How does El Ni ñ o stir up the global climate? What is the impact on our country?, Frequent high temperature records | Global | China

This summer, there have been frequent "barbecue" patterns worldwide. The European Union's climate monitoring agency, the Copernicus Climate Change Service, recently stated that the global average temperature in early June was the highest on record for the same period. The National Oceanic and Atmospheric Administration of the United States issued an alert on June 8th this year, stating that the El Ni ñ o phenomenon has already occurred and is expected to continue into winter, possibly developing into a moderate or strong El Ni ñ o phenomenon. What exactly is El Ni ñ o? Is global high temperatures caused by El Ni ñ o? How does it stir up the global climate? How should we deal with it?

Is El Ni ñ o a weather phenomenon?

We often mention "El Ni ñ o" and like to add the word "event" after it. So what exactly is "El Ni ñ o"?

"El Ni ñ o" is the Spanish transliteration. This is because a long time ago, people living along the coasts of Peru and Ecuador were the first to notice the abnormal phenomena of ocean and weather changes. El Ni ñ o is not actually a weather phenomenon, but a climate phenomenon; It cannot happen today and disappear the day after tomorrow, usually lasting for 9-12 months. Once an El Ni ñ o event occurs, the sea surface temperature in the equatorial central and eastern Pacific Ocean will experience sustained and widespread abnormal warming. According to the discrimination criteria, if the sea surface temperature index in the critical area reaches or exceeds 0.5 ℃ and lasts for at least 5 months, it can be determined as an El Ni ñ o event.

Under normal circumstances, the circulation near the equator is distributed, and a large amount of warm seawater flows from east to west, forming stable ocean currents. This ocean current causes a higher temperature of seawater on the western side of the Pacific Ocean, while the temperature on the eastern side is lower, resulting in relatively dry air and a relatively dry climate. But during special periods, this situation is exactly the opposite. The originally humid climate tends to be dry, while the originally dry climate tends to be humid. Simply put, precipitation decreases in areas that should be rainy, but increases in areas that should be dry, which is known as the El Ni ñ o phenomenon.

Is this round of high temperatures caused by El Ni ñ o?

So, is this round of high temperatures caused by El Ni ñ o? Will we usher in the "hottest year" in history? Let's first understand through the data.

Since 1980, the global average temperature has broken records 12 times, with 10 of them occurring during the year of El Ni ñ o. In the context of global warming, the stronger the intensity of El Ni ñ o, the more significant the increase in global average temperature. For example, from 2014 to 2016, the intensity of El Ni ñ o reached a super strong level, and the global average temperature set new records continuously in these three years. Climate experts predict that the El Ni ñ o phenomenon occurred earlier and has a large development potential, with a probability of developing to moderate intensity in winter at 90%.

Zhou Bing, Chief Climate Service Officer of the China Meteorological Administration: This year's climate, both in China and globally, is very abnormal. Asia has ushered in the hottest April in history. Monitoring shows that the global average temperature in May was the warmest since 1850. After entering June, many areas in northern China experienced high temperatures above 40 ℃. Due to the occurrence of El Ni ñ o events, the world is bound to be hotter this year than in 2022. Last year, the heatwave in the south was mainly controlled by the subtropical high pressure system in the western Pacific for a long time. In fact, this year, the position of the subtropical high pressure system will be southward, so it is most likely that China will experience high temperatures this year in the southern region. The high temperatures in the north are related to the process of high-pressure control in the westerlies, so there will not be prolonged high temperatures in the north like last year. However, due to the influence of El Ni ñ o, the overall temperature is mainly high.

What is the impact of this El Ni ñ o on China's climate?

So, what impact does El Ni ñ o have on China's climate? Experts say that this El Ni ñ o has a significant impact on China's winter climate and summer precipitation. On the one hand, the development of El Ni ñ o will lead to an increase in rainfall in the south of China and a decrease in rainfall in the north during the summer, resulting in a situation of flooding in the south and drought in the north. It is necessary to be alert to the occurrence of waterlogging in southern cities; On the other hand, El Ni ñ o will lead to warmer winters, and even warm winters.

Zhou Bing, Chief Climate Service Officer of the China Meteorological Administration: With the response of the subtropical monsoon region to El Ni ñ o, the rainy season has begun to come more fiercely and the intensity of precipitation is also relatively high. Therefore, it can be considered that the current rainy season in the middle and lower reaches of the Yangtze River is to some extent an indirect response to El Ni ñ o. Because our country is located upstream of El Ni ñ o, the climate that mainly affects our country is the East Asian monsoon system, and the most important member of the East Asian monsoon system is the Western Pacific Subtropical High. To some extent, El Ni ñ o will affect the changes in the position of the subtropical high pressure system in the western Pacific, and after the changes, it will be directly related to the precipitation in the Yangtze River Basin. With the development of El Ni ñ o. During this autumn and winter season, most areas in northern China may experience less precipitation, highlighting the phenomenon of drought. In southern China, precipitation may increase, and some cities may also experience urban waterlogging in autumn. After entering winter, the probability of warm winters in China increases.

Actively responding to El Ni ñ o emissions reduction is urgent

Experts say that an El Ni ñ o of moderate or higher intensity is bound to increase the frequency, scope, and intensity of extreme weather. So, how should we respond? In fact, the impact of El Ni ñ o on global temperature usually manifests within one year after its occurrence, so the impact of this El Ni ñ o on temperature may be most pronounced in 2024. International experts and scholars suggest that the impact of climate change is becoming increasingly significant, touching on many aspects of the Earth's ecosystem. Reducing emissions has become a focal issue in the international community to address climate challenges. In April this year, the United Nations Intergovernmental Panel on Climate Change released a report calling on countries to take in-depth, rapid, and sustained carbon reduction actions to mitigate the impact of climate change.