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Upper Air Training Session. February 2009. Upper Air Meeting. NOOOOOOO! Updates to RRS Workstation User Guide Stay fresh on what to do when problems arise. Release Times. Synoptic flights Ob time (H) minus 60 min Example: release for 12Z ob should occur at 11Z
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Upper Air Training Session February 2009
Upper Air Meeting • NOOOOOOO! • Updates to RRS Workstation User Guide • Stay fresh on what to do when problems arise
Release Times • Synoptic flights • Ob time (H) minus 60 min • Example: release for 12Z ob should occur at 11Z • Release window: H-60 to H+30 (1 ½ hr to get a balloon up) • Special flights • H-30 min • Example: release for 18Z ob should occur at 1730Z • Release window: H-30 to H+30 (1 hr to get a balloon in the air) • If release is detected even one second early or late, ob time will be logged differently
Release Times Cont’d • If you release outside of the release window: • Do not edit the messages or release time; let the software do its thing • Make a note in the remarks section of the B-29 and UA2009 that you released too early or too late
Message Transmission Times • Parts A and B • No later than H+60 min • Ex: A and B messages for a 12Z flight should be transmitted by 13Z • Typically ready by H+15 min • Parts C and D • No later than H+150 min (2 hr 30 min) • Ex: for a 12Z flight, should be transmitted by 1430Z • Typically ready by H+60 min
No GPS At Baseline • Before you reject… • Verify the signal strength and that the bottom status bar is indicating GPS height • Disconnect/reconnect battery • Reset the SPS (Click “SPS Reset” button on the Hardware Status Display • Click “Power On/Off UPS” button the Hardware Status Display • If all of these steps fail to produce GPS data, reject the instrument
RRS Doesn’t Recognize Release • Click the manual release icon (little man holding yellow balloon) • Flashing blue screen says “Release Detected”…click O.K. • Look at the “Received PTU” display to determine where pressure continually decreased • Change release time • Click “Tools” → “Release Time” → put in correct release time → click “OK”
Missing Data • Caused by signal loss (if all PTU data is missing) • Signal loss can be caused by several things • Frequency shift • Antenna not tracking properly • locked on to sidelobe • MCU overload (antenna locks up) • Radiosonde or battery failure
Missing Data Checklist • Signal Strength • Frequency • TRS status display
Missing Data Checklist Cont’d • “Tracking is suspended” • Antenna has locked up and will need to be reset; could take up to two min • After antenna is reset, place in “Search” mode • Verify the signal strength • “TRS is ready” • Antenna has likely locked on to a sidelobe or shifted off of the signal • Place antenna in “Search” mode • Verify that the signal strength returns
Superadiabatic Lapse Rates • RRS generates check messages for all supers • ≥ 34◦C/km within 1 km of surface • ≥ 15◦C/km beyond 1 km • If there is a check message for a superadiabatic lapse rate – fix it! • Do not smooth more than 1 minute
Wet Bulb Effect • Evaporative cooling on the temp sensor causes erroneous superadiabatic lapse rates • Sonde travels through saturated layer • Condensation forms on temp sensor • Sonde travels through dry layer • Water evaporates off of the sensor, absorbing latent heat • Temp sensor experiences a “cooling sensation”
Wet Bulb Effect Cont’d • Delete all erroneous temps until check messages go away • More than 3 minutes: terminate the flight
RH Problems • Dry Bias • ERRONEOUS Rapid drying off the surface • Mark up to 1 min of data • Layers of 1% RH • Less than 15 min: leave it alone • More than 15 min: delete all RH data from the beginning of the 1% through termination • Erratic RH data • Delete it!
Wind Problems • Common to see “Check” messages for wind direction/speed changes • 12 or more check messages: • Compare winds to profilers and the previous flight • If winds are not reasonable, delete all erroneous winds • Missing Winds • More than a few minutes, notify SDM and the Lead Forecaster • Both can request a second release
Tips to Avoid Problems • Always verify signal strength and frequency immediately prior to and after release • To avoid TRS lock-up • EL angle ≥ 60◦, the antenna in should be in “Manual” track mode • Be sure to correctly prepare the battery and radiosonde • Prepare the battery properly • Soak for 2 min
Tips to Avoid Problems Cont’d • Soak at the proper time • Always shake the battery out with 10 arm swings outside • Change the battery water before the 00Z flight soaking • Make sure the temp boom is positioned at a 90◦ angle • Always “Calculate” and “Accept” your baseline values before release • Check the “Thanks” report
B-29 and Spreadsheet Remarks • Significant wx at release, especially when using extra gas • Any problems with the flight or equipment • When a 2nd or 3rd release occurs • Radiosondes are rejected • If the flight is a special flight, note who requested it and why
Odds and Ends • Caps on cylinders if not connected to supply hose • Tell us if supplies are needed