A 17-year vessel-level dataset of port congestion, operational mode, and idling emissions at five major US ports (2009-2025)

Daily-census, vessel-level record of cargo/tanker dwell time at five US port complexes (Los Angeles/Long Beach, New York/New Jersey, Houston, Savannah, Seattle), 2009-2025, from terrestrial AIS (209.5M in-port position reports). Three products: (i) monthly per-port dwell metrics (1,016 port-months); (ii) per-vessel operational-mode hours - anchor/berth/manoeuvre/transit via NOAA charted anchorage areas (268,103 vessel-months); (iii) a CARB-calibrated idling-emissions layer (CO2/NOx/PM2.5) for LA/Long Beach. Internally validated against a verified 2022 benchmark; externally corroborated vs the NY Fed GSCPI and CARB; era-seam and emission cross-checks documented. Companion papers: Communications Earth & Environment (analysis) and Scientific Data (descriptor). Report emissions as relative change; absolute CO2 intensity is method-dependent (band 24-69 t/ship-day).