Arctic roots of 'upside-down' weather

It's cold in Kirkcaldy, freezing in Frankfurt and brass monkeys in Bryn Mawr... a winter spell with weather that's unusually - well - wintry.

But not everywhere; in fact, other places in the Northern Hemisphere are seeing weather that's unseasonably warm.

In Goose Bay in Newfoundland, it's barely getting below 0C - bikini weather, relatively speaking, given that the average minimum for January is -23C.

The cause of what one weather service refers to as these "upside down" conditions is an extreme of the Arctic Oscillation (AO).

Essentially, air pressure is measured at various places across the Arctic and at the middle latitudes of the Northern Hemisphere - about 45 degrees north, roughly the latitude of Milan, Montreal or Vladivostok.

The difference between the average readings for the two latitudes gives the state of the Arctic Oscillation index.

A "positive" state is defined as relatively high pressure in mid-latitudes and relatively low pressure over the polar region. "Negative" conditions are the reverse.

And what we have at the moment is an unusually extreme negative state.

The graph below comes from the US government's Climate Prediction Center and shows the variability of the index from 1950 to 2009.

The text on the graph is a little unclear as I've had to shrink it a bit, but you can see at the bottom right the current negative conditions developing during December - and here's the original.

Over at the New York Times, they've compiled a different graph that shows how extreme these few weeks are turning out to be - unmatched since the early 1960s, a period that saw several winters in the UK featuring extended spells of cold, snowy weather.

What the negative AO conditions mean is that cold air spills out of the Arctic down to mid-latitudes, which this time round includes much of Europe, tracts of the US and China.

For the UK, this implies a higher chance of cold northerly or easterly winds.

But if you live in places that are usually cold at this time of year - such as Goose Bay - you'll see a concomitant rise in temperatures compared with what happens during "positive" AO conditions, when the cold air is confined to more northerly latitudes.

A little more than a decade ago, I visited Yakutsk in Siberia which lies close to one of the candidates for the title of "coldest place on the planet" - the village of Oymyakon, which has seen the mercury plummet as low as -71C.

I don't know how balmy it is in Oymyakon right now but in Yakutsk itself, the daily minimum is a mere -35C - that's 10C warmer than the January average.

Despite the name "Arctic Oscillation", there's little discernible pattern to how the pressure difference varies, or what causes it - perhaps "Arctic Random Fluctuation" would be a better name.

Some researchers have linked an apparent increase in the average state of the index from the 1960s to the 1990s to man-made global warming, but you would have to say the jury is definitely still out.

(The AO is linked to another naturally varying phenomenon, by the way - the North Atlantic Oscillation (NAO), the variability in the pressure difference between Iceland and the Azores - in fact, some hold that the NAO is just a sub-set of the AO.)

So the question of how long the unusually wintry UK conditions will last is really a question of how long the Arctic Oscillation will remain in its extreme negative state - and a week to 10 days seems to be the favoured timescale.

Two killer whale types found in UK Waters

Scientists have revealed for the first time there is not one but two types of killer whale living in UK waters.

Each differs in its appearance and diet, with males of one type being almost two meters larger than the other.

The killer whales could be at an early stage of becoming two separate species, the researchers say.

The international group of scientists has published its results in the journal Molecular Ecology.

"It's exciting to think about two very different types of killer whale in the waters around Britain," says Dr Andy Foote from the University of Aberdeen, UK, who undertook the study.

"Killer whales aren't really a species that we think of as being a regular visitor to Britain, but in fact we have two forms of these killer whales in our waters," he told the BBC.

Scientists have found different forms of killer whales that occupy particular niches in the Pacific and the Antarctic, but this is the first time that they have been described in the North Atlantic.

Dr Andy Foote undertook the study along with colleagues from universities and museums in Denmark and the UK.

Killer whales (Orcinus orca), otherwise called orcas, live in family groups called pods.

As the largest member of the dolphin family, killer whales are known for their intelligence and range of hunting behaviours.

Tooth work

There was very little prior to this study to suggest that different types of killer whale would be found in the North Atlantic.

However, Dr Foote and colleagues studied teeth from remains of killer whales stranded over the past 200 years and found a difference in tooth wear.

Differences in tooth wear: Type 1 (top) and type 2 (below)

"We found that one form, which we call 'type 1' had severely worn teeth in all adult specimens," explains Dr Foote.

"The other form, 'type 2', had virtually no tooth wear even in the largest adults."

In the wild, killer whales that "suck up" herring and mackerel display this tooth wear.

Knowing this, the researchers suspected a difference in diet and ecological niche between the two groups.

Dolphin predator

Using stable isotope analysis that gives clues to the orcas' diet, the scientists found that type 1 is a generalist feeder, consuming fish and seals.

