function thread(threadid, title, poster, threaddate, threadtime, message, postid)
{
this.threadid = threadid;
this.title = title;
this.poster = poster;
this.threaddate = threaddate;
this.threadtime = threadtime;
// Post object, contains the post data
this.post = new post(message, postid);
}
// This function is used to show the posts of the thread.
function post(message, postid) {
this.postid = postid;
this.message = message;
}
var threads = new Array(15);
threads[0] = new thread(3844754, 'Ozone Hole 2009: size of USA', 'joe24Jscientist', 'Yesterday', '02:58 PM','http://www.noaanews.noaa.gov/stories2009/20091117_ozone.html
reached its 2009 peak circumference in late September, according to measurements by NOAA researchers. Slightly smaller than the North American continent, the ozone hole covered 9.2 million square miles, according to NOAA satellite observations. This ranks as the 10th largest since satellite measurements began in 1979.
','36281180');
threads[1] = new thread(3817018, 'Leonid Meteor Shower - Monday night / Tuesday morning', 'paulg', '11/13/09', '05:20 PM','Hi Everybody,
Meteor showers are always of high-interest to our viewers, and this year\'s Leonid show will be better than normal due to no moonlight...skies will be darker, so we\'ll see more of the faint meteors than if there was a full moon.
','36088943');
threads[3] = new thread(3788840, 'SOLAR flight around the world: GREAT WEBSITE WITH PHOTOS', 'joe24Jscientist', '11/05/09', '11:57 AM','http://www.solarimpulse.com/
Where does the idea of the Solar Impulse come from? Bertrand Piccard came up with this idea following Orbiter 3. This successful world tour in 1999 conveyed a great deal of enthusiasm. It is precisely this enthusiasm that must be mobilized to make people aware of the challenge of the 21st century: reconcile economic and ecologic interests. Promoting the use of new technologies not only to give credibility to sources of alternative forms of energy but also to show that we must spare today\'s resources.
Which are the concrete objectives of this operation? To show what can be achieved using renewable energies and encourage their use. We want a strong symbol capable of striking the minds. In this respect, Solar Impulse will be our ambassador. The message we want to share is that it is essential to develop new technologies to allow our society to reduce its energetic consumption. As it is almost unthinkable that people will accept to diminish their life standards, we must develop efficient equipments that consume less, as well as alternative sources of energy and first of all solar energy.
Why is the wingspan of the plane so important? Firstly, a longer wingspan allows the improvement of its aerodynamic efficiency by reducing the importance of induced drag. This produces a weaker airplane sink-rate and thus reduces the power of the motors required to maintain it in a horizontal position. The second advantage of a large wingspan is the benefit from a greater surface on which to place the solar cells.
What area still limits the plane\'s performance? It is above all, the energetic density of the batteries. Their stocking capacity is still limited and their influence has a great bearing on the total mass of the airplane. By doubling their storage capacity, it would be possible to allow a second person on board and therefore carry out longer flights.
What will happen in case of a breakdown? In other words, what are the risks for the pilot? If the pilot wastes his energy during the night, he will have to interrupt the flight before the next sunrise. But isn\'t it also the case of our generation running the risk of not being able to hand down the planet to future generations without a major human and technological disaster? The pilot will be equipped with a parachute, but our world doesn\'t have any such protection to face the climate change! In other words, the greatest risk is not flying on board of the Solar Impulse, but keeping on wasting our world\'s energy and raw materials!
What is the output of solar cells? The output of the cells reserved for the project is about 20%. Two criteria are used for this selection: the output, but also the weight. The cells chosen are made of silicon mono-crystalline of a fine thickness. Today there exist more high-performance technologies with up to 30% output, but they are also heavy. It is obvious that a significant improvement of this output would also improve the airplane\'s performance and reduce its wingspan or increase the payload.
What does photovoltaic mean? Cells are photovoltaic, when they directly transform the photons (light) into electricity. But there are thermal solar panels that allow water to be heated either for houses or for producing the steam used to turn the turbines that generate electricity.
Why not a world tour without stopovers? For the time being this is not feasible because even if we are able to reach "perpetual flight" there will be a human limitation. The plane\'s cockpit is very small and can only accommodate one pilot. He won\'t be able to physically endure these conditions more than 4 to 5 days. The world tour without stopovers could be made possible as soon as 2 pilots can embark. One must know that it took was 60 years between the first world tour with stopovers and the first world tour without stopovers in a traditional motor airplane...
What technological developments can we expect after the completion of the world tour? It\'s difficult to say, but we can already expect multiple developments in fields of weight and energy saving, in components efficiency, in the greater reliability of electrical engines, in a better output of solar cells, energy storage or improvements of cabin pressurisation systems. But we will first have to develop know-how before communicating the technologies.
