Infrared and millimetre-wave scintillometry in the suburban environment – Part 1: Structure parameters

[摘要] Scintillometry, a form of ground-based remote sensing, provides thecapability to estimate surface heat fluxes over scales of a few hundredmetres to kilometres. Measurements are spatial averages, making thistechnique particularly valuable over areas with moderate heterogeneity suchas mixed agricultural or urban environments. In this study, we present thestructure parameters of temperature and humidity, which can be related tothe sensible and latent heat fluxes through similarity theory, for asuburban area in the UK. The fluxes are provided in the second paper of thistwo-part series. A millimetre-wave scintillometer was combined with aninfrared scintillometer along a 5.5 km path over northern Swindon. Thepairing of these two wavelengths offers sensitivity to both temperature andhumidity fluctuations, and the correlation between wavelengths is also usedto retrieve the path-averaged temperature–humidity correlation. Comparisonis made with structure parameters calculated from an eddy covariance stationlocated close to the centre of the scintillometer path. The performance ofthe measurement techniques under different conditions is discussed. Similarbehaviour is seen between the two data sets at sub-daily timescales. For thetwo summer-to-winter periods presented here, similar evolution is displayedacross the seasons. A higher vegetation fraction within the scintillometersource area is consistent with the lower Bowen ratio observed (midday Bowenratio < 1) compared with more built-up areas around the eddycovariance station. The energy partitioning is further explored in thecompanion paper.

[学科分类] 几何与拓扑