Now showing items 2019-2038 of 3446

• #### Nitrogen flux in the northern Bering Sea

Much of the primary production occurring over the Bering Sea continental shelf is thought to be associated with both ice edge and spring blooms. The nature of summer production over the shelf is now being addressed. A general model is presented for summer phytoplankton production along the Bering Sea shelf break front and subsequent transport of phytodetritus into the northern Bering Sea. Production associated with the shelf break front is estimated to be 200 g $\cdot$ C $\cdot$ m$\sp{-2}$ over a 120-day growing season and is supported by nutrients from the Bering Slope Current. A portion of the biomass accumulating over the front is advected into the Chirikov Basin, supplying 26% of the daily carbon demand of the benthos. The Bering Slope Current bifurcates at Cape Navarin and one branch, referred to as the Anadyr Current, flows north through Anadyr and Bering Straits. Nutrients in the Anadyr Current support an intense surface bloom over the western Chirikov Basin where total nitrogen uptake rates are $>$6.0 mg-at N $\cdot$ m$\sp{-2} \cdot$ h$\sp{-1}$ and nitrate contributes up to 50% of the total nitrogen uptake. Modified Bering Shelf water contains phytoplankton at two depths: both a surface accumulation and a deep layer. Nitrate contributes $<$35% to total nitrogen uptake rates of 1.80 mg-at N $\cdot$ m$\sp{-2} \cdot$ h$\sp{-1}$ in this water. Nitrogen productivity is lowest in Alaskan Coastal water (1.0 mg-at N $\cdot$ m$\sp{-2} \cdot$ h$\sp{-1}$) where nitrate uptake averages only 15% of the total. A simple nitrogen budget suggests that 29% and 62% of the annual nitrogen productivity in modified Bering Shelf and Anadyr waters, respectively, is exported through Bering Strait into the southern Chukchi Sea for deposition. Improved estimates of the rates of urea production and uptake by phytoplankton in the northern Bering Sea were made after determining the change in $\sp{15}$N-atom % enrichment of urea during incubations. Estimates of uptake rates increased by up to 83% using a $\sp{15}$N accumulation model and by $>$210% using a $\sp{15}$N disappearance model. However, a discrepancy exists between the $\sp{15}$N-urea removed from the aqueous phase and the $\sp{15}$N accumulated in the particulate phase. The ability to find in the particulate fraction the $\sp{15}$N removed from solution as $\sp{15}$N-urea was improved by 72% following removal of the $>$20-$\mu$m particulate fraction.
• #### Nitrogen oxide photochemistry in high northern latitudes during spring

The transport of NOy reservoir species from midlatitudes into the Arctic and the thermal and photochemical breakup of these species has been proposed to be the most important NOx source during spring, and may have an important influence on the ozone budget. This has not yet been shown to be correct. The objective of this research is to understand the sources of NOx and ozone in high latitudes during spring. To measure NOx, a high sensitivity chemiluminescence NO detector and a photolytic converter for NO$\sb2$ were constructed. The detection limits for NO and NO$\sb2$ were 1.70 and 5.67 part per trillion (pptv) in a one-hour average, respectively. Springtime NOx measurements were carried out concurrently with measurements of ozone, PAN, J(NO$\sb2$), and other species during 1994 at the Zeppelin station on Svalbard, and during 1993 and 1995 at Poker Flat, Alaska. The median mixing ratios of NOx, PAN and ozone at Svalbard were 23.7, 237.0 pptv, and 39.0 parts per billion (ppbv), respectively. During a few ozone depletion events in the Arctic marine boundary layer ozone and NOx mixing ratios were as low as 4 ppbv and 0.9 pptv, respectively. Halogen chemistry is probably responsible for both effects. The median NOx, PAN and ozone mixing ratios at Poker Flat were 79.5 pptv, 85.9 pptv, and 40.6 ppbv, respectively. During April and May diurnal cycles of PAN, ozone and temperature were observed and anticorrelated with the water mixing ratio. We interpret this to be the result of mixing with higher layers of the troposphere during the day. At both locations thermal PAN decomposition was an important NOx source. At Svalbard PAN decomposition was small, and the in-situ ozone production rates are an insignificant contribution to the ozone budget. Because of the higher temperatures, PAN decomposition rates, NOx mixing ratios, and in-situ ozone production rates are higher at Poker Flat. A contribution from this production to the overall ozone budget was visible during some periods. These results indicate that stable ozone precursors which are transported into the Arctic from anthropogenic sources can influence the ozone budget in high latitudes.
• #### Nitrogen oxide photochemistry in marine air over the eastern Pacific

