The AGU created a new archiving site for preprints called ESSOAR

The Earth and Space Science Open Archive (ESSOAr) is a community server established to accelerate the open discovery and dissemination of Earth and space science early research outputs, including preprints and posters presented at major scientific meetings. In the future, other rich conference presentations may be added.

I submitted my AGU poster on ENSO and QBO to the site, and it appears that it is the first submitted along with a climate change preprint

The browse topic screen for latest submissions:

My presentation is here, tagged under a few topic categories
https://www.essoar.org/doi/abs/10.1002/essoar.b1c62a3df907a1fa.b18572c23dc245c9.1