We present a dataset of daily resolution climatic time series that has been compiled for the European Climate Assessment (ECA). As of December 2001, this ECA dataset comprises 199 series of minimum, maximum and/or daily mean temperature and 195 series of daily precipitation amount observed at meteorological stations in Europe and the Middle East. Almost all series cover the standard normal period 1961-90, and about 50% extends back to at least 1925. Part of the dataset (90%) is made available for climate research on CDROM and through the Internet (at http://www.knmi.nl/samenw/eca).A comparison of the ECA dataset with existing gridded datasets, having monthly resolution, shows that correlation coefficients between ECA stations and nearest land grid boxes between 1946 and 1999 are higher than 0.8 for 93% of the temperature series and for 51% of the precipitation series. The overall trends in the ECA dataset are of comparable magnitude to those in the gridded datasets.The potential of the ECA dataset for climate studies is demonstrated in two examples. In the first example, it is shown that the winter (October-March) warming in Europe in the 1976-99 period is accompanied by a positive trend in the number of warm-spell days at most stations, but not by a negative trend in the number of cold-spell days. Instead, the number of cold-spell days increases over Europe. In the second example, it is shown for winter precipitation between 1946 and 1999 that positive trends in the mean amount per wet day prevail in areas that are getting drier and wetter.Because of its daily resolution, the ECA dataset enables a variety of empirical climate studies, including detailed analyses of changes in the occurrence of extremes in relation to changes in mean temperature and total precipitation.

Tropical plumes (TPs) reflect tropical–extratropical interaction associated with the transport of moisture from the Tropics to extratropical latitudes. They are observed in satellite images as continuous narrow cloud bands ahead of upper-level subtropical troughs at times when the subtropical jet is highly perturbed. Rainstorms usually develop in the exit regions of TPs, so their presence over northern Africa has an impact on the precipitation regime in the southeastern Mediterranean. Based on satellite images and rainfall measurements from Israel, 10 TPs over eastern North Africa between 1988 and 2005 in which considerable rain was recorded were selected. Using the NCEP–NCAR reanalysis data, the structure and evolution of these TPs were characterized and their regional canonical features were identified. A typical TP that occurred in March 1991 is described in detail. The main canonical characteristics are as follows: the TP development is preceded by an incubation period, expressed either as a stationary upper-level trough, persisting 2–6 days, or as two consecutive TP pulses; the preferred location for TP origin is 5°–15°N, 5°W–15°E; the TP is separated from the underlying dry Saharan PBL; the subtropical trough undergoes a phase locking with the lower tropical trough; the cloudiness in the TP-induced rainstorm is mostly stratified with continuous moderate rain, originating from midlevel moisture; and the TP tends to be followed by a midlatitude cyclogenesis over the eastern Mediterranean. This analysis proposes several explanations for the efficiency of the TPs in transporting moisture over a 2000-km distance.

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We collected and analyzed Br − breakthrough curve (BTC) data to identi fy the parameters controlling transport from a series of soil cores and a fi eld-scale tracer test at the Shale Hills Criti cal Zone Observatory (SH-CZO) in central Pennsylvania. The soil cores were retrieved from a conti nuous hole that extended through the soil profi le to quanti fy also how solute transport behavior changes with depth and weathering. Additi onally, we performed a fi eldscale doublet tracer test to determine transport behavior in the weathered shale bedrock. Hydraulic conducti vity and porosity were as low as 10 −15 m s −1 and 0.035, respecti vely, in the shale bedrock and upward of 10 −5 m s −1 and 0.45, respecti vely, in the shallow soils. Bromide BTCs demonstrated signifi cant tailing in soil cores and fi eld tracer experiments, which does not fi t classical advecti on-dispersion processes. To quanti fy the behavior, numerical simulati on of solute transport was performed with both a mobile-immobile (MIM) model and a conti nuous-ti me random walk (CTRW) approach. One-dimensional MIM modeling results yielded low mass transfer rates (<1 d −1 ) coupled with large immobile domains (immobile/mobile porosity rati o of 1.5-2). The MIM modeling results also suggested that immobile porosity was a combinati on of soil texture, fractures, and porosity development on shale fragments. One-dimensional CTRW results yielded a parameter set indicati ve of a transport regime that is consistently non-Fickian within the soil profi le and bedrock. These modeling results confi rm the important role of preferenti al fl ow paths, fractures, and mass transfer between more-and less-mobile fl uid domains and advance the need to incorporate a conti nuum of mass transfer rates to more accurately quanti fy transport behavior within the SH-CZO.Abbreviati ons: ADE, advecti on-dispersion equati on; BTC, breakthrough curve; CTRW, conti nuous-ti me random walk; MIM, mobile-immobile; pdf, probability density functi on; PSD, parti cle size distributi on; SH-CZO, Shale Hills Criti cal Zone Observatory; TPL, truncated power law.The SH-CZO has been developed as a natural laboratory to predict the creation and function of regolith within a multidisciplinary context. Th e fl ow of water and transport of solutes within this catchment are key to dating groundwater, estimating soil weathering rates, predicting nutrient availability, classifying primary and secondary fl uid pathways, and identifying controls on the residence time of solutes in the subsurface (Amundson et al., 2007;Brantley et al., 2007;Anderson et al., 2008;Dere et al., 2010). Identifying groundwater age is a useful means to investigate watershed-scale processes including discharge and recharge areas, preferential fl ow paths, and drought vulnerability or resource protection (Kazemi et al., 2006). Calculating groundwater ages has traditionally been accomplished by advection-only models (e.g., Reilly et al., 1994), although the importance of dispersion and diff usion processes is well recognized (e.g....