SARCCM student Haifeng Zhang’s work has been featured in the recent issue of Marine Matters Issue 25
SARCCM student Haifeng Zhang’s work has been featured in the recent issue of Marine Matters Issue 25:
Investigating sea surface temperature (SST) diurnal variation (DV) over the tropical warm pool (TWP) region
Sea surface temperature diurnal variation, or diurnal warming, normally refers to the daily temperature rise in the upper few meters of the ocean. Diurnal warm layers have typical temperature differences relative to the body of water below in the order of 0.5-3°C. However, in some extreme cases such as when the wind is very calm and solar radiation is very strong, the differences can reach values up to 7-8°C. It is expected that the proper inclusion of sea surface temperature diurnal variation effects in air-sea coupled models, numerical weather prediction models, and climate models can enhance the model accuracy. Therefore, a comprehensive study of the spatial extent, frequency and amplitude of diurnal warming events is essential, particularly over the tropical warm pool region (90°E-170°E, 25°S-15°N) given its special location and role in global climate. University of New South Wales student Haifeng Zhang’s PhD project is using IMOS satellite and modelled data to focus on the description of the general features (Zhang et al., 2016a) and seasonal patterns (Zhang et al., 2016b) of diurnal variation events, the relationship between diurnal variation events and the driving meteorological variables (winds, solar radiation, etc.) It also has evaluated empirical diurnal variation models, physical diurnal variation models, and air-sea coupled model with diurnal variation scheme implemented. Initial results have shown the large amplitude (up to 6-8°C) and high frequency (especially in the austral summer) of sea surface temperature diurnal variation events over the tropical warm pool region. The more important role of morning winds, in comparison to 24-hour mean winds, has also been highlighted, which could be useful for diurnal variation model improvement. A future research will investigate the relationship between diurnal variation events and other meteorological phenomena, such as Madden-Julian Oscillation and precipitation.
Zhang, H., H. Beggs, L. Majewski, H. Wang, and A. Kiss (2016a), Investigating sea surface temperature diurnal variation over the Tropical Warm Pool using MTSAT- 1R data, Remote Sens. Environ., 183, 1–12, doi:10.1016/j.rse.2016.05.002.
Zhang, H., H. Beggs, X. H. Wang, A. E. Kiss, and C. Griffin (2016b), Seasonal patterns of SST diurnal variation over the Tropical Warm Pool, J. Geophys. Res., 121, doi:10.1002/2016JC012210.