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PACJET Projects
HMT 2004
GPS Realtime Water Vapor
West Coast RUC
ETL Profiler Network
Press Materials
About Pacjet
CALJET Summary
Societal Impacts and User Input
Linkages to National Priorities
  Data Assimilation Implementation Plan
March 2001 Program Status Report
PACJET 2001 Poster NSSL Briefing
Program Documents
PACJET and a Long-term Effort to Improve 0-24 h West Coast Forecasts
Overview Poster
Research Participants
NOAA Research
  ETL,   NSSL,   FSL,   AL,   CDC
National Weather Service Western Region
  Eureka,   Hanford,   Medford,   Monterey,   Oxnard,   Portland,   Reno,   Sacramento,   San Diego,   Seattle,   CNFRC
Office of Marine and Aviation Operations
Naval Postgradute School
SUNY Stony Brook
National Centers for Environmental Prediction
  EMC,   HPC,   MPC
National Environmental Satellite, Data and Information Service
Operational Forecasting Components
COMET Presentation
West Coast RUC Aircraft Obs via AWIPS
Applications Development
Research Components
Modeling Research Components
Related Experiments
Winter Storm Reconnaissance (Central Pac.)
CRPAQS (CA Air Quality)
IMPROVE (Microphysics)
THORPEX (Synoptic Targeting)
Observing Systems
Wind Profiler Network
Satellite Products
NOAA S-band Radar
Media Contacts
2001 - Monterey, CA
July 13-14 2000 (Boulder, CO)
July Workshop Agenda
September 1999 - Monterey, CA
1999 Planning Workshop Figures
June 1998 - CALJET


PACJET presents an opportunity for realistic field testing of a promising UAV, the AEROSONDE. The goal is to conduct at least one successful flight from Hawaii to the west coast in the context of a significant storm and with over-the-horizon communication with the UAV. The capabilities of the AEROSONDE appear to be well suited to PACJET's goal of measuring the low-level jet.


In flight reconnaissance report
Observations from the P-3 aircraft will be synthesized into a brief report that contains measurements of several key aspects of storms 200-500 km offshore, or roughly 6-12 h before the heaviest rain is anticipated to reach shore. The types of measurements are based on the unique array of instruments on board the P-3, including a surveillance radar on its belly, a Doppler radar on its tail, a scanning radar altimeter to measure sea state from aloft, dropsondes, and low-altitude flights to pinpoint the low-level jet and its water vapor content. The message will contain information that forecasters and the forecast user communities identified as key to the watch/warning program and to emergency management at two planning workshops held in 1999 and 2000. Before a flight, these groups will be alerted that such reports will become available in the next 24 hours. During a flight the reconnaissance message will be posted on the PACJET web page roughly every 2 hours.

Developmental flight report format.
Tail Radar Data
The tail radar on the P-3 is a Doppler radar and provides detailed measurements of the vertical and kinematic (wind) structure of storms in a swath roughly 80 km wide (40 km on either side of the aircraft). These data have proved especially useful in research, and will provide real-time measurements of the intensity of precipitation and depth of the storm, as well as the height of the freezing level that will be included in the reconnaissance message.

Data from the P3 Tail radar during CALJET.
Fuselage Radar Data
The belly radar is not a Doppler radar, but it provides radar reflectivity measurements out to a range of roughly 200 km. This capability allows on-board assessment of the position, orientation, and strength of rain bands. Rain band motion can be determined by tracking them over roughly an hour.

Data from the P3 Fuselage Radar during CALJET.
PACJET Flight data system
The flight data system currently installed on the P3 will allow the flight reconnaissance report to be transmitted twice an hour. Efforts are being made to acquire an satellite transmission system which would provide greater bandwidth and two-way communication between the plane in flight and the operations center.

Schematic of P3 data system.

Wind Profiler Network

CRPAQS basemap
Profiler deployment for CRPAQS.

