Simulating the equivalent radar reflectivity of cirrus at 94 GHz using an ensemble model of cirrus ice crystals: a test of the Met Office global numerical weather prediction model

In this paper an ensemble model of ice crystals previously used to simulate the short‐wave scattering properties of cirrus is now applied to simulate its equivalent radar reflectivity (Ze) at 94 GHz. It is shown that the ensemble model conserves the mass of aggregating ice crystals when compared against in situ derived mass‐dimensional (m‐D) relationships. The ensemble model derived m‐D relationship is applied to the Rayleigh–Gans approximation to obtain a new parametrized radar reflectivity forward model for general circulation models (GCMs). The derived forward model is parametrized as a function of ice mixing ratio and in‐cloud temperature, and it is shown that the forward model error is generally well within ±2 dBZe using a linear fit; this new parametrization negates the need for an ‘effective diameter’.

[1]  A. Korolev,et al.  Small Ice Particles in Tropospheric Clouds: Fact or Artifact? Airborne Icing Instrumentation Evaluation Experiment , 2011 .

[2]  W. Landman.  Climate change 2007: the physical science basis , 2010 .

[3]  P. Kaye,et al.  The Ability of the Small Ice Detector (SID-2) to Characterize Cloud Particle and Aerosol Morphologies Obtained during Flights of the FAAM BAe-146 Research Aircraft , 2010 .

[4]  Steven Platnick,et al.  Influence of ice particle model on satellite ice cloud retrieval: lessons learned from MODIS and POLDER cloud product comparison , 2009 .

[5]  Anthony J. Baran,et al.  Testing an ensemble model of cirrus ice crystals using midlatitude in situ estimates of ice water content, volume extinction coefficient and the total solar optical depth , 2009 .

[6]  Anthony J. Baran,et al.  A review of the light scattering properties of cirrus , 2009 .

[7]  Graeme L. Stephens,et al.  Retrieval of ice cloud microphysical parameters using the CloudSat millimeter‐wave radar and temperature , 2009 .

[8]  P. Yang,et al.  Relationship between ice water content and equivalent radar reflectivity for clouds consisting of nonspherical ice particles , 2008 .

[9]  Greg Michael McFarquhar,et al.  Impact of small ice crystal assumptions on ice sedimentation rates in cirrus clouds and GCM simulations , 2008 .

[10]  Damian R. Wilson,et al.  Evaluating cloud systems in the Met Office global forecast model using simulated CloudSat radar reflectivities , 2008 .

[11]  K. Sassen,et al.  Global distribution of cirrus clouds from CloudSat/Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) measurements , 2008 .

[12]  Validation and determination of ice water content‐radar reflectivity relationships during CRYSTAL‐FACE: Flight requirements for future comparisons , 2008 .

[13]  P. Field,et al.  Determination of the Combined Ventilation Factor and Capacitance for Ice Crystal Aggregates from Airborne Observations in a Tropical Anvil Cloud , 2008 .

[14]  P. Field,et al.  Snow Size Distribution Parameterization for Midlatitude and Tropical Ice Clouds , 2007 .

[15]  Dong L. Wu,et al.  Cloud ice: A climate model challenge with signs and expectations of progress , 2007 .

[16]  A. Heymsfield.  On measurements of small ice particles in clouds , 2007 .

[17]  Steven Platnick,et al.  High Cloud Properties from Three Years of MODIS Terra and Aqua Collection-4 Data over the Tropics , 2007 .

[18]  A. Baran,et al.  A self‐consistent scattering model for cirrus. I: The solar region , 2007 .

[19]  M. Freer,et al.  Importance of small ice crystals to cirrus properties: Observations from the Tropical Warm Pool International Cloud Experiment (TWP‐ICE) , 2007 .

[20]  J. Foot,et al.  Some observations of the optical properties of clouds , 2006 .

[21]  Claudia J. Stubenrauch,et al.  Cloud Properties and Their Seasonal and Diurnal Variability from TOVS Path-B , 2006 .

[22]  P. Field,et al.  Shattering and Particle Interarrival Times Measured by Optical Array Probes in Ice Clouds , 2006 .

[23]  R. Hogan,et al.  The Retrieval of Ice Water Content from Radar Reflectivity Factor and Temperature and Its Use in Evaluating a Mesoscale Model , 2006 .

[24]  Bryan A. Baum,et al.  Bulk Scattering Properties for the Remote Sensing of Ice Clouds. Part I: Microphysical Data and Models. , 2005 .

[25]  Richard Cotton,et al.  Parametrization of ice‐particle size distributions for mid‐latitude stratiform cloud , 2005 .

[26]  P. Field,et al.  Radar scattering by aggregate snowflakes , 2005, physics/0505083.

[27]  Anthony J. Baran,et al.  The dependence of cirrus infrared radiative properties on ice crystal geometry and shape of the size‐distribution function , 2005 .

[28]  A. Baran.  On the Radiative Properties of Cirrus Cloud , 2005 .

[29]  P. Field,et al.  Theory of growth by differential sedimentation, with application to snowflake formation. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[30]  Peter N. Francis,et al.  On the radiative properties of cirrus cloud at solar and thermal wavelengths: A test of model consistency using high‐resolution airborne radiance measurements , 2004 .

[31]  Timothy J. Garrett,et al.  Small, highly reflective ice crystals in low‐latitude cirrus , 2003 .

