#所见所得, it's all scientific#
On the morning of August 21, 2023, Beijing time, a rare hurricane Hilary made landfall from the Pacific coast of Mexico, then crossed the US-Mexico border and entered California at an intensity equivalent to a continental tropical storm. Hurricane Hillary became the first hurricane to enter California since Nora in 1997 and the strongest hurricane to enter California since Hurricane Long Beach in 1939.
First, Hillary Clinton went deep into the United States to sprinkle torrential rain
Before making landfall, Hillary brought a downpour to Santa Rosalia in Baja California Sur, Mexico. According to officials, the flooding killed one person. As the hurricane moved inland California, Hurricane Hillary Clinton caused flooding, mudslides and power outages.
Affected by Hurricane Hillary, August 20 was the wettest August day on record in downtown Los Angeles and San Diego, California, according to the National Weather Service. On that day, the two cities saw 63 millimeters and 46 millimeters of rain, respectively, to torrential levels, and the storm also brought gusts of 113 kilometers per hour to parts of California, knocking down trees and power lines, and reportedly leaving 40,000 residents without power.
Second, California's death valley has become a dead river
Even Death Valley National Park, one of the hottest areas in the world, received more than 50 millimeters of rainfall, Death Valley National Park was closed due to flooding, and many roads in Las Vegas, Nevada, were damaged by flooding.
Torrential rainfall flooding is undoubtedly surprising again in Death Valley, a basin located in southeastern California that is the lowest, driest, and hottest place in North America. It has an average altitude of -86 meters, an average annual rainfall of less than 50 mm, and an average annual temperature of 25.5 degrees Celsius. Death Valley once set a record for the world's highest temperature – on July 10, 1913, the temperature reached 56.7 degrees Celsius. The main reason why Death Valley is so hot and arid is that it is surrounded by mountains that block the moist air from the Pacific Ocean. At the same time, Death Valley is also under the control of a subtropical high pressure, resulting in high ground pressure, stable air and low precipitation. However, on August 20, 2023, Death Valley experienced a rare torrential flood.
These rains poured down in just 3 hours, equivalent to 75% of the average annual rainfall. These rains triggered flash floods that turned an otherwise dry riverbed into a muddy river. The U.S. National Park Service says it could take months to repair all damaged roads.
Third, global climate anomalies
NASA notes that August is a typical dry month in Southern California, and wet and rainy weather like this year's is clearly very unusual. And some of California's hardest-hit areas are the typically dry desert areas of Southern California. This phenomenon shows strong anomalies in the global climate and raises concerns about the effects of climate change.
Some researchers believe that the impact of El Niño on current climate anomalies has begun to be non-negligible. El Niño is a naturally occurring climate pattern associated with warming ocean surface temperatures in the central and eastern tropical Pacific Oceans. It occurs on average every two to seven years and usually lasts 9 to 12 months. El Niño events alter global atmospheric and ocean circulation, leading to extreme weather events such as droughts, floods, hurricanes, and more in many parts of the world. According to a report released by the World Meteorological Organization (WMO), strong El Niño conditions already existed in the tropical Pacific in July 2023, predicting a moderate to strong El Niño in the autumn and winter seasons in the northern hemisphere this year.
Professor Petri Taalas, Secretary-General of the World Meteorological Organization, said that "Hillary" is one of the extreme weather events brought about by the El Ni phenomenon. At the same time, due to the effects of El Niño, the western region of the United States will face higher temperatures and lower humidity, increasing the risk of wildfires. On the other hand, El Niño will also have different effects on other regions. For example, southern China is likely to see more heavy rainfall, while Southeast Asia is likely to see less precipitation and drought. Therefore, we need to pay close attention to the dynamics of global climate change and take appropriate countermeasures to mitigate the loss and impact of disasters.
#Hebei heavy rain ## strong convective weather ## weather # # heavy rain # #新华社: Japanese strong discharge of nuclear sewage self-destructs the national image ##学者: 3 anomalies appeared on Qixi this year## Japan chose the cheapest solution to deal with nuclear sewage ##飓风希拉里#