Final Report for DOE Grant DE-FG02-06ER64160 Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations using ARM Observations. Page: 2 of 7

                                
1. Introduction

This report briefly summaries the work performed at KNMI under DOE Grant DE-F602-06ER64160
which, in turn was conducted in support of DOE Grant DE-FG02-90ER61071 lead by E. Clothieux of
Penn. State U. The specific work at KNMI revolved around the development and application of the
EarthCARE simulator to ground-based multi-sensor simulations.
2. The EarthCARE simulator (ECSIM).
EarthCARE is an ESA/JAXA satellite mission to be launched in 2016. The mission is composed of a
cloud profiling radar, an advanced cloud/aerosol lidar, a multi-spectral imager and a three-view Broad-
Band Radiometer (See https://earth.esa.int/web/guest/missions/esa-future-missions/earthcare) . The
combination of the active and passive sensor on one platform is a unique feature of EarthCARE and
will enable the mission to probe the vertical structure of the atmosphere and relate the observed
structure to the top of atmosphere radiances and fluxes. By doing so, EarthCARE will provide
observations critical for the accurate modeling of 3-D radiation field. The unique combinations of co-
located sensors will continue the record of active satellite (i.e. lidar+radar) cloud and aerosol
observations begun with CloudSat and CALIPSO but also enable new and exciting cloud/aerosol
related process studies to be carried out.
The EarthCARE (ECSIM) simulator was originally developed in support of EarthCARE. ECSIM is a
comprehensive multi-instrument simulator framework together with various component models [1,2].
Central to the idea behind ECSIM is the idea of being able to conduct 'end-to-end' simulations (Figure
1) . That is, based on a defined atmospheric scene simulated observations are generated using accurate
forward and instrument models. Retrieval algorithms can then applied to the simulated observations
and the accuracy and precision of the results may be compared to the input "truth". The direct
comparison with the "truth" cannot be accomplished using real measurements. However, by
conducting radiative transfer calculations based on retrieval products it is possible to compare e.g.
surface or TOA fluxes and/or radiance against real measurements. The simulation environment can
also be used to facilitate such studies enabling radiative closure strategies that could be applied to real
measurements to be quantitatively evaluated in terms of accuracy and precision.