Intense Tropical Cyclones Arriving Earlier Each Decade, Reveals Study
Intense tropical cyclones, known for their devastating impact on communities worldwide, are arriving earlier each decade due to the effects of climate change, according to a recent study co-authored by a University of Hawai’i at Mānoa atmospheric scientist. The research, published in the journal Nature, highlights that Category 4 and 5 hurricanes (with maximum wind speeds greater than 131 miles per hour) have been making landfall three to four days earlier with each passing decade since the 1980s.
The findings of the study have significant implications for communities affected by these extreme weather events. When intense tropical cyclones occur earlier than usual, they cause unexpected problems for communities, says Pao-Shin Chu, an atmospheric sciences professor at UH Mānoa. Chu notes that the earlier arrival of these storms can overlap with other weather systems, such as local thunderstorms and seasonal monsoon rainfall, compounding the impact and straining emergency response efforts.
While research on the changing characteristics of intense hurricanes under a warming climate has been extensive, little is known about changes in their seasonal cycle. To address this gap, the study utilized satellite data, historical tropical cyclone tracks, NOAA rainfall records, and various statistical methods to analyze the shifting patterns. The researchers discovered a significant shift of intense tropical cyclones from autumn to summer months in most tropical oceans, including the eastern North Pacific, the western North Pacific, the South Pacific, the Gulf of Mexico, and the Atlantic coast of Florida and the Caribbean.
The observed trend of earlier arrivals was consistent across multiple data sources, surprising the researchers. It was surprising to consistently see earlier arrivals when we independently assessed satellite data and conventional ground-based observations of intense tropical cyclones, Chu explains.
The study also incorporated simulations from multiple global climate models, which revealed that warmer oceanic conditions developing earlier favored the earlier onset of intense tropical cyclones. Furthermore, the warming trend was primarily driven by greenhouse gas forcing. In a future with high carbon dioxide emissions, the earlier shifting trend is projected to be amplified, says Chu.
The earlier onset of intense tropical cyclones has significant consequences, particularly in South China and the Gulf of Mexico, where it contributes to an earlier onset of extreme rainfall. The study emphasizes that understanding these changes in hurricane activity is crucial for disaster prevention, resource management, and community preparedness.
Given the seasonal advance of intense tropical cyclones, their potential simultaneous occurrence with other high-impact weather events is a serious concern. Chu believes that it is important for society to recognize and address this issue. Understanding potential changes in hurricane activity in response to global warming is important for disaster prevention, resource management, and community preparedness, Chu concludes.
As we witness the increasing frequency and intensity of intense tropical cyclones, it becomes even more urgent for communities and policymakers to take proactive measures to mitigate their impact. The study provides vital insights into the changing patterns of intense hurricanes and emphasizes the need for timely actions to protect vulnerable regions from the devastating consequences of these extreme weather events.
