Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unique weather radar to investigate snowfall

20.03.2006


The Department of Physical Sciences at the University of Helsinki has acquired a state-of-the-art polarimetric weather radar. The new radar is reserved exclusively for research. Its most important meteorological research target is the physics of rain clouds, and scientists intend to focus on snow and sleet in particular. Snowfall and its polarimetric measurements have hardly been studied anywhere else in the world, although in the Finnish conditions, for instance, snowfall is one of the key weather elements.



The first test measurements of the prototype radar built for the University’s radar laboratory provided good evidence for the potential of a polarisation weather radar. The largest road traffic catastrophe in the Helsinki metropolitan area took place on 17 March 2005, with several multiple pile-ups on all Helsinki. The new radar was just undergoing test runs and it immediately revealed the meteorological factors which led to the accidents.

Radar images showed that the road conditions before the accident were dry and cold with only slight snowfall. There was, however, supercooled water in the air, which made the road surfaces slippery immediately prior to the accidents. At the time of the accidents, a narrow zone of heavy snowfall arrived from the south, suddenly reducing visibility. In places, this was followed by a larger area of snowfall with a high content of supercooled water.


Radar signals distinguish rain from snow

As the above example shows, the polarisation weather radar can reveal meteorological factors behind accidents. There is no radar as efficient in every aspect anywhere else in the world. Its exceptional features include an antenna with top-class properties, a versatile and powerful transmitter and an ability to measure two perpendicular polarisations.

The radar works by simultaneously transmitting two differently polarised microwaves to the atmosphere and receiving their reflected signals from the rain. The slight differences in the weak reflected signals with different polarisations enable scientists to deduce whether the precipitation falls as water, snow, hail or sleet, and gives information on the quantity and quality of the various precipitation particles (water drops, ice crystals, snow flakes or hailstones) over distances up to 200 km at all levels of the atmosphere. This is not possible using conventional weather radars, which only show where there is precipitation without being able to distinguish between rain or snow.

The radar’s transmitter is designed so that it can transmit either ordinary microwave pulses or what is called coded pulses. This makes it possible to further improve the radar’s measuring capacity with the help of new mathematical processing methods of radar signals. Indeed, research at the University is also being carried out to develop radar technology and further improve its measuring capacity.

The University’s radar was manufactured in Finland. The properties required from the radar were defined by Timo Puhakka, PhD, radar laboratory manager, and the radar was designed and built by Vaisala Oyj in co-operation with the radar laboratory.

The radar is located at the University’s Kumpula campus, on top of the Physicum building under a round dome, which acts as a landmark for the campus.

Radar meteorology has been one of the focal areas of meteorological research at the University of Helsinki for more than 35 years. The University’s radar laboratory boasts radar meteorological expertise of the highest level and it is widely known internationally.

Minna Meriläinen | alfa
Further information:
http://www.helsinki.fi

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>