Comparison of Himawari-8 AHI SST with Shipboard Skin SST Measurements in the Australian Region

Minglun Yang,Helen Beggs,Yukio Kurihara,Lei Guan,Nicole Morgan,Misako Kachi

doi:10.3390/rs12081237

Abstract

Sea surface temperature (SST) measurements from the geostationary satellite Himawari-8 Advanced Himawari Imager (AHI) are compared with in situ skin SSTs derived from shipboard Infrared SST Autonomous Radiometers (ISAR) in the Australian region. The mean bias and standard deviation of the differences between Himawari-8 AHI and ISAR skin SST of best quality are 0.09 K and 0.30 K, with total matchups numbering 2701. Shipboard bulk SST measurements at depths between around 7.1 and 9.9 meters are compared with the matchups in a case study. Analyses show significant differences between skin and bulk SST measurements of maximum value 2.23 K under conditions of high diurnal warming. The results also demonstrate that Himawari-8 AHI skin SST with high temporal resolution has the ability to accurately measure diurnal warming events.

Highlights

Sea surface temperature (SST) is used as a key variable in numerical weather prediction and in global climate modeling
Seven cruises of shipboard infrared radiometer Infrared SST Autonomous Radiometers (ISAR) skin SST data are compared with Japan Aerospace Exploration Agency (JAXA) Himawari-8 Advanced Himawari Imager (AHI) skin SST products in the Australian region
Using Himawari-8 AHI skin SST centered in cloud-free 7 × 7 grid cells and ISAR skin SST with quality level (QL) ≥ 4, the results show good agreement

Summary

Introduction

Sea surface temperature (SST) is used as a key variable in numerical weather prediction and in global climate modeling. JAXA Himawari-8 AHI skin SST products were compared with drifting and tropical moored buoy data. Shipboard infrared radiometers provide the potential to obtain a matched set of in situ and coincident satellite skin SST data that can be used to validate the JAXA Himawari-8 AHI skin SST. The ISAR was developed by the University of Southampton (http://www.isar.org.uk) It is a self-calibrating instrument and was designed for in situ skin SST measurements with an accuracy of around 0.1 K [12]. All ISAR skin SST measurements located in the same satellite 0.02◦ grid cell are averaged, matched with quality level five Himawari-8 AHI skin SST data. SBE 38 bulk SST measurements are compared with both ISAR and Himawari-8 AHI skin SST for a case study. The ship’s wind speed data, measured from sensors ~25 m above the summer load line, from the meteorological dataset [14] are used in the analysis

Results

Conclusions

Discussion