Applying the SIMBA Data Fusion Framework to OLYMPEX: Multi-Platform Observational Analysis of an Intensively Sampled Orographically Enhanced Precipitation Event

Recently developed, the System for Integrating Multi-platform data to Build the Atmospheric column (SIMBA) framework offers researchers a streamlined tool to fuse spatially coincident precipitation observations to a common 3-D grid, writing the result to a single, versatile NetCDF file. While originally designed for data fusion in support of NASA’s Global Precipitation Measurement (GPM) mission Ground Validation Program at the NASA Wallops Precipitation Research Facility, SIMBA has now been applied to observations collected during the GPM Olympic Mountains Experiment (OLYMPEX). Data from surface-based point, profiling, scanning and space-based active and passive microwave instruments provide a view of the state of the atmospheric column which can be used to infer precipitation characteristics and study precipitation processes. Using SIMBA for OLYMPEX case studies has several advantages, particularly for evaluating the complete vertical profile of precipitation and how the various fields change with range along the Quinault River Valley.

This presentation will include a brief overview of SIMBA and focus on initial results from a SIMBA-based investigation of the 3 December 2015 OLYMPEX case. The event is notable as an example of orographic precipitation enhancement in the Olympic Mountain region during the passage of an evolving baroclinic system, as well as a successful, highly orchestrated period of multi-aircraft, ground radar, and GPM satellite targeted data collection. OLYMPEX instrumentation available in SIMBA includes: NASA NPOL (S-band), NASA D3R (Ka-/Ku-band), NEXRAD 88D (S-band), CSWR DOW6 (X-band), and vertically profiling NASA Micro Rain (K-band) radars, the GPM Microwave Imager (GMI; 10-183 GHz) and Dual-frequency Precipitation Radar (DPR; Ka-/Ku-band), and a host of surface-based rain gauges and disdrometers (work to support additional platforms, including airborne observations, is continually ongoing). Multi-platform radar views of specific precipitation features will be used to demonstrate the benefits and limitations, particularly for the space-based DPR, of collecting and interpreting data in regions of complex topography. Derived drop size distribution (DSD) parameters (e.g., D_m, N_w) along coastal and valley ranges, as well as profiles of these parameters through the depth of the atmospheric column, are considered to assess DSD variations and terrain impacts – this will include a cursory comparison with MRR profiles and surface-based disdrometer observations. Results will serve as a detailed, initial exhibit of the utility of the SIMBA atmospheric column data product.