The history of rainfall data time-resolution in a wide variety of geographical areas

Collected rainfall records by gauges lead to key forcings in most hydrological studies. Depending on sensor type and recording systems, such data are characterized by different time-resolutions (or temporal aggregations), ta. We present an historical analysis of the time-evolution of ta based on a large database of rain gauge networks operative in many study areas. Globally, ta data were collected for 25,423 rain gauge stations across 32 geographic areas, with larger contributions from Australia, USA, Italy and Spain. For very old networks early recordings were manual with coarse time-resolution, typically daily or sometimes monthly. With a few exceptions, mechanical recordings on paper rolls began in the first half of the 20th century, typically with ta of 1 h or 30 min. Digital registrations started only during the last three decades of the 20th century. This short period limits investigations that require long time-series of sub-daily rainfall data, e.g, analyses of the effects of climate change on short-duration (sub-hourly) heavy rainfall. In addition, in the areas with rainfall data characterized for many years by coarse time-resolutions, annual maximum rainfall depths of short duration can be potentially underestimated and their use would produce errors in the results of successive applications. Currently, only 50% of the stations provide useful data at any time-resolution, that practically means ta = 1 min. However, a significant reduction of these issues can be obtained through the information content of the present database. Finally, we suggest an integration of the database by including additional rain gauge networks to enhance its usefulness particularly in a comparative analysis of the effects of climate change on extreme rainfalls of short duration available in different locations

The history of rainfall data time-resolution in a wide variety of geographical areas

Collected rainfall records by gauges lead to key forcings in most hydrological studies. Depending on sensor type and recording systems, such data are characterized by different time-resolutions (or temporal aggregations), ta. We present an historical analysis of the time-evolution of ta based on a large database of rain gauge networks operative in many study areas. Globally, ta data were collected for 25,423 rain gauge stations across 32 geo graphic areas, with larger contributions from Australia, USA, Italy and Spain. For very old networks early re cordings were manual with coarse time-resolution, typically daily or sometimes monthly. With a few exceptions, mechanical recordings on paper rolls began in the first half of the 20th century, typically with ta of 1 h or 30 min. Digital registrations started only during the last three decades of the 20th century. This short period limits investigations that require long time-series of sub-daily rainfall data, e.g, analyses of the effects of climate change on short-duration (sub-hourly) heavy rainfall. In addition, in the areas with rainfall data characterized for many years by coarse time-resolutions, annual maximum rainfall depths of short duration can be potentially underestimated and their use would produce errors in the results of successive applications. Currently, only 50% of the stations provide useful data at any time-resolution, that practically means ta = 1 min. However, a sig nificant reduction of these issues can be obtained through the information content of the present database. Finally, we suggest an integration of the database by including additional rain gauge networks to enhance its usefulness particularly in a comparative analysis of the effects of climate change on extreme rainfalls of short duration available in different locations

Principales características de los registros pluviométricos de las estaciones pluviométricas incluidas en el conjunto de datos de Morbidelli et al. [Dataset]

Rainfall records collected by gauges lead to key forcings in most hydrological studies. Depending on the type of sensor and recording systems, such data are characterised by different temporal resolutions (or temporal aggregations), ta. We present a historical analysis of the temporal evolution of ta based on a large database of operational rain gauge networks in many study areas. Globally, data were collected from 25,423 rain gauge stations in 32 geographical areas, with major contributions from Australia, USA, Italy and Spain. For very old networks, the first recordings were manual with a coarse temporal resolution, usually daily or sometimes monthly. With some exceptions, mechanical recordings on paper rolls started in the first half of the 20th century, usually with times of 1 h or 30 min. Digital records began only during the last three decades of the 20th century. This short period limits research requiring long time series of sub-daily rainfall data, e.g. analysis of the effects of climate change on short-duration (sub-hourly) intense rainfall. Furthermore, in areas with rainfall data characterised over many years by coarse temporal resolutions, the annual maximum depths of short-duration rainfall can potentially be underestimated and their use would lead to errors in the results.Currently, only 50% of the stations provide useful data at any temporal resolution, which practically means ta = 1 min. However, a significant reduction of these problems can be obtained through the information content of the present database. Finally, we suggest an integration of the database by including additional rain gauge networks to improve its usefulness, particularly in a comparative analysis of the effects of climate change on short duration extreme precipitation available at different locations.Los registros de lluvia recopilados por medidores conducen a forzamientos clave en la mayoría de los estudios hidrológicos. Dependiendo del tipo de sensor y de los sistemas de registro, dichos datos se caracterizan por diferentes resoluciones temporales (o agregaciones temporales), ta. Presentamos un análisis histórico de la evolución temporal de ta basado en una gran base de datos de redes de pluviómetros operativas en muchas áreas de estudio. A nivel mundial, se recopilaron datos de 25.423 estaciones pluviómetros en 32 áreas geográficas, con mayores contribuciones de Australia, EE. UU., Italia y España. Para las redes muy antiguas, las primeras grabaciones eran manuales con una resolución temporal aproximada, normalmente diaria o, a veces, mensual. Con algunas excepciones, los registros mecánicos en rollos de papel comenzaron en la primera mitad del siglo XX, normalmente con tiempos de 1 h o 30 min. Los registros digitales comenzaron sólo durante las últimas tres décadas del siglo XX. Este corto período limita las investigaciones que requieren largas series temporales de datos de precipitaciones subdiarias, por ejemplo, análisis de los efectos del cambio climático en precipitaciones intensas de corta duración (subhorarias). Además, en las áreas con datos de lluvia caracterizados durante muchos años por resoluciones temporales gruesas, las profundidades máximas anuales de lluvia de corta duración pueden potencialmente subestimarse y su uso produciría errores en los resultados de aplicaciones sucesivas. Actualmente, sólo el 50% de las estaciones proporcionan datos útiles en cualquier resolución temporal, lo que prácticamente significa ta = 1 min. Sin embargo, se puede obtener una reducción significativa de estos problemas a través del contenido de información de la presente base de datos. Finalmente, sugerimos una integración de la base de datos mediante la inclusión de redes de pluviómetros adicionales para mejorar su utilidad, particularmente en un análisis comparativo de los efectos del cambio climático sobre las precipitaciones extremas de corta duración disponibles en diferentes ubicaciones.Metadatos de la evolución temporal de tiempo de resolución de los registros pluviométricos (ta) 25.423 estaciones pluviométricas de 32 áreas geográficas diferentes de todo el planet