Ramón Jardí i Borrás

Ramon Jardí i Borras (Tivissa, November 13, 1881 – June 5, 1972)^[1] was a Catalan meteorologist, astronomer and seismologist. He participated in the foundation of the Meteorological Service of Catalonia (1921–1939).^[1] He was member of the Academy of Sciences and Arts (1914),^[1] professor of electricity at Industrial School University (1917),^[1] professor at the University of Barcelona (1930–1951)^[1] and a member of the Institut d'Estudis Catalans (1926–1931).^[1]

Biography

Ramon Jardí studied at the Faculty of Science, where he specialized in Physical Science. After obtaining his doctorate, he taught at the University of Barcelona (1930–1951).^[1]

In the engineering field, he started making a few modifications to the Bourdon's anemograph that was installed at the Fabra Observatory because it had some design problems. He named the new and improved model "Bourdon-Jardí" and it has been in operation up to this date.

Upon approval of the creation of the Meteorological Service of Catalonia by the Permanent Council of the Commonwealth of Catalonia in September 1919, Eduard Fontserè was appointed as director of this Meteorological Service. He appointed Ramon Jardí as his assistant.^[1]

While he was director of the "Fabra Observatory," he represented the Meteorological Service of Catalonia at the international meetings of the Conference of Directors of Meteorological Services. He was very appreciated for the work he carried out and gained high international prestige.^[1]

Pluviometer of intensities

Pluviometer of intensities (Jardí, 1921)

The pluviometer of intensities (or Jardi's pluviometer), it's a tool that measures the average intensity of rainfall in a certain interval of time. The device was initially designed to record the rainfall regime in Barcelona but eventually spread globally throughout the world.^[2][3]

History

In 1921, the president of the Commonwealth of Catalonia of that time, Josep Puig i Cadafalch, explained to Eduard Fontserè, his concerns about the need to achieve a method to measure the intensity of the rainfall. The reason for this was a huge downpour had fallen in Barcelona not long ago. To figure this out, Fontserè commissioned Ramon Jardí with the construction of a pluviometer that could record a similar rainfall.^[3] Before the end of this year 1921, the Pluviometer of intensities designed by Dr. Jardí was already working in the Meteorological Service of Catalonia. Plenty of patented copies of this pluviometer would be mass-produced later on by two international companies: Richard (Paris) and Casella (London).^[3]

In June 1927, two pluviometers of intensities "Richard-Jardí" entered into operation, one in the Department of Meteorology (which had a bad end), the other in the "Fabra Observatory". Thanks to the "Richard-Jardí" pluviometer, and to the uninterrupted activity of the Fabra Observatory, Barcelona has a record of "almost-instantaneous" intensities of rainfall, which is the must comprehensive in the world (over 80 years).^[3]

Pluviometer's operation

It employs the principle of feedback .. the incoming water pushes the buoy upwards , making the lower "adjusting conic needle" to let pass the same amount of water that enters into the container, this way.. the needle records on the drum the amount of water flowing through it at every moment -in mm of rainfall per square-meter

It consists of a rotating drum that rotates at constant speed , this drum drags a graduate sheet of cardboard, which has the time at the abscissa while the y axis indicates the height of rainfall in mm of rain. This height is recorded with a pen that moves vertically, driven by a buoy, marking on the paper the instantaneous rainfall rate over a period of time (the cardboard sheet is usually for one day).

While the rain falls, the water collected by the external funnel passes into the cylindrical reservoir and raises the buoy... that makes the pen's arm to raise in the vertical axis.. marking the cardboard accordingly. If the rainfall does not vary, the water level in the container remains constant, and while the drum rotates, the pen's mark it's -more or less- a horizontal line, proportional to the amount of water that is falling. When the pen reaches the top edge of the recording paper, it means that the buoy is "up high in the tank" leaving the tip of the conic needle it completely uncovers the regulating hole (that is the maximum flow that the apparatus is able to record). If the rain suddenly decreases, then the buoy drops at the same speed -as the cylindrical reservoir empties. That movement corresponds to a steep slope line that can reach the bottom of the recorded cardboard, if it stops raining.

The Pluviometer of intensities allowed to record the precipitation over the time and the years (particularly in Barcelona (95 years), apart from many other places around the world, as Hong-Kong).^[2][4]

To measure the average intensity of rainfall in a certain interval of time, the Pluviometer of intensities uses the formula:

${\textstyle \frac{h (\Delta \mathit{T})}{\Delta \mathit{T}}= \mathit{i}\, }$

In fact, the intensity of the rain is not constant but varies over time, therefore the cardboard recording can be defined as instant rain intensity (as its name defines):

${\textstyle \lim_{\Delta\mathit{T}\rightarrow 0} \frac{h(\Delta\mathit{T})}{\Delta\mathit{T}} =\mathit{i}(\mathit{t})}$

See also

• Fabra Observatory

References

1. Barcelona; Real Academia de Ciencias y Artes (1973). Nómina del personal académico y anuario de la corporación (PDF). RACAB. Retrieved October 23, 2011.
2. Water Resources Series. United Nations. 1967. Retrieved October 23, 2011.
3. Tivissa; Josep Camps; Jaume Escoda i Cabré; Jaume Massons (1993). Llibre homenatge al Dr. Jardí i Borràs. 8460612481 9788460612483 publisher = Tivissa Ajuntament. Retrieved May 22, 2015.
4. Hong Kong; Great Britain. Foreign and Commonwealth Office (1974). Jardi report Workman Chen, Hong Kong (PDF). HMSO. Retrieved October 23, 2011.