Dr. Yong-Fu Lin

Research Center for Critical Issues, ACADEMIA SINICA

Abstract：
Sunspot activity is known to exhibit increase and decrease in a regular cycle that lasts about eleven years. This 11-year solar cycle modulate the amount of solar radiation sent to power earth’s climate system. Here, we show that this solar cycle leads to a 0.2°C sea surface temperature (SST) variation in the northeastern Pacific. The solar cycle's influence begins in the lower stratosphere, affecting the Hadley circulation in the troposphere and subsequently influencing SST in the Northeastern Pacific. This SST change extends into the tropical Pacific, affecting the frequency of specific El Nino and La Nina events in the central Pacific (CP). More CP El Nino events occur during active solar phases, while CP La Nina events dominate during inactive solar phases. Additionally, the solar cycle is linked to off-season super typhoon occurrences in the western North Pacific. This connection is mediated through SST variations. Amplified by atmospheric and ocean interactions, the solar cycle leads to noticeable SST changes, affecting super typhoon frequency during active or inactive solar periods. This mechanism's effectiveness has increased since the Atlantic Multi-decadal Oscillation (AMO) shifted to a warm phase in the 1990s. Understanding these solar influences can improve super typhoon and ENSO activity predictions, enhancing decadal disaster preparedness and planning.