The polar vortex is a large mass of very cold air that always hovers around the North Pole. It is called vortex because it moves counterclockwise. This area of low pressure lies about 20,000 meters above the surface of the earth.
The polar vortex keeps cold air moving in a tight pattern around the poles. It is usually stronger during the wintertime and weaker in summer. However, sometimes it becomes unstable and breaks out to the south. Because a continent like North America lacks high east-west oriented mountain ranges, the polar vortex can move far south into the continental US . This happens mostly when Greenland and Alaska experience higher than normal temperatures.
When such polar air masses travel southwards, many parts of the American Midwest witness not only temperatures far below zero but also snowfall and heavy winds.
The polar vortex is nothing new, but climatologists suggest that it has been leaving its normal patterns more often in recent years, possibly connected to global climate change.
climatologist = person who studies the weather and the climate zones of the earth
continental US = all the states except Hawaii and Alaska
counterclockwise = in the opposite direction of the way hands of a clock move
experience = have
global climate change = temperatures are steadily rising because of more CO2 emissions in the atmosphere
hover = to stay in one place in the air
lack = does not have
low pressure = condition in the atmosphere that affects the weather; low pressure areas lead to the rise of air and rainfall
pattern = here: the regular way something moves
suggest = here: to say that something is true
surface = top part of the earth
tight = very close
unstable = to suddenly change its path
vortex= a mass of wind or water that spins quickly and pulls things to its center
Polar bears could become extinct faster than predicted. That is because there is a shortage of food in their habitat and scientists have now found out that polar bears need more energy than previously thought.
As a result of global warming, Arctic ice is melting quickly, so that polar bears have to travel further in search of food. In a study that has spanned the last three years, scientists found out that polar bears have to travel one and a half times more than in the past. As a result, they lose weight.
Experiments conducted with modern technology show how polar bears move and behave. High-tech GPScollars were put on 9 female polar bears. Their movements and energy consumption have been tracked over a period of 12 days. Results show that a few of them lost up to 10%of their weight.
According to the World Wildlife Fund, polar bears spend half of their time hunting for something to eat. They rely mostly on young seals as the main source of food, but the seal population is getting scarce because of the melting ice.
A polar bear needs about 12000 kilocalories a day to stay healthy and even more to put on the body fat it needs to survive the winter months.
Over the past ten years, the number of polar bears has declined by 40%. Ice on their habitat, Arctic Sea ice is decreasing at a rate of 14% per decade. It is currently at its lowest level in 40 years.
according to = as reported by …
behave = act in certain situations
body fat = here: the fat an animal needs to protect itself from the cold weather
collar = band of leather or plastic that is around an animal’s neck
conduct = carry out
currently = at the moment
decade = ten years
decline = to go down
decrease = become lower
energy consumption = the amount of energy you need and use up
extinct = to die out and not exist anymore
global warming = increase in the atmosphere’s temperature caused by more carbon dioxide and other gases
further = a longer distance
GPS = system that shows where your position is on earth through a system of radio signals
habitat = natural home of a plant or animal
lose weight = become thinner
melt = when ice turns into water
predict = to say that something will happen before it does
previously = at an earlier time
rely = here: eat
scarce = not very much left
scientist = person who is trained in science and works in a lab
seal = large sea animal that eats fish and lives near coasts
shortage = not enough
source = where something comes from
span = period of time between two events
study = piece of work that is done to find out more about a subect
survive = stay alive
track = monitor, watch closely
World Wildlife Fund = organisation that wants to protect the environment and save animals and plants
According to the American space agency NASA, the world’s ozone layer is slowly recovering. A report states that, for the first time, scientists have observed a decrease in the amount of chlorine in the ozone layer over Antarctica.
Ozone in the atmosphere is essential because it protects life on our planet by absorbing dangerous ultraviolet radiation, which causes skin cancer and damages plant life. Is the 1980s, scientists discovered a hole in the ozone layer, which has become larger ever since. It is especially large over the Antarctic continent and Australia.
Shortly after the discovery, an international agreement, the Montreal Protocol, was signed, banning the use of substances that are responsible for the destruction of the ozone layer. It limits the use of CFCs, chemical compounds that rise into the upper layers of the atmosphere where they are broken down by the sun’s ultraviolet light. In the process, chlorine is released which destroys the ozone molecules.
Since the ban has taken effect major companies have started looking for alternatives to CFCs.
Changes in the ozone level are usually measured during the Antarctic winter, between July and September, when temperatures are lower and results are more accurate. Since 2005, there has been a 20% rise in the amount of ozone. Even though it is the first time that the hole in the ozone layer has become smaller it will take decades to recovercompletely.