Can solar energy replace oil? Solar energy alone cannot. The future energy supply will certainly be based on a large diversification of sources: solar, but also wind, hydroelectric, tidal and, geothermic. Until this goal has been reached, there will still be an important demand for oil, coal and nuclear power.
Why is the cause of sustainable development progressing so slowly, when the risks of pollution and climate change are undeniable? Because protecting the environment too often still remains associated with a restriction of mobility and financial sacrifice. The economic benefits offered by a true policy of sustainable development must be shown, including new products, new prospects, new sectors offering jobs, market share and profitability.
Do you think it would be possible to replace conventional airlines with solar ones in the near future? Currently, technology only allows the transport of a single person on a flight of 24 hours, and then with a wingspan of 60 to 80 meters. But if we go back into history, when the great Wright brothers got their first plane to fly a distance of 200 meters in 1903, could they have imagined that 66 years later, two men would walk on the moon?
','36056676');
threads[4] = new thread(3786385, 'The stats are in: USGS says that Atlanta floods are "extremely rare"', 'paulg', '11/04/09', '04:54 PM','
Atlanta Floods Extremely Rare
The epic flooding that hit the Atlanta area in September was so extremely rare that, six weeks later this event has defied attempts to describe it. Scientists have reviewed the numbers and they are stunning.
“At some sites, the annual chance of a flood of this magnitude was so significantly less than 1 in 500 that, given the relatively short length of streamgaging records (well less than 100 years), the U.S. Geological Survey cannot accurately characterize the probability due to its extreme rarity," said Robert Holmes, USGS National Flood Program Coordinator. “Nationwide, given that our oldest streamgaging records span about 100 years, the USGS does not cite probabilities for floods that are beyond a 0.2 percent (500-year) flood.”
“If a 0.2 percent (500-year) flood was a cup of coffee, this one brewed a full pot,” said Brian McCallum, Assistant Director for the USGS Georgia Water Science Center in Atlanta. “This flood overtopped 20 USGS streamgages – one by 12 feet. The closest numbers we have seen like these in Georgia were from Tropical Storm Alberto in 1994. This flood was off the charts.”
The rains returned water levels in the region’s two largest reservoirs, Lake Lanier and Allatoona Lake, to pre-drought levels. Lake Lanier rose by more than three feet to 1068 feet by Sept. 25 and returned to full pool in October. Allatoona Lake rose to 853.25 feet on Sept 23, more than 13 feet over full pool of 840 feet.
“The flooding in Atlanta is certainly near the top of the list of the worst floods in the United States during the past 100 years,” said Holmes. “For comparable drainage areas, the magnitude of this flood was worse than the 1977 Kansas City flood, which caused tremendous destruction and loss of life. It is a testament to the diligence of county officials and emergency management teams that more lives were not lost in Georgia.”
Significant property losses, however, were a near certainty from this event. According to the National Weather Service, some locations recorded up to 20 inches of rain from 8:00 pm on Sept. 20 to 8:00 pm the following day. Culverts and sewers are not usually designed for events of this magnitude because they are so rare and it is cost prohibitive.
“Applying rainfall frequency calculations, we have determined that the chance of 10 inches or more occurring at any given point are less than one hundredth of one percent”, said Kent Frantz, Senior Service Hydrologist for the National Weather Service at Peachtree City. “This means that the chance of an event like this occurring is 1 in 10,000.”
For this analysis, USGS reviewed high-water-mark surveys and indirect peak discharge computations throughout the flood-affected region. Scientists gather these data from the field during floods and in their immediate aftermath to supplement or in this case, to provide data after a gage is destroyed. Some notable results:
In Cobb County, Sweetwater, Noonday, Butler, and Powder Springs creeks flooded so severely that the annual chance of a worse event is far smaller than 0.2 percent (500-year) flood. On Sweetwater Creek near Austell, Ga., high-water marks showed a peak stage of 30.8 feet. The peak flow (31,500 cubic feet per second) was more than double the previous peak flow recorded at this site during the last 73 years. The previous peak, caused by the remnants of Hurricane Dennis in July 2005, was almost 10 feet lower at 21.87 feet.
In Douglas County, the Dog River near Fairplay overtopped the USGS stream gage by 12 feet. The peak stage was 33.8 feet, with a peak discharge of 59,900 cubic feet per second. This is well beyond the 0.2 percent annual exceedence probability (500-year) flood.
Gwinnett, DeKalb and Rockdale counties also had record flooding. Suwanee Creek floods were beyond the 0.2 percent annual exceedence probability (500-year) flood.
On the Chattahoochee, the USGS gage at Vinings reached a peak stage of 28.12 feet with 40,900 cubic feet per second, which represents between a between a 1.0 to 0.5 percent annual exceedence probability (100- to 200-year) flood.
In Georgia the USGS maintains a network of nearly 300 streamgages that provide data in real time. Data from these streamgages are used by local, state and federal officials for numerous purposes, including public safety and flood forecasting by the National Weather Service. A map of these gages and graphs of discharge for the last seven days is available online.
','36044637');
threads[5] = new thread(3784066, 'JPL Addresses a Weakness in Climate Models', 'jimgandy', '11/04/09', '01:21 AM','There is a press release on the NASA website, dated 11/3/09, discussing a recent paper published by JPL scientists in the Journal of Climate. It is in the global climate change section and can be accessed at:
The study addresses a weakness in climate models, namely the way the models simulate clouds. The press release does a good job of clarifying a highly technical paper.
Citation:
Kahn, B. H., and J. Teixeira (2009), A global climatology of temperature and water vapor variance scaling from the Atmospheric Infrared Sounder, J. Climate, 22, 5558\'5576, doi: 10.1175/2009JCLI2934.1 ','36034544');
threads[6] = new thread(3780659, 'Global Tree Death Patterns Reveal Emerging Climate Change Risks for Forests', 'jimgandy', '11/02/09', '11:16 PM','Forests have been suggested as part of a plan to help sequester CO2. However, a recent story on the USGS website indicates that such a plan may be at risk because of climate change. The story can be accessed at:
The actual report is online in the journal Forest Ecology and Management. Here is the abstract:
Greenhouse gas emissions have significantly altered global climate, and will continue to do so in the future. Increases in the frequency, duration, and/or severity of drought and heat stress associated with climate change could fundamentally alter the composition, structure, and biogeography of forests in many regions. Of particular concern are potential increases in tree mortality associated with climate-induced physiological stress and interactions with other climate-mediated processes such as insect outbreaks and wildfire. Despite this risk, existing projections of tree mortality are based on models that lack functionally realistic mortality mechanisms, and there has been no attempt to track observations of climate-driven tree mortality globally. Here we present the first global assessment of recent tree mortality attributed to drought and heat stress. Although episodic mortality occurs in the absence of climate change, studies compiled here suggest that at least some of the world\'s forested ecosystems already may be responding to climate change and raise concern that forests may become increasingly vulnerable to higher background tree mortality rates and die-off in response to future warming and drought, even in environments that are not normally considered water-limited. This further suggests risks to ecosystem services, including the loss of sequestered forest carbon and associated atmospheric feedbacks. Our review also identifies key information gaps and scientific uncertainties that currently hinder our ability to predict tree mortality in response to climate change and emphasizes the need for a globally coordinated observation system. Overall, our review reveals the potential for amplified tree mortality due to drought and heat in forests worldwide.
','36018272');
threads[7] = new thread(3780598, 'Recent Acceleration of Global Sea Level Rise', 'jimgandy', '11/02/09', '10:50 PM','If you are looking for information on the rise of global sea level, there is a report published in the November 2009 issue of the Journal of Climate worth noting. The reference is:
Merrifield, M.A., S.T. Merrifield, and G.T. Mitchum, 2009: An Anomalous Recent Acceleration of Global Sea Level Rise.J. Climate, 22, 5772–5781.
Abstract:
Tide gauge data are used to estimate trends in global sea level for the period from 1955 to 2007. Linear trends over 15-yr segments are computed for each tide gauge record, averaged over latitude bands, and combined to form an area-weighted global mean trend. The uncertainty of the global trend is specified as a sampling error plus a random vertical land motion component, but land motion corrections do not change the results. The average global sea level trend for the time segments centered on 1962–90 is 1.5 ± 0.5 mm yr-1 (standard error), in agreement with previous estimates of late twentieth-century sea level rise. After 1990, the global trend increases to the most recent rate of 3.2 ± 0.4 mm yr-1, matching estimates obtained from satellite altimetry. The acceleration is distinct from decadal variations in global sea level that have been reported in previous studies. Increased rates in the tropical and southern oceans primarily account for the acceleration. The timing of the global acceleration corresponds to similar sea level trend changes associated with upper ocean heat content and ice melt.
The full story is available at:
http://ams.allenpress.com/perlserv/?request=get-toc&issn=1520-0442&volume=22&issue=21 ','36017982');
threads[8] = new thread(3771764, 'USGS Public Lecture Series: Science in Action', 'jimgandy', '10/30/09', '11:46 AM','Paul Gross posted an excellent resource entitled Excellent Climate Change Visuals from NASA. I thank Paul and highly recommend it.
In addition, I found a public lecture series on the USGS website. It can be access at:
The lecture series are held once a month in Reston, VA. Not all of the lectures are available on video. However, the videos of the earlier lectures are available in the archive area accessed at:
There are presentations covering a wide range of topics involving the USGS. The archive goes back to April, 2009 which is when the series began. If you are researching a topic of a story, this may provide you with some good information.
','35973182');
threads[9] = new thread(3771705, 'NASA: Interactions with Aerosols Boost Warming Potential of Some Gases', 'jimgandy', '10/30/09', '11:11 AM','It\'s not just CO2 that is a concern. Other greenhouse gases and aerosols are often ignored in the discussion. NASA scientists have just published a study involving two other greenhouse gases and their interaction with aerosols. The report is published in the latest issue of Science:
There are three other articles of interest in the same issue of Science, two of which are related to the NASA study. The abstracts are below:
Beyond Climate Science
Eric J. Barron
The United States is moving rapidly into an age of climate-related decisions involving mitigation and adaptation, following decades of focusing on reducing uncertainties in attribution and prediction. But the nation lacks a deliberate approach to generating the "environmental intelligence" needed to support good decisions.
Eric J. Barron is director of the National Center for Atmospheric Research, Boulder, Colorado.
Almut Arneth,1,2,*Nadine Unger,3Markku Kulmala,2Meinrat O. Andreae4
The push toward cleaner air in Beijing before the 2008 Olympic Games was a vivid reminder of the need to control air pollution, not only in Asia but in many regions of the world (1). There is mounting evidence for particle- and ozone-related health effects (2, 3). Furthermore, ozone and aerosol particles affect Earth\'s radiation balance (4, 5): Many aerosols cool the atmosphere (a negative forcing), whereas ozone and black carbon aerosol have a warming effect (a positive forcing). There is thus a strong motivation for treating air pollution control and climate change in common policy frameworks (5, 6). However, recent model studies (7–9) have shown that changes in pollutant and precursor emissions, atmospheric burden, and radiative forcing are not necessarily proportional. Furthermore, as Shindell et al. report on page 716 of this issue, current models do not capture many of the complex atmospheric processes involving aerosols and reactive trace gases (10).
1 Department of Physical Geography and Ecosystem Analysis, Lund University, 22362 Lund, Sweden. 2 Department of Physics, University of Helsinki, 00014 Helsinki, Finland. 3 NASA Goddard Institute for Space Studies, Center for Climate Systems Research, Columbia University, New York, NY 10025, USA. 4 Max Planck Institute for Chemistry, Biogeochemistry Department, 55020 Mainz, Germany.
As of 2008, over half of humanity lives in cities. The number of megacities (with populations over 10 million) grew from 3 in 1975 to 19 in 2007, and is projected to increase to 27 in 2025 (1). These megacities are the engines of growing economies, but are also very large sources of air pollutants and climate-forcing agents. The growth of megacities greatly aggravates the health impacts of polluted air, yet it may also provide an opportunity to mitigate climate change, if implemented air quality policies are designed to also reduce global warming.
1 Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305, USA. 2 State Key Lab for Environment Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
','35972626');
threads[10] = new thread(3766126, 'Excellent Climate Change Visuals from NASA', 'paulg', '10/28/09', '01:00 PM','Last weekend, NASA\'s Jet Propulsion Lab sponsored a symposium to show the public the latest data and scientific evidence about global warming. At my request, NASA has created a special webpage for broadcast meteorologists with access to the PowerPoint presentations for each speaker. This is a tremendous resource for us, and you can access the PowerPoints at http://climate.nasa.gov/ClimateSymposium/.
Again, NASA has done this just for us...please take the time to check it out.
Paul ','35941982');
threads[11] = new thread(3759609, 'STATISTICS & GLOBAL COOLING/WARMING?', 'joe24Jscientist', '10/26/09', '02:29 PM','
"The case that the Earth might be cooling partly stems from recent weather. Last year was cooler than previous years. It\'s been a while since the super-hot years of 1998 and 2005. So is this a longer climate trend or just weather\'s normal ups and downs?
According to an analysis of the numbers done by several independent statisticians for The Associated Press...."
','35911296');
threads[12] = new thread(3755347, 'New Media: Future of TV and new media', 'joe24Jscientist', '10/24/09', '05:19 PM','A bit off topic as far as "stories" are concerned...
but if you are wondering what is the future of TV, new media, radio etc
for your career this is a revealing report in powerpoint-pdf form (quick and easy)
','35888120');
threads[13] = new thread(3751921, 'PewCenterResearh Poll: Americans Cooling to Global Warming', 'jimgandy', '10/23/09', '10:39 AM','A new poll has been released by Pew Center Research. To see the poll go to:
','35870410');
threads[14] = new thread(3749021, 'Wind Energy: A Scare for Bats and Birds', 'jimgandy', '10/22/09', '01:13 PM','This is a developing story from the USGS. There is a multimedia presentation at:
The transcript is not posted yet, but this may be of interest to those of you in areas with wind farms. Why is this important? A question to be answered.