Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: C. Notarnicola x
  • All content x
Clear All Modify Search
G. Cappelluti, A. Morea, C. Notarnicola, and F. Posa

Abstract

This paper describes an algorithm that is aimed at the identification of cloudy and clear pixels in Moderate-Resolution Imaging Spectroradiometer (MODIS) images to support earth science and nowcasting applications. The process from geolocated and calibrated data allows one to obtain cloud masks with four clear-sky confidence levels for five different cloud system types. The technique has been developed using the MODIS cloud-mask algorithm heritage, but the threshold tests performed have been executed without comparing solar reflectances and thermal brightness temperatures with thresholds determined in advance, but instead with thresholds carried out from classification methods. The main advantage of this technique is that the thresholds are obtained directly from the images. Seventy-five percent of the spectral signatures (known as end members) derived from the winter images in the detection of the various cloud types and 80% of the summer end members can be considered as being well discriminated. Furthermore, it seems that the end members characterizing the different cloud systems are constant throughout the various seasons of the year (they vary with a confidence level of 60%), whereas those describing clear sky change in a notable manner (the associated confidence level is 99%). The algorithm is able to produce cloud masks pertinent to limited regions at a mesoscale level, which may be a key factor for nowcasting purposes. This work shows that the use of end members and spectral angles, as opposed to spectral thresholds, should be carefully examined because of the fact that it might be simpler or that higher performances may be achieved at a regional scale.

Full access
B. Wolf, C. Chwala, B. Fersch, J. Garvelmann, W. Junkermann, M. J. Zeeman, A. Angerer, B. Adler, C. Beck, C. Brosy, P. Brugger, S. Emeis, M. Dannenmann, F. De Roo, E. Diaz-Pines, E. Haas, M. Hagen, I. Hajnsek, J. Jacobeit, T. Jagdhuber, N. Kalthoff, R. Kiese, H. Kunstmann, O. Kosak, R. Krieg, C. Malchow, M. Mauder, R. Merz, C. Notarnicola, A. Philipp, W. Reif, S. Reineke, T. Rödiger, N. Ruehr, K. Schäfer, M. Schrön, A. Senatore, H. Shupe, I. Völksch, C. Wanninger, S. Zacharias, and H. P. Schmid

Abstract

ScaleX is a collaborative measurement campaign, collocated with a long-term environmental observatory of the German Terrestrial Environmental Observatories (TERENO) network in the mountainous terrain of the Bavarian Prealps, Germany. The aims of both TERENO and ScaleX include the measurement and modeling of land surface–atmosphere interactions of energy, water, and greenhouse gases. ScaleX is motivated by the recognition that long-term intensive observational research over years or decades must be based on well-proven, mostly automated measurement systems, concentrated in a small number of locations. In contrast, short-term intensive campaigns offer the opportunity to assess spatial distributions and gradients by concentrated instrument deployments, and by mobile sensors (ground and/or airborne) to obtain transects and three-dimensional patterns of atmospheric, surface, or soil variables and processes. Moreover, intensive campaigns are ideal proving grounds for innovative instruments, methods, and techniques to measure quantities that cannot (yet) be automated or deployed over long time periods. ScaleX is distinctive in its design, which combines the benefits of a long-term environmental-monitoring approach (TERENO) with the versatility and innovative power of a series of intensive campaigns, to bridge across a wide span of spatial and temporal scales. This contribution presents the concept and first data products of ScaleX-2015, which occurred in June–July 2015. The second installment of ScaleX took place in summer 2016 and periodic further ScaleX campaigns are planned throughout the lifetime of TERENO. This paper calls for collaboration in future ScaleX campaigns or to use our data in modelling studies. It is also an invitation to emulate the ScaleX concept at other long-term observatories.

Full access