The Northern Hemisphere has taken a beating from extreme weather in recent years — the 2003 European heat wave, the 2010 Pakistan flood and the 2011 heat wave in the United States, for example. These events, in a general sense, are the result of the global movement of air. Giant waves of air in the atmosphere normally even out the climate, by bringing warm air north from the tropics and cold air south from the Arctic. But a new study suggests these colossal waves have gotten stuck in place during extreme weather events.
"What we found is that during several recent extreme weather events these planetary waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in before, the heat just stays." How long these weather extremes last is critical, the researchers say. While two or three days of 86 degrees Fahrenheit (30 degrees Celsius) pose little threat, 20 days or more can lead to extreme heat stress, which can trigger deaths, forest fires and lost harvests.
The researchers created equations to model the motion of the massive air waves, determining what it takes to make the waves plough to a stop and build up. The team then used these models to crunch daily weather data from the U.S. National Centers for Environmental Prediction. During extreme weather events, the waves were indeed trapped and amplified, the scientists found. They also saw a significant increase in the occurrence of these trapped waves.
Here's how the waves may be getting trapped: The burning of fossil fuels causes more warming in the Arctic than in other latitudes, because the loss of snow and ice means heat gets absorbed by the darker ground, not reflected (as it would by the white snow). This warming lessens the temperature difference between the Arctic and northern latitudes like Europe. Since these differences drive air flow, a smaller difference means less air movement. Also, land areas warm and cool more easily than oceans. The result is an unnatural pattern of air flow that prevents the air waves from circulating over land.
The study's results help explain the spike in summer weather extremes. Previous research had shown a link between climate change and extreme weather, but did not identify the mechanism. "This is quite a breakthrough, even though things are not at all simple - the suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability." The 32-year period studied provides a good explanation of past extreme weather events, the researchers say, but is too short to make predictions about how often such events may occur in the future.
name them, each of them, every one of them,
or else the years go right by and
none of them belong to you.**
Herb Gardner
LARGEST QUAKES -
Live Seismograms - Worldwide (update every 30 minutes)
This morning -
None 5.0 or larger.
Yesterday -
2/25/13 -
5.5 SOUTHERN PACIFIC OCEAN
5.4 SOUTHEAST OF RYUKYU ISLANDS
5.3 SANTA CRUZ ISLANDS
5.7 EASTERN HONSHU, JAPAN
5.2 WESTERN XIZANG
5.0 FIJI REGION
5.0 SOUTH OF KERMADEC ISLANDS
5.2 SOUTH OF KERMADEC ISLANDS
5.1 SOUTH OF KERMADEC ISLANDS
TROPICAL STORMS -
In the South Indian Ocean -
Tropical Cyclone Rusty was located approximately 335 nm east-northeast of Learmonth, Australia.
Tropical Cyclone Eighteen was located approximately 180 nm southeast of Cocos Island, Australia.
Australian Port Evacuates as Cyclone Threatens Iron Ore Mines - The approach of Severe Tropical Cyclone Rusty toward the north-west Australian coast triggered orders for the evacuation of parts of Port Hedland, site of the world's biggest bulk export terminal.
Tropical Cyclone Rusty has intensified, it has an eye spanning 20 nautical miles, and is expected to unleash a significant storm surge in northern Western Australia. Authorities are warning residents in low lying areas to evacuate with a threat of flooding, high winds and a coastal tide. People in parts of Port Hedland have been told to leave now ahead of an expected storm surge as Tropical Cyclone Rusty takes aim at the Pilbara coast. Communities across WA's Pilbara region are bracing for wild weather.
"Rusty's intensity, size and slow movement is also likely to lead to a very dangerous storm tide as the cyclone centre nears the coast. Tides are likely to rise significantly above the normal high tide mark with damaging waves." The Australian Bureau of Meteorology has also warned the cyclone will bring more rainfall to the area than is expected for a tropical storm of this size.
Tropical Cyclone Haruna hits southwestern Madagascar - National disaster authorities and aid agencies are struggling to reach remote areas of Madagascar's southwestern coast where thousands of people are thought to have been made homeless by the cyclone. Ex-cyclone Haruna is expected to dissipate in the Southern Indian Ocean under increasing wind shear in the next day or two. Haruna is being blown apart several hundred miles away from La Reunion Island.
