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 Novel method for investigating pore geometry in rocks
18.06.2018 | Kyushu University, I2CNER

nachricht Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Creating a new composite fuel for new-generation fast reactors

20.06.2018 | Materials Sciences

Game-changing finding pushes 3D-printing to the molecular limit

20.06.2018 | Materials Sciences

Could this material enable autonomous vehicles to come to market sooner?

20.06.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>