Satellite Products

Cooperative Institute for Meteorological Satellite Studies (CIMSS)
Real-time GOES winds.
Specialized GOES wind products based on a feature tracking technique were produced by CIMSS as part of the CALJET experiment in 1998. A unique component of this data set is the availability of super-rapid-scan (1-min sampling) GOES images. These data were used to assess the impact of shortening the time between images used in feature tracking. Standard approaches used 30-min between samples, but tests in tropical storms had suggested more frequent sampling could improve areal coverage in regions where cloud features had a shorter lifetime than 30 min. The figures shown here represent the results of this test using a 5-min lag between images for both IR and visible channels. These are compared to results using 30 min lag, and confirm that the areal data coverage increases significantly. Using statistical internal consistency checks it was determined that the optimal time lag was about 5-min. Wind vectors calculated using shorter lags had higher internal variance that resulted from the increased influence of satellite pointing uncertainty as the distance between features decreased, i.e., with shorter time lags. Based on these results, a new GOES scan pattern is being developed that should provide a set of 3 consecutive 5-minute interval images, once every hour around the clock during PACJET over the domain shown here. In addition to the GOES wind products, GOES sounder moisture products (total precipitable water vapor, and cloud-top pressure) will be available at 3-hourly intervals.

GOES-9 VIS Cloud Drift Winds
30 Min Data
Using Routinely Available Data
(30 Min)
5 Min Data
Using Super Rapid Scan Data
(5 Min)
GOES-9 IR Cloud Drift Winds
30 Min Data
Using Routinely Available Data
(30 Min)
5 Min Data
Using Super Rapid Scan Data
(5 Min)
Cloud Parameters
Cloud Top Pressure
Total Water Vapor
Total Precipitable Water Vapor

Cooperative Institute for Research in the Atmosphere (CIRA) AMSU Data
Tutorial: Polar Satellite Products for the Operational Forecaster: Microwave
Cloud Liquid Water
Cloud Liquid Water
Rain Rate
Rain Rate
AVN Geopotential Height
AVN Geopotential Height
AMSU Geopotential Height
AMSU Geopotential Height

ETL Satellite Climate Research Group
Water Vapor and Winds
SSM/I Water Vapor with Quickscat Winds
A number of satellite products and images will be produced at ETL during PACJET both for large-scale monitoring and algorithm calibration/validation efforts. Data from numerous operational satellites are currently archived by ETL and will be used to support the PACJET field program. Some examples of satellite products planned for PACJET include individual overpass and daily composite satellite derived estimates of precipitation, cloud liquid water, total precipitable water, and ocean surface wind speed from SSM/I passive microwave observations. Other satellite products will include daily surface wind vectors from the Quikscat scatterometer and sea surface temperature estimates from GOES and AVHRR data. An example image of SSM/I derived total precipitable water with surface wind vectors from QuikScat is shown here. In addition, mid and upper tropospheric water vapor imagery from the microwave SSM/T2 and AMSU-B moisture sounders will be available.

Sband data S-band data
Sband Radar deployed for CALJET S-band radar deployed at CALJET

ETL S-band Radar

A new S-band vertical profiler with a coupler option for extending the dynamic range of the radar's receiver has been developed by the NOAA Environmental Technology Laboratory and successfully field tested during CALJET. The 30 dB of added dynamic range provided by the coupler allows the profiler to record radar reflectivity measurements in moderate-to-heavy precipitation that otherwise would not have been possible with this system because of receiver saturation. The radar hardware, signal processor, and operating software are based on existing S-band and UHF profiler technology developed at the NOAA Aeronomy Laboratory. Results from a side-by-side comparison with the NOAA K-band radar were used to determine the calibration and sensitivity of the S-band profiler. In a typical cloud profiling mode of operation, the sensitivity is -14 dBZ at 10 km or -25 dBZ at 3 km. During CALJET, the profiler was deployed at Cazadero, California, near the crest of the coastal mountains in a region climatologically prone to flooding. The profiler was part of an integrated observing system designed for measuring physical processes associated with orographic precipitation enhancement. The CALJET S-band dataset is also being applied to the problem of quantitative precipitation estimation using the WSR-88D (NEXRAD) network.
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