02242nas a2200181   4500008004100000245012300041210006900164260001200233300001400245490000700259520163300266100002101899700002501920700002401945700001701969700001701986856005702003       2016                        eng d00aPatterns of hydrologic connectivity in the McMurdo dry valleys, Antarctica: a synthesis of 20 years of hydrologic data0 aPatterns of hydrologic connectivity in the McMurdo dry valleys A  c04/2016  a2958-29750 v303 a<p>Streams in the McMurdo Dry Valleys (MDVs) of Antarctica moderate an important hydrologic and biogeochemical connection between upland alpine glaciers, valley-bottom soils, and lowland closed-basin lakes. Moreover, MDV streams are simple but dynamic systems ideal for studying interacting hydrologic and ecological dynamics. This work synthesizes 20&thinsp;years of hydrologic data, collected as part of the MDVs Long-Term Ecological Research project, to assess spatial and temporal dynamics of hydrologic connectivity between glaciers, streams, and lakes. Long-term records of stream discharge (Q), specific electrical conductance (EC), and water temperature (T) from 18 streams were analysed in order to quantify the magnitude, duration, and frequency of hydrologic connections over daily, annual, and inter-annual timescales. At a daily timescale, we observe predictable diurnal variations in Q, EC, and T. At an annual timescale, we observe longer streams to be more intermittent, warmer, and have higher median EC values, compared to shorter streams. Longer streams also behave chemostatically with respect to EC, whereas shorter streams are more strongly characterized by dilution. Inter-annually, we observe significant variability in annual runoff volumes, likely because of climatic variability over the 20 record years considered. Hydrologic connections at all timescales are vital to stream ecosystem structure and function. This synthesis of hydrologic connectivity in the MDVs provides a useful end-member template for assessing hydrologic connectivity in more structurally complex temperate watersheds.&nbsp;</p>1 aWlostowski, Adam1 aGooseff, Michael, N.1 aMcKnight, Diane, M.1 aJaros, Chris1 aLyons, Berry  uhttp://onlinelibrary.wiley.com/doi/10.1002/hyp.10818