Variability of Diurnal Sea Surface Temperature during Short Term and High SST Event in the Western Equatorial Pacific as Revealed by Satellite Data

Abstract

Near-surface diurnal warming is an important process in the climate system, driving exchanges of water vapor and heat between the ocean and the atmosphere. The occurrence of the hot event (HE) is associated with the high diurnal sea surface temperature amplitude (δSST), which is defined as the difference between daily maximum and minimum sea surface temperature (SST). However, previous studies still show some inconsistency for the area of HE occurrence and high δSST. The present study produces global δSST data based on the SST, sea surface wind data derived from microwave radiometers, and solar radiation data obtained from visible/infrared radiometers. The value of δSSTs are estimated and validated over tropical oceans and then used for investigating HE in the western equatorial Pacific. A three-way error analysis was conducted using in situ mooring buoy arrays and geostationary SST measurements by the Himawari-8 and Geostationary Operational Environmental Satellite (GOES). The standard deviation error of daily and 10-day validation is around 0.3 °C and 0.14–0.19 °C, respectively. Our case study in the western Pacific (from 110°E to 150°W) shows that the area of HE occurrence coincided well with the area of high δSST. Climatological analysis shows that the collocated area between high occurrence rate of HE and high δSST, which coincides with the western Pacific warm pool region in all seasons. Thus, this study provides more persuasive evidence of the relation between HE occurrence and high δSST.

Retrieval of Daily Mean VIIRS SST Products in China Seas

“…Therefore, it is little feasible to obtain daily mean SST data through satellite data fusion. At this time, various estimation models for SST diurnal variation are established by utilization of solar radiation, sea surface wind speed, precipitation and other data [45,48,49]. It is challenging to obtain high frequency observations of wind speed and precipitation in a large area and there are many boundary conditions and limitations exist to the estimation models.…”

“…In contrast, the strong wind speed (8 m/s) dominates the SST diurnal variation when the insolation is weak (580 W/m 2 ) in region X2 (Figure A1d,h). It causes convergent currents and transfers heat from the surface to the deeper water, which slows down sea surface warming and leads to small magnitude of SST diurnal variability [48]. Therefore, the amplitude of diurnal SST variation in region X1 is greater than that in region X2.…”

Ocean Remote Sensing Techniques and Applications: A Review (Part II)

“…During the day, most of the incoming solar radiation is entered into the near-surface ocean (5 m depth), leading to the formation of thermal stratification (layers of different temperatures) in the ocean. This effect is exacerbated by the light winds (low wind speeds) [98,[120][121][122]. On the other hand, the water column gradually cools from the surface during the night [120].…”

“…On the other hand, the water column gradually cools from the surface during the night [120]. This heating and cooling cycle creates a diurnal cycle in SST, which is very important in improving the ocean-atmosphere models [120,122]. SST can be measured by deploying temperature sensors on different instruments, such as in situ moored and drifting buoys, ships (with a thermometer into a bucket of seawater), and offshore platforms, as well as airborne and spaceborne RS systems [99].…”

Validation of Sea Surface Temperature from GCOM-C Satellite Using iQuam Datasets and MUR-SST in Indonesian Waters

“…For the Indonesian Seas area, previously Sukresno et al (2018) used this method to validate the Himawari-8 satellite data using in situ data from the Indonesian buoy. ree-way error analysis has also been used to validate diurnal amplitude of SST using in situ mooring buoy data and Satellite SST of Himawari-8 and Geostationary Operational Environmental Satellite (GOES) (Wirasatriya et al, 2020).…”