01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-04-0301 |
| Title of Abstract | Contrasting Pacific and Indian Ocean Trade Wind Responses to the Interdecadal Pacific Oscillation |
| Authors | KARTHIKA G*, ROXY MATHEW KOLL |
| Organisation | INDIAN INSTITUTE OF TROPICAL METEOROLOGY, PUNE |
| Address | VALAPPIL HOUSE, DESOM. P. O, ALUVA ERNAKULAM, KERALA, India Pincode: 683102 E-mail: karthika26j@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Trade winds are winds that predominantly blow from the east in the tropical region. These winds play a vital role in maintaining Earthâ¿¿s climate balance by redistributing heat and driving ocean currents. They also influence the precipitation pattern of the tropics. Seasonal shifts in the convergence zones of trade winds contribute to the development of the monsoon systems. Understanding the changes in trade winds due to climate change is crucial for predicting future climate scenarios and assessing their potential impacts on different parts of the world. This study investigates the underlying causes of trade wind variability in the Indian and Pacific oceans. We define a trade wind area for each season for both northerly and southerly wind regimes, based on the consistency of wind speed and direction. From the wind strength in these regions, we construct a trade wind index, which represents the interannual variability of trade winds for each season and ocean basin. Unlike the tropical Pacific, which is dominated year-round by easterly trade winds, the tropical Indian Ocean exhibits strong seasonality, with annual mean westerlies influenced by the boreal summer monsoon circulation. We found that trade wind indices of the Indian and Pacific oceans show strong correlation with the Interdecadal Pacific Oscillation (IPO). Indian Ocean trade winds, including the monsoon winds, show a positive correlation (0.61 for JJA) whereas Pacific ocean trade winds show a negative correlation. The correlation of Pacific trade winds with the IPO can be explained by the changes in zonal pressure gradient due to the IPO. We further examine how Indian Ocean trade winds are influenced by Pacific decadal variability through the associated changes in sea level pressure and sea surface temperature. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Trade wind, pacific decadal variability, monsoon winds, climate change |
| For Awards | no |