Generation of Simulated Atmospheric Datasets for Ingest into Radiative Transfer Models Jason A. Otkin, Derek J. Posselt, Erik R. Olson, and Raymond K. Garcia Cooperative Institute for Meteorological Satellite Studies Space Science and Engineering Center University of Wisconsin–Madison

Outline Review prior MURI-funded MM5 model simulations – Convective initiation event (IHOP) – Upper-tropospheric jet streak (THORPEX) Compare WRF & MM5 model simulations of a severe weather outbreak Examine the most recent MURI-funded model simulation – WRF simulated extratropical cyclone (ATREC) Data processing with 32-CPU Altix system

Procedure 1.Use a sophisticated mesoscale model (such as the MM5 or WRF) to produce a highly realistic simulated atmospheric dataset 2.Use forward model calculations performed on simulated temperature, water vapor, and cloud microphysical profiles to generate infrared spectra with high spectral resolution 3.Retrieve temperature and water vapor from top of atmosphere radiances and compare with original simulated atmosphere to assess retrieval accuracy

MM5 Model Characteristics Non-hydrostatic numerical model that solves the full non-linear primitive equations on user-defined terrain- following sigma levels Prognostic variables include perturbation pressure, u, v, w, q w, as well as mixing ratios for other microphysical variables Employs a 24-category topography and land-use dataset with varying horizontal resolution

MM5 Model Characteristics Can run multiple 1- and 2-way interactive and moving nests Includes programs for FDDA, 3DVAR, and analysis nudging Contains a sophisticated LSM to provide heat and moisture fluxes at the surface

MM5 Model Characteristics Employs leap frog temporal differencing with an Asselin filter to remove “computational mode” noise arising from the leap frog scheme 2 nd order centered differencing scheme used for the horizontal and vertical advection terms Contains 4 th order horizontal diffusion/filter terms MM5 has an effective resolution of ~10 *  x

IHOP Convective Initiation Event Objectives: Demonstrate satellite potential to observe moisture convergence prior to convective initiation Demonstrate potential to observe fine-scale rapidly-evolving water vapor structures GOES micron imagery: UTC 12 June 2002 Event Overview: Mostly clear environment preceding late afternoon convection Very complex low-level moisture structures and wind fields Convection initiated in the presence of strong convergence along a fine- scale low-level water vapor gradient

IHOP Convective Initiation Event MM5 Model Configuration: 4 km grid spacing with 60 vertical levels Initialized at 06 UTC on 12 June with 10-km RUC data and then run for 24 hours Nudged toward RUC analyses during 6-hr spin-up period Goddard microphysics MRF planetary boundary layer RRTM/Dudhia radiation OSU land-surface model No cumulus parameterization Geographical region covered by MM5 domain

IHOP Simulation Results Observed GOES-11 imagerySimulated GOES-11 imagery 1900 UTC

IHOP Simulation Results Observed GOES-11 imagerySimulated GOES-11 imagery 2000 UTC

IHOP Simulation Results Observed GOES-11 imagerySimulated GOES-11 imagery 2100 UTC

IHOP Simulation Results Observed GOES-11 imagerySimulated GOES-11 imagery 2200 UTC

IHOP Simulation Results Observed GOES-11 imagerySimulated GOES-11 imagery 2300 UTC

IHOP Simulation Results Color-shaded plot depicts 2-meter mixing ratio White iso-surfaces encompass cloud boundaries Wind vectors at 1.5 km AGL

THORPEX Jet Streak Case Overview: Significant upper-level jet streak with winds in excess of 180 knots Mixture of clear skies with scattered areas of lower- and upper-level clouds Domain coverage includes Aqua overpass, ER-2 flight, and G4 dropsondes Extensive observations were taken as part of THORPEX, GWINDEX, and NOAA NCEP Winter Storms Research Program GOES micron imagery: 2100 UTC 12 March 2003 – 0400 UTC 13 March 2003