Type 2, on the other hand, is a specialist feeder that scientists suspect exclusively feeds on marine mammals such as small dolphins and whales.

This specialisation for alternate ecological niches has also resulted in a difference in shape and appearance.

"The two types also differed in length, with type 2 adult males being almost two metres larger than types 1 males," Dr Foote says.

The researchers also found that colour, pattern and number of teeth vary between the groups.

Dr Foote says the fish feeding type 1 killer whales are found across the North East Atlantic and around Britain.

The cetacean hunting type 2 killer whales are regularly seen off the west coast of Scotland and Ireland.

New species

Genetic analysis indicates the two types belong to two different populations.

"Type 1 specimens were from closely related populations, but the type 2 whales were more closely related to a group of Antarctic killer whales," Dr Foote explains.

Comparing the findings with studies on killer whales around the world shows that killer whales have radiated to fill different ecological niches.

"It's similar to how Darwin's finches have adapted to different ecological roles in the Galapagos, but on a larger scale," Dr Foote notes.

He suggests this could be an important discovery for the future of the animals.

"They seem to have occupied completely different ecological niches and have started to diverge morphologically. This divergence may eventually lead to the two types becoming different species."

He also recommends the two types be considered "evolutionary significant units" and monitored separately in order to more effectively conserve one of the oceans most charismatic animals.

Nasa's Kepler planet-hunter detects five worlds

Nasa's Kepler Space Telescope has detected its first five exoplanets, or planets beyond our Solar System.

The observatory, which was launched last year to find other Earths, made the discoveries in its first few weeks of science operations.

Although the new worlds are all bigger than our Neptune, the US space agency says the haul shows the telescope is working well and is very sensitive.

The exoplanets have been given the names Kepler 4b, 5b, 6b, 7b and 8b.

They were announced at an American Astronomical Society meeting in Washington DC.

The planets range in size from an object that has a radius four times that of Earth, to worlds much bigger than even our Jupiter.

And they all circle very close to their parent stars, following orbits that range from about 3.2 to 4.9 days.

This proximity and the fact that the host stars are themselves much hotter than our Sun means Kepler's new exoplanets experience an intense roasting.

Intriguing density

Estimated temperatures go from about 1,200C to 1,650C (2,200F to 3,000F).

"The planets we found are all hotter than molten lava; they all simply glow with their temperatures," said Bill Borucki, Kepler's lead scientist from Nasa's Ames Research Center in Moffett Field, California.

THE KEPLER SPACE TELESCOPE Will study more than 100,000 suns Continuously for 4 to 6+ years Tuned to see Earth-size planets Will target the habitable zone Will also see Mars to Jupiter sizes

"In fact the upper two are hotter than molten iron and looking at them might be like looking at a blast furnace. They are very bright in their own right and certainly no place to look for life."

Kepler 7b will intrigue many scientists. It is one of the lowest-density exoplanets (about 0.17 grams per cubic centimetre) yet discovered.

"The average density of this planet with its core is about the same as Styrofoam," explained Dr Borucki. "So it's an amazingly light planet, something I'm sure theoreticians will be delighted to look at in terms of trying to understand [its] structure."

Kepler blasted into space atop a Delta II rocket from Cape Canaveral Air Force Station on 6 March, 2009.

It is equipped with the largest camera ever launched into space. The telescope's mission is to continuously and simultaneously observe more than 100,000 stars.

It senses the presence of planets by looking for a tiny "shadowing" effect when one of them passes in front of its parent star.

'Water worlds'

Kepler's detectors, built by UK firm e2v, have extraordinary sensitivity.

Nasa says that if the observatory were to look down at a small town on Earth at night from space, it would be able to detect the dimming of a porch light as somebody passed in front of it.

Artist's impression: Four of the five are bigger than a Jupiter

The space agency hopes this sensitivity will lead it to planets that are not only Earth-size but which orbit their stars at distances more favourable to life, where liquid water might potentially reside on their surfaces.

The mission's scientists told the AAS meeting that Kepler had measured hundreds of possible planet signatures but that these needed further investigation to establish their true nature.

To confirm the existence of the most ideal Earth-like planets would take a few years, they warned.

In the meantime, all detections will help scientists improve their statistics on the distributions of planet size and orbital period.

The follow-up observations needed to confirm the new exoplanets' existence used a suite of ground-based facilities including the Keck I telescope in Hawaii.

Cancer drugs 'treat' aggressive childhood brain tumours

Aggressive childhood brain tumours could be treatable with a novel combination of two existing cancer drugs, a study suggests.

Researchers led by the Institute of Cancer Research (ICR) examined 90 tumours from children and found two new genetic abnormalities in nine of them.

They were then able to kill these abnormal tumours, in laboratory tests, by combining the two existing drugs.

