¶ Balloon-Borne Sounding System (SONDE)
¶ Instrument Description
SONDE is a balloon borne instrument which is launched in relatively regular intervals throughout the day. The system measures multiple atmospheric variables and is plotted on a skew-T log-P diagram. All ARM SONDE systems currently in use use the digiCORA-III production system.
- For more information see the SONDE Instrument web page.
¶ Additional Information
- Vaisala RS92-SGP Radiosonde
- For more information about reading Skew T Diagrams see the Skew T Mastery website. It is free to register.
¶ Expected Operations
Normal Operations
| Criteria | Value |
|---|---|
| Acceptable ascent rate | 4-6 m/s |
| height & pressure target for a successful launch | 20 km & 50 hPa |
Measured values
| Quantity | Units | NetCDF field | Uncertainty | Resolution |
|---|---|---|---|---|
| Pressure | hPa | pres | 1 hPa | 0.1 hPa |
| Temperature | °C | tdry | 0.5 oC | 0.1 oC |
| Relative Humidity | % | rh | 5% | 1% |
| Wind speed | m/s | wspd | 0.1 m/s | |
| Wind direction | deg | dir | 1 deg |
Derived values
| Quantity | Units | NetCDF field |
|---|---|---|
| Altitude | m | alt |
| Dew Point | °C | dp |
| Ascent Rate | m/s | alt |
| Latitude of Sonde | ° | lat |
| Longitude of Sonde | ° | lon |
| u-component of wind velocity | m/s | u_wind |
| v-component of wind velocity | m/s | v_wind |
¶ Expected Operations
¶ Metrics
The SONDE metrics table are slightly different from the other instruments as the table is split up by height and not time. Each sonde launch gets its own metrics table which means there may be multiple metrics tables per day.
¶ Plots
¶ Statistics Table
This table is for comparing the surface values reported in the sonde b1 level data and raw data. Go through the columns
- Time difference between the time indicating start of ascent and closest time record in the raw file
- MET Altitude
- SONDE Closest Altitude to MET Altitude
- MET Temperature at Time of Sonde Launch
- SONDE Temperature at the same altitude of the MET station
- SONDE Surface Temperature Recorded in the B1-Level File. This will just be the first record in the launch
- RAW Data Surface Temperature
- RAW Data Temperature at Time of Starting Ascent
- SONDE Surface RH Recorded in the B1-Level File
- RAW Data Surface RH
- RAW Data RH at Time of Starting Ascent
Skew-T
Normal Skew-T diagram of the sonde data
Sonde Path
The lat/lon path of the sonde mapped onto a google earth background. The plot below the path is of the Temperature and Altitude recorded in time
¶ Known Issues
¶ Known Behaviors
None documented at this time. Document some here.
¶ Past Problems
List of past problems for this instrument that DO need to be mentioned in your DQA's:
Stepping in dew point temperature data
Wet bulb effect
Missing wind data vs. calm winds
Tracking after balloon burst
- This image shows two different profiles for the Temperature and Relative Humidity plots. The Sonde continued tracking after the balloon was burst, creating an unusual atmospheric profile.
Not allowing sensor acclimation prior to launch
A very useful link
This site describes a number of issues that may arise with radiosondes.