Environmentalists around the world have welcomed the announcement, stating that we can actually save the environment by acting decisively.
absorb = take something in
according to = as reported by …
accurate = exact
act decisively = to do something about a problem
agreement = promise by two or more countries to take action
announcement = official statement
atmosphere = mixture of gases that surrounds a planet
ban = forbid
break down = chemical change
cancer = serious disease in which cells in your body grow in an uncontrolled way
CFCs = chlorofluorocarbons = a gas used in refrigerators and spray cans; they are responsible for the destruction of the ozone layer
chlorine = greenish-yellow gas with a strong smell, that is also used to keep swimming pools clean; it is one of the gases that are responsible for the destruction of the ozone layer
completely = fully
compound = substance containing two or more atoms
decade = ten years
decrease = when something goes down
destruction = when something is damaged completely
discover = find for the first time
environmentalist = person who cares about nature and the world we live in
especially = above all
essential = very important and necessary
even though = true, but other things are true too
limit = control, check
measure = to find out how big something is
molecule = smallest unit made up of two or more atoms
observe = watch closely
protect = to keep something safe
recover = to return to a normal condition
release = set free
responsible = the reason for
scientist= person who is trained in science and works in a lab
sign = put your name on a document
state = say in public
substances = elements; material
take effect = start
ultraviolet radiation= light that comes from the sun but cannot be seen; it makes your skin darker
Thousands of penguin babies have starved to death in the eastern Antarctic recently . Observers found thousands of unhatched eggs and lifeless baby penguins on the coast. According to scientists , only two baby penguinssurvived during the 2017 breeding season. Adélie penguins live in colonies that consist of thousands of animals. It is the second time that a whole colony has been wiped out after no babies survived in 2015.
The World Wildlife Fund says that krill fishing in the area has led to the starving of penguin babies. Officials state that fishing in the area may permanentlyendanger the whole penguin population in the Antarctic.
Another reason for the declining number of Adélie penguins is possibly climate change. In regions where ice gets thicker, adult penguins must travel further away from the shore in order to find food. When they get back they find many of their babies already dead.
The WWF and other organisations now demand that the eastern Antarctic coastline be declared a Marine Protected Area in order to help endangered penguins. Commercial fishing should be banned around these areas .
Adélie penguins live along the Antarctic coast and usually breed from October to February. They lay eggs in nests made up of stones.
according to = as said by …
adult = grownup
ban = forbid
breed = two or more animals get together in order to have babies
commercial fishing = fishing in order to make money
consist of = made up of
declare = to officially say that something exists
declining = going down
demand = want to have
endanger = to put a person or an animal in danger
krill = small shellfish
lifeless = dead
Marine Protected Area = area in the ocean where fishing and mining is banned and where animals and plants are protected
permanently = exist for a long time in the future
observer = a person who watches something closely
official = person who is in a high position in an organisation
shore = coast; where land meets the sea
starve = to die because you do not have enough to eat
survive = to live on after a dangerous situation
unhatched = if a baby animal does not come out of an egg
wipe out = destroy completely, so that nothing is left
World Wildlife Fund = organisation that protects endangered animals and plants
Scientists have discovered a gigantic hole that has reappeared in the Antarctic ice. It is about the size of the Netherlands and is located around the Weddell Sea.
In the 1970s climatologists found a similar hole at almost the same spot. At that time they didn’t have the observation equipment that they have now, so they couldn’t study the hole closely enough. After a few years it disappeared . Last year, the hole came up again.
Researchers cannot explain how the hole emerged. One theory is that warmer salt water from deep under the Antarctic ice sheet may have come up and mixed with cold water near the surface, thus , melting the ice sheet above. Normally a thick layer of ice covers Antarctica at the end of the southern winter. Scientists also claim that it may be connected to climate change and global warming.
Such a hole in the ice is called a polynya. Although not totally uncommon, it is strange that the hole in the Antarctic ice has appeared very far from its edge . Usually such holes are found in coastal regions.
Climatologists are not sure whether the hole will have an impact on the water temperature in the world’s oceans. If warmer water continues to surface to the top of the hole it may stay there for a longer period of time because it would then be difficult for ice layers to form.
Severe weather conditions during the Antarctic winter make it difficult to find holes in the ice . This is the second time in two years that such a hole has emerged , although last year’s was not that big.
although = while
claim = to say that something is true even if you cannot prove it
climatologist = person who studies the weather and how it changes the climate on earth
coastal = where land meets the sea
disappear = go away
discover = to find something that has not been there before
edge = the part of an object that is furthest from the centre
emerge = come out from somewhere
equipment = the tools or machines you need to do something
gigantic = huge; very big
global warming = the increase in the temperature of the atmosphere
ice sheet = area of thick ice that covers the North and South Poles
impact = influence, change
layer = material or substance between two other things
reappear = to come again, after it has gone away for some time
researcher = a person who studies a subject in order to find out more about it
scientist = a person who is trained in science and works in a lab