The Influence of Snow Cover on the Seasonal Variation of Global Clumping Index Products

The foliage Clumping Index (CI) quantifies the level of foliage grouping within a distinct canopy structure relative to a random distribution. It is a key structure parameter for the ecological, hydrological, and land surface models. In this study, we investigate the influence of snow cover on the seasonal variation of global CI products derived from the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) parameter products using the improved RTCLSR kernel-driven model. Results indicated that the cover of snow can lead to a much larger CI and thus considerably decrease the quality of the CI product. Statistics in 2006 indicates that more than 85% low quality pixels are covered by the snow. The average CI for evergreen needleleaf forests in winter will decrease about 0.1 after deducing the influence of snow covered pixels. The influence of snow cover should be carefully considered and corrected when analyzing the seasonal variation of the global CI product.

[1]  H. Fang,et al.  Estimation of canopy clumping index from MISR and MODIS sensors using the normalized difference hotspot and darkspot (NDHD) method: The influence of BRDF models and solar zenith angle , 2016 .

[2]  J. Chen,et al.  Global mapping of foliage clumping index using multi-angular satellite data , 2005 .

[3]  Hongliang Fang,et al.  Intercomparison of clumping index estimates from POLDER, MODIS, and MISR satellite data over reference sites , 2015 .

[4]  Xiaoning Zhang,et al.  A visualization tool for the kernel-driven model with improved ability in data analysis and kernel assessment , 2016, Comput. Geosci..

[5]  T. Nilson A theoretical analysis of the frequency of gaps in plant stands , 1971 .

[6]  Yang Li,et al.  A modified version of the kernel-driven model for correcting the diffuse light of ground multi-angular measurements , 2018, Remote Sensing of Environment.

[7]  Rong Wang,et al.  Inter- and intra-annual variations of clumping index derived from the MODIS BRDF product , 2016, Int. J. Appl. Earth Obs. Geoinformation.

[8]  A. Strahler,et al.  Global clumping index map derived from the MODIS BRDF product , 2012 .

[9]  Michael Sprintsin,et al.  Long term and seasonal courses of leaf area index in a semi-arid forest plantation , 2011 .

[10]  Alan H. Strahler,et al.  An algorithm for the retrieval of the clumping index (CI) from the MODIS BRDF product using an adjusted version of the kernel-driven BRDF model , 2018 .

[11]  T. Black,et al.  Foliage area and architecture of plant canopies from sunfleck size distributions , 1992 .

[12]  Peng Gong,et al.  Foliage Clumping Index Over China's Landmass Retrieved From the MODIS BRDF Parameters Product , 2012, IEEE Transactions on Geoscience and Remote Sensing.

[13]  K. Wilson,et al.  How the environment, canopy structure and canopy physiological functioning influence carbon, water and energy fluxes of a temperate broad-leaved deciduous forest--an assessment with the biophysical model CANOAK. , 2002, Tree physiology.

[14]  R. Ceulemans,et al.  Under-story contributions to stand level GPP using the process model SECRETS , 2006 .

[15]  Alan H. Strahler,et al.  A Method for Improving Hotspot Directional Signatures in BRDF Models Used for MODIS , 2016 .

[16]  Martha C. Anderson,et al.  Utility of an image-based canopy reflectance modeling tool for remote estimation of LAI and leaf chlorophyll content at the field scale , 2009 .