But one expert says the findings remain "far off being applicable to patients".

In the UK, about 400 children are diagnosed with brain tumours every year.

The research, published in the journal Clinical Cancer Research, brought together scientists from the UK, France, Portugal, Brazil and America.

The abnormal tumours - known as glioblastomas, aggressive and often fatal cancers of the brain's glial cells - contained too many copies of the EGFR gene and mutations of the gene the scientists say have never before been found in children.

They tried to block the EGFR gene with a drug, erlotinib (Tarceva), used in clinical trials to treat adult glioblastomas, but identified a molecule specific to the children's cells - platelet-derived growth factor receptor (PGFR) - that was making it ineffective.

But when they combined erlotinib with a drug, imatinib (Glivec), they hoped would block the PGFR molecules, they killed a significant number of the cancer cells.

Dr Chris Jones, who led the research, said it proved "that cancers may look the same, but it is only when you get down to the genetic level that you can truly understand them and devise treatments".

Professor Geoff Pilkington, of the Brainstrust charity, said the research, though fascinating, was at too early a stage to turn into a treatment for patients.

"This sort of twin therapy is a good thing to consider for the future," he said.

Bur he added: "The cells of the brain seem to be unusually resistant to anything thrown at them."

Giving up smoking 'raises diabetes risk'

Giving up smoking sharply increases the risk of developing type-two diabetes, a US study suggests.

Researchers found quitters had a 70% increased risk of developing type-two diabetes in the first six years without cigarettes compared with non-smokers.

This is because they tend to put on weight.

However, the Annals of Internal Medicine study stressed that this should not be used as an excuse to carry on smoking.

The Johns Hopkins team also stress that smoking is a well known risk factor for type-two diabetes - as well as many other health problems, such as heart disease, stroke and cancer.

Researcher Dr Jessica Yeh said: "If you smoke, give it up. That's the right thing to do.

"But people have to also watch their weight."

The study, based on 10,892 middle aged adults who were followed for up to 17 years, found the risk of developing type-two diabetes was highest in the first three years after giving up smoking.

Around 1.8% of people giving up smoking developed type 2 diabetes each year during that period.

If quitters avoided developing the condition for 10 years, then their long-term risk returned to normal.

People who made no effort to give up smoking had a constant 30% increased risk of type-two diabetes compared with non-smokers.

Blood sugar

Type-two diabetes means the body either fails to make enough of the hormone insulin, or cannot make proper use of it, leading to uncontrolled blood sugar levels.

Untreated this can cause serious disease, and complications such as blindness, kidney failure and nerve damage.

One of the major risk factors for the condition is being overweight, and the rise in obesity across the developed world has been blamed for a big increase in type-two diabetes.

The researchers found those who smoked the most and those who gained the most weight had the highest likelihood for developing diabetes after they quit.

On average, during the first three years of the study, quitters gained about 8.4lb (3.8kg).

The researchers said doctors should keep in mind the importance of weight control when counselling people about giving up smoking.

Quitters tend to put on weight because smoking acts to suppress appetite.

The use of nicotine replacement therapy has been shown to blunt the weight gain associated with giving up smoking.

Martin Dockrell, of the anti-smoking charity Ash, said: "The researchers are clear that smokers should quit but - especially if you are a heavy smoker or are already overweight - you might want to gently increase your exercise when you quit.

"If you are a smoker who is also overweight you should talk to your doctor about how to get the best from quitting.

"A little more exercise could help improve your sense of well being, reduce weight gain and undo some of the harm done by smoking leading to a healthier, happier you."

Natasha Marsland, of the charity Diabetes UK, said: "On no account should people use the theoretical results of this study as an excuse not to give up smoking.

"The health benefits of giving up smoking far outweigh the risk of developing type-two diabetes from modest, short-term weight gain."

Egypt archaeologists discover huge tomb near Cairo

Archaeologists in Egypt have said they have discovered the largest known tomb in the ancient necropolis of Sakkara, to the south of Cairo.

The tomb dates back 2,500 years to the 26th Dynasty and contains important artefacts, including mummified eagles.

It is one of two newly discovered tombs found by an Egyptian team working close to the entrance of Sakkara, the burial ground for Egypt's ancient capital.

The tomb consists of a big hall hewn out of the limestone rock.

There are a number of small rooms and passageways where ancient coffins, skeletons and well-preserved clay pots were discovered, as well as the mummies of eagles.

Egypt's chief archaeologist, Zahi Hawass, who announced the discovery, said that early investigations showed that although the tomb dated back to the 26th Dynasty, it had been used several times.

He said it was most likely to have been robbed at the end of the Roman period.

Other excavations at Sakkara are continuing and Mr Hawass said the latest finds confirm that the site still contains undiscovered secrets.