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.1126/science.1092779 . 10.1126/science.1092779 Barthlott , C. , and C. Hoose , 2018 : Aerosol effects on clouds and precipitation over central Europe in different weather regimes . J. Atmos. Sci. , 75 , 4247 – 4264 , https://doi.org/10.1175/JAS-D-18-0110.1 . 10.1175/JAS-D-18-0110.1 Best , M. J. , and Coauthors , 2011 : The Joint UK Land Environment Simulator (JULES), model description—Part 1: Energy and water fluxes . Geosci. Model Dev. , 4 , 677 – 699 , https://doi.org/10.5194/gmd-4
.1126/science.1092779 . 10.1126/science.1092779 Barthlott , C. , and C. Hoose , 2018 : Aerosol effects on clouds and precipitation over central Europe in different weather regimes . J. Atmos. Sci. , 75 , 4247 – 4264 , https://doi.org/10.1175/JAS-D-18-0110.1 . 10.1175/JAS-D-18-0110.1 Best , M. J. , and Coauthors , 2011 : The Joint UK Land Environment Simulator (JULES), model description—Part 1: Energy and water fluxes . Geosci. Model Dev. , 4 , 677 – 699 , https://doi.org/10.5194/gmd-4
regime change; this does not apply to the case considered here.) The forcings refer to a prescribed initial meteorological situation (e.g., the sounding), surface sensible and latent heat fluxes, radiative cooling of the atmosphere, and the large-scale advection of temperature and moisture. The latter can be included through realistic lateral boundary conditions [as in typical limited-area numerical weather prediction (NWP) simulations] or through prescribed tendencies imposed over a finite
regime change; this does not apply to the case considered here.) The forcings refer to a prescribed initial meteorological situation (e.g., the sounding), surface sensible and latent heat fluxes, radiative cooling of the atmosphere, and the large-scale advection of temperature and moisture. The latter can be included through realistic lateral boundary conditions [as in typical limited-area numerical weather prediction (NWP) simulations] or through prescribed tendencies imposed over a finite
Distinct Impacts of Aerosols on an Evolving Continental Cloud Complex during the RACORO Field Campaign, resulting in a decreased cloud cover and optical depth and suppressed precipitation for a daytime DCC. A study of ARE on sea breezes by Grant and van den Heever (2014) has shown that aerosols suppress the precipitation due to reducing downwelling shortwave radiation and surface latent heat fluxes. The aerosol semidirect effect is dependent on the locations of an aerosol layer relative to the clouds and underlying surface ( Lindeman et al. 2011 ; Wang et al. 2013b ). For the case that aerosols lay
, resulting in a decreased cloud cover and optical depth and suppressed precipitation for a daytime DCC. A study of ARE on sea breezes by Grant and van den Heever (2014) has shown that aerosols suppress the precipitation due to reducing downwelling shortwave radiation and surface latent heat fluxes. The aerosol semidirect effect is dependent on the locations of an aerosol layer relative to the clouds and underlying surface ( Lindeman et al. 2011 ; Wang et al. 2013b ). For the case that aerosols lay
latent and sensible fluxes. The 12-h simulations (i.e., from 0730 to 1930 local time) apply evolving sensible and latent surface fluxes, as in Grabowski et al. (2006) [see Fig. 1 in G15 and the appendix in Grabowski et al. (2006) ]. The model setup is exactly the same as in G15 . A horizontal domain of 50 km × 50 km is covered by a uniform 400-m grid. In the vertical, the domain extends up to 24 km, applying 81 levels with a stretched grid. The vertical grid length is around 100 m near the
latent and sensible fluxes. The 12-h simulations (i.e., from 0730 to 1930 local time) apply evolving sensible and latent surface fluxes, as in Grabowski et al. (2006) [see Fig. 1 in G15 and the appendix in Grabowski et al. (2006) ]. The model setup is exactly the same as in G15 . A horizontal domain of 50 km × 50 km is covered by a uniform 400-m grid. In the vertical, the domain extends up to 24 km, applying 81 levels with a stretched grid. The vertical grid length is around 100 m near the
Mechanisms Contributing to Suppressed Precipitation in Mt. Hua of Central China. Part I: Mountain Valley CirculationModels (AeroCom) project. Dust emissions follow Zhao et al. (2010) , with vertical dust fluxes calculated with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) dust emission scheme ( Ginoux et al. 2001 ). The emitted dust particles are distributed into the MOSAIC aerosol size bins following a theoretical expression based on the physics of scale-invariant fragmentation of brittle materials derived by Kok (2011) . The main aerosol compositions over the region are sulfate and black
Models (AeroCom) project. Dust emissions follow Zhao et al. (2010) , with vertical dust fluxes calculated with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) dust emission scheme ( Ginoux et al. 2001 ). The emitted dust particles are distributed into the MOSAIC aerosol size bins following a theoretical expression based on the physics of scale-invariant fragmentation of brittle materials derived by Kok (2011) . The main aerosol compositions over the region are sulfate and black
