No. 775: Weather forecasting technology grows more sophisticated (September 20, 2013)

Technology:

Weather radar stationed in 
Okinawa Prefecture

Three organizations involved in weather forecasting are developing approaches to faster and more precise weather forecasting. Meteorological Research Institute will introduce new radio detection and ranging (radar) that observes clouds from the top to the bottom and examines the moves of raindrops and winds in every 10 seconds. Called Phased Array Radar, the new radar emits radio waves to nearly all altitudes using X band that has an about 3-cm wavelength in place of the existing radar that changes the altitude mechanically. Japan Meteorological Agency has 20 radars across the country, but the existing radars collect information on clouds once in every five minutes. The new radar can perform the same job once in every 10 seconds. That is, it can tell the picture that raindrops fall onto the ground almost in real time and give a possibility to observe the tornado formation close to the ground. It plans to construct a forecasting system by developing software for analysis and computation in five years.  

National Research Institutue for Earth Science and Disaster Prevention plans to develop a supersensitive small radar for precise observation of the inside of clouds before it starts to rain using millimeter waves that have a wavelength of about 8.5 mm. Based on the water volume inside clouds, the radar can distinguish between water and ice. It precisely computes the development of clouds, rainfall time, and rainfall location for the precise forecasting of heavy rain. Weathernews stationed a small weather radar that is an improved version of X-band radar for aircraft in about 80 locations across the country. The small radar gets data in every six seconds near the ground surface by limiting the observation angle to 120 degrees.   

Phased Array Radar