Frozen jet stream links Pakistan floods, Russian fires - Raging wildfires in western Russia have reportedly doubled average daily death rates in Moscow. Diluvial rains over northern Pakistan are surging south – the UN reports that 6 million have been affected by the resulting floods. It now seems that these two apparently disconnected events have a common cause. They are linked to the heatwave that killed more than 60 in Japan, and the end of the warm spell in western Europe. The UNUSUAL WEATHER in the US and Canada last month also has a similar cause.
According to meteorologists monitoring the atmosphere above the northern hemisphere, UNUSUAL HOLDING PATTERNS IN THE JET STREAM are to blame. As a result, weather systems sat still. Temperatures rocketed and rainfall reached extremes. Renowned for its influence on European and Asian weather, the jet stream flows between 7 and 12 kilometres above ground. In its basic form it is a current of fast-moving air that bobs north and south as it rushes around the globe from west to east. Its wave-like shape is caused by Rossby waves – powerful spinning wind currents that push the jet stream alternately north and south like a giant game of pinball.
In recent weeks, meteorologists have noticed a change in the jet stream's normal pattern. It's waves normally shift east, dragging weather systems along with it. But in mid-July they ground to a halt over the UK. There was a similar pattern over the US in late June. Stationary patterns in the jet stream are called "blocking events". They are the consequence of strong Rossby waves, which push westward against the flow of the jet stream. They are normally overpowered by the jet stream's eastward flow, but they can match it if they get strong enough. When this happens, the jet stream's meanders hold steady, creating the perfect conditions for extreme weather.
A static jet stream freezes in place the weather systems that sit inside the peaks and troughs of its meanders. Warm air to the south of the jet stream gets sucked north into the "peaks". The "troughs" on the other hand, draw in cold, low-pressure air from the north. Normally, these systems are constantly on the move – but not during a blocking event. And so it was that Pakistan fell victim to torrents of rain. The blocking event coincided with the summer monsoon, bringing down additional rain on the mountains to the north of the country. It was the final straw for the Indus's congested river bed.
Similarly, as the static jet stream snaked north over Russia, it pulled in a constant stream of hot air from Africa. The resulting heatwave is responsible for extensive drought and nearly 800 wildfires at the latest count. The same effect is probably responsible for the heatwave in Japan, which killed over 60 people in late July. At the same time, the blocking event put an end to unusually warm weather in western Europe.
Blocking events are not the preserve of Europe and Asia. Back in June, a similar pattern developed over the US, allowing a high-pressure system to sit over the eastern seaboard and push up the mercury. Meanwhile, the Midwest was bombarded by air from the north, with chilly effects. Instead of moving on in a matter of days, "the pattern persisted for more than a week".
So what is the root cause of all of this? Meteorologists are unsure. Climate change models predict that rising greenhouse gas concentrations in the atmosphere will drive up the number of extreme heat events. Whether this is because greenhouse gas concentrations are linked to blocking events or because of some other mechanism entirely is impossible to say. The resolution in climate models is too low to reproduce atmospheric patterns like blocking events. So they cannot say anything about whether or not their frequency will change.
There is some tentative evidence that the sun may be involved. Earlier this year an astrophysicist showed that winter blocking events were more likely to happen over Europe when solar activity is low – triggering freezing winters. Now he says he has evidence from 350 years of historical records to show that low solar activity is also associated with summer blocking events. "There's enough evidence to suspect that the jet stream behaviour is being modulated by the sun." Blocking events have been UNUSUALLY COMMON over the last three years, for instance, causing severe floods in the UK and heatwaves in eastern Europe in 2007. Solar activity has been low throughout.
The only real security that a man will have in this world is a reserve of knowledge, experience, and ability.**
Henry Ford
LARGEST QUAKES -
This morning -
5.3 VANUATU
5.0 CENTRAL PERU
Yesterday -
8/11/10 -
5.4 JAVA, INDONESIA
5.3 BOUGAINVILLE REGION, P.N.G.
5.2 VANUATU
5.9 VANUATU
5.3 VANUATU
5.0 VANUATU
TROPICAL STORMS -
Former Tropical depression 05 was 148 nmi SW of Apalachicola, Florida.
Tropical depression DIANMU was 249 nmi NW of Tokyo, Japan.
Tropical Storm Dianmu approaches Japan's north after killing five in Korea. Japan’s Meteorological Agency issued warnings for heavy rain, high waves, storm surges and landslides as Tropical Storm Dianmu approached. Sustained winds slowed to 83 kilometers (52 miles) per hour as Dianmu left the Korean peninsula and began tracking through the Sea of Japan toward the main island of Honshu. The storm was forecast to make landfall close to Akita city in northern Japan late Wednesday. Dianmu is expected to cross northern Honshu and skirt the southern coast of the island of Hokkaido. Dianmu is the goddess who commands thunder and lightning in Chinese mythology.
A tropical depression in the eastern Gulf of Mexico dissipated before reaching the coast, where as much as 8 inches of rain may fall by the weekend. The system, with maximum sustained winds of 30 miles (45 kilometers) per hour, was about 170 miles south of Mobile, Alabama, and moving northwest at 12 mph, a center advisory reported just before 5 p.m. Miami time Wednesday. Its remnants were expected to wash ashore overnight somewhere from southeastern Louisiana to the Florida Panhandle.