THORPEX Jet Streak Case Geographical region covered by MM5 domains MM5 Model Configuration: km grid spacing with 50 vertical levels Initialized at 12 UTC on 11 March with 1° AVN data and then run for 48 hours Goddard microphysics Eta planetary boundary layer RRTM/Dudhia radiation No land-surface model Grell cumulus scheme on outer two domains with explicit convection on inner 4-km domain

THORPEX Simulation Results Observed GOES-10 imagerySimulated GOES-10 imagery 2200 UTC

THORPEX Simulation Results Observed GOES-10 imagerySimulated GOES-10 imagery 2300 UTC

THORPEX Simulation Results Observed GOES-10 imagerySimulated GOES-10 imagery 0000 UTC

THORPEX Simulation Results Observed GOES-10 imagerySimulated GOES-10 imagery 0100 UTC

THORPEX Simulation Results Observed GOES-10 imagerySimulated GOES-10 imagery 0200 UTC

WRF Model Characteristics Integrates fully compressible non-hydrostatic equations on a mass-based terrain-following coordinate Can be run either for idealized or real-data cases Options for one and two-way interactive nests Contains a prototype moving nest

WRF Model Characteristics Option to use 2 nd or 3 rd order Runge-Kutta temporal integration Option to use 2 nd to 6 th order horizontal and vertical advection schemes Effective resolution is ~ 7 *  x

WRF Model Characteristics Includes the NOAH LSM to calculate surface moisture and energy fluxes –Land use categories determine the surface properties at each grid point Version 2 contained a basic version of 3DVAR with a research grade version to be released later this month

WRF-MM5 Comparison: Northern Plains Severe Weather Outbreak Occurred during the evening of June 2003 Over 100 tornadoes reported across the region Manchester, SD destroyed by F4 tornado Very complex cloud conditions to model

Model Configuration 42 hr simulation initialized at 1200 UTC 23 June x 290 grid point domain with 4 km horizontal spacing and 50 vertical levels MM5WRF Goddard microphysics MRF PBL RRTM/Dudhia radiation Explicit cumulus convection OSU land surface model WSM6 microphysics YSU PBL RRTM/Dudhia radiation Explicit cumulus convection NOAH land surface model

Horizontal Variability MM5WRF 2.5 km Water Vapor Mixing Ratio Liquid Cloud Water WRF has much finer horizontal resolution than the MM5 WRF effective resolution is ~7*  x MM5 effective resolution is ~10*  x

Simulated Ice Microphysics WSM6 scheme generates less (more) ice mass in the upper (middle) troposphere - WSM6 contains a new diagnosis of ice crystal concentration Much lower altitude of the ice mixing ratio maximum in the WRF simulation - Goddard scheme assumes a constant sedimentation rate while a variable rate is used by the WSM6 scheme

Simulated Ice Microphysics MM5 Goddard scheme assumes a constant ice diameter of 20  m WRF WSM6 employs a method that relates the mean ice diameter to the amount of ice mass and the number concentration of ice particles - Generates a more realistic distribution of ice particle sizes

Simulated Radiances WRF simulation is characterized by much greater horizontal variability

ATREC Extratropical Cyclone Case Overview: Intense extratropical cyclone developing over the Gulf Stream Significant cloud shield with extensive region of stratiform precipitation Scattered convection along trailing cold front

ATREC Extratropical Cyclone Case WRF Model Configuration: 1070x1070 grid point domain with 2 km grid spacing and 50 vertical levels Initialized at 00 UTC on 05 December with 1° GFS data and then run for 24 hours WSM6 microphysics Yonsei University (YSU) planetary boundary layer RRTM/Dudhia radiation NOAH land-surface model Explicit cumulus Geographical region covered by WRF domain

SGI Altix We are able to perform very large memory-intensive model simulations with very fine horizontal resolution Used hardware money received by Allen Huang from the Navy DURIP program to purchase 24 CPUs with 192 Gb of memory Used grant money received by Bob Aune to purchase 8 additional CPUs Approximately 3 times faster than old cluster 10 Tb of external disk storage