Development of marine heat waves (MHWs) in the Chile-Peru Current System (CPCS) is influenced by multiple physical processes at the air-sea interface whose individual role in these destructive events is difficult to infer. We identified MHW events from sea surface temperature (SST) anomalies from time periods of extreme ocean warming...
Atmospheric boundary layers become stably stratified at night over land when the surface becomes colder than the air layer above. In stable nocturnal boundary layers (SNBL), turbulence becomes weak and intermittent, terrain-induced phenomena such as drainage currents or gravity-waves emerge and the surface heterogeneity is enhanced. Because of their complexity...
The physical framework or matrix in which the biological processes of aquatic ecosystems occur is currently under investigation at the Castle Lake Research Station. Special attention has been given these physical parameters in view of their close interrelationship with important biological properties within the lake (as exemplified by the rate...
The energy budget of a pumice desert surface was analyzed under clear skies during early, mid-and late summer periods. The pumice site is in the semi-arid plateau region of Central Oregon at an elevation of about 1500 meters. The flat pumice surface is approximately 250 hectares in extent, and is...
The net mass balance fluctuations of Arctic and Sub-Arctic glaciers, north of 47.5°
North latitude, are described over a 45-year period from 1957 to 2002 using two
parameters derived from a gridded climatology reanalysis. Variability among 185
measured glaciers was represented according to two main components. The first
component represents...
A change to a warmer, drier climate beginning as early as 1900 was responsible
for triggering a dramatic, rapid retreat of Collier Glacier, Oregon, between 1924 and
1940. Although there was a dramatic decrease in precipitation contemporaneous with this observed "step-function" response of mass loss, it is unclear if climate...
As a result of a warming climate, subsequent declining snowpack, and a century of fire suppression, forest fires are increasing across the western United States. However, we still do not fully understand how forest fire effects snowpack energy balance, nor the volume and availability of snow melt and associated water...
Headwater streams are an integral part of the ecological health of the greater stream network as they provide valuable biological habitat, provide upwards to 95% of total in channel flow, while providing downstream reaches with important constituents such as sediment and woody debris. Small headwater streams are particularly susceptible to...
This thesis presents the results of an investigation into the interactions between the present-day South Cascade Glacier and the former Mauna Kea ice cap at short (annual to centennial) and long (millennial and multimillennial) time scales. To quantify the response of South Cascade Glacier to atmospheric conditions, a surface energy...
This thesis presents two related studies on the methodology for creating, and
subsequently analyzing, an inverse food web model of an intertidal seagrass bed. The first study (Chapter 2) describes, for the first time in the literature, a method for incorporating isotopic information gained from Bayesian mixing models into an...
An integrative method for monitoring glacier geometry change and mass balance is presented and applied to the Pacific Northwest, USA. Acting as a baseline for interpretation of future changes in glacier size and shape, we first derive a new inventory of regional glacier cover using remotely sensed data. To investigate...