Models predict that photochemistry is the primary contribution to the observed spring surface ozone maxima in the Northern Hemisphere. Nitrogen oxides (NOx) are the limiting reagents for photochemical ozone production. This fact leads to an apparent paradox, because the short lifetime of NOx should lead to a low mixing ratio of NOx far from source regions. However, chemical reservoirs of NOx such as peroxyacetyl nitrate (PAN) may provide a transport pathway for delivering NOx to 'clean' marine Pacific air masses. A coastal site in Washington, was chosen to investigate the relationship of NOx, PAN and ozone in marine air from the Pacific during two consecutive spring campaigns in 1997 and 1998. In this work, we develop a simple PAN decomposition model and comparie the modeled to the measured PAN mixing ratios. We estimate ozone formation using the deviation in the measured NO to NO₂ ratio, from the Leighton cycle.
• #### Nitrogen oxides in the arctic stratosphere: Implications for ozone abundances

In the high latitude winter stratosphere, NO$\sb2$ sequesters chlorine compounds which are extremely efficient at destroying ozone. During the nighttime, NO$\sb2$ reacts with ozone to form $\rm N\sb2 O\sb5$ which acts as a reservoir of NO$\sb2$. Under heavy aerosol loading, $\rm N\sb2O\sb5$ may react with water on aerosol surfaces to form HNO$\sb3$, a reservoir more resistant to photolysis. This heterogeneous reaction results in reduced NO$\sb2$ concentration when the sun returns at the end of the winter. A spectrograph system has been developed to measure scattered zenith skylight and thereby determine stratospheric NO$\sb2$ slant column abundance. Conversion of the measured slant column abundance to vertical column abundance requires dividing by the air mass. The air mass is the enhancement in the optical path for the scattered twilight as compared to a vertical path. Air mass values determined using a multiple scattering radiative transfer code have been compared to those derived using a Monte Carlo code and were found to agree to within 6% at a 90$\sp\circ$ solar zenith angle for a stratospheric absorber. Six months of NO$\sb2$ vertical column abundance measured over Fairbanks during the winter 1992-93 exhibited the daylight diminished and increased as the sunlight hours lengthened. The overall seasonal behavior was similar to high-latitude measurements made in the Southern Hemisphere. The ratios of morning to evening column abundance were consistent with predictions based on gas-phase chemistry. The possible heterogeneous reaction of $\rm N\sb2O\sb5$ on sulfate aerosols was investigated using Fourier Transform Infrared Spectrometer measurements of $\rm HNO\sb3$ column abundance and lidar determinations of the aerosol profile. Using an estimated $\rm N\sb2O\sb5$ column abundance and aerosol profile as input to a simple model, significant $\rm HNO\sb3$ production was expected. No increase in $\rm HNO\sb3$ column abundance was measured. From this set of data, it was not possible to determine whether significant amounts of $\rm N\sb2O\sb5$ were converted to $\rm HNO\sb3$ by this heterogeneous reaction. Better estimates of the $\rm N\sb2O\sb5$ and aerosol profile, and a more continuous set of $\rm HNO\sb3$ measurements, are needed to determine if $\rm HNO\sb3$ was actually produced.
• #### Nitrogen oxides in the Arctic troposphere