[32]  P. Field,et al.  Universality in snowflake aggregation , 2003, physics/0310164.

[33]  Graeme L. Stephens,et al.  The CloudSat Mission , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[34]  W. Paul Menzel,et al.  The MODIS cloud products: algorithms and examples from Terra , 2003, IEEE Trans. Geosci. Remote. Sens..

[35]  Robert Wood,et al.  Ice Particle Interarrival Times Measured with a Fast FSSP , 2003 .

[36]  Stephen L. Durden,et al.  Observations and Parameterizations of Particle Size Distributions in Deep Tropical Cirrus and Stratiform Precipitating Clouds: Results from In Situ Observations in TRMM Field Campaigns , 2002 .

[37]  E. O'connor,et al.  The CloudSat mission and the A-train: a new dimension of space-based observations of clouds and precipitation , 2002 .

[38]  David L. Mitchell,et al.  Effective Diameter in Radiation Transfer: General Definition, Applications, and Limitations , 2002 .

[39]  George A. Isaac,et al.  Parameterization of effective ice particle size for high‐latitude clouds , 2002 .

[40]  G. Stephens,et al.  Cirrus Cloud Ice Water Content Radar Algorithm Evaluation Using an Explicit Cloud Microphysical Model , 2002 .

[41]  P. Francis,et al.  A scattering phase function for ice cloud: Tests of applicability using aircraft and satellite multi‐angle multi‐wavelength radiance measurements of cirrus , 2001 .

[42]  J. Walter Strapp,et al.  Laboratory Measurements of the Response of a PMS OAP-2DC , 2001 .

[43]  R. Gerdes,et al.  Cyclones over Fram Strait: impact on sea ice and variability , 2001 .

[44]  A. Illingworth,et al.  Toward More Accurate Retrievals of Ice Water Content from Radar Measurements of Clouds , 2000 .

[45]  P. Francis,et al.  Aircraft measurements of the solar and infrared radiative properties of cirrus and their dependence on ice crystal shape , 1999 .

[46]  Damian R. Wilson,et al.  A microphysically based precipitation scheme for the UK meteorological office unified model , 1999 .

[47]  Ping Yang,et al.  Average ice crystal size and bulk short-wave single-scattering properties of cirrus clouds , 1998 .

[48]  Larry D. Travis,et al.  Light scattering by nonspherical particles : theory, measurements, and applications , 1998 .

[49]  Andrew J. Heymsfield,et al.  The Definition and Significance of an Effective Radius for Ice Clouds , 1998 .

[50]  H. Isaka,et al.  Cloud-Radiation Studies During the European Cloud and Radiation Experiment (EUCREX) , 1998 .

[51]  B. Soden,et al.  Large-scale ice clouds in the GFDL SKYHI general circulation model , 1997 .

[52]  Greg Michael McFarquhar,et al.  Microphysical Characteristics of Three Anvils Sampled during the Central Equatorial Pacific Experiment , 1996 .

[53]  Sergey Y. Matrosov,et al.  Radar and Radiation Properties of Ice Clouds , 1995 .

[54]  P. Francis.  Some Aircraft Observations of the Scattering Properties of Ice Crystals , 1995 .

[55]  P. Francis,et al.  Improved Measurements of the Ice Water Content in Cirrus Using a Total-Water Probe , 1995 .

[56]  K. Liou,et al.  Light scattering by nonspherical particles: remote sensing and climatic implications , 1994 .

[57]  B. Draine,et al.  Discrete-Dipole Approximation For Scattering Calculations , 1994 .

[58]  Paul W. Stackhouse,et al.  The Relevance of the Microphysical and Radiative Properties of Cirrus Clouds to Climate and Climatic Feedback , 1990 .

[59]  R. Lawson,et al.  Performance of Some Airborne Thermometers in Clouds , 1990 .

[60]  J. Mitchell,et al.  C02 and climate: a missing feedback? , 1989, Nature.

[61]  G. Sarton,et al.  Notes and Correspondence , 1940, Isis.

[62]  A. Heymsfield,et al.  Using in situ estimates of ice water content, volume extinction coefficient, and the total solar optical depth obtained during the tropical ACTIVE campaign to test an ensemble model of cirrus ice crystals , 2011 .

[63]  P. Field,et al.  Corrigendum: Radar scattering by aggregate snowflakes , 2008 .

[64]  Stephan Havemann,et al.  A new parametrization for the radiative properties of ice crystals: Comparison with existing schemes and impact in a GCM , 2007 .

[65]  Rao Rui-zhong.  Single-scattering Properties of Cirrus Clouds in Infrared Region , 2004 .

[66]  Paul H. Kaye,et al.  Discrimination of micrometre-sized ice and super-cooled droplets in mixed-phase cloud , 2001 .

[67]  Yoshihide Takano,et al.  Light Scattering and Radiative Transfer in Ice Crystal Clouds , 2000 .

[68]  W. Menzel,et al.  Eight Years of High Cloud Statistics Using HIRS , 1999 .

[69]  K. Liou,et al.  Single-scattering properties of complex ice crystals in terrestrial atmosphere , 1998 .

[70]  J. Foot,et al.  Some observations of the optical properties of clouds. II: Cirrus , 1988 .

[71]  D. Parsons,et al.  Size Distributions of Precipitation Particles in Frontal Clouds. , 1979 .