Atmospheric News
NOAA: January 2006 Warmest on Record for US
The National Climatic Data Center reports that the United States experienced its warmest January on record, with an average temperature of 39.5 degrees F. This is 8.5 degrees F (4.7 degrees C) above the 1895-2005 mean of 31.0 degrees F, the Climatic Data Center in Asheville, N.C. , says.
The Center says the jet stream remained unusually far to the north during January 2006, trapping cold air in Canada and Alaska, while allowing relatively warm Pacific air to influence the temperatures across the contiguous U.S., warming much of the nation. In early February, the jet stream was giving way to a more typical winter pattern, the National Weather Service’s Climate Prediction Center said. The February outlook calls for below normal temperatures in the mid-Atlantic, the Southeast, and the inter-mountain West, and above-normal temperatures in the Southwest, the northern Plains and Alaska.
For the complete overview see http://www.ncdc.noaa.gov/oa/climate/research/2006/jan/national.html
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Wyoming Cloud Seeding Experiment Underway
A five-year, $8.8 million pilot project to examine whether seeding clouds with silver iodide produces a measurable increase in snowfall over Wyoming's Medicine Bow, Sierra Madre, and Wind River mountain ranges began in January.
Scientists from the National Center for Atmospheric Research (NCAR) and partner institutions are deploying both airborne and ground-based instruments from January 16 to February 13 and again from March 10 to 31 to gather project data.
Microwave radiometers are capturing variations in snow-producing clouds over the target areas, including amounts and duration of water vapor and liquid water in the clouds. Instruments at selected sites are tracking precipitation rates, common meteorological variables, background air quality, and ecosystem characteristics.
NCAR's partners in the observations include the University of Wyoming, the South Dakota School of Mines and Technology, the Desert Research Institute, and the U.S. Forest Service.
Weather Modification, Inc., a private company based in Fargo, N.D., is seeding the target area's snow clouds. WMI is also providing a research aircraft and several ground-based instruments for observations.
Cloud seeding is big business. Western states spend millions each year seeding clouds with silver iodide to increase snow or rain, but studies to evaluate the method's effectiveness, at least on a large scale, have been inconclusive. The Wyoming Water Development Commission (WWDC) has funded the Wyoming Weather Modification Pilot Program to resolve whether cloud-seeding might provide Wyoming users with a low-cost source of fresh water.
Even a modest 10% increase in snowpack in the project's targeted areas would provide between 130,000 and 260,000 acre-feet of water in additional runoff each spring, a WWDC report says. Conservative estimates value the extra water between $2.4 and $4.9 million. These numbers do not include values for generating more hydroelectric power, enhancing recreation and tourism, improving water quality, and other environmental benefits. At $6.60 to $13.00 per acre-foot, the technique would be a bargain; water from Wyoming's new High Savery Dam runs $158.93 per acre-foot, the WWDC says.
For more information see:
www.ucar.edu/news
Wyoming Cloud Seeding Pilot Program
www.rap.ucar.edu/projects/wyoming/index.html
Wyoming Water Development Commission
http://wwdc.state.wy.us/
Weather Modification, Inc.
www.weathermod.com
.
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Climate Prediction Center Forecasts La Nina
The National Weather Service’s Climate Prediction Center announced the official return of La Niña in early February. Center forecasters predicted La Niña was forming nearly in mid-January. Oceanic sea surface temperatures met the operational definition of La Niña for the November through January period. La Niña is the periodic cooling of ocean waters in the east-central equatorial Pacific, which can impact the typical alignment of weather patterns around the globe. The Climate Prediction Center forecasts this La Niña will likely persist into late spring, and possibly into summer.
Internationally, La Niña impacts during the Northern Hemisphere winter typically include enhanced rainfall across Indonesia and northern Australia, as well as in the Amazon Basin and in southeastern Africa and below-average rainfall across the eastern half of the equatorial Pacific and eastern equatorial Africa.
Typically, La Niña events favor increased Atlantic hurricane activity, however, Jim Laver, director of the Climate Prediction Center says, "It is too early to say with confidence what effects this La Niña event will have on the 2006 hurricane season."
La Niña events recur approximately every three to five years. The last La Niña occurred in 2000-2001 and was a relatively weak event compared to the 1998-2000 event.
