Abstract.We describe the construction of a new version of the Europewide E-OBS temperature (daily minimum, mean and maximum values) and precipitation dataset. This version provides an improved estimation of interpolation uncertainty through the calculation of a 100-member ensemble of realizations of each daily field. The dataset covers the period back to 1950, and provides gridded fields at a spacing of 0.25• x 0.25 • in regular latitude/longitude coordinates. As with the original E-OBS dataset, the ensemble version is based on the station series collated as part of the ECA&D initiative. Station density varies significantly over the domain, and over time, and a reliable estimation of interpolation uncertainty in the gridded fields is therefore important for users of the dataset. The uncertainty quantified by the ensemble dataset is more realistic than the uncertainty estimates in the original version, although uncertainty is still underestimated in data-sparse regions. The new dataset is compared against the earlier version of E-OBS and against regional gridded datasets produced by a selection of National Meteorological Services (NMSs). In terms of both climatological averages and extreme values, the new version of E-OBS is broadly comparable to the earlier version. Nonetheless, users will notice differences between the two E-OBS versions, especially for precipitation, which arises from the different gridding method used. Keypoints:• An improved uncertainty estimate is provided through the generation of multiple realizations• The new dataset is broadly consistent with the original version

Significant trends in precipitation extremes over Europe since the middle of the 20th century have been found in earlier studies. Most of these studies are based on descriptive indices of moderate extremes that occur on average a few times per year. Here we have analyzed rarer precipitation events which occur on average once in 5, 10 and 20 years in the 1950s and 1960s using extreme value theory. We have focused on the 1-d and 5-d precipitation amounts in Northern and Southern Europe in all four seasons. Changes over the time period 1951-2010 are studied by considering five consecutive 20-year time intervals with 10-year overlap. Despite considerable decadal variability, our results indicate that 5-, 10-and 20-year events of 1-d and 5-d precipitation for the first 20-year period generally became more common during this 60-year period. For all regions, seasons and return periods, the median reduction in return period between the first and last 20-year periods is ∼21% with variations between a decrease of ∼2% and ∼58%.

[1] In this study we introduce a daily high-resolution land-only observational gridded data set for sea level pressure covering the European region as a new addition to the E-OBS gridded data sets of daily temperatures and precipitation amounts. This data set improves upon existing products in terms of spatial resolution and extent. The data set is delivered on the same four spatial resolutions as the other E-OBS data sets: 0.25°by 0.25°and 0.5°by 0.5°on a regular latitude-longitude grid and 0.22°by 0.22°and 0.44°by 0.44°on a rotated pole grid. We show that there is a good agreement in the long-term mean and standard deviation with popular reanalysis grids. In areas with a relatively high number of stations, the gridded data is closer to the station data than the reanalysis products. There is also a very good agreement with daily weather charts for selected storm events.Citation: van den Besselaar, E. J. M., M. R. Haylock, G. van der Schrier, and A. M. G. Klein Tank (2011), A European daily high-resolution observational gridded data set of sea level pressure,

[1] A European average temperature with monthly resolution is constructed based on the E-OBS daily data set with near real-time updates for monitoring. Taken together, the European average temperature and the associated gridded daily maps of surface temperature from the E-OBS data set provide a detailed record of European climate variability and change since 1950. Both are based on validated station data provided by the European National Meteorological and Hydrological Services. A quantitative analysis of the uncertainty sources to the European average temperature indicates that the uncertainties due to urbanization, statistical interpolation, and the potential inhomogeneities in the input records to E-OBS dominate the total uncertainty estimate. In the aggregation of the interpolation uncertainty from the daily to the monthly level and then to a European averaged value, the effective sample size and the effective spatial degrees of freedom are estimated to account for spatial and temporal coherency in the uncertainty estimates. The European average temperature shows that 7 years of the top 10 warmest years are from the period starting as recent as the year 2000 and a clear upward trend in annual average temperatures over the last few decades is visible. The most recent year in the top 10 coldest years is 1987. It also shows that warming in Europe is accelerating compared to the warming over the global land masses and to a lesser extent compared to the Northern Hemisphere land masses over the period 1980-2010.

The UV-Excess Survey of the Northern Galactic Plane images a 10 • ×185 • wide band, centered on the Galactic Equator using the 2.5m Isaac Newton Telescope in four bands (U, g, r, Hei5875) down to ∼21 st-22 nd magnitude (∼20 th in Hei5875). The setup and data reduction procedures are described. Simulations of the colours of main-sequence stars, giant, supergiants, DA and DB white dwarfs and AM CVn stars are made, including the effects of reddening. A first look at the data of the survey (currently 30% complete) is given.