You can use ZoteroBib (see next box) to render a reference and in-text citation in AGU style. You can check the results against the AGU guide below.
If you don't see a format covered, go to Purdue's Owl and follow the APA style. For information specifically about citing data, see the resource immediately below.
You can use ZoteroBib to create a list of citations, for a bibliography at the end of a paper, in a style that you select from "10,000 +" styles.
This .gif at James Madison University provides a quick overview of how to create a list of citations and then paste into your paper.
For some more details about using ZoteroBib, see this video:
We have seen how to create a bibliography to put at the end of your paper. For details about doing an in-text citation, in which you cite a brief reference to a citation within the text of your paper, which points to the full citation in the bilbliography at the end of your paper, see this tutorial: NOTE: change the citation style if this feature does not work. This video is from the Royal College of Nursing: