Monsoonal and annual energy fluxes variations in the atmospheric surface layer over a coastal region of the tropical ocean

Abstract The tropical coastal ocean is a vital jigsaw-piece to understanding exchanges of energy, moisture, and carbon between the atmosphere and the ocean biospheres. Latent and sensible heat fluxes, micro-climate variables, and surface water temperature data in the atmospheric surface layer were collected using an instrumented tower at a tropical coastal ocean (5 ∘ 28’6”N, 100 ∘ 12’1”E). The instrumented tower was installed on a stainless-steel platform extending a pre-existing pier. Data were collected for two years, i.e., November 2015 to October 2017, which encompassed two annual cycles of the Monsoons. The first objective of this work is to describe the Monsoonal and annual patterns of latent (LE) and sensible (H) heats while the second objective is to link the micro-climate variables to the energy fluxes on the seasonal and annual time scales. The inter-annual variation of energy input into the study is minimal (3% and 4% in the values recorded for the R G and R n ). The average albedo was 0.29 and the Bowen ratio was 0.11. Annual changes in LE and H between the two years were apparent both at 14% increased and decreased, respectively. LE is largely modulated by the Monsoons, where it is higher in the Northeast Monsoon (dry and hot) than the Southwest Monsoon (wet and cold). Conversely, H did not exhibit appreciably changes with the Monsoon and mostly followed the downward R n trend. Variations between Monsoons are ten times larger than between years, thus highlighting its significance in controlling the regional conditions. Between the Northeast and Southwest Monsoons, the change in LE, i.e., Δ LE recorded was −30% while that of H, i.e., Δ H was ＋18%. These results have important applications in improving numerical weather models and closing the energy budget.