内容发布更新时间 : 2024/7/3 15:58:35星期一 下面是文章的全部内容请认真阅读。

http://www.ebigear.com/reslist-367-1.html

Unit 3

Part I

D. warmer/ green house effect/ sea levels/climate zones

As 1998 ends and people look forward to the last year of the century, the World Almanac spoke with experts about what comes next. Almanac editorial director says the experts believe the next century will bring lots of changes.

Warm, of course, that our climate is going to continue getting warmer. That’s the subject, by the way, of another new article on the 1999 World Almanac. The greenhouse effect, exactly what causes it, and what steps to be taken to, perhaps to alleviate global warmings. I’ve seen recently that 1998 is going to go down as the warmest year ever on record. And so that’s going to be a major issue of the next century, and possible tremendous consequences of the global warmings, whether it is rising sea levels affecting th coastal areas; changes in climate zones affecting what crops can be grown, and in what regions. This is potentially a very significant trend to be watched. E. Cyclone: North or south of equator/Typhoon:/Hurricane: Eastern Pacific

Major ocean storms in the northern part of the world usually develop in late summer or autumn over waters near the equator. They are known by several different names. Scientists call these storms cyclones when they happen just north or south of the equator in the Indian Ocean. In the western Pacific Ocean or the China Sea, these storms are called typhoons. In the eastern Pacific and Atlantic Ocean, they are called hurricanes.

Part II

A. Outline1. A. weather pattern/global climate

B. 1. twice a decade2. 12-18 monthsC. 1. warmer weather/2. wetter than usual/ drierD. the decline of windsII. 1. droughts

B. a cyclic weather pattern/ about twice a decade/ wetter/drier/ cold water away from South America’s west/ to expand eastward toward the America’s / move eastward too/ the weather

arond the world/ droughts/ rains and flooding/ on the South American fishing industry/ to

- 1 -

http://www.ebigear.com/reslist-367-1.html

become depletive/ the strength of it/

Satellite readings confirm that conditions are right for another El Nino, a cyclic weather

pattern that affects the global climate.

El Nino’s normally show up about twice a decade and it lasts about 12 to 18 months,

bringing warmer weather to parts of the earth. Some regions become wetter than usual,

others drier. The El Nino, which began in 1991 has lingered through this year. Although

several years might have been expected to pass before the next one, an American-French

satellite observing the oceans has found a sign that El Nino may come back quicker than

expected.

These kinds of things still happen. This is Brig Jacker, an oceanographer of the US Naval

Research Laboratory in Mississippi.

Every year is unpredictable. One year might be El Nino year, one year might not. Generally

El Nino’s come in four year cycles. But there’s nothing to say that you can’t have two

El Nino years in a row.

El Nino’s begin with the decline of winds pulling cold water away from South America’s

west coast to around the equator. This allows warm water in the western Pacific Ocean to

- 2 -

http://www.ebigear.com/reslist-367-1.html

expand eastward toward the America’s. At the same time, the clouds and rain over the warm

water move eastward too. Radar aboard the American-French satellite detected the hint that

such water movement began in early August and reached South America two months later. It

saw a ripple called a “Calvin wave” moving slowly eastward. Such pulses sometimes give rise to El Nino conditions in the eastern equatorial Pacific.

El Nino’s can change the weather around the world, but how much depends on its strength. A

strong one in 1982 and 1983 has been linked to droughts in Australia and Indonesia, rains

and flooding in South America, and unseasonably in 1991 has caused trouble. It has been

associated with devastating floods in the US southeast last year and in the US Midwest this

year. El Nino’s are hard on the South American fishing industry. The warm waters prevent

nutrients rich cold water from rising to the surface, causing fish stocks to become

depletive. Mr. Jacker said a new El Nino apparently would be mild but he is not betting on

it yet.

The US Naval oceanographer says predictions are difficult because the strength of El Nino

depends on how winds affect the Calvin wave that has moved across the Pacific.

Part III Lick Observatory

- 3 -