| Charuchittipan, D; Babel, W; Mauder, M; Leps, JP; Foken, T: Extension of the averaging time in eddy-covariance measurements and its effect on the energy balance closure, Boundary-Layer Meteorology, 152, 303-327 (2014), doi:10.1007/s10546-014-9922-6 | |
| Abstract: The modified ogive analysis and the block ensemble average were employed to investigate the impact of the averaging time extension on the energy balance closure over six land-use types. The modified ogive analysis, which requires a steady-state condition, can extend the averaging time up to a few hours and suggests that an averaging time of 30 min is still overall sufficient for eddy-covariance measurements over low vegetation. The block ensemble average, which does not require a steady-state condition, can extend the averaging time to several days.However, it can improve the energy balance closure for some sites during specific periods, when secondary circulations exist in the vicinity of the sensor. These nearsurface secondary circulations mainly transport sensible heat, and when near-ground warm air is transported upward, the sensible heat flux observed by the block ensemble average will increase at longer averaging times. These findings suggest an alternative energy balance correction for a ground-based eddy-covariance measurement, in which the attribution of the residual depends on the ratio of sensible heat flux to the buoyancy flux. The fraction of the residual attributed to the sensible heat flux by this energy balance correction is larger than in the energy balance correction that preserves the Bowen ratio. |
Aktuelle Termine
Aktuelle Termine
| BayCEER Short Courses: |
|---|
| Fr. 26.04.2024 aktuell Mobile Film Making Workshop (for students of BayCEER) |
| Ökologisch-Botanischer Garten: |
| So. 28.04.2024 Führung | Den Sängern auf der Spur: Vogelstimmen im ÖBG (zus. mit LBV) |
| So. 05.05.2024 Führung | Faszination Englische Gärten: Gestaltung und Pflanzen |
| So. 05.05.2024 Midissage | da capo - Ausstellung von Doris Bocka |
| Mi. 15.05.2024 Kurzführung | "Botanische Mittagspause" |