Observed sea breeze life cycle in and around NYC: Impacts on UHI and ozone patterns

This observational study investigates New York City (NYC) impacts on summer sea breeze fronts (SBFs) during a 2018 LISTOS Campaign day with regional heat wave and O3 episode. A morning urban island peaked at 8.3 °C then induced convergences into the City, trapping its NO2 emissions. SBFs came ashore 0700 EST from Atlantic along southern Long Island (LI), LI Sound northern Connecticut; 2-h later another formed over Jersey. The Ocean front was retarded NYC noon, while all merged by 1400 continued inland for four more hours. High first appeared 0900 downwind of NYC. By 1100 EST, new surface peak north in Hudson River Valley (HRV). maxima merged, peaking 143 ppb 1300 behind SBF near maximum temperatures 39 °C. Trajectories ending site PBL passed NYC, arrived before episode, recirculated back SB flow. HRV showed pollutant transport twice, advection northward narrow ocean SBF.