Tested the 1286 puzzle with the monthly ice-core data

Downloaded the 2023 study's supplementary spreadsheets. No eclipse descriptions survive for 1284 to 1286. The monthly sulfate shows Antarctica rising from August 1285 and Greenland a year later, but a calibration against 1229, 1257 and 1276 showed Greenland lags like that after other eruptions too, so the lag is a dating drift and says nothing about where the volcano was. Result: the eruption probably happened in the first half of 1285, and the idea that its veil stayed in the south is weakened. A good example of why every pattern needs a calibration check.