Russian scientists developed a technique, which allows studying the way hurricanes move and finding out the amount of heat and moisture they carry to mid-latitudes and mid-high latitudes from tropics. The technique is based upon data of Earth’s satellite monitoring in the microwave range.

New technique was tested on the Alberto hurricane, which had hit Atlantic regions in summer 2000. New method is universal – it suits any hurricane, strong and long enough. Huge advantage of new development is the ability to estimate potential energy of a hurricane, i.e., the amount of water vapour, absorbed by the tropical cyclone. Satellite spectrometers are unable to detect water vapour, since they observe environment in visual and ultra-violet light ranges, that is why said frequency channels are informative only for quite thin (10-100 meters) upper layer of cloud systems. Radio frequencies can raise the cloudy curtain over the processes, taking place where ordinary spectrometers turn blind.

Let me describe the root of the matter in simple words. Satellite spectrometers, which perform survey in visual and ultra-violet light ranges allow “seeing” the structure of tropical storms and studying their upper layer. New software, designed in Russia, allows automated recognition of moving spiral cloud structures as hurricanes – atmospheric vortexes with low atmospheric pressure and wind velocity exceeding 120 kmph.

 

 

At the same time images, taken in the microwave range, allows estimating the amount of water vapour in sites, which at first sight lack water at all – in the centre or the “eye” of a hurricane. Here first problem appears: images from different satellites do not evenly cover the surface of the ocean. We need maps without blanks on them. The second problem is that we need to synchronize data, coming from different spectrometers, located on different satellites. Both problems are solved by the technique, developed by the Russian scientists.

Researchers developed software, which uses long-term data for building global radio-thermal fields of our planet and helps to synchronize satellite data in various radiation ranges. Software is perfect for studying hurricane “contents” in the microwave range as well.

Researchers performed an experiment, and its result was the amount of water vapour, mist and large-drop cloud systems inside the Alberto hurricane. Same calculations can be done for any strong enough storm. Values, which scientists received, can help determining how a hurricane contributes to the process of global heat transfer from the tropics to higher latitudes. We know that the Earth receives almost all heat, coming from the Sun, in the tropical zone. It is very important to know how a hurricane contributes to the process of global heat transfer, since hurricanes are specific sinks of excessive heat, which “smooth” atmospheric temperature gradient between the poles and the equator. Of course, we shouldn’t forget about convection, also an effective mechanism of heat distribution.

Source: Russian Science News

Kizilova Anna