Major ground-based and airborne observations for the Olympic Mountains Experiment (OLYMPEX) field campaign took place between November 2015 and January 2016, with additional ground sampling continuing through February 2016, on the Olympic Peninsula in the Pacific Northwest of the United States. This field campaign provided ground-based validation support of the findings resulting from the Global Precipitation Measurement (GPM) Core Observatory satellite that is a joint effort between the NASA GPM program and the Japanese Aerospace Exploration Agency (JAXA).
As for all GPM Ground Validation (GPM GV) campaigns, NASA's Global Hydrometeorology Resource Center Distribued Active Archive Center (GHRC DAAC) provides a collaboration portal to help investigators exchange planning information and to support collection of real-time data as well as campaign science, project, and instrument status reports during the campaign. GHRC DAAC serves as the GPM GV archive.
Learn more by viewing the videos Researchers Gear Up for OLYMPEX and time-lapse of snowfall during OLYMPEX.
The primary objectives of OLYMPEX included:
| Study Dates | November 10, 2015 - February 16, 2016 |
|---|---|
| Season of Study | Boreal winter, cold, wet |
| Region | Olympic Mountains and Peninsula |
| Spatial Bounds | N: 48.5° W: -126° E: -122° S: 46° |
| Phenomena Studied | Atmospheric rivers, snow microphysics, convective precipitation |
Multiple instruments were flown on the UND Citation II, NASA ER-2, and NASA DC-8 aircrafts, as well as installed on ground stations, during the OLYMPEX Field Campaign. The instruments were used to observe atmospheric phenomena, such as atmospheric rivers, precipitation characteristics, and cloud microphysics.
The instruments included particle probes, the Advanced Microwave Precipitation Radiometer (AMPR), a Cloud Physics LiDAR (CPL), a High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP), a Cloud Radar System (CRS), Advanced Vertical Atmospheric Profiling System (AVAPS), and many different types of parsivels and disdrometers. Support data were also collected during the OLYMPEX field campaign, consisting of various satellite, model output, and operational datasets.
| Platform Type | Platform | Relevant Instrument | How are the Data Used? |
|---|---|---|---|
Airborne | UND Citation II | Particle Probes | Cloud liquid water Ice water content Cloud microphysics Cloud droplet size Particle size distribution |
| NASA ER-2 | Radar reflectivity Precipitation Cloud droplet distribution Layer optical depth Brightness temperature | ||
| NASA DC-8 | APR-3 Dropsondes | Atmospheric pressure Atmospheric temperature Wind direction and magnitude Radar reflectivity Precipitation rate Brightness temperature | |
Ground Station | Ground stations | DOW D3R Rain Gauges Parsivels Disdrometers | Precipitation rate Total precipitation Cloud microphysics Radar reflectivity |
The above timeline highlights events within the field campaign of particular scientific interest.
Several atmospheric river events were observed in which a long fetch of warm-sector water vapor influx impacted the Olympic Mountains, as well as other weather events that were dominated by warm-frontal and cold-frontal dynamics or unstable frontal conditions.
Data collected from these weather event were and are still being used to validate precipitation algorithms for both the GPM Microwave Imager (GMI) and the Dual-frequency Precipitation Radar (DPR) instruments, understand how precipitation behaves at different latitudes, and how the precipitation in clouds over the Pacific Ocean is different from over the coastline and mountains. Major findings from this field campaign are still being discovered today.
Houze, R.A., L.A. McMurdie, W.A. Petersen,et al. (2017). The Olympic Mountains Experiment (OLYMPEX). Bull. Amer. Meteor. Soc., 98, 2167–2188. doi:10.1175/BAMS-D-16-0182.1
Hou, A. Y., R. K. Kakar, S. Meeck, A. A. Azarbarzin, C. D. Kummerow, M. Kojima, R. Oki, K. Nakamura, and T. Iguchi (2014). The Global Precipitation Measurement Mission. Bull. Amer. Meteor. Soc., 95, 701-722. doi:10.1175/BAMS-D-13-00164.1