The Japanese system

The second eddy covariance system developed by the National Institute for Resources and Environment (NIRE, Tsukuba, Japan) was put into operation at the end of 1998, but because of technical difficulties, the system started to provide usable data in the beginning of March, 1999.

The new system was installed on a separate 10 m mast (which is also used in the concentration profiling system described in section ) at 3 m height. Thus, it has a very limited flux source area (Schmid, 1994, 1997), which means that information gathered by the system is representative to a circle of a maximum radius of 300 m around the mast following the meteorological rule of thumb (Businger, 1986).