The entity CRU working on climate change incorporates WeMOI index, created by UB researchers, to study the weather in the Mediterranean area

Image of an intense precipitation in Barcelona, taken at the Fabra Observatory. Photograph by Alfons Puertas, published in <i>Atles de Núvols de l'Observatori Fabra</i>.
Image of an intense precipitation in Barcelona, taken at the Fabra Observatory. Photograph by Alfons Puertas, published in Atles de Núvols de l'Observatori Fabra.
Research
(05/02/2019)

Singularities of geography and orography of the western Mediterranean make it impossible to apply some of the indexes to understand and predict meteorological phenomena in wide areas of the planet. For instance, NAO (North Atlantic Oscillation) index is not applied in this area, although it is used to make predictions in a great part of Western Europe. Therefore, UB climatologists created an own index for this area of the world: WeMOI (North Atlantic Oscillation). After more than ten years, this index has been distinguished as a useful and rigorous tool and has been incorporated to the ten indexes of this kind in the website Climatic Research Unit (CRU), one of the most distinguished institutions worldwide regarding the study of the climate change. From now on, the authors of WeMOi are thinking about working on the practical application of this index, revealed to be a good indicator for the risk of intense precipitations in this area of the Mediterranean, and to launch future collaborations with the Meteorological Service of Catalonia.

 

Image of an intense precipitation in Barcelona, taken at the Fabra Observatory. Photograph by Alfons Puertas, published in <i>Atles de Núvols de l'Observatori Fabra</i>.
Image of an intense precipitation in Barcelona, taken at the Fabra Observatory. Photograph by Alfons Puertas, published in Atles de Núvols de l'Observatori Fabra.
Research
05/02/2019

Singularities of geography and orography of the western Mediterranean make it impossible to apply some of the indexes to understand and predict meteorological phenomena in wide areas of the planet. For instance, NAO (North Atlantic Oscillation) index is not applied in this area, although it is used to make predictions in a great part of Western Europe. Therefore, UB climatologists created an own index for this area of the world: WeMOI (North Atlantic Oscillation). After more than ten years, this index has been distinguished as a useful and rigorous tool and has been incorporated to the ten indexes of this kind in the website Climatic Research Unit (CRU), one of the most distinguished institutions worldwide regarding the study of the climate change. From now on, the authors of WeMOi are thinking about working on the practical application of this index, revealed to be a good indicator for the risk of intense precipitations in this area of the Mediterranean, and to launch future collaborations with the Meteorological Service of Catalonia.

 

WeMOi is calculated measuring the atmospheric pressure in two parts of the Mediterranean area: on the one hand, the south western area of the Iberian Peninsula, in the San Fernando Observatory (Cadiz), and on the other the Po Valley (north of Italy), specifically in the Padova Observatory (Venice). Other indexes gathered by CRU are also based on the atmospheric pressure measured in two spots, strategically situated. When the values of the indexes are in a situation regarded as normal or common, they are in a positive phase, while when they are altered they enter the negative phase of the index. In WeMOi, when there are low pressures in the gulf of Cadiz and anticyclones in the north of Italy, the index is in a negative value and there is a potential risk of high precipitations. Actually, torrential rains that take place in eastern Iberian Peninsula coincide with the most negative phase of WeMOi, in October.

Javier Martín Vide, professor of Physical Geography and current director of the Water Research Institute (IdRA), presented a first trial on WeMOi in 2002. In 2006, Martín Vide and UB climatologist Joan Albert Bustins, from the Department of Geography of the UB, published the article “The Western Mediterranean Oscillation and rainfall in the Iberian Peninsula” in the journal International Journal of Climatology. WeMOi is still one of the research lines of the Research Group of Climatology of the UB, led by Javier Martín Vide, and the study target of predoctoral researcher of this group Laia Arbiol Roca.