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IMPROVE-II: Improvement of Microphysical Parameterization through Observational Verification Experiment II


As in IMPROVE-1, the UW Department of Atmospheric Sciences in Seattle was the Forecasting and Operations Control Center (FOCC) for IMPROVE-2. Between IOPs, the S-Pol radar was used for surveillance of incoming storms, and this radar imagery was available to forecasters at the FOCC. When forecasts indicated that a frontal system was approaching within ~200 km of the Washington Coast, 3-hourly launches of rawinsondes were commenced at Salem, as well as at the mobile sonde unit and the ISS installation at Black Butte. Ice crystal observers began taking measurements when precipitation commenced at near Santiam Pass.

The Convair-580 and P-3 aircraft departed from Paine Field, Washington, when the S-Pol radar showed precipitation features of interest making landfall on the Oregon coast. The Convair-580 was guided into precipitation features of interest off the Washington Coast by air-to-ground communications with a scientist at the S-Pol radar site who had real-time displays of the S-Pol radar images with the location of the Convair-580 overlaid. The basic flight pattern was a vertical stack of horizontal legs, starting near cloud top, and working down to the minimum safe altitude over the terrain. from close to the ocean surface to the top of the cloud system or to the maximum altitude of the Convair-580 (~7.25 km), with the aircraft generally moving with the ambient flow as it descends. Meanwhile, the P-3 flew a "lawn-mower" pattern of north-south legs at minimum safe altitude over the terrain to measure the Doppler velocity structure over the entire study area. The P-3 also was used on some flights to perform microphysical legs as described above for the Convair-580.

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Temporal coverage

Begin Date 2001-11-26 00:00:00
End Date 2001-12-22 23:59:59

Spatial coverage

Map data from IBCSO, IBCAO, and Global Topography.

Maximum (North) Latitude: 46.00, Minimum (South) Latitude: 42.80
Minimum (West) Longitude: -125.10, Maximum (East) Longitude: -120.50