Master\u27s Project: Relationship With and Within the Land at a Preschool - Grade 12 School

This project explored the role that relationship with and within a place can play in fostering environmental and community ethics at Riverstone International School in Boise, Idaho. Riverstone International School is an organization recognized for its academic achievement and outdoor program, however, recent events and dialogues have indicated that it does not necessarily always outwardly or inwardly embody right environmental or social relationships. This project focused primarily on two groups, with different, but ultimately convergent objectives: 1) teachers remembering stories associated with the place and, 2) students reimagining what environmental stewardship could look like. Each of these processes provided an opportunity to strengthen individual and collective awareness of responsibility and possibility for growth. Ultimately the process resulted in visible changes to the school campus, deepened relationships, and deepened understanding of individual values, strengths and callings, especially in relation to those voiced and practiced by the school. An additional and related focus of the project was the author’s own reflection on, and nurturing of, his personal and leadership practices which ultimately resulted in reframing of personal and professional calling

Shrinking sea ice, increasing snowfall and thinning lake ice: a complex Arctic linkage explained

The dramatic shrinkage of Arctic sea ice is one of the starkest symptoms of global warming, with potentially severe and far-reaching impacts on arctic marine and terrestrial ecology (Post et al 2013 Science 341 519–24) and northern hemisphere climate (Screen et al 2015 Environ. Res. Lett. 10 084006). In their recent article, Alexeev et al (2016 Environ. Res. Lett. 11 074022) highlight another, and unexpected, consequence of Arctic sea ice retreat: the thinning of lake ice in northern Alaska. This is attributed to early winter 'ocean effect' snowfall which insulates lake surfaces and inhibits the formation of deep lake ice. Lake ice thinning has important consequences for Arctic lake hydrology, biology and permafrost degradation

Representing moisture fluxes and phase changes in glacier debris cover using a reservoir approach

Due to the complexity of treating moisture in supraglacial debris, surface energy balance models to date have neglected moisture infiltration and phase changes in the debris layer. The latent heat flux (QL) is also often excluded due to the uncertainty in determining the surface vapour pressure. To quantify the importance of moisture on the surface energy and climatic mass balance (CMB) of debris-covered glaciers, we developed a simple reservoir parameterization for the debris ice and water content, as well as an estimation of the latent heat flux. The parameterization was incorporated into a CMB model adapted for debris-covered glaciers. We present the results of two point simulations, using both our new “moist” and the conventional “dry” approaches, on the Miage Glacier, Italy, during summer 2008 and fall 2011. The former year coincides with available in situ glaciological and meteorological measurements, including the first eddy-covariance measurements of the turbulent fluxes over supraglacial debris, while the latter contains two refreeze events that permit evaluation of the influence of phase changes. The simulations demonstrate a clear influence of moisture on the glacier energy and mass-balance dynamics. When water and ice are considered, heat transmission to the underlying glacier ice is lower, as the effective thermal diffusivity of the saturated debris layers is reduced by increases in both the density and the specific heat capacity of the layers. In combination with surface heat extraction by QL, subdebris ice melt is reduced by 3.1% in 2008 and by 7.0% in 2011 when moisture effects are included. However, the influence of the parameterization on the total accumulated mass balance varies seasonally. In summer 2008, mass loss due to surface vapour fluxes more than compensates for the reduction in ice melt, such that the total ablation increases by 4.0 %. Conversely, in fall 2011, the modulation of basal debris temperature by debris ice results in a decrease in total ablation of 2.1 %. Although the parameterization is a simplified representation of the moist physics of glacier debris, it is a novel attempt at including moisture in a numerical model of debris-covered glaciers and one that opens up additional avenues for future research

Thermal and dynamic behaviour of supraglacial clasts and the origin of sorting in supraglacial debris covers

