Comparison of AMSR-2 wind speed and sea surface temperature with moored buoy observations over the Northern Indian Ocean

  • B Nanda Kishore Reddy
  • R Venkatesan
  • Krishna K Osuri
  • Simi Mathew
  • Jagadeesh Kadiyam
  • K Jossia Joseph


The Northern Indian Ocean (NIO) is unique due to seasonal reversal of wind patterns, the formation of vortices and eddies which make satellite observations arduous. The veracity of sea surface wind (SSW) and sea surface temperature (SST) products of sun-synchronous AMSR-2 satellite are compared with high-temporal moored buoy observations over the NIO. The two year-long (2013–2014) comparisons reveal that the root-mean-square-error (RMSE) of AMSR-2 SST and SSW is \(<0.4{^{\circ }}\hbox {C}\) and \(<1.5\hbox { ms}^{-1}\), respectively, which are within the error range prescribed for the AMSR-2 satellite (\(\pm 0.8{^{\circ }}\hbox {C}\), \(\pm 1.5\hbox { ms}^{-1})\). The SST–wind relation is analyzed using data both from the buoy and satellite. As a result, the low-SST is associated with low-wind condition (positive slope) in the northern part of the Bay of Bengal (BoB), while low SST values are associated with high wind conditions (negative slope) over the southern BoB. Moreover, the AMSR-2 displayed larger slope for SST–wind relation and could be mainly due to overestimation of SST and underestimation of wind as compared to the buoy. The AMSR-2 SSW exhibited higher error during post-monsoon followed by monsoon season and could be attributed to the high wind conditions associated with intense oceanic vortices. The study suggests that the AMSR-2 products are reliable and can be used in tropical air–sea interactions, meso-scale features, and weather and climate studies.


AMSR-2 SST sea surface wind speed moored buoys Northern Indian Ocean 



The authors gratefully acknowledge the financial support from the SERB (ECR/2016/001637), Department of Science & Technology, Govt. of India. We thank Dr Wentz F J of Remote Sensing Systems for making the AMSR-2 SST and wind speed 3-day average product available on their website Freeware Ferret and NCL are used in this study. The authors are also thankful to the Ministry of Earth Sciences (MoES), Govt. of India, for maintaining the moored buoy network over the NIO. The authors also thank the anonymous reviewers for their constructive and valuable suggestions that helped to improve the quality of the manuscript.


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Copyright information

© Indian Academy of Sciences 2018

Authors and Affiliations

  1. 1.Department of Earth and Atmospheric SciencesNIT RourkelaRourkelaIndia
  2. 2.National Institute of Ocean Technology (NIOT)ChennaiIndia
  3. 3.Indian Institute of TechnologyIndoreIndia

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