Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Model For Arctic Zone

23.01.2006


The development of a new dielectric model of tundra and forest-tundra for remote probing from space is being performed by Russian researchers from the L.V. Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences (Krasnoyarsk) jointly with the US colleagues from Michigan. The researches are sponsored by the U.S. Civilian Research & Development Foundation (CRDF) and the Federal Agency for Science and Innovation (Rosnauka). The new model will make basis for more accurate and trustworthy climatic forecasts.



Northern sub-polar areas, these being not only boundless lands of Siberia, but also vast territories of Canada and Alaska, are going through hard times. Consequences of global warming make the strongest impact on them. The temperature is rising, ice cover is decreasing, permafrost is thawing, flora is changing, arctic birds and animals are migrating. The majority of sub-polar areas is remote and difficult of access. Therefore remote probing from space is becoming now the main method of their investigation. This includes microwave and radar sounding and radiometry. Radiosounding data can provide information about streams of warm and moisture between the surface of the earth and atmosphere taking into account soil thawing and freezing. Researchers state that trustworthiness of global climate models can be increased if they take into account changes in moisture and heat streams. Reliability of moisture and heat streams determination by radiosounding depends in principle on physical reliability of the so-called soil and flora dielectric models. Russian researchers have set about to develop this particular model for tundra and forest-tundra.

The soil, per se, represents a dielectric, the properties of which may be characterized by permittivity. The latter mainly depends on water content in the soil. When soil moisture freezes and then thaws out, the soil permittivity changes abruptly. Magnitude of such sudden changes depends significantly on the content of the so-called bound soil moisture not frozen at temperatures below freezing. These fluctuations are reflected in sudden changes of brightness temperature and radar signals at microwave probing of soil. Brightness temperature – is one of important characteristics of thermal balance of the surface. It is equal to the temperature of absolute black body, which would create irradiation of the same strength in the investigated frequency band. As strength of microwave irradiation is proportionate to the black body temperature, introduction of the brightness temperature notion noticeably simplifies radiometry methods and data interpretation.


Several years ago, Siberian researchers suggested the spectroscopic dielectric model of moist soils. It took into account the mineral composition, organic matter content, volumetric moisture, temperature and wave frequency. From their part, the US colleagues developed and justified the model, binding brightness temperature with moisture and heat streams.

Now the researchers set a task to combine these two models. A new improved model for remote probing may be checked in operation by comparing it to the longstanding surface observations data. And then, the researchers believe, it will be possible to apply the model to various soils and flora found in subpolar Arctic, thus noticeably increasing the quality of climatic forecasts.

“These results are particularly important for the community of researchers who deal with remote probing in view of the scheduled space projects HYDROS and SMOS,” emphasized Valery Mironov (L.V. Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences), Corresponding Member, responsible for the Russian-US project.

Sergey Komarov | alfa
Further information:
http://www.informnauka.ru

More articles from Earth Sciences:

nachricht NASA's AIM observes early noctilucent ice clouds over Antarctica
05.12.2016 | NASA/Goddard Space Flight Center

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>