......the CAB stays a constant from January - June each year, then somewhere around July 10th give or take a week a steady decrease from that 4.2-4.4 value occurs every year. The depth of that decrease varies significantly but the duration is identical, and the refreeze begins also within quite a limited calendar period until it again rises into the 4.2-4.4 range.
The 5 day average NSIDC average that Gerontocrat reports here every day peaked at 3.2M km2 in March.
Any # of 4.2 - 4.4M km2 is coming from a different area measure. The complexity of an internet discussion involving multiple measures of the same 2D attribute (area) from a single agency (NSIDC) makes productive exchange unlikely. It becomes
too confusing.
NSIDC's CAB size is ~3.2M km2. There is no double measure from a single agency.
In addition to this definition, there used to be a web site called Cryosphere Today (CT for short) that had regional area data and/or charts, in which the CAB was defined as ~4.4M km2. That website is no longer active. However, a certain user called Wipneus, you may have heard of him, has decided to recreate the CT Area data by analysing and number crunching the raw data coming from NSIDC. The same Wipneus has done the same with the raw data coming from JAXA and from UH Hamburg, and on his website the ArctischePinguin he publishes this data daily, using the same regional demarcations of CT.
Wipneus also made some tweaks and improvements to the algorithm of deciding how much area there is, resulting in his Home Brew AMSR2 data thread. I recommend to read its beginning posts, they could teach you a lot.
All this happened before my time here. How do I know this then? Because I have been an avid reader of the forum for the past 5 years.
Having come to some realizations about the regional data, I once (or thrice) posted a suggestion to split the CAB to several sectors (Pacific-facing, Siberian-facing, Atlantic-facing) each having a distinct melting season behavior, and a much smaller CAB. No one took up on my suggestion. I could do the calculations myself, but it's too difficult for me, so I just shut up.
If you want to advance the cause of science - don't complain, be a doer: petition the NSIDC for a new demarcation of the regions. Will they listen? Dunno. Haven't tried.
Alternatively, do what Wipneus did, and number-crunch a new regional demarcation. Can you? Dunno.
Alternatively, use the data you are given, and don't complain, especially not on the leading threads. Just my take on it.