We describe a revised collection of the number of sunspot groups from 1610 to the present. This new collection is based on the work of Hoyt and Schatten (Solar Phys. 179, 189, 1998). The main changes are the elimination of a considerable number of observations during the Maunder Minimum (hereafter, MM) and the inclusion of several long series of observations. Numerous minor changes are also described. Moreover, we have calculated the active-day percentage during the MM from this new collection as a reliable index of the solar activity. Thus, the level of solar activity obtained in this work is greater than the level obtained using the original Hoyt and Schatten data, although it remains compatible with a grand minimum of solar activity. The new collection is available in digital format.

A peaks-over-threshold (POT) approach is used to study trends in extreme rainfall over the Iberian Peninsula (IP) at a daily scale. Records from 52 observatories regularly distributed over Iberia with no missing data were available for the common period from 1958 to 2004. The POT approach was used because it is particularly effective at extracting information concerning true extreme events. A generalized Pareto distribution fit was made to the data involving time-dependent parameters to account for possible temporal changes in the frequency distribution. These parameters were analyzed for trends in the return-level period, of importance for engineering purposes. A time-varying threshold was defined and an automatic declustering scheme was used to select independent extreme events exceeding the threshold. The results indicate a high variability of extreme events over the coastline of the IP, greater over the Mediterranean coast than over the Atlantic coast. The calculation of the trends for the 2-yr return level yielded a large proportion of negative trends for all three seasons considered: 58% for winter, 63% for spring, and 69% for autumn. The parametric approach also revealed an increase in the area with a positive trend of the 20-yr return level relative to the 2-yr return period, especially in autumn in the east of the IP.

Aims. The Maunder minimum (MM) of greatly reduced solar activity took place in 1645–1715, but the exact level of sunspot activity is uncertain because it is based, to a large extent, on historical generic statements of the absence of spots on the Sun. Using a conservative approach, we aim to assess the level and length of solar cycle during the MM on the basis of direct historical records by astronomers of that time. Methods. A database of the active and inactive days (days with and without recorded sunspots on the solar disc) is constructed for three models of different levels of conservatism (loose, optimum, and strict models) regarding generic no-spot records. We used the active day fraction to estimate the group sunspot number during the MM. Results. A clear cyclic variability is found throughout the MM with peaks at around 1655–1657, 1675, 1684, 1705, and possibly 1666, with the active-day fraction not exceeding 0.2, 0.3, or 0.4 during the core MM, for the three models. Estimated sunspot numbers are found to be very low in accordance with a grand minimum of solar activity. Conclusions. For the core MM (1650−1700), we have found that (1) A large portion of no-spot records, which correspond to the solar meridian observations, may be unreliable in the conventional database. (2) The active-day fraction remained low (below 0.3−0.4) throughout the MM, indicating the low level of sunspot activity. (3) The solar cycle appears clearly during the core MM. (4) The length of the solar cycle during the core MM appears for 9 ± 1 years, but this is uncertain. (5) The magnitude of the sunspot cycle during MM is assessed to be below 5–10 in sunspot numbers. A hypothesis of the high solar cycles during the MM is not confirmed.

In this study trends in extreme rainfall over the Iberian Peninsula at a daily scale in the second half of the twentieth century have been detected and analyzed. For this goal 35 stations evenly distributed over the region of study covering the period 1958–97 have been studied. Two different approaches have been used. The first one consists of the nonparametric Mann–Kendall test and the Sen method. The second approach is based on the statistical theory of extreme values, involving time-dependent parameters in order to be able to reflect possible temporal changes in the frequency distribution. Results from both methods agree, confirming the reliability of the analysis. Negative trends are found for the west and southwest of the Iberian Peninsula in spring and winter. In autumn a spatial dipolar pattern appears, but trends are not so evident.

[1] This study provides the first long‐term assessment of changes in precipitation associated with different rainfall categories over the Iberian Peninsula (IP). Using recently digitized data from 27 stations in Portugal and Spain, we have examined trends of precipitation indices for the complete period 1903–2003 and the two subperiods 1903–1953 and 1954–2003. These indices were evaluated seasonally according to five rainfall categories: total rainfall (≥0.2 mm), light rainfall (≥0.2 and <2.5 mm), moderate rainfall (≥2.5 and <7.5 mm), intense rainfall (≥7.5 mm), and very intense rainfall (≥15 mm). For the complete period 1903–2003, we have found that the total number of rainy days and that of light rainfall are increasing at many observatories over the IP for all seasons (except in the western zone of Portugal and the Cádiz gulf, where they are decreasing). Both subperiods show opposite behaviors in fall and spring. During the first (second) subperiod spanning 1903–1953 (1954–2003), we can find a generalized decrease (increase) in the number of rainy days in fall in all rainfall categories. In spring, an increase in the number of rainy days is found mainly for total, moderate, and intense categories for the first subperiod, and a slight decrease during the second. In winter, we have verified a decrease in the number of rainy days mainly for total, moderate, and intense rainfall categories in the second subperiod. Finally in relation to the maximum length of dry spells for both subperiods, most observatories show significant trends opposite those of the total number of rainy days. It is worth noticing that the contrasting evolution of trends found between the first and second halves of the twentieth century could only be characterized in this work following a recent comprehensive digitization of historical Iberian precipitation data from the first decades of the twentieth century.