Auto-correlation analysis of ocean surface wind vectors

Journal of Earth system science

Sujit Basu1¹  A K Varma1¹  Jignesh Kshatriya1¹  Abhijit Sarkar1¹ 

[1]Oceanic Sciences Division, Meteorology and Oceanography Group, Space Applications Centre (ISRO), Ahmedabad, India.$$

关键词: Surface wind speed;    data buoy;    time series;    auto-correlation;    microwave radiometer.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The nature of the inherent temporal variability of surface winds is analyzed by comparison of winds obtained through different measurement methods. In this work, an auto-correlation analysis of a time series data of surface winds measured in situ by a deep water buoy in the Indian Ocean has been carried out. Hourly time series data available for 240 hours in the month of May, 1999 were subjected to an auto-correlation analysis. The analysis indicates an exponential fall of the auto- correlation in the first few hours with a decorrelation time scale of about 6 hours. For a meaningful comparison between satellite derived products and in situ data, satellite data acquired at different time intervals should be used with appropriate `weights', rather than treating the data as concurrent in time. This paper presents a scheme for temporal weighting using the auto-correlation analysis. These temporal `weights' can potentially improve the root mean square (rms) deviation between satellite and in situ measurements. A case study using the TRMM Microwave Imager (TMI) and Indian Ocean buoy wind speed data resulted in an improvement of about 10%.

【 授权许可】

Unknown