noticeable impact on growth conditions in the Northern Hemisphere, which were the worst of the last 600 years, with summers being on average colder than the mean. The climate impact has been noted in the growth rings of a centuries-old ocean quahog (a mollusc) individual that was found in Iceland, as well as in tree rings from Taiwan, eastern Tibet, Siberia, the Urals and Yamal Peninsula in Russia, Canada, the Sierra Nevada and White Mountains both in California, Lake Zaysan in Kazakhstan and in Mexico. Notably, the climate impacts became manifest only in 1601; in the preceding year, they may have been suppressed by a strong El Niño event. Other climate effects attributed to the Huaynaputina eruption include: In climate simulations, after the 1600 eruption a strengthening of the Atlantic meridional overturning circulation is observed along with sea ice growth, followed after a delay by a phase of decreased strength. An extraordinarily strong El Niño event in 1607–1608 and a concomitant northward shift of the Southern Hemisphere storm tracks have been attributed to the Huaynaputina eruption. Intense winds were reported from the present-day Philippines. Manila galleons reportedly were faster when crossing the Pacific Ocean after 1600, perhaps owing to volcanically-induced wind changes. A change in the Atlantic Multidecadal Variability around 1600 has been attributed to the Huaynaputina eruption. Long-term climate effects Temperatures decreased for a long time after the Huaynaputina eruption in the extratropical Northern Hemisphere. Together with the 1257 Samalas eruption and the 1452/1453 mystery eruption, the Huaynaputina eruption may have led to the Little Ice Age, or to the coldest period of the Little Ice Age in Europe during the "Grindelwald Fluctuation" between 1560-1630. Glacier growth, Arctic sea ice expansion and climatic cooling has been noted after these eruptions, and a cooling peak occurred around the time of the Huaynaputina eruption. In general, volcanic sulfate aerosol production was higher during the Little Ice Age than before or after it. In the Andes, the Little Ice Age had already begun before the 1600 eruption, although a major expansion of glaciers in the Peruvian Cordillera Blanca occurred at the time. The 1600 eruption of Huaynaputina occurred at the tail end of a cluster of mid-sized volcanic eruptions, which in a climate simulation had a noticeable impact on Earth's energy balance and were accompanied by a 10% growth of Northern Hemisphere sea ice and a weakening of the subpolar gyre which