In Gobabeb, Namibia SWD, LWD and DIR are each measured redundant with two instruments of the same make (not in this data base). The differences between the pairs are used in the quality control. This is done manually by inspecting plots of half-day diurnal courses of the pairs and their differences. Values are removed mostly in the morning due to daily cleaning. Other reasons for larger differences are birds, insects, or people at the station. There are regular fog events varying in frequency over the year. Usually, the fog appears in the second half of the night and disappears a few hours after sunrise. The case temperatures of pyrgeometers practically never drop below dewpoint but there can be water deposition of the dome.

MAINTENANCE The tracker site is checked on a daily basis usually between 6 and 7 UTC. Instruments are visually inspected and cleaned if necessary. QUALITY CONTROL IN GENERAL SWdn, LWdn and DN are each measured redundant with two instruments of the same make (SWdnred, LWdnred, DNred, not in BSRN data base). The differences between the pairs are used to flag erroneous values. This is done manually by inspecting plots of half-day diurnal courses of the pairs and their differences. Values are flagged mostly in the morning due to daily cleaning. Other reasons for larger differences are birds, bird deposits (seldom), or people at the station. Individual causes for flags are not reported unless the flag length is substantial and the cause is known. There are regular fog events varying in frequency over the year. Usually the fog appears in the second half of the night and disappears a few hours after sunrise. The case temperatures of pyrgeometers practically never drop below dewpoint but there can be water deposition of the dome. There are regular fog events varying in frequency over the year. Usually the fog appears in the second half of the night and disappears a few hours after sunrise. The case temperatures of pyrgeometers practically never drop below dewpoint but there can be water deposition of the dome. Drying of wet pyrgeometer domes now indicated with a *. GRAPHICAL QC SWdn minus SWdnred typically negative with amplitudes up to 15 W/m2. DN minus DNred typically positive with amplitudes from 5 to 10 W/m2. Negative amplitude with -8 W/m2 on Oct 29. Several days with fog (13, 14, 16, 17, 18, 19, 24, 25, 26, 27).