Print Email Facebook Twitter Mapping the aerodynamic roughness of the Greenland Ice Sheet surface using ICESat-2 Title Mapping the aerodynamic roughness of the Greenland Ice Sheet surface using ICESat-2: Evaluation over the K-transect Author van Tiggelen, Maurice (Universiteit Utrecht) Smeets, Paul C. J. P. (Universiteit Utrecht) Reijmer, Carleen H. (Universiteit Utrecht) Wouters, B. (TU Delft Physical and Space Geodesy; Universiteit Utrecht) Steiner, Jakob F. (Universiteit Utrecht; International Centre for Integrated Mountain Development) Nieuwstraten, Emile J. (Universiteit Utrecht) Immerzeel, Walter W. (Universiteit Utrecht) van den Broeke, Michiel R. (Universiteit Utrecht) Date 2021 Abstract The aerodynamic roughness of heat, moisture, and momentum of a natural surface are important parameters in atmospheric models, as they co-determine the intensity of turbulent transfer between the atmosphere and the surface. Unfortunately this parameter is often poorly known, especially in remote areas where neither high-resolution elevation models nor eddy-covariance measurements are available. In this study we adapt a bulk drag partitioning model to estimate the aerodynamic roughness length (z0m) such that it can be applied to 1D (i.e. unidirectional) elevation profiles, typically measured by laser altimeters. We apply the model to a rough ice surface on the K-transect (west Greenland Ice Sheet) using UAV photogrammetry, and we evaluate the modelled roughness against in situ eddy-covariance observations. We then present a method to estimate the topography at 1 m horizontal resolution using the ICESat-2 satellite laser altimeter, and we demonstrate the high precision of the satellite elevation profiles against UAV photogrammetry. The currently available satellite profiles are used to map the aerodynamic roughness during different time periods along the K-transect, that is compared to an extensive dataset of in situ observations. We find a considerable spatiooral variability in z0m, ranging between 10-4 m for a smooth snow surface and 10-1 m for rough crevassed areas, which confirms the need to incorporate a variable aerodynamic roughness in atmospheric models over ice sheets. To reference this document use: http://resolver.tudelft.nl/uuid:8cc6ce37-6284-4f91-8dad-835b5bdeec5e DOI https://doi.org/10.5194/tc-15-2601-2021 ISSN 1994-0416 Source The Cryosphere, 15 (6), 2601-2621 Part of collection Institutional Repository Document type journal article Rights © 2021 Maurice van Tiggelen, Paul C. J. P. Smeets, Carleen H. Reijmer, B. Wouters, Jakob F. Steiner, Emile J. Nieuwstraten, Walter W. Immerzeel, Michiel R. van den Broeke Files PDF tc_15_2601_2021.pdf 17.91 MB Close viewer /islandora/object/uuid:8cc6ce37-6284-4f91-8dad-835b5bdeec5e/datastream/OBJ/view