Upper AIr Soundings at Neumayer
Upper air soundings are carried out routinely once a day between 10 and 12 UTC. They include profile measurements of pressure, temperature, relative humidity and wind vector. Since March 1992 ozone measurements have also been performed about once a week. Usually the profiles start at 2 m above ground (32 - 42 m above sea level) and end between 15 and 37 km.
For the soundings VAISALA RS92 radiosondes, carried by helium-filled balloons (TOTEX 600, 800, 1500) are used. The data is coded (FM35-Temp) and transferred directly via email to the Global Telecommunication System (GTS) where it contributes to weather forecasting.
To obtain the ozone profiles an additional ozone sensor (VAISALA, ECC/6A) is been attached to the radiosonde. The wind vector is determined with the aid of the GPS navigation system. Data reception and evaluation were originally carried out by a MicroCora System (VAISALA). In March 1992 the MicroCORA was replaced by the DigiCORA II (VAISALA). Since November 2003 a DigiCora III is used.
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Mean Vertical Profiles from Neumayer
The mean temperature profiles show a well pronounced tropopause and a relatively warm stratosphere in summer. During winter, the temperature in the stratosphere drops below -85 deg. Celsius.
The relative humidity continuously decreases with height in the troposhere and is close to zero in the stratosphere. This effect is partly caused by the fact that relative air humidity is defined with respect to the absolute water vapour pressure above a plain pure water surface which is always greater than the absolute water vapour pressure over ice.
Easterly winds (negative zonal component) dominate the lower tropospheric wind field up to a height of 4000 m during winter and 6000 m during summer. In higher levels strong westerlies dominate during wintertime, indicating the well established polar vortex during the dark season. Very strong stratospheric winds (above 50 m/s), advecting warm air from the lower latitudes, are observed each year during spring.
The meridional wind component is usually light from the south (positive values) at all heights during the entire year.
Zonal and meridional wInd profiles
Temperature and humidity profiles
Typical time-height sections from Neumayer (1993)
Neumayer 1993
Temperature
Meridional wind
Zonal wind
Wind direction
Archiving and Retrieving Data
At AWI the upper air soundings are archived together with the routine 3-hourly weather observation and surface radiation measurements in a relational database (SYBASE). Upper air soundings are available since 21 February 1983. Current soundings normally reach the database once a year.
The data in the database can be retrieved directly in two different forms:
- mean pressure levels (up to one month at a time),
- full height resolution (day by day).
Current news about the status of the database can be found here.