For more see:
NOAA ENSO Update http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/index.html
Sea Surface Temperature Satellite Imagery
http://www.osdpd.noaa.gov/PSB/EPS/SST/climo&hot.html
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Changes to Land Cover May Enhance Global Warming in Amazon, Reduce It in Midlatitudes
Scientists at the National Center for Atmospheric Research (NCAR), in Boulder, say new simulations of 21st-century climate show that human-produced changes in land cover could produce additional warming in the Amazon region comparable to that caused by greenhouse gases. However, the same changes could counteract greenhouse warming by 25% to 50% in some midlatitude areas. The results were published in the December 9 issue of Science.
Lead author Johannes Feddema (University of Kansas) carried out the modeling work with six coauthors from NCAR while on sabbatical at the center. The team linked NCAR’s Land Surface Model with the global-scale Parallel Climate Model, developed by scientists at NCAR and the U.S. Department of Energy under DOE sponsorship.
To bracket a range of possibilities, the group examined two contrasting scenarios for greenhouse emissions and land cover put forth by the Intergovernmental Panel on Climate Change. The more pessimistic scenario assumed that emissions will increase steadily, while the more optimistic scenario assumes rapid gains in energy efficiency.
The results for the first scenario show that deforestation adds 2°C (3.6°F) or more to surface temperature across the Amazon by 2100. Cooling occurs in the nearby Pacific and Atlantic waters with a weakening of the large-scale Hadley circulation that drives tropical and subtropical climate. In turn, moisture penetrates further north and produces a cooling, moistening influence across the U.S. Southwest during that region’s summer monsoon.
While deforestation acts to warm the tropics by replacing forests with less productive pasture, converting midlatitude forests and grasses to cropland tends to act as a cooling influence, because the crops tend to reflect more sunlight and release more moisture into the air. Feddema and colleagues found that expanded agriculture tends to counteract global warming by as much as 50% across parts of North America, Europe, and Asia. In Canada and Russia, boreal forests add to regional warming as they spread north over time.
Although the two IPCC scenarios studied agree on the impacts of land use in some regions, they produce contrasting results in others. The next step for Feddema and colleagues is to utilize the NCAR-based Community Climate System Model, which will provide higher-resolution results. They also hope to incorporate the effects of urban areas on regional climate.
The simulations were supported by the DOE, the National Science Foundation, and the University of Kansas. NSF is NCAR’s primary sponsor. Opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of NSF.
For more see http://www.ucar.edu/news/releases
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NOAA Budget Outlined
President Bush's proposed 2007 budget, announced on February 7, 2006, includes $904 million for NOAA's Weather and Water Programs, including a net program increase of $46.1 million, according to NOAA.
NOAA's total budget request is $3.68 billion, including a net program increase of $345 million. The agency said the requested amount for the Weather and Water Programs includes increases to strengthen NOAA's ability to sustain and improve services in observations, research, warning dissemination and forecasting. Improvements include $12.4 million to operate NOAA's tsunami detection and warning capabilities and expand its scope into the Atlantic and Caribbean basins. Observing enhancements include $1.4 million to operate and maintain hurricane data buoys that are critical to monitoring and predicting hurricanes. The NOAA Wind Profiler Network will receive a $3.5 million increase for an upgrade to operate at a different frequency. NOAA will also use $2.5 million to ensure uninterrupted delivery of meteorological data for the protection of life and property as well as the economic health of the nation.
The complete NOAA Budget Summary is online at http://www.corporateservices.noaa.gov/%7Enbo/07bluebook_highlights.html
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Weather Service Enhances Tornado Ratings
The National Weather Service recently announced plans to implement the Enhanced Fujita (EF) Tornado Scale to replace the original Fujita (F) Scale. The EF Scale will continue to rate tornadoes on a scale from zero to five, but ranges in wind speed will be more accurate with the improved rating scale. The National Weather Service has approved the EF Scale and expects it to be fully implemented by February 2007.
T. Theodore Fujita developed the F Scale in 1971 by to rate tornadoes and estimate associated wind speed based on damage. The EF Scale refines and improves the original scale. It was developed by the Texas Tech University Wind Science and Engineering Research Center, along with a forum of wind engineers, universities, private companies, government organizations, private sector meteorologists and Weather Service meteorologists from across the country.
