TY  - JOUR
A1  - Kokhanovsky, Alexander
A1  - Lamare, Maxim
A1  - Danne, Olaf
A1  - Brockmann, Carsten
A1  - Dumont, Marie
A1  - Picard, Ghislain
A1  - Arnaud, Laurent
A1  - Favier, Vincent
A1  - Jourdain, Bruno
A1  - Le Meur, Emmanuel
A1  - Di Mauro, Biagio
A1  - Aoki, Teruo
A1  - Niwano, Masashi
A1  - Rozanov, Vladimir
A1  - Korkin, Sergey
A1  - Kipfstuhl, Sepp
A1  - Freitag, Johannes
A1  - Hoerhold, Maria
A1  - Zuhr, Alexandra
A1  - Vladimirova, Diana
A1  - Faber, Anne-Katrine
A1  - Steen-Larsen, Hans Christian
A1  - Wahl, Sonja
A1  - Andersen, Jonas K.
A1  - Vandecrux, Baptiste
A1  - van As, Dirk
A1  - Mankoff, Kenneth D.
A1  - Kern, Michael
A1  - Zege, Eleonora
A1  - Box, Jason E.
T1  - Retrieval of Snow Properties from the Sentinel-3 Ocean and Land Colour Instrument
JF  - Remote sensing
N2  - The Sentinel Application Platform (SNAP) architecture facilitates Earth Observation data processing. In this work, we present results from a new Snow Processor for SNAP. We also describe physical principles behind the developed snow property retrieval technique based on the analysis of Ocean and Land Colour Instrument (OLCI) onboard Sentinel-3A/B measurements over clean and polluted snow fields. Using OLCI spectral reflectance measurements in the range 400-1020 nm, we derived important snow properties such as spectral and broadband albedo, snow specific surface area, snow extent and grain size on a spatial grid of 300 m. The algorithm also incorporated cloud screening and atmospheric correction procedures over snow surfaces. We present validation results using ground measurements from Antarctica, the Greenland ice sheet and the French Alps. We find the spectral albedo retrieved with accuracy of better than 3% on average, making our retrievals sufficient for a variety of applications. Broadband albedo is retrieved with the average accuracy of about 5% over snow. Therefore, the uncertainties of satellite retrievals are close to experimental errors of ground measurements. The retrieved surface grain size shows good agreement with ground observations. Snow specific surface area observations are also consistent with our OLCI retrievals. We present snow albedo and grain size mapping over the inland ice sheet of Greenland for areas including dry snow, melted/melting snow and impurity rich bare ice. The algorithm can be applied to OLCI Sentinel-3 measurements providing an opportunity for creation of long-term snow property records essential for climate monitoring and data assimilation studies-especially in the Arctic region, where we face rapid environmental changes including reduction of snow/ice extent and, therefore, planetary albedo.
KW  - snow characteristics
KW  - optical remote sensing
KW  - snow grain size
KW  - specific surface area
KW  - albedo
KW  - Sentinel 3
KW  - OLCI
Y1  - 2019
U6  - https://doi.org/10.3390/rs11192280
SN  - 2072-4292
VL  - 11
IS  - 19
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Sicard, Adrien
A1  - Thamm, Anna
A1  - Marona, Cindy
A1  - Lee, Young Wha
A1  - Wahl, Vanessa
A1  - Stinchcombe, John R.
A1  - Wright, Stephen I.
A1  - Kappel, Christian
A1  - Lenhard, Michael
T1  - Repeated evolutionary changes of leaf morphology caused by mutations to a homeobox gene
JF  - Current biology
N2  - Elucidating the genetic basis of morphological changes in evolution remains a major challenge in biology [1-3]. Repeated independent trait changes are of particular interest because they can indicate adaptation in different lineages or genetic and developmental constraints on generating morphological variation [4-6]. In animals, changes to "hot spot" genes with minimal pleiotropy and large phenotypic effects underlie many cases of repeated morphological transitions [4-8]. By contrast, only few such genes have been identified from plants [8-11], limiting cross-kingdom comparisons of the principles of morphological evolution. Here, we demonstrate that the REDUCED COMPLEXITY (RCO) locus [12] underlies more than one naturally evolved change in leaf shape in the Brassicaceae. We show that the difference in leaf margin dissection between the sister species Capsella rubella and Capsella grandiflora is caused by cis-regulatory variation in the homeobox gene RCO-A, which alters its activity in the developing lobes of the leaf. Population genetic analyses in the ancestral C. grandiflora indicate that the more-active C. rubella haplotype is derived from a now rare or lost C. grandiflora haplotype via additional mutations. In Arabidopsis thaliana, the deletion of the RCO-A and RCO-B genes has contributed to its evolutionarily derived smooth leaf margin [12], suggesting the RCO locus as a candidate for an evolutionary hot spot. We also find that temperature-responsive expression of RCO-A can explain the phenotypic plasticity of leaf shape to ambient temperature in Capsella, suggesting a molecular basis for the well-known negative correlation between temperature and leaf margin dissection.
Y1  - 2014
U6  - https://doi.org/10.1016/j.cub.2014.06.061
SN  - 0960-9822
SN  - 1879-0445
VL  - 24
IS  - 16
SP  - 1880
EP  - 1886
PB  - Cell Press
CY  - Cambridge
ER  -