Identifying non-stationary groundwater level response to North Atlantic ocean- atmosphere teleconnection patterns using wavelet coherence

The first comprehensive use of wavelet methods to identify non-stationary time- frequency relations between North Atlantic ocean-atmosphere teleconnection patterns and groundwater levels is described. Long-term hydrogeological time series from three boreholes within different aquifers across the UK are analysed to identify statistically significant wavelet coherence between the North Atlantic Oscillation, East Atlantic pattern, and the Scandinavia pattern and monthly groundwater-level time series. Wavelet coherence measures the cross- correlation of two time series as a function of frequency, and can be interpreted as a correlation coefficient value. Results not only indicate that there are common statistically significant periods of multiannual-to-decadal wavelet coherence between the three teleconnection indices and groundwater levels in each of the boreholes, but they also show that there are periods when groundwater levels at individual boreholes show distinctly different patterns of significant wavelet coherence with respect to the teleconnection indices. The analyses presented demonstrate the value of wave- let methods in identifying the synchronization of groundwater-level dynamics by non-stationary climate variability on time scales that range from interannual to decada

VAMAS interlaboratory study for desorption electrospray ionization mass spectrometry (DESI MS) intensity repeatability and constancy

A VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study for desorption electrospray ionization mass spectrometry (DESI MS) measurements has been conducted with the involvement of 20 laboratories from 10 countries. Participants were provided with an analytical protocol and two reference samples: a thin layer of Rhodamine B and double-sided adhesive tape, each on separate glass slides. The studies comprised acquisition of positive ion mass spectra in predetermined m/z ranges. No sample preparation was required. Results for Rhodamine B show that very consistent craters may be generated. However, inadequacies of the spray and sample stage designs often lead to variable crater shapes. The average repeatability for Rhodamine B is 50%. Yet, repeatabilities better than 20% can be achieved. Rhodamine B proved to be an excellent reference sample to check the sample erosion crater, the sample stage movement and memory effects. Adhesive tape samples show that their average absolute intensity repeatability is 30% and the relative repeatability is 9%. The constancy of these spectra from relative intensities gives day-to-day average relative repeatabilities of 31%, three times worse than the short-term repeatability. Significant differences in the spectra from different laboratories arise from the different adventitious adducts observed or from contaminants that may cause the higher day-to-day variations. It is thought that this may be overcome by allowing some 20 ppb of sodium to be always present in the solvent, to be the dominating adduct. Repeatabilities better than 5% may be achieved with adequate control

Correction to VAMAS Interlaboratory Study for Desorption Electrospray Ionization Mass Spectrometry (DESI MS) Intensity Repeatability and Constancy

Correction to VAMAS Interlaboratory Study for Desorption Electrospray Ionization Mass Spectrometry (DESI MS) Intensity Repeatability and Constanc

Water availability, infrastructure and ecosystems

This chapter establishes linkages between climate change and various aspects of water management. Adaptation and resilience-building options are presented with respect to water storage – including groundwater – and water supply and sanitation infrastructure, and unconventional water supply options are described. Mitigation options for water management systems are also presented