Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NCAR observing system finds high-level moisture with global implications

12.02.2003


Hard-to-detect clouds and water vapor, hidden until now from most atmospheric sensors, could be helping to shape global climate. An instrument package developed by the National Center for Atmospheric Research (NCAR) has detected layers of moisture, indicative of high-level cirrus clouds, that were missed by standard weather balloons and other instruments. The findings are being presented by NCAR scientist Junhong Wang on Tuesday, February 11, in Long Beach, California, at the annual meeting of the American Meteorological Society (AMS).



The undetected moisture and clouds between about 5 and 9 miles high (8-14 kilometers) probably have little effect on daily weather forecasts, but their omission may be corrupting our view of long-term climate. On average, cirrus clouds tend to warm the planet, as they allow sunlight to enter the atmosphere while trapping radiation emitted from the ground.

"Even small amounts of water vapor and cirrus clouds at these heights are extremely important for climate, as they strongly affect Earth’s radiation budget," says Richard Anthes, president of the University Corporation for Atmospheric Research, which operates NCAR. Anthes notes that radiosonde data are often used in computer models to predict the weather, and that the resulting weather analyses are then used for analyzing climate, including the calibration of models that simulate previous and future climates. "It is possible that decades of climate records have underestimated the amount of cirrus clouds in the global atmosphere," says Anthes.


Wang’s study analyzes humidity data collected from the lowest few miles of the atmosphere by radiosondes (weather balloons). Over 1,500 radiosondes are launched each day around the world, forming the backbone of the planet’s weather observing system. Wang and colleagues compared readings from the two inexpensive humidity sensors commonly used on radiosondes with data from Snow White, a high-quality sensor developed by the Swiss firm Meteolabor AG. Snow White is part of a reference-radiosonde package developed at NCAR and deployed in the International H20 Project (IHOP2002), a collaborative study led by NCAR last spring.

In the cold air from about 26,000 to 42,000 feet high, the team found that standard sensors nearly always showed relative humidities ranging from about 10% to 30%. In contrast, more than half of the Snow White deployments showed areas of moisture at these altitudes with relative humidities from 90% to 100%--a strong sign of clouds. In one of these cases, a NASA ground-based lidar (laser-based radar) taking part in IHOP2002 analyzed air near the track of a Snow White deployment. The lidar confirmed that high clouds were actually present.

How do these clouds escape detection? Many of them are "subvisible cirrus," so faint they can’t be seen by the naked eye. "Both ground- based observers and space-based satellites have trouble distinguishing these clouds," according to David Carlson, head of the NCAR Atmospheric Technology Division.

Wang and colleagues hope that their reference radiosonde system, which includes Snow White, will help improve the quality of radiosondes used for day-to-day observing. It may also help scientists correct the data from years past. "If developed and deployed soon," says Wang, "a reference radiosonde could help repair and improve data records over time and space."

NCAR scientist Kevin Trenberth, an expert on global climate, says better observations are critical, especially in the cold, high reaches more than five miles above ground. "Essentially the current radiosondes are not useful for measuring humidity at temperatures below about -4 degree F," says Trenberth. "We need a climate observing system that does a whole lot better."


###
The AMS, founded in 1919, promotes the development and dissemination of information on atmospheric, oceanic, and hydrologic sciences. The society publishes nine well-respected scientific journals, sponsors scientific conferences, and supports public education programs across the country. Additional information on the AMS and its annual meeting is available on the Internet at http://www.ametsoc.org/ams.

The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under primary sponsorship by the National Science Foundation. Opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.


"A Reference Radiosonde System for Improving Water Vapor Measurement in IHOP_2002"
Symposium: Observing and Understanding the Variability of Water in Weather and Climate
83rd Annual Meeting, American Meteorological Society
Long Beach, California
Tuesday, February 11, 11:30 AM

Anatta | EurekAlert!
Further information:
http://www.ucar.edu/communications/newsreleases/2003
http://www.ucar.edu/ucar/

More articles from Earth Sciences:

nachricht Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

NASA's fermi finds possible dark matter ties in andromeda galaxy

22.02.2017 | Physics and Astronomy

Wintering ducks connect isolated wetlands by dispersing plant seeds

22.02.2017 | Life Sciences

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>