Nitrogen oxides play a critical role in tropospheric photochemistry. In order to characterize these compounds in the arctic troposphere, ground-level concentrations of total reactive nitrogen (NO$\sb{y}$) and NO were determined over an extended period at a site near Barrow, Alaska. A high-sensitivity instrument developed for this purpose was used in three measurement campaigns: summer 1988, spring 1989, and March-December 1990. During the 1990 campaign, the detection limit for NO was 3-10 pptv (depending on averaging period), and the NO$\sb{y}$ uncertainty was $\pm$26%. A screening algorithm was applied to the data to eliminate effects from local (Barrow) sources, and the remaining data were divided into "background periods" (unaffected by local or regional NO$\sb{x}$ sources), and "events" (periods when emissions from a regional NO$\sb{x}$ source--the Prudhoe Bay oil-producing region--apparently impacted Barrow). These measurements revealed a sharp seasonal cycle of background NO$\sb{y}$ concentrations, with high values in early spring (median 560-620 pptv) and $\sim$70 pptv (median) during summer. This cycle is similar to that of other compounds in arctic haze but is partially attributed to a reduction in NO$\sb{y}$ lifetime due to organic nitrate decomposition as temperatures and insolation increased. Evidence indicates that the springtime arctic NO$\sb{y}$ reservoir was primarily composed of stable removal-resistant species, including PAN and other organic nitrates. PAN decomposition as temperatures rose in late spring likely caused an observed pulse of NO to $\sim$35 pptv (maximum hourly average); hourly-average NO concentrations were otherwise generally $<$8 pptv. NO$\sb{x}$ production from PAN decomposition due to the onset of spring or southward advection may affect springtime O$\sb3$ levels both in the Arctic and in the northern mid-latitudes. NO$\sb{y}$ and O$\sb3$ concentrations were positively correlated during summer, possibly indicating long-range transport of both and/or the presence of a mid-tropospheric NO$\sb{y}$ reservoir combined with a stratospheric O$\sb3$ source. A number of events with substantially elevated NO$\sb{y}$ concentrations (to 16 ppbv) were observed in air not impacted by emissions from the town of Barrow. Substantial evidence indicates that these events were a result of NO$\sb{x}$ emissions from the Prudhoe Bay region ($\sim$300 km to the ESE), which is also expected to affect measurements of other compounds at the Barrow site.
• #### Nitrogen resource analysis and modelling of an eelgrass (Zostera marina L.) meadow in Izembek Lagoon, Alaska

Nitrogen limitation in beds of eelgrass, Zostera marina L., was examined by correlating plant standing stock and sediment nitrogen supplies, by measurement of nitrogen uptake in eelgrass roots and leaves, and by experimental manipulation of plant-nitrogen interaction. Eelgrass standing stock and sediment nitrogen across an eelgrass meadow were analyzed. Correlation was found between the integrated interstitial ammonium pool and shoot density and other morphological characteristics. A model of eelgrass growth predicted the effect of nitrogen utilization on biomass production and growth rates; nitrogen limitation controlled growth throughout the summer in ammonium-poor eelgrass beds but only at the peak growth periods in ammonium-rich areas. Prediction of nitrogen enrichment effects similar to literature findings confirmed the impact of nitrogen limitation. Simulation of the spatial and seasonal influences of nitrogen and light as controls on eelgrass growth demonstrated the recurrent effects of dominant environmental limitations within an eelgrass meadow.
• #### Nitrogen retention in the riparian zone of watersheds underlain by discontinuous permafrost

Riparian zones function as important ecotones for reducing nitrate concentration in groundwater and inputs into streams. In the boreal forest of interior Alaska, permafrost confines subsurface flow through the riparian zone to shallow organic horizons, where plant uptake of nitrate and denitrification are typically high. Two research questions were addressed in this study: 1) how does riparian zone nitrogen retention vary in watersheds underlain by discontinuous permafrost, and 2) what is the contribution of denitrification to riparian zone nitrogen retention? To estimate the contribution of the riparian zone to watershed nitrogen retention, I analyzed groundwater chemistry using an end-member mixing model. To assess the importance of denitrification as a mechanism of nitrogen retention, I conducted field denitrification assays using the acetylene block technique. Over the summer, nitrogen retention averaged 0.75 and 0.22 mmol N m⁻² d⁻¹ in low and high permafrost watersheds, respectively. Compared with the fluvial export of nitrogen, the retention rate of nitrogen in the riparian zone is 10 - 15% of the loss rate in stream flow. Denitrification accounted for a small proportion (3%) of total nitrogen retention in the riparian zone. Variation in nitrogen retention between watersheds did not account for differences in stream nitrate concentration between watersheds.
• #### Nitrogen utilization during spring phytoplankton bloom development in the southeast Bering Sea