The storm was forecast to push seas to about 12 feet in the area where BP Plc is drilling a relief well to permanently plug the oil spill. Work on the well was stopped Tuesday, and drilling can probably resume Aug. 16 or 17 after the storm passes.
The hurricane center said 3 inches to 5 inches of rain was likely along the northern Gulf Coast, with 8 inches in some areas. The storm’s surge is expected to be 1 foot to 2 feet above normal along the coast and just east of where it goes ashore. Louisiana's governor declared a state of emergency ahead of the storm, saying in a statement posted on the state’s website that the declaration was needed “given the threatened tropical storm conditions and complicating factors created by the oil spill.”
The hurricane center is also tracking two other systems. One, in the central Atlantic, has been given a 50 percent chance of organizing into a cyclone in the next two days, and the other off northern South America has a 10 percent chance. The central-Atlantic system will stay at sea and won’t be a threat to the U.S. The other is worth watching, although it “still has a long way to go. I feel the Gulf will remain threat-free through the first half of next week." After that, there are some threats looming. High-altitude winds called shear and dust from the Sahara that has been preventing African waves from growing into tropical cyclones are just about gone. “With low shear and little in the way of Saharan dust, these storm complexes that are emerging off Africa will have a free ride. These storms that form off Cape Verde will be the real deal and not the teaser storms we’ve been dealing with.”
HEAVY RAINS, SEVERE STORMS, FLOODING, LANDSLIDES -
INDONESIA - “Extreme weather changes have already hit Indonesia. The weather is currently unfriendly; we need to remind people to be careful.” The Meteorology, Climatology and Geophysics Agency earlier forecast that this year’s dry season would arrive in Sumatra, Java, Bali, Sulawesi and Maluku sometime from May to June. The forecast was then revised to July due to UNEXPECTED rises in sea temperatures that caused massive evaporation and heavy rains. In March, the agency had issued an annual weather forecast stating that the dry season would fall in June at the latest. However, rains continue to sweep several big cities in the country, including Jakarta.
SNOW AND COLD -
Snow in Brazil, below zero Celsius in the River Plate and tropical fish frozen. For a second day running it snowed Wednesday (August 5) in Southern Brazil and in twelve of Argentina’s 24 provinces including parts of Buenos Aires as a consequence of the polar front covering most of the continent’s southern cone with zero and below zero temperatures. In Argentina the phenomenon extended to Northern provinces, geographically sub-tropical, while in the Patagonia and along the Andes snow reached over a metre deep, isolating villages and causing yet undisclosed losses to crops and livestock. The extreme cold weather was expected to peak Thursday dawn with below zero temperatures and even lower with the wind chill factor.
Last Wednesday a northbound cold front hit the Patagonia and central Argentine regions. In Patagonia, minimum temperatures went as low as minus 10 Celsius with even lower numbers in snowy regions, while maximum temps were in the range of zero to 7 Celsius. Because of the freezing temperatures power consumption SET NEW RECORDS both in Argentina and Uruguay. Although residential demand was satisfied, hundreds of industries suffered an anticipated blackout.
In related news, reports from landlocked Bolivia indicate that to the east of the country in tropical areas temperatures plummeted to zero causing “millions of dead fish” in rivers that normally flow in an environment of 20 Celsius. The province is suffering a “major environmental catastrophe” and the population was warned not to make use of water from rivers (because of the dead fauna and flora). “The last time something of this magnitude happened was 47 years ago."
Over 1 million fish and thousands of alligators, turtles, dolphins and other river wildlife are floating dead in numerous Bolivian rivers in the three eastern/southern departments of Santa Cruz, Beni and Tarija. The extreme cold front that hit Bolivia in mid-July caused water temperatures to dip below the minimum temperatures river life can tolerate. As a consequence, rivers, lakes, lagoons and fisheries are brimming with decomposing fish and other creatures.
UNPRECEDENTED: Nothing like this has ever been seen in this magnitude in Bolivia. Inhabitants of riverside communities report the smell is nauseating and can be detected as far as a kilometer away from river banks. River communities, whose livelihoods depend on fishing, fear they'll run out of food and will have nothing to sell. Authorities are concerned there will be a shortage of fish in markets and are more concerned by possible threats to public health, especially in communities that also use river water for bathing and drinking, but also fear contaminated or decaying fish may end up in market stalls. They've begun a campaign to ensure market vendors and the public know how to tell the difference between fresh and unhealthy fish. In university fish ponds and commercial fisheries the losses are also catastrophic. [Reportedly the number has now climbed to 6 million.]
YouTube video showing the masses of dead fish. It's in Spanish, but "dead fish are dead fish".
FISH DEATHS -
Tens of thousands of dead fish have washed ashore along the Delaware Bay in southern New Jersey. State environmental and wildlife officials say it's not yet clear what killed the fish, which appear to exclusively small menhaden, also known as peanut bunker. The wash-up, discovered yesterday morning, encompassed a large stretch of the shoreline just north of Cape May. The heaviest amounts were in an area of Middle Township known as Pierce's Point. Water samples taken by federal environmental officials found no indication of toxic phytoplankton species, such as red tide. State officials also are analysing oxygen levels in the water.
HEALTH THREATS -
RECALLS & ALERTS:
-Fresh Express is Veggie Lovers Salad due to a possible health risk from Listeria monocytogenes.
