In the frame of the PEACHI project, sea ice freeboard maps are computed for each SARAL/AltiKa cycle during winter, starting from cycle 08. The first step of the processing is to classify the waveforms as lead or sea ice echoes. The off-nadir leads are edited before computing the heights above the mean sea surface of leads and sea ice (hooking effects). The freeboard is then deduced as the difference between sea ice and leads heights. The maps are obtained by averaging the along-track freeboard per 1°x2° boxes over the entire SARAL/AltiKa cycle.

DATE DATA Cycle 01 (2013/03/14 - 2013/04/18) Cycle 02 (2013/04/18 - 2013/05/23) Cycle 03 (2013/05/23 - 2013/06/27) Cycle 04 (2013/06/27 - 2013/08/01) Cycle 05 (2013/08/01 - 2013/09/05) Cycle 06 (2013/09/05 - 2013/10/10) Cycle 07 (2013/10/10 - 2013/11/14) Cycle 08 (2013/11/14 - 2013/12/19) Cycle 09 (2013/12/19 - 2014/01/23) Cycle 10 (2014/01/23 - 2014/02/27) Cycle 11 (2014/02/27 - 2014/04/03) Cycle 12 (2014/04/03 - 2014/05/08) Cycle 13 (2014/05/08 - 2014/06/12) Cycle 14 (2014/06/12 - 2014/07/17) Cycle 15 (2014/07/17 - 2014/08/21) Cycle 16 (2014/08/21 - 2014/09/25) Cycle 17 (2014/09/25 - 2014/10/30) Cycle 18 (2014/10/30 - 2014/12/04) Cycle 19 (2014/12/04 - 2015/01/08) Cycle 20 (2015/01/08 - 2015/02/12) Cycle 21 (2015/02/12 - 2015/03/19) Cycle 22 (2015/03/19 - 2015/04/03) Cycle 23 (2015/04/03 - 2015/05/28) Cycle 24 (2015/05/28 - 2015/07/02) Cycle 25 (2015/07/02 - 2015/08/06) Cycle 26 (2015/08/06 - 2015/09/10) Cycle 27 (2015/09/10 - 2015/10/15) Cycle 28 (2015/10/15 - 2015/11/19) Cycle 29 (2015/11/19 - 2015/12/24) Cycle 30 (2015/12/24 - 2016/01/28)  Freeboard  Freeboard

Freeboard height in cm (difference between sea ice and leads heights) estimated from AltiKa measurements on Arctic ocean, from 2013 (cycle 08). Credits CNES-CLS-LEGOS.

In addition, the following movie illustrates the evolution of sea ice extent from Saral/AltiKa in the Arctic and Antarctic regions from March 2013. Each map corresponds to the percentage (per box) of waveforms classified as sea ice.