Interactions between a high latitude, continental shelf, spring phytoplankton bloom and water column physics and chemistry were studied using measured rates of nitrogen uptake. Peak bloom conditions commenced when the mixed layer shallowed and minimized respirational losses. Integrative light-mixing growth models were accurate during early bloom stages. An advection-diffusion model associated peak bloom nitrate uptake with pycnocline mixing rates of 2.1 m d * in an 18 m mixed layer. The accumulation of surface buoyancy was a reliable index of peak bloom temporal and spatial "patchiness" since mixing rates influenced both respirational losses and nutrient supply. Maximum nitrogen specific uptake rates (h r .- 1 ), unlike those of carbon, coincided with peak bloom conditions. Although species com positions among peak bloom periods were similar, particulate C/N ratios were not. Apparently, both intercellular factors and prevailing mixing conditions influence specific uptake rates and cell composition. A large proportion of new (nitrate) to total productivity was associated with the dominance of the early bloom forming diatoms in the mixed layer. In the absence of these net plankton the residual nanoplankton dominated community exhibited a greater dependence on regenerated nitrogen. Nitrate uptake averaged 700 mg-at m during the spring bloom and 1 g-at m-2 year-1 The yearly f factor was 0.40. Nitrogen uptake based carbon productivity was 188 g C m -2 year -1 A mass balance of the inorganic carbon system indicates that nitrate uptake alone cannot account for all the carbon leaving the surface layer. The correspondence between 1SN0~ uptake measurements and nitrate decreases suggests the diffusion of slope water into the middle shelf is slow. Large scale meteorological patterns may be responsible for the inter annual variability observed in production. Frequent May storm activity prolonged peak bloom periods, while calm conditions promoted extensive Chijl layers. The passage of atmospheric low pressure system s was also associated with the cross shelf "pumping" of water masses.
• #### Niugneliyukut (We Are Making New Words): A Community Philosophy Of Language Revitalization

The Alutiiq language on Kodiak Island (Alaska) is severely threatened, with only 37 resident speakers. The Alutiiq communities of Kodiak are engaged in a multifaceted heritage revitalization movement, which includes cultural education, revitalization of arts, and language revitalization. The language revitalization effort includes education, materials development, documentation, and terminology development (creation of new words) as a means of making the language more viable. The Kodiak Alutiiq New Words Council began in the fall of 2007. This language revitalization strategy is new to the Alutiiq community, and little research has been done on Alaska Native or Indigenous terminology development as a form of heritage revitalization. There is a need to understand the New Words Council in terms of its role in the wider language and heritage revitalization efforts, as well as understanding the value of the council to its members. The Kodiak New Words Council is a contemporary heritage revitalization effort that entails development of new Alutiiq terms, and is part of a broader social movement to revitalize Alutiiq language and culture. Some past research on cultural heritage revitalization movements in Indigenous communities have focused on historical inaccuracies and 'inventedness' of new cultural forms, rather than the value and meaning of these efforts to their participants. Critiques of 'invention' scholarship counter that it denies Indigenous communities' agency and authority over their own cultural forms, and overlooks ongoing efforts for justice, sovereignty and healing. This study focuses attention on the social and historical context of heritage revitalization and its meaning to participants. Benefits of the council go beyond the formal goal of developing new words to modernize the language. Participants put great value on social benefits of the New Words Council, such as empowerment, connection to culture and identity, and healing. They further measure the success of the New Words Council in terms of participation, commitment, and continuity. Ultimately, this language revitalization effort is part of a broader effort of self-determination and community survival.
• #### Nmda Receptors In Hibernating Arctic Ground Squirrels

Hibernation is a unique physiological state characterized by suppressed metabolism and body temperature that is interrupted by multiple, brief periods of arousal throughout the hibernation season. Blood flow fluctuates during hibernation and arousal in a reperfusion-like manner without causing neurological damage. Previous studies show that hippocampal slices from hibernating animals tolerate experimental oxygen nutrient deprivation and N-methyl-D-aspartate (NMDA) toxicity better than slices from euthermic animals. However, the cellular mechanisms underlying these examples of tolerance remain unclear. Tolerance to NMDA toxicity suggests that modulation of NMDA receptors (NMDAR) contributes to intrinsic tissue tolerance in slices from hibernating Arctic ground squirrels (hAGS, Spermophilus parryii). NMDAR are one subtype of glutamate receptors. NMDAR play critical roles in excitatory synaptic transmission, synaptic plasticity, learning and memory, and excitotoxicity. NMDAR1 (NR1) is a fundamental subunit of NMDAR and required for receptor function. The main focus of the current project was to test the hypothesis that NMDAR are down-regulated in hAGS compared with interbout euthermic AGS (ibeAGS) and to explore the potential mechanisms of this down-regulation. NMDAR function can be modulated by protein phosphorylation, subunit composition, and internalization. Hence, the aim of chapter 2 was to determine the distribution of NRl in hAGS and ibeAGS using immunohistochemistry. The aim of chapter 3 was to examine NMDAR function in cultured hippocampal slices from hAGS, ibeAGS, and rats using calcium imaging, and to investigate potential modulation of NMDAR such as phosphorylation and internalization for altered function using western blot analysis. Given that synaptic remodeling and functional changes after arousal from hibernation, and NMDAR play an important role in learning and memory, the aim of chapter 4 was to address the effects of hibernation on learning and memory in AGS using an active avoidance task. Here, we report that NMDAR in hAGS are down-regulated via decreased phosphorylation of NR1. This down-regulation is not due to changes in NR1 distribution and internalization. In addition, the fraction of NR1 in the functional membrane pool in AGS is less than in rats. These findings provide evidence that modulation of NMDAR contributes to neuroprotection observed in hAGS.