SEVERE RAIN STORMS, FLOODING, LANDSLIDES -
Australia - Gympie flood peak revised up. More businesses and some homes are now at risk in the southeast Queensland town of Gympie, with the flood peak revised up to 19 metres.
HEAVY SNOW / EXTREME COLD -
U. S. - 2nd round of heavy snow in Plains, Midwest; 2 dead. The nation's midsection again dealt with blizzard conditions Monday, closing highways, knocking out power to thousands in Texas and Oklahoma and even bringing hurricane-force winds to the Texas Panhandle.
Already under a deep snowpack from last week's storm, Kansas was preparing for another round of heavy snow Monday evening and overnight, prompting some to wonder what it could do for the drought. "Is it a drought-buster? Absolutely not. Will it bring short-term improvement? Yes." The storm is being blamed for two deaths on Monday. In northwest Kansas, a 21-year-old man's SUV hit an icy patch on Interstate 70 and overturned. And in the northwest town of Woodward, Okla., heavy snow caused a roof to collapse, killing one inside the home. Earlier on Monday, blizzard warnings extended from the Oklahoma and Texas panhandles into south-central Kansas.
Meanwhile to the east, lines of thunderstorms crossed Arkansas, Louisiana and Florida, bringing heavy rain and an occasional tornado warning. As many as 10,000 people lost power in Oklahoma, as did thousands more in Texas. Colorado and New Mexico were the first to see the system Sunday night, with up to 2 feet falling in the foothills west of Denver. As it moved into the Texas and Oklahoma panhandles Monday, the storm ground travel to a halt, closing miles of interstates and state highways. The National Weather Service in Lubbock reported at one point that as many as 100 vehicles were at a standstill on Interstate 27.
Extremely strong winds whipped around at least a foot or more of snow in the Texas Panhandle, and a hurricane-force gust of 75 mph was recorded at the Amarillo airport. Amarillo recorded the biggest snowfall total in Texas — 19 inches, just short of the record of 19.3 — while Fritch was second with 16. The Oklahoma Highway Patrol closed all highways in the Panhandle and much of the state's northwest because of blizzard conditions. Several dozen motorists have reported being stranded or have abandoned their vehicles.
While the wintry precipitation is "a shot in the arm," the drought in the Plains and Midwest is far from over. 12 inches of snow is equivalent to about 1 inch of rain. "We would need 2-4 feet of snow to just erase the October to present deficits," in Kansas. Snow is more efficient than summer rain in replenishing soil moistures because rain tends to run off or evaporate during the summer months. But it can take months or years for pastures and rangeland to recover to the point where there is good forage there for livestock. "There is a lag coming out of drought where some of these impacts will linger on long after 'climatological drought' is gone. And there is always a sense of false security there."
The storm could be deadly for grazing cattle, with the wind pushing animals into a fenced corner where they could suffocate from the drifts. "This type of snow is a cattle-killer." Parts of Kansas are bracing for anywhere from 8 to 24 inches of snow as the system moves through the state overnight. Wichita figures to take another hit after last week's storm that dumped about a foot and a half of snow. Through the day Tuesday, the storm is forecast to spin toward the upper Midwest, bringing snow to Chicago and eventually Detroit before heading toward Buffalo, N.Y, and northern New England in the middle of the week.
Wheat farmers were hopeful that Oklahoma's third winter storm in the past week would help make a dent in a drought that has gripped the state since last summer.
HEALTH THREATS -
RECALLS & ALERTS
- Dakota Specialty Milling has initiated a recall of a limited number of its specialty flours and grain blends in cooperation with the Food and Drug Administration due to the possible presence of fragments of thin metal wire from a defective screen on one of its manufacturing lines at a milling facility.
- King Arthur Flour has initiated a recall of a limited number of its bags of flour due to the possible presence of small (7-9 mm) blue polyurethane balls that are used in the sifting process. The balls have a smooth surface and no sharp edges and are made from food grade material.
- Hy-Vee, Inc. issued a recall of certain bags of Hy-Vee dog food due to elevated levels of a chemical contaminant commonly found in corn.
