[A-OS11] 陸域海洋相互作用ー惑星スケールの物質輸送

[AOS11-08] Role of tropical oceans in global terrestrial vegetation

*Swadhin Behera¹、Roma Varghese²、Venkata Ratnam Jayanthi¹、Takeshi Doi¹、Mukund Dev Behera² (1.Application Laboratory, JAMSTEC, 3173-25 Showa-machi, Yokohama 236-0001、2.Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, India)

キーワード：El Nino, IOD, El Nino Modoki, NDVI remote teleconnection

Here we discuss the profound influences of climate phenomena like Indian Ocean Dipole (IOD), El Niño, and El Niño Modoki on terrestrial vegetation through atmospheric teleconnections. Three pure events of positive IOD, El Niño and El Niño Modoki are picked to understand their unique associations with the global terrestrial vegetation. The 2019 positive IOD event was found to have a strong association with positive Normalized Difference Vegetation Index (NDVI) anomalies of mid- and high-latitudes during boreal summer. The positive NDVI anomalies turned to negative anomalies as season progressed suggesting a stronger impact of air temperature anomalies associated with IOD teleconnection. The Asian-African ecosystems have shown a seasonal lag response as the positive anomalies persisted from boreal summer to winter in these areas. The analysis of the 2005 El Niño Modoki event reveals that, while it influences global NDVI anomalies similar to El Niño, its overall impact on a global scale appears to be less pronounced. Regional teleconnections during the boreal summer show notable negative NDVI anomalies in Europe, eastern Russia, southern Africa, Brazil, and Argentina, while positive anomalies are observed in Australia, Alaska, and northeast China, with surface air temperature anomalies acting as mediators of El Niño Modoki signals in NDVI.