Extreme high temperature climate swept across western North America.

Extreme high temperature climate swept across western North America.

Extreme high temperature climate swept across western North America. The high temperature process is not only hot during the day, but also sultry at night. After nightfall, although the temperature drops, the humidity increases obviously. According to the US Census Bureau's survey of American housing, only 44% of housing units in Seattle and about 79% of housing units in Portland have air conditioning.

1 On June 26th, 2008, the extreme high temperature climate swept through the western part of North America. In Washington, Oregon, USA and British Columbia, Canada, the temperatures that should have been cool in summer have obviously increased, and heat waves have hit-some parts of western North America are experiencing a rare test of high temperature and heat waves.

How hot is it?

According to the statistics of the local meteorological department in Oregon, on June 26th, the highest temperatures and trout in Dell, Portland and Vancouver all tied or broke the local historical records.

As can be seen from the above figure, the temperature continued to rise on 27th in Eugene, Oregon (1Fahrenheit ≈43.8 degrees Celsius), Portland (1 1 2 Fahrenheit ≈44.4 degrees Celsius) and Vancouver (1 12). Among them, mcminn Ville (11Fahrenheit ≈43.8 degrees Celsius) broke the original maximum temperature record of1July, 926 10, making the temperature record of the past hundred years a thing of the past.

Such a high temperature is not normal.

The west coast of the North American continent, extending from the northwest coast of the United States to the south of Alaska, has a typical maritime climate. Located at 40-65 north latitude on the west side of the mainland, it is a climate zone dominated by ocean airflow flowing to the mainland, with mild winter, cool summer and abundant rainfall.

For example, the following figure shows the temperature trend of Portland Airport from 1940 to 20 19. The highest temperature was in July and August, and it was only about 80F (about 26℃) at the hottest time, and it never exceeded 1 10F, but it reached 165438 yesterday.

The main reason for this rare high temperature is the change of atmospheric circulation form. Generally speaking, westerly jet moves from west to east, but recently the jet anomaly turns to north-south direction, extending obviously to the north, giving the subtropical high system more northward space.

At the same time, the Hawaiian high, which evolved from the northern edge of the North Pacific subtropical high, spread northward, directly covering the western part of North America. Under the control of subtropical high, downdraft prevailed and the weather was sunny and hot. Therefore, this rare high temperature weather appeared.

The high temperature process is not only hot during the day, but also sultry at night. After nightfall, although the temperature drops, the humidity increases obviously. Especially at night, there is a temperature of 80F or even higher. The combination of high temperature and high humidity makes the body feel very hot.

According to the US Census Bureau's survey of American housing, only 44% of housing units in Seattle and about 79% of housing units in Portland have air conditioning. For people without air conditioning, it will be very uncomfortable and even life-threatening to encounter such high temperature.

The influence of high temperature on individuals is also very different. Generally speaking, the elderly are most vulnerable to high temperatures.

In addition, some studies show that the influence of high temperature weather varies with different carriers. People in high-temperature areas are more tolerant, and sudden high temperature in rare high-temperature areas will have a greater impact. For example, the high temperature in California is obviously not as deadly as that in Oregon and Washington.

Although the impact of high temperature is not as immediate and obvious as tornadoes, floods and typhoons, the weather impact lasts for a long time, even as long as a week, so we should be vigilant.

& gt& gt For example 1936, North America experienced a rare high-temperature weather process, which occurred during the Great Depression. The high-temperature heat wave of that year lasted from the end of June to the beginning of September, and more than 5,000 people died.

At present, the record high temperatures in the northwestern United States and southwestern Canada are still continuing. Even the highest temperature in Portland will reach 1 15F (about 46℃), and Seattle will reach 1 13F (about 45℃) on Monday, which will continue to set a new record for the highest temperature.

Starting from Tuesday, the high temperature zone will move eastward and inland, and the more serious impact may appear later.

Extreme high temperature climate swept across western North America. Humans need to be vigilant. How to reduce extreme climate?

Whether it is the extreme weather phenomenon in North America today or volcanic eruption. Can be explained by science. Of course, we are actually more concerned about the extreme climate problem, which is fundamentally caused by climate change. The root cause may still be related to global warming, which is now a trend and getting more and more severe. In May of 20021year, the earth's carbon dioxide concentration climbed to 4 19ppm again.

Therefore, it is a new high in the same period. I don't know if it will hit a new high in June. This is another key issue. If it reaches a new high, perhaps the extreme high temperature in North America will appear in many parts of the world in the future, and what we see now is only the tip of the iceberg. Humans really need to be vigilant, because the root cause of extreme climate can be said to be the increase of global warming factors.

In addition to the greenhouse gases directly emitted by human beings, there are also natural "greenhouse gases" that are also emitted after the global warming. For example, methane in polar permafrost can still increase the greenhouse effect of the earth, so this is already a "double-effect" model. Only by fundamentally reducing the chain effect of greenhouse gas emissions can the earth have a chance to change.