossible to follow the growth or sublimation of individual particles in real cirrus as a balloon or aircraft probe is necessarily capturing a single snapshot of a particle at some undefined point in its lifetime. Because of these challenges, some of the most fundamental thermodynamic parameters and physical characteristics of ice particle surfaces are still highly uncertain at cirrus-relevant temperatures and pressures. Specifically, the equilibrium vapor pressure with respect to
, sublimation of ice crystals in precipitation falling beneath a cloud, or cloud-base detrainment instability ( Emanuel 1981 ), may have caused convective instability (rather than dynamical shear instability) that created the vertical wind oscillations. Using high-resolution numerical simulations, Lane et al. (2003) and Lane and Sharman (2008) investigated turbulence caused by the breaking of convectively induced internal gravity waves or KH waves, above and near cumulonimbus clouds. According to Knox
, sublimation of ice crystals in precipitation falling beneath a cloud, or cloud-base detrainment instability ( Emanuel 1981 ), may have caused convective instability (rather than dynamical shear instability) that created the vertical wind oscillations. Using high-resolution numerical simulations, Lane et al. (2003) and Lane and Sharman (2008) investigated turbulence caused by the breaking of convectively induced internal gravity waves or KH waves, above and near cumulonimbus clouds. According to Knox
challenge as it is often the result of interactions among many intricate processes, both microphysical and dynamical. Herein, the focus is on the effects of sublimation on the timing and intensity of snow. At first glance, sublimation may seem less consequential than the much-more-studied effects of melting and evaporation (e.g., Wexler et al. 1954 ; Homan and Uccellini 1987 ; Szeto and Stewart 1997 ; Gallus and Segal 1999 ; Kain et al. 2000 ; Frick and Wernli 2012 ). However, sublimation can have
challenge as it is often the result of interactions among many intricate processes, both microphysical and dynamical. Herein, the focus is on the effects of sublimation on the timing and intensity of snow. At first glance, sublimation may seem less consequential than the much-more-studied effects of melting and evaporation (e.g., Wexler et al. 1954 ; Homan and Uccellini 1987 ; Szeto and Stewart 1997 ; Gallus and Segal 1999 ; Kain et al. 2000 ; Frick and Wernli 2012 ). However, sublimation can have
Impacts of Vertical Nonuniform Beam Filling on the Observability of Secondary Ice Production due to Sublimationthe differential phase Φ DP between the horizontal and vertical polarization channels—is more sensitive to small, anisotropic hydrometeors (e.g., Ryzhkov et al. 1998 ), and is thus well-suited to detect large increases in the concentration of small particles due to SIP in the presence of larger particles. Carlin et al. (2021) reported similar regions of enhanced K dp within the snow sublimation zone of numerous stratiform precipitation cases. The K dp in these regions often exceeded 0
the differential phase Φ DP between the horizontal and vertical polarization channels—is more sensitive to small, anisotropic hydrometeors (e.g., Ryzhkov et al. 1998 ), and is thus well-suited to detect large increases in the concentration of small particles due to SIP in the presence of larger particles. Carlin et al. (2021) reported similar regions of enhanced K dp within the snow sublimation zone of numerous stratiform precipitation cases. The K dp in these regions often exceeded 0
1. Background The lack of measurements of ice single crystal sublimation in air has resulted in a glaring gap in our knowledge of ice crystal response to nonequilibrium conditions. An early study of solid prismatic ice crystals sublimating in air was by Shaw and Mason (1955) . They measured the sublimation rates of the basal and prism faces of single crystals of ice attached to a substrate. Some of their crystals did not sublimate until a certain undersaturation was reached, a result probably
1. Background The lack of measurements of ice single crystal sublimation in air has resulted in a glaring gap in our knowledge of ice crystal response to nonequilibrium conditions. An early study of solid prismatic ice crystals sublimating in air was by Shaw and Mason (1955) . They measured the sublimation rates of the basal and prism faces of single crystals of ice attached to a substrate. Some of their crystals did not sublimate until a certain undersaturation was reached, a result probably
downstream water supply ( Wahl 1992 ). At each point in a landscape, the snow evolution can be described by a snow/water mass balance. Given the energies associated with melt and sublimation processes, the mass balance is intimately coupled to the energy balance. Changes in mass and energy balances govern the snow-cover distribution and evolution at each point in space and time, and include precipitation (solid and liquid), snowmelt, snow metamorphism (affecting factors such as density, thermal
downstream water supply ( Wahl 1992 ). At each point in a landscape, the snow evolution can be described by a snow/water mass balance. Given the energies associated with melt and sublimation processes, the mass balance is intimately coupled to the energy balance. Changes in mass and energy balances govern the snow-cover distribution and evolution at each point in space and time, and include precipitation (solid and liquid), snowmelt, snow metamorphism (affecting factors such as density, thermal
JUNE 1985 B. KOCHTUBAJDA AND E. P. LOZOWSKI 597The Sublimation of Dry Ice Pellets Used for Cloud Seeding B. KOCHTUBAJDAAlberta Research Council, Atmospheric Sciences Department, Edmonton, Alberta, Canada T6H 5R7 E. P. LOZOWSKIUniversity of Alberta, Meteorology Division, Edmonton, Alberta, Canada(Manuscript received 13 January 1984, in final form 15 December 1984
JUNE 1985 B. KOCHTUBAJDA AND E. P. LOZOWSKI 597The Sublimation of Dry Ice Pellets Used for Cloud Seeding B. KOCHTUBAJDAAlberta Research Council, Atmospheric Sciences Department, Edmonton, Alberta, Canada T6H 5R7 E. P. LOZOWSKIUniversity of Alberta, Meteorology Division, Edmonton, Alberta, Canada(Manuscript received 13 January 1984, in final form 15 December 1984
Colorado alpine region ( Berg 1986 ; Groisman et al. 1997 ). Déry and Yau (1999) estimate that between 10 and 60 blowing-snow events occur per year on the Alaskan North Slope. Blowing-snow events involve erosion, horizontal transport, deposition, and in-transit snow sublimation and play an important role in the spatial and temporal distribution of water and energy fluxes in many high-latitude regions. Tabler (1975a) estimated that over half of wind-transported snowfall sublimates in the high
Colorado alpine region ( Berg 1986 ; Groisman et al. 1997 ). Déry and Yau (1999) estimate that between 10 and 60 blowing-snow events occur per year on the Alaskan North Slope. Blowing-snow events involve erosion, horizontal transport, deposition, and in-transit snow sublimation and play an important role in the spatial and temporal distribution of water and energy fluxes in many high-latitude regions. Tabler (1975a) estimated that over half of wind-transported snowfall sublimates in the high
atmosphere. The presence of snowcover for much of the year has a major influence on the surface energy balance and hydrology of boreal forests. Intercepted snow on a forest canopy has a large exposed surface area, and a large fraction of the annual snowfall over boreal forests in dry continental climates sublimates from the canopy without ever reaching the ground ( Schmidt and Troendle 1992 ; Pomeroy and Gray 1995 ; Lundberg and Halldin 2001 ). Snow on the ground below the canopy, however, is sheltered
atmosphere. The presence of snowcover for much of the year has a major influence on the surface energy balance and hydrology of boreal forests. Intercepted snow on a forest canopy has a large exposed surface area, and a large fraction of the annual snowfall over boreal forests in dry continental climates sublimates from the canopy without ever reaching the ground ( Schmidt and Troendle 1992 ; Pomeroy and Gray 1995 ; Lundberg and Halldin 2001 ). Snow on the ground below the canopy, however, is sheltered
