Modelling monthly precipitation with circulation weather types for a dense network of stations over Iberia

Abstract

Abstract. Precipitation over the Iberian Peninsula (IP) is highly variable and shows large spatial contrasts between wet mountainous regions to the north, and dry regions in the inland plains and southern areas. In this work, we modelled the relationship between atmospheric circulation weather types (WTs) and monthly precipitation for the wet half of the year (October to May) using a 10 km grid derived from a highdensity dataset for the IP (3030 precipitation series, overall mean density one station each 200 km 2 ). We detected two spatial gradients in the relationship between WTs and precipitation. The percentage of monthly precipitation explained by WTs varies from northwest (higher variance explained) to southeast (lower variance explained). Additionally, in the IP the number of WTs that contribute significantly to monthly precipitation increase systematically from east to west. Generally speaking, the model performance is better to the west than to the east where the WTs approach produce the less accurate results. We applied the WTs modelling approach to reconstruct the long-term precipitation time series for three major stations of Iberia (Lisbon, Madrid, Valencia).

Assessment of an extended version of the Jenkinson–Collison classification on CMIP5 models over Europe

“…A sensitivity test of Unclassified days on grid sizes and resolutions was performed in Demuzere et al (2009b), concluding that the number of these days would decrease with grid resolution. Other authors did not consider the Unclassified type due to the few cases in the particular study area and they decided to regroup Unclassified days among the retained classes (Trigo and DaCamara 2000;Cortesi et al 2013;El Kenawy et al 2014). Previous studies found a significant increase of portion of Unclassified days in summer and autumn when applying JC classification.…”

“…This classification, originally developed for the British Isles, has been one of the most prominent WT classification schemes applied in mid-high latitudes. An extensive number of studies that use the JC procedure can been found in the literature and they have mainly focused on Europe: Trigo and DaCamara (2000), Linderson (2001), Goodess and Jones (2002), Spellman (2000), Chen (2000), Grimalt et al (2012), Lorenzo et al (2008), Post et al (2002), Buishand and Brandsma (1997), Cortesi et al (2013), among others. Besides these areas, this scheme has been applied in other regions where it has been rarely used so far, such as USA (Wilby et al 1995), China (Liwei et al 2006), Taiwan (Lai 2010), Chile (Espinoza et al 2014), the Arabian Peninsula (El Kenawy et al 2014), or Russia (Spellman 2015).…”

“…Therefore, atmospheric variability can be analysed in terms of changes of frequencies of specific synoptic weather types (WT) (Huth 2000). Numerous WT classifications have been used for a wide range of applications: human mortality (Kassomenos et al 2001); surface climate variables, such as precipitation (Goodess and Jones 2002;Trigo and DaCamara 2000;Lorenzo et al 2008;Cortesi et al 2013) or temperature (Chen 2000;Post et al 2002); extreme events, such as storms (Donat et al 2010a), or droughts (Paredes et al 2006;Vicente-Serrano and López-Moreno 2006); environmental variables, such as wildfire Abstract A gridded, geographically extended weather type classification has been developed based on the Jenkinson-Collison (JC) classification system and used to evaluate the representation of weather types over Europe in a suite of climate model simulations. To this aim, a set of models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) is compared with the circulation from two reanalysis products.…”

Multi-decadal classification of synoptic weather types, observed trends and links to rainfall characteristics over Saudi Arabia

“…Hybrid anti-cyclonic (HYA) F < |Z| < 2F and Z < 0 point of view, a smaller number of weather types ensure a reasonable sample size for each type (Cortesi et al, 2013). To this end, the automated Lamb weather type method generates a daily circulation database for 10 basic groups (eight directional and two synoptic).…”

Isotopic and hydrogeochemical characterization of high-altitude karst aquifers in complex geological settings. The Ordesa and Monte Perdido National Park (Northern Spain) case study

“…A relatively simple way to analyse the origin of rainfall in the PNOMP is to relate synoptic general atmospheric circulation patterns (ACPs) to local-scale precipitation (Goodess and Palutikof, 1998;Cortesi et al, 2013;Sapriza-Azuri et al, 2013, among others). This requires a method for classifying the ACPs into a discrete set of consistent ACP types.…”