About the CryoVal Sea Ice Project

The goal of the European Space Agency (ESA) CryoSat-2 radar altimeter mission, launched in April 2010, is to provide the scientific community with accurate measurements of mass and thickness fluctuations in the Earth’s land and marine ice fields. Such measurements are of particular importance for the testing and verification of mesoscale and regional numerical models that include cryospheric components, and for improving our understanding and predictions of the impact of a changing climate on the cryosphere.

To support the realisation of the mission's science goals and in response to the wider user community requirement for measurements which are supported by estimates of their uncertainty, ESA has initiated a programme of ground and airborne activities called CryoVEx (CryoSat Validation Experiments) to quantify the uncertainty in Cryosat products. In particular two major CryoVEx campaigns were carried out in 2011 and 2012.

In parallel to the CryoSat-2 mission, the National Aeronautics and Space Administration (NASA) in the United States successfully launched and operated the IceSat-1 satellite from 2003 to 2009 and is currently preparing a follow-on satellite mission IceSat-2 for launch in ~ 2016. To ensure continuity of science and data, NASA has started the IceBridge programme with a focus on large-scale airborne campaign activities to collect data that will help scientists bridge the gap in polar observations between IceSat-1 and -2.

The combined use of data from the ESA CryoSat and NASA IceSat missions by the science community is expected to bring with it benefits and science return above and beyond what the missions could achieve taken in isolation. To realise these benefits, however, requires a careful and thorough assessment of the specific uncertainties affecting each mission and new approaches to cross-calibrate the data time series from each mission.

The CryoVal-SI project is focused on addressing the error budgets for sea ice making use of extensive in- situ, airborne and satellite datasets acquired in multi-year sea ice regions north of Greenland and Canada complemented by seasonal ice datasets acquired near Svalbard.

Study Objectives

The main objectives of the study are:

The establishment and documentation of error sources and overall budgets for CryoSat and IceSat missions over sea ice to be used as a framework for evaluating the validation of CryoSat products and preliminary concepts for linking CryoSat with IceSat missions (e.g. biases and residual uncertainties);
The consolidation of satellite, airborne and ground data from the CryoVex and IceBridge campaigns over sea ice leading to a reference database of measurements to support both the direct evaluation of CryoSat product accuracy and address cross- calibration with IceSat.
Analysis using the reference consolidated database to i) quantify and document the uncertainties in CryoSat measurement data and ii) provide a preliminary quantitative assessment of biases between CryoSat and IceSat products.
Provide conclusions and recommendations on the design and objectives of future sea ice campaign activities, in particular focusing on the achievements to date and addressing gaps in CryoSat validation and cross-calibration with IceSat.