Time Trends and Seasonal Variation of the Rainwater Chemical Composition in Spain

Abstract

ABSTRACT

On the Relationship between Acid Rain and Cloud Type

“…13 The main sources of pollutants for these Spanish EMEP stations and the characteristics of acid wet deposition also have been documented. [2][3][4] The three classes of rain present a different temporal distribution. Whereas the frontal rain episodes can be found during the whole year, meso-γ storms are distributed from June to December (both included), but the mesoscale convective precipitation is only registered from September to November (both included).…”

“…The location of the Spanish EMEP stations and their characteristics has been widely described in most of the mentioned papers. [2][3][4]6 The data used correspond to the daily chemical analysis of wet deposition from January 1990 to December 1994. For the mentioned 5-year period, both the Roquetas and the Logroño stations show annual cycles and no trend.…”

“…Several regression models for the different analyzed ions of the EMEP stations for this time interval have been proposed. 4 Daily meteorological bulletins published by the Instituto Nacional de Meteorología together with the enhanced infrared (IR) METEOSAT satellite imagery were used to identify the meteorological origin of the rain. Also, to classify a storm as a mesoscale or a small-scale storm, the reports of the convective systems characteristics during 1990-1994 were analyzed following the methodology exposed by Hernández et al 13 First, to identify a storm as a Mesoscale Convective System (MCS), the continuous cold cloud shield of -52 ºC IR temperature is used.…”

“…The temporal variations of these ion concentrations were investigated using a multiple regression model in which the effects of annual cycle, long-term trends, and the amount of precipitation were included. 4 Most of the variations in SO 4 2-and NO 3 -were attributed to a systematic annual cycle and to an effect of precipitation quantity.…”

“…2 Using a technique based on the Potential Source Contribution Function, the Iberian Peninsula was identified as the main source of acidifying potential. 3 The concentrations of H + , SO 4 2-, and NO 3 -were chosen to analyze the acidic deposition because of their influence in the acid rain problem. The temporal variations of these ion concentrations were investigated using a multiple regression model in which the effects of annual cycle, long-term trends, and the amount of precipitation were included.…”