Friday, July 15, 2011
Thursday, July 14, 2011
Aircraft punch holes in clouds, leave snow in their wake
Aircraft punch holes in clouds, leave snow in their wake
We've seen recently that air travel can have an oversized impact on the atmosphere, at least relative to emission of things like greenhouse gasses, because they seed clouds that can persist for hours. Now, researchers have taken a detailed look at what happens when aircraft fly through clouds that already exist. Under many circumstances, it turns out that the aircraft have the opposite effect, causing pressure changes that trigger the formation of large holes in the cloud, with the missing water falling out as snow.
Holes in clouds, like the one shown above, have been associated with the passage of aircraft since the 1940s, but it hasn't been clear how significant this process is. By the 1980s, researchers had found that propeller-driven aircraft produce large pressure changes in their wake, which produce a lot of ice crystals if they pass through supercooled clouds. More recent work showed just how large this effect can be: propellers can induce temperature drops of up to 30°C, while the wings of jets can lower the temperature by 20°C. If a cloud is already in the area of -10 to -20°C, that means the airplane should cause ice to crystalize out of clouds.
The new paper shows what happens as a result of these crystals. Modeling indicates that the heat released by ice formation causes an updraft in the immediate vicinity of where an aircraft passes. This carries most of the ice crystals back upward, with the exception of the heaviest, which fall through the updraft as snow. On the periphery of the updraft, a corresponding downdraft causes evaporation of the water in the cloud, which gradually expands the hole. This self-sustaining cycle should cause the hole to expand for up to an hour after the aircraft passes, and vastly expands the area affected by the aircraft's passage.
The researchers looked at satellite and radar imagery to see whether they could spot the equivalent of what their model was showing. Could they ever. Radar near a Denver airport showed lines of snow formation that followed curved paths typical of airliners. Clouds over the continental US showed extended trains of holes and channels that followed flight paths verified on air transportation records. "Some holes reached lengths of >100 km and were detected for four or more hours," the authors note. From the point where they were detected on radar, the holes would double their area within a half hour, and continued to expand out to a full hour.
The authors don't expect that the formation of snow is significant enough to do much more than cause small amounts of localized snow in the immediate vicinity of the airport. But the satellite imagery suggests that heavy air travel can cause a measurable drop in the total area covered by clouds under the right conditions. Along with the earlier results, the new work indicates that, although aircraft only disturb a small area of the atmosphere, the disturbances they cause can persist and propagate long enough to have an unexpectedly large impact on our planet.
Science, 2011. DOI: 10.1126/science.1202851 (About DOIs).
Foreclosure filings down, but experts say it's not good news
When looking over recent statistics, it may seem as if the economy is improving. But some experts say those stats are misleading, and there's more to the story as to why home foreclosure filings are declining.
Foreclosures come in all shapes and sizes, and for buyers, they're a bargain. “Bank owned properties are priced to sell. They want multiple offers in the first week, they want to sell within 30-60 days, and they want to be the lowest price on the market for what's similar,” says Brooke O'Malley, Owner/Broker at Club Realty.
O'Malley says the Suncoast's housing market is actually quite good. “We're at about a 6 month inventory, which is a very healthy market. We're running into multiple offer situations across the board, in all price ranges, probably about 80% of the time.”
In Sarasota County, only 236 home foreclosures were filed last month, compared to 364 in June 2010. But despite those encouraging numbers, Judge Lee Haworth, who is the Administrative Judge over foreclosure cases, says that news isn't so good. “The cases are not able to get through the court system, so they can be put back into inventory, and that's really one of the issues we're struggling with.”
State funding ran out, and the Rocket Docket, which expedited foreclosure proceedings, ended last month. Judge Haworth says that will stagnate cases. “Before we could get a hearing time 30-40 days out pretty easily, because we had the 3 judges and the 4 case managers to process the paper and get things ready. We don't have them anymore, so that means we're looking at 3-4 months out to get those cases resolved.”
O'Malley says in the end, that could hamper the progress the housing market has made. “Over the time the prices have come down more and more than they may have if they would have just foreclosed quickly.”
Judge Haworth and the Chief Judge plan to approach lawmakers in our area to request additional support for the programs needed to process the foreclosure filings. In the meantime, Judge Haworth is putting on free seminars for homeowners who need help with foreclosures. The next “Hope for Homeowners” seminar is on Saturday at the Venice Community Center.
Sunday, May 29, 2011
Friday, May 27, 2011
JFK Worried Moon Mission Was a 'Stunt,' New Tapes Show
The tape is being released on Wednesday's 50th anniversary of Kennedy's speech to Congress in which he set out a moon landing as a goal to be achieved within the decade. The May 25, 1961, address came soon after Alan Shepard Jr. became the first American launched into space on May 5, 1961, following a similar Soviet feat on April 12, 1961.
But much of the patriotic fervor about space, fueled by Cold War competition with the Soviet Union, had dissipated by late 1963, at least in the mind of Kennedy, who was seeing huge expenditures as a political negative. The tape of his conversation with Webb is being released by the John F. Kennedy Presidential Library and Museum on its website.
Some historians have argued that Kennedy was trying to find a way out, especially as he prepared for a 1964 reelection campaign where cost, and the lack of significant progress, could become an issue. The conversation underscores his qualms but also his ultimate attempt to stay with the program while casting it in a different light, perhaps as function of defense or national security needs, not solely the prestige of feats in space.
Webb, whose comments prove prescient, makes a thoughtful case for persisting and for the ultimate scientific and intellectual benefits. But he makes clear that, even if Kennedy wins reelection, we would not be landing on the moon before a second term ended, seemingly disappointing Kennedy, whose voice drops at Webb's cautionary note. Ultimately, Neil Armstrong became the first to set foot there on July 20, 1969.
Kennedy grouses that he will be forced to defend the program during the upcoming campaign when "we won't have had anything for a year and a half." And he's clearly disappointed when Webb tells him that we may "fly by" the moon during a second Kennedy term but not land.
Webb diplomatically challenges the president's assumption of sharply diminished public interest. And as the conversation goes on, Kennedy turns pragmatic and wonders less about the program's utility than he does how he might repackage selling it.
"But it seems to me what we've got to try and do is for the reasons you suggested: we've got to wrap around in this country a military use for what we're doing and spending in space. If we don't, it does look like a stunt and too much money," Kennedy declares.
"If we can show that that's true but there's also a very significant military use. Now how are we going to do that?"
Near the end Kennedy concedes, "I think this can be an asset, this program. I think in time, it's like a lot of things; this is mid-journey and therefore everybody says, 'What the hell are we making this trip for?' But at the end of the thing they may be glad we made it." Through the chat, Webb makes the case for staying the course and assured, "You're going to have both science and technology appreciating your leadership in this field. Without a doubt in my mind. And the young, of course, see this much better than in my generation."
"And I predict you are not going to be sorry, no sir, that you did this."
Less banger for your buck: The Memorial Day BBQ will cost you 29% more this year thanks to inflation
Read more: http://www.dailymail.co.uk/news/article-1390822/Memorial-Day-cookout-cost-29-year-thanks-inflation.html#ixzz1Nb5Cboff
$500 Million Obama Administration Program Will Help Kids 'Sit Still' in Kindergarten
Fed's secret loans to banking giants revealed
Read more: http://www.smh.com.au/business/world-business/feds-secret-loans-to-banking-giants-revealed-20110526-1f5zb.html#ixzz1NYNu4vGB
TSA Thug Grabs Crotch of Injured Vet
