Surface Radiation Measurements at the Neumayer Ground Station (Antarctica)

Since March 1982 surface radiation balance measurements have been carried out
at the German Antarctic Georg-von-Neumayer Station of the Alfred Wegener
Institute for Polar and Marine Research (AWI).

The radiation signals are taken at one minute intervals and stored as averages
over 10 minutes. They include:

- global radiation (pyranometer CM11, Kipp+Zonen),
- reflected solar radiation (pyranometer CM11, Kipp+Zonen),
- downward long-wave radiation (pyrradiometer Lange),
- upward long-wave radiation (pyrradiometer Lange),
- sunshine duration (Solar 111, Haenni).

In March 1992 the radiation measurements at Neumayer were extended in order to
fulfill the standards of the Baseline Surface Radiation Network (BSRN). The
pyrradiometer were replaced by pyrgeometers (PIR Eppley), the averaging period
was reduced to 5 minutes, and the following quantities are now additionally
measured:

- diffuse sky radiation (pyranometer CM11, Kipp+Zonen),
- direct solar radiation (NIP, Eppley mounted on a sun tracker),
- OG1 (global>530nm, pyranometer CM11, Kipp+Zonen),
- RG8 (global>695nm, pyranometer CM11, Kipp+Zonen),
- UV (300-370nm, TUVR, Eppley).

The pyranometers and pyrgeometers are ventilated with slightly preheated air to
minimize hoar frost problems and zero offsets during cloudless and windless
conditions. The instruments were maintained continuously several times per day
throughout the year. After one year of operation they are re-calibrated at the
German Weather Bureau according the World Radiometric Reference (WRR).

At AWI, the radiation measurements - averaged over 10 & 5 minutes - are
archived together with the data from the mast measurements, daily upper air
soundings and routine synoptic surface observations in a relational database
(SYBASE). Additionally some derived quantities (Iqbal 1983) such as the solar
elevation, extraterrestrial solar insolation, astronomical sunshine duration
are available.

In order to obtain daily averaged radiation data, each day was subdivided into
eight 3-hourly intervals (0-3, 3-6, ..., 21-24 UTC). For each 3-hourly interval
an average was derived irrespective of the number of measurements. This
procedure was chosen in order to minimize problems resulting from missing
values. If one or more 3-hourly averages were missing, no daily average was
calculated.

Daily averaged radiation data are available from 13 March 1982 till 28 February
1994. They can be retrieved directly via World Wide Web:
'http://www.bremerhaven.de/sixcms/detail.php?id=13742'.