1. Evaluation for China L band radiosonde Dr. LI Wei CMA Meteorological Observation Centre

2. 气象探测中心 Meteorological Observation Center Distribution on Sites

3. 气象探测中心 Meteorological Observation Center Type Sensors GTS1GTS1-2 advanced version TemperatureRod thermistor diameter 1 mm Rod thermistor Diameter 1.2 mm Bead thermistor diameter 0.5 mm PressureSilicon piezoresistance Aneroid capsule capacitor HumidityCarbon hygristorThin-film capacitor

4. 气象探测中心 Meteorological Observation Center GTS1 GTS1-2 & GTS1-2 advanced version

5. 气象探测中心 Meteorological Observation Center RS92 as reference radiosonde. Multiple radiosondes attached on one balloon.

6. 气象探测中心 Meteorological Observation Center Error separating method Principle: (1) If there are enough sample data, the data distribution will be normalization. (2) Two radiosondes with the same sensors between which the statistical systematic errors (SE) should be near zero. And the STD of each them should be approximately equal.

7. 气象探测中心 Meteorological Observation Center Analytical Methods of Dynamic Measurement Error 1)Taking RS92 as a standard and GTS1, GTS1-2 as tests, the STD of the tests is given by formula (1): (1) 2) As the principle, the separated STD of RS92 is given by formula (2): (2) So the individual STD of RS92, GTS1 and GTS1-2 can be achieved.

8. 气象探测中心 Meteorological Observation Center Comparative Trial Data description Comparative trials sites : Yangjiang, Xinlinhaote and Nanjing upper-air stations The number of releasing sounding balloons: 65 Available data sets: 59 Methods of trails: GTS1RS92 GTS1-2RS92GTS1RS92 GTS1-2 GTS1-2 advanced RS92 Yangjiang, Xinlinhaote YangjiangNanjing

9. 气象探测中心 Meteorological Observation Center Results of comparative Trial comparative results (RS92 is standard) P (hPa) T ( ℃ ) U (%RH) STDSESTDSESTDSE GTS1 ≥500hPa 0.76-1.22 ≥100hPa 0.230.12 ≥-25 ℃ 5.53-7.78 GTS1-20.59-0.28 0.320.055.972.22 GTS1-2 advanced 0.13-0.12 GTS1 < 500hPa 0.65-0.98 <100hPa 0.670.14 <-25 ℃ 8.472.78 GTS1-20.48-0.45 0.400.0910.53-4.55 GTS1-2 advanced 0.31-0.31

10. 气象探测中心 Meteorological Observation Center Pressure GTS1-2 GTS1 hPa

11. 气象探测中心 Meteorological Observation Center Pressure GTS1-2 GTS1-2 advanced version

12. 气象探测中心 Meteorological Observation Center Temperature GTS1 GTS1-2

13. 气象探测中心 Meteorological Observation Center Temperature GTS1-2 advanced version

14. 气象探测中心 Meteorological Observation Center Humidity GTS1 GTS1-2

15. 气象探测中心 Meteorological Observation Center Wind DirectionWind Speed GTS1 & GTS1-2 (using the same type of L-band radar)

16. 气象探测中心 Meteorological Observation Center Wind DirectionWind Speed

17. 气象探测中心 Meteorological Observation Center 5. Conclusion (1) The temperature sensor of radiosonde used in China has been changed from the rod-shaped thermistor to bead thermistor gradually, the measurement accuracy has been improved significantly, and the radiation error has also been effectively corrected. (2) At present, the GTS1-2 radiosonde has better performance than GTS1, but the humidity measurement still exist a certain gap compared with RS92.

18. 气象探测中心 Meteorological Observation Center (3) Through software algorithm, bias for pressure measurement can be corrected largly. (4)Current operational wind calculation method has relative large wind pulse affection, and some real results reflecting the wind speed and direction have also been smoothed. The moving average vector method can better eliminate the pulsation effect. If using the 1 minute moving average window to calculate the upper-air wind per second, it can be consistent with GPS wind measurement.

19. 气象探测中心 Meteorological Observation Center