Dataset contains continuous particle counts from GRIMM EDM264 Pro particle counter with an attached meterological station that were collected from the Tara Schooner during the first year of the TREC expedition (2023). Date includes date, time, particle counts from PM1 to PM10 or size fraction from 0.25 µm to 35 µm. Contextual environmental variables include, temp., relative humiditiy, precipitation, Pressure, Wind velocity and direction.