• #### Nocturnal Processing Of Nitrogen Oxide Pollution At High Latitudes: Off-Axis Cavity Ring-Down Spectroscopy Method Development And Field Measurement Results

Nitrogen oxides, or NOx, play a central role in ozone and nitric acid (HNO3) pollution in the troposphere. Reactions of nitrate radical (NO3) and dinitrogen pentoxide (N2O 5) result in the removal of NOx and ozone from the nighttime atmosphere. In this thesis, we describe the configuration, operation, and performance of an off-axis cavity ring-down spectroscopy (oa-CRDS) field instrument designed for measuring NO3 and N2O5. Furthermore, we report results of an N2O5 instrument intercomparison conducted using an atmospheric simulation chamber in Julich, Germany. The results of the intercomparison demonstrate that the oa-CRDS instrument is an excellent tool for measuring NO3 and N2O 5. Also reported in this thesis are the results of two field campaigns aimed at characterizing NOx removal from the nocturnal pollution plume arising from Fairbanks, AK. The results from the field campaigns suggest ice is responsible for catalyzing N2O5 heterogeneous hydrolysis in cold, high-latitude plumes. When air masses are sub-saturated with respect to ice, the data show longer lifetimes (&sim;20 minutes) and elevated N2O5 levels while ice-saturated air masses show shorter lifetimes (&sim;6 minutes) and suppressed N2O 5 levels. Lastly, we present vertical profiles of N2O 5 measured above the seasonal snow pack. The results of the profiling studies suggest that N2O5 can be removed by heterogeneous hydrolysis on ice in the snow pack. Our findings indicate that catalysis on ice surfaces is largely responsible for nocturnal processing of N2O 5 leading to nitric acid production and loss of NOx in high latitude plumes.
• #### Nome as place

Inspired by finding a sense of place within the Circumpolar North this project examines this artist’s personal connection to Nome, Alaska with a contemporary photographic approach utilizing the historical Platinum Palladium photographic process. The use of the Platinum Palladium process explores the artist’s connection to place, the idea of landscape, cultural iconography, and connects it to historic trends in the field of photography.
• #### Non-invasive methods for obtaining occupancy probabilities and density estimates of Interior Alaska's mesocarnivore populations

Mesocarnivore species worldwide have been shown to be significant drivers of ecological communities. Changes in their abundance and distributions are known to cause cascading effects throughout ecosystems, and changes to the landscape and climate will likely lead to shifts in mesocarnivore population sizes and distributions. However, the current status of these species in some of the world's most susceptible landscapes is not known. I assessed the impacts of abiotic factors on the distributional patterns and abundance of boreal mesocarnivores and evaluated methods commonly used to estimate density and occupancy. I conducted non-invasive winter surveys of coyotes (Canis latrans), red foxes (Vulpes vulpes), lynx (Lynx canadensis), wolverines (Gulo gulo), and marten (Martes americana) in the interior of Alaska. Overall, mesocarnivore occupancy was most strongly influenced by snow depth and snow compaction as well as habitat type. Canid species used areas with shallow and compact snow while mustelid species used deeper and fluffier snow conditions most often, and lynx used areas with shallow and fluffy snow. Forested habitat types were used most commonly across all mesocarnivores. Prey abundance and the presence of human activity were less influential to mesocarnivore occupancy patterns than snow conditions and habitat, suggesting that a changing boreal climate may have a strong, direct influence on the distribution of these mesocarnivores. Estimating current population status of these species is particularly important in areas that are most susceptible to change, and I used two occupancy-modeling methods and a spatially explicit capture-recapture density estimator to assess coyote and red fox populations. Occupancy and density are two distinct parameters, however, the simplicity of occupancy (both in