On 10/6/22 13:40, Brooks Harris via tz wrote:
Predicting length of day (LOD) is a tricky business with no real consensus. ... From what I can tell C04 is *the* 'consensus' of LOD as a matter of practical common use.
Sure, but C04 describes LOD in the past. I was referring to LOD in the future. C04 is published with 30-day latency which is not enough for some apps, and I think even the IERS Daily Rapid EOP data have one-day latency. So even if you want to know LOD "now" you need to predict based on what it was earlier; and of course if you want to know LOD next week you must predict. Michalczak and Ligas[1] have a brief summary of some competing prediction approaches in their introduction. If you want to predict LOD for the next five millennia, which is what I had been talking about, the error bars get considerably larger and it is indeed a tricky business. [1] Michalczak M, Ligas M. The (ultra) short term prediction of length-of-day using kriging. Adv Space Res. 2022;70(3):610-620. https://doi.org/10.1016/j.asr.2022.05.007