IJIS:
11,782,166 km2(May 8, 2016)
Largest one-day drops of JAXA/IJIS extent in spring melting season, start to current calendar date (2003-2016)
1. 154,512 April 10, 2004
2. 132,772 April 25, 2013
3. 130,413 May 8, 20164. 129,382 April 11, 2004
5. 127,666 April 12, 2004
If not due to a sensor or processing glitch, the April 10 to April 14 2004 ice extent drop must have been a remarkable event, losing 583,000 km2 in five days. I assume that it was a large-scale wind and/or current ice compaction event rather than melting.