temperature (PT, calculated from temperature and pressure data derived from the ECMWF-AUX) difference between the surface and the 700-hPa pressure level (PT surface − PT 700-hPa ) ( Klein and Hartmann 1993 ). The mean of the difference between saturated specific humidity and ambient specific humidity (VaporD) at the 500- and 700-hPa levels was computed using CWC information ( Redelsperger et al. 2002 ). Instantaneous values for CRF were obtained from the CloudSat radiative fluxes and heating rate (2B
temperature (PT, calculated from temperature and pressure data derived from the ECMWF-AUX) difference between the surface and the 700-hPa pressure level (PT surface − PT 700-hPa ) ( Klein and Hartmann 1993 ). The mean of the difference between saturated specific humidity and ambient specific humidity (VaporD) at the 500- and 700-hPa levels was computed using CWC information ( Redelsperger et al. 2002 ). Instantaneous values for CRF were obtained from the CloudSat radiative fluxes and heating rate (2B
Review of Aerosol–Cloud Interactions: Mechanisms, Significance, and Challengesshowed that surface sensible heat flux is essential for maintaining a regime of open cells of marine stratocumulus ( Kazil et al. 2014 ). Satellite observations revealed reduced cloud drop effective radius and increased drop concentrations on the transitions from open to closed cells ( Rosenfeld et al. 2006 ; Goren and Rosenfeld 2014 ). This is most evident in ship tracks, which closed the areas of open cells ( Goren and Rosenfeld 2012 ). Satellite observations also revealed an increased occurrence
showed that surface sensible heat flux is essential for maintaining a regime of open cells of marine stratocumulus ( Kazil et al. 2014 ). Satellite observations revealed reduced cloud drop effective radius and increased drop concentrations on the transitions from open to closed cells ( Rosenfeld et al. 2006 ; Goren and Rosenfeld 2014 ). This is most evident in ship tracks, which closed the areas of open cells ( Goren and Rosenfeld 2012 ). Satellite observations also revealed an increased occurrence
Aerosol- and Droplet-Dependent Contact Freezing: Parameterization Development and Case Study. The phoretic forces, thermophoresis and diffusiophoresis, occur when cloud droplets are either evaporating or growing by condensation. These all combine to determine the total collision efficiency. The flux of aerosols to a collector drop falling at terminal velocity was determined by Wang et al. (1978) . This model includes the effect of Brownian motion and the phoretic forces on the collision efficiency, which is given by where is the collision kernel (m 3 s −1 ) due to phoretic forces and
. The phoretic forces, thermophoresis and diffusiophoresis, occur when cloud droplets are either evaporating or growing by condensation. These all combine to determine the total collision efficiency. The flux of aerosols to a collector drop falling at terminal velocity was determined by Wang et al. (1978) . This model includes the effect of Brownian motion and the phoretic forces on the collision efficiency, which is given by where is the collision kernel (m 3 s −1 ) due to phoretic forces and
Effect of Aerosols on Freezing Drops, Hail, and Precipitation in a Midlatitude Stormfreezes because of an outward-directed heat flux. During this process, the ice shell depth increases. The process of freezing in this case is described following Pruppacher and Klett (1997 , p. 678). If FDs collect supercooled droplets, both dry and wet growths of FDs are possible. To determine the type of growth, the surface particle temperature is calculated using the heat balance equation at the particle surface. Dry growth occurs when the surface temperature is . Otherwise, the FD is assumed
freezes because of an outward-directed heat flux. During this process, the ice shell depth increases. The process of freezing in this case is described following Pruppacher and Klett (1997 , p. 678). If FDs collect supercooled droplets, both dry and wet growths of FDs are possible. To determine the type of growth, the surface particle temperature is calculated using the heat balance equation at the particle surface. Dry growth occurs when the surface temperature is . Otherwise, the FD is assumed
A Dynamic Link between Ice Nucleating Particles Released in Nascent Sea Spray Aerosol and Oceanic Biological Activity during Two Mesocosm Experiments, 2014 : Sources and composition of submicron organic mass in marine aerosol particles . J. Geophys. Res. Atmos. , 119 , 12 977 – 13 003 , doi: 10.1002/2014JD021913 . 10.1002/2014JD021913 Fuentes , E. , H. Coe , D. Green , G. de Leeuw , and G. McFiggans , 2010 : On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol—Part 1: Source fluxes . Atmos. Chem. Phys. , 10 , 9295 – 9317 , doi: 10.5194/acp-10-9295-2010 . 10.5194/acp-10
, 2014 : Sources and composition of submicron organic mass in marine aerosol particles . J. Geophys. Res. Atmos. , 119 , 12 977 – 13 003 , doi: 10.1002/2014JD021913 . 10.1002/2014JD021913 Fuentes , E. , H. Coe , D. Green , G. de Leeuw , and G. McFiggans , 2010 : On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol—Part 1: Source fluxes . Atmos. Chem. Phys. , 10 , 9295 – 9317 , doi: 10.5194/acp-10-9295-2010 . 10.5194/acp-10