The transition zone from a discontinuous to a continuous debris cover is an extensive part of many glacier ablation zones. Although responsible for the highest specific melt rates of debris-covered glaciers, transition zones have received little research and are poorly understood. Here we consider the interactions between emergent clasts and melting ice surfaces at Glacier d'Estelette and Miage Glacier (Italian Alps). Debris-ice interactions are complex because dispersed heterogenous debris both enhances and retards melt rate in the same locality, depending on the distribution of clast sizes. Observations reveal that thermal and dynamic clast interactions with the glacier surface increase the transport rate of coarse clasts, and initiate vertical sorting at the point when a continuous debris layer forms. This happens because, in summer, clasts exceeding the critical thickness for melt slide over the glacier surface. In contrast finer thermally-embedded material is transported at ice surface velocity and become covered by coarser material from upslope. Once established, debris-cover texture allows sorting to develop as the cover thickens downglacier. A two-layer temperature profile results, in which a coarse, drier clast layer of low thermal conductivity overlies a finer-grained, moist layer of higher thermal conductivity. Transition-zone processes establish inverse grading at the initiation of a debris cover, allowing subsequent sorting to operate as the cover thickens downstream. The processes by which this occurs are unknown, but analogy with periglacial active layers suggests convection within a frost-susceptible lower fine layer and eluviation of fines supplied by aeolian deposition and in-situ clast distintegratio

Seasonal and elevational contrasts in temperature trends in Central Chile between 1979 and 2015

We analyze trends in temperature from 18 temperature stations and one upper air sounding site at 30°–35° S in central Chile between 1979–2015, to explore geographical and season temperature trends and their controls, using regional ocean-atmosphere indices. Significant warming trends are widespread at inland stations, while trends are non-significant or negative at coastal sites, as found in previous studies. However, ubiquitous warming across the region in the past 8 years, suggests the recent period of coastal cooling has ended. Significant warming trends are largely restricted to austral spring, summer and autumn seasons, with very few significant positive or negative trends in winter identified. Autumn warming is notably strong in the Andes, which, together with significant warming in spring, could help to explain the negative mass balance of snow and glaciers in the region. A strong Pacific maritime influence on regional temperature trends is inferred through correlation with the Interdecadal Pacific Oscillation (IPO) index and coastal sea surface temperature, but the strength of this influence rapidly diminishes inland, and the majority of valley, and all Andes, sites are independent of the IPO index. Instead, valley and Andes sites, and mid-troposphere temperature in the coastal radiosonde profile, show correlation with the autumn Antarctic Oscillation which, in its current positive phase, promotes subsidence and warming at the latitude of central Chile

Eisenstein Series, Crystals, and Ice

Automorphic forms are generalizations of periodic functions; they are functions on a group that are invariant under a discrete subgroup. A natural way to arrange this invariance is by averaging. Eisenstein series are an important class of functions obtained in this way. It is possible to give explicit formulas for their Fourier coe cients. Such formulas can provide clues to deep connections with other elds. As an example, Langlands' study of Eisenstein series inspired his far-reaching conjectures that dictate the role of automorphic forms in modern number theory. In this article, we present two new explicit formulas for the Fourier coe cients of (certain) Eisenstein series, each given in terms of a combinatorial model: crystal graphs and square ice. Crystal graphs encode important data associated to Lie group representations while ice models arise in the study of statistical mechanics. Both will be described from scratch in subsequent sections. We were led to these surprising combinatorial connections by studying Eisenstein series not just on a group, but more generally on a family of covers of the group. We will present formulas for their Fourier coe cients which hold even in this generality. In the simplest case, the Fourier coe cients of Eisenstein series are described in terms of symmetric functions known as Schur polynomials, so that is where our story begins.National Science Foundation (U.S.) (DMS-0844185)National Science Foundation (U.S.) (DMS-1001079)National Science Foundation (U.S.) (DMS-0844185)United States. National Security Agency (NSA grant H98230-10-1-0183

Optionen zur Sicherung der Humusversorgung im viehlosen Ökolandbau unter Berücksichtigung von Humusbilanz und Betriebswirtschaft

An adequate supply of organic matter to arable soils is essential for the maintenance of soil productivity. Still, management implications can cause a trade-off with economics, as measures for soil organic matter management may not directly induce ecosystem services that increase the profitability of the system. This is especially true with regard to stockless organic farming systems, where well-proven measures, as the integration of fodder legumes in crop rotations, may not seem attractive with regard to the revenue. In this article we evaluate strategies for soil organic matter management in stockless organic farming systems based on scenarios for different soil-climate conditions in Germany to deal with this challenge. Several options to make use of synergies between soil organic matter management and profitability could be identified. In particular, the integration of fodder legumes, even on the cost of cash crop shares in rotations, may cause a win-win situation, if the biomass of the legumes can be used in a profitable way that creates a mobile nutrient pool and allows for a return of organic matter, as e.g. biogas production