1 1. FY08 GOES-R3 Project Proposal Title Page  Title: Investigation of Daytime-Nighttime Inconsistencies in Cloud Optical Parameters  Project Type: Product Development Proposal  Status: New  Duration: 1 year  Leads: »Bryan A. Baum (SSEC/CIMSS)  Other Participants: »Andrew Heidinger (NOAA/STAR)

2 2. Project Summary  Project focuses specifically on daytime/nighttime differences in LWP/IWP (liquid/ice water path)  LWP/IWP is derived from ice/liquid cloud particle size and optical thickness  Problem in a nutshell is that the particle size retrieved from use of solar channels is different from that retrieved from IR channels

3 3. Motivation/Justification  Supports NOAA Mission Goal(s): - Climate: Understand climate variability and change - Weather and Water: Assess historical record and impact of potential changes in cloud properties over CONUS  Proposed research is necessary for building a well-documented record of cloud property CDRs to enable assessment of potential impact of regional and global changes in cloud properties  Goal is to mitigate daytime/nighttime discontinuity in multidecadal cloud products

4 4. Methodology  Research will be performed by investigating the retrievals of ice/water cloud properties (effective particle size/optical thickness) using a combination of imager data (MODIS, AVHRR) and a variety of radiative transfer calculations  Will intercompare several different forward radiative transfer models to ensure that simulated satellite radiances are consistent  Will investigate the influence of global surface albedo and emittance maps on the retrievals  Will also investigate the influence of the assumed microphysical properties on the ensuing cloud bulk scattering/absorption properties

5 5. Summary of Previous Results  Several papers have been published that discuss the derivation of improved ice cloud bulk scattering/absorption models (see below)  These models will form the basis for the study, and may be updated if a NASA ROSES proposal submitted by Dr. Baum in 2006 is funded (selection is imminent) Baum, B. A., A. J. Heymsfield, P. Yang, and S. T. Bedka, 2005a: Bulk scattering models for the remote sensing of ice clouds. Part 1: Microphysical data and models. J. Appl. Meteor., 44, Baum, B. A., P. Yang, A. J. Heymsfield, S. Platnick, M. D. King, Y.-X. Hu, and S. T. Bedka, 2005b: Bulk scattering models for the remote sensing of ice clouds. Part 2: Narrowband models. J. Appl. Meteor., 44, Baum, B. A., P. Yang, S. L. Nasiri, A. K. Heidinger, A. J. Heymsfield, and J. Li, 2007: Bulk scattering properties for the remote sensing of ice clouds. Part 3: High resolution spectral models from 100 to 3250 cm -1. J. Appl. Meteor. Clim., Vol. 46,

6 6. Expected Outcomes  Successful completion of this work will entail a better understanding of why the differences are occurring between daytime and nighttime cloud property retrievals.  Research may influence the derivation and use of static look-up tables (LUTs) of cloud optical properties being prepared for GOES-R AWG cloud team. LUTs are critical for the retrieval of cloud effective particle size and optical thickness.  Will document the work through the preparation and submittal (and eventual publication) of at least one peer-reviewed journal article

7 7. Major Milestones  FY08 »Organize algorithms and ancillary data »Understand differences in simulated radiances from set of radiative transfer models (adding/doubling and discrete ordinates) »Document changes between each set of retrieved cloud properties (particle size/optical thickness) obtained from comparison of measured to observed radiances »Analyze results of each set of cloud properties to gauge affect of each modification »Prepare journal article on results

8 8. Funding Profile (K)  Summary of leveraged funding »Dr. Baum has 25K for GOES-R Cloud AWG activities, specifically for preparing/documenting a set of LUTs for use in geostationary cloud retrievals »If a NASA ROSES 2006 proposal is selected for funding, Dr. Baum will be able to update the ice cloud bulk scattering models, which may be of use to this study. However, selection of this proposal is not critical for this study as existing models are already available (see previous slide) Funding SourcesProcurement Office Purchase Items FY07FY08FY09 GOES-R3 0$55K Other Sources

9 9. Expected Purchase Items  FY08 »$55K: STAR CIMSS Grant for 1 scientist at (0.25 FTE, or 3 months) time from 1/1/2008 to 12/31/2008 Budget consists of: 1) Personnel support (for Dr. Baum, including benefits, IT charges, overhead, etc): $53K 2) Contracts: N/A 3) Software charges: N/A 4) Equipment: N/A 5) Travel: N/A 6) Publication charges: 1 2K per article