Limitations of the original F Scale may have led to inconsistent ratings, including possible overestimates of associated wind speeds. The EF Scale incorporates more damage indicators and degrees of damage than the original F Scale, allowing more detailed analysis and better correlation between damage and wind speed. The original F Scale historical data base will not change. An F5 tornado rated years ago is still an F5, but the wind speed associated with the tornado may have been somewhat less than previously estimated. A correlation between the original F Scale and the EF Scale has been developed. This makes it possible to express ratings in terms of one scale to the other, preserving the historical database.
For details see http://www.spc.noaa.gov/efscale/
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DOE Flights Reveal Details About Ice Particles in Clouds
Early results of an international climate experiment over Darwin, Australia, include superior images of ice crystals in high-altitude tropical cirrus clouds. A team of international climate scientists started the series of carefully orchestrated flights to obtain key in situ data about tropical clouds in early February. The group is using a space-age aircraft equipped with a suite of highly sophisticated sensors, called Proteus.
Scientists hope that these images, combined with data from other aircraft probes, will provide a complete data set of detailed information about ice clouds, particularly the numbers of small ice crystals—something that is very important for understanding how clouds affect radiation and climate, the researchers said.
The Cloud Particle Imager, an instrument developed by SPEC Inc., captured the images. It provides very high resolution images of ice crystals. These were obtained as the Proteus aircraft was climbing through a thin layer of aged cirrus clouds, collecting data to help scientists determine how the properties of ice clouds, including particle size and shape, vary with temperature and altitude. These factors influence the longevity of the cloud, and therefore the amount of radiative energy both reaching and escaping the earth.
The Proteus, funded by the ARM Program, is one of five instrumented research aircraft taking part in the Tropical Warm Pool International Cloud Experiment, or TWP-ICE, which is led by the ARM Program and the Australian Bureau of Meteorology.The experiment’s objectives are to collect comprehensive cloud and atmospheric property measurements of both cirrus clouds and deep convective (thunderstorm) clouds--which are the source for much of the cirrus observed in the tropics. The experiment is taking place in an area approximately 200 km in diameter, centered on Darwin.
Other aircraft participating in the experiment include a Twin Otter, also funded by the ARM Program; a Dimona, sponsored by the Australian Bureau of Meteorology; and an Egrett and a Dornier, sponsored by the Natural Environmental Research Council in the United Kingdom. These aircraft fly at altitudes ranging from 50 meters to 17 kilometers, and contain sensitive instruments for measuring various cloud properties, aerosol properties, temperature and humidity.
The experiment concludes on February 13.
For more information see http://science.arm.gov/twpice/daily_report.php
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NOAA To Begin Ranking Northeast Snowstorms
Starting this winter, the National Oceanic and Atmospheric Administration will begin ranking Northeast snowstorms to categorize the impact of the storms on the area. The Northeast Snowfall Impact Scale, or NESIS, will quickly calculate the impact of a powerful snowstorm soon after it strikes, and give it a rank, similar to methods used to categorize the strength of tornadoes.
Until now, NOAA scientists had no way of sizing up a snowstorm's intensity with an index as understandable as the Saffir-Simpson scale for hurricanes, or the Fujita scale for tornadoes. While winds are used to measure hurricane intensity, NESIS will rank the severity of an East Coast snowstorm based on snowfall amount and the population of the affected areas. With NESIS, scientists can quickly assess a snowstorm's impact today, compare it with a storm of the past and assign it one of five categories: Notable, Significant, Major, Crippling or Extreme.
Paul Kocin, a winter storm expert at The Weather Channel and Louis Uccellini, director of the the National Weather Service’s National Centers for Environmental Prediction in Camp Springs, Md., developed NESIS.Thomas R. Karl, director of the National Climatic Data Center in Asheville, N.C., is leading the effort to put NESIS into action, starting with this year's snowstorms.
NCDC combined a mathematical model that Kocin and Uccellini developed into an automated Geographical Information System that determines the magnitude of each major snowstorm soon after it strikes. The NCDC, the official archive of U.S. weather and climate records, will be expanding the analysis to review all major storms that have hit the Northeast since the late 1800s.
More information is online at http://www.ncdc.noaa.gov/oa/climate/research/snow-nesis/
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