Daily Archives: January 13, 2015

Mountain Climate Trends Artificially Amplified

Jared W. Oyler, Solomon Z. Dobrowski, Ashley P. Ballantyne, Anna E. Klene, Steven W. Running. Artificial Amplification of Warming Trends Across the Mountains of the Western United States. Geophysical Research Letters, DOI: 10.1002/2014GL062803

Observations from the main mountain climate station network in the western United States (US) suggest that higher elevations are warming faster than lower elevations. This has led to the assumption that elevation-dependent warming is prevalent throughout the region with impacts to water resources and ecosystem services. Here, we critically evaluate this network’s temperature observations and show that extreme warming observed at higher elevations is the result of systematic artifacts and not climatic conditions. With artifacts removed, the network’s 1991–2012 minimum temperature trend decreases from +1.16 °C decade−1 to +0.106 °C decade−1 and is statistically indistinguishable from lower elevation trends. Moreover, longer-term widely used gridded climate products propagate the spurious temperature trend, thereby amplifying 1981–2012 western US elevation-dependent warming by +217 to +562%. In the context of a warming climate, this artificial amplification of mountain climate trends has likely compromised our ability to accurately attribute climate change impacts across the mountainous western US.

Click here for paper (fee).

Drinking Water Microbiology

Caitlin R Proctor, Frederik Hammes. Drinking water microbiology—from measurement to management Current Opinion in Biotechnology June 2015 33:87-94

New microbial tools enable detailed quantification and characterization of complex drinking water (DW) microbiomes. Many opportunities exist from source to tap to apply this knowledge toward management of the microbiology. This requires consideration of the microbiome continuum across all phases harboring microbes (planktonic cells, biofilms, and cells attached to loose deposits) and across all stages (source, treatment, distribution, and premise). Biofilters can be optimized toward specific compound removal and can seed the distribution network (DN) with beneficial bacteria. Disinfection aggressively controls the microbiome, but may select for unwanted bacteria. Within premise plumbing, dramatic changes occur with unavoidable stagnation and pipe material influence. To supply safe DW sustainably, it is imperative that the field progress from characterization toward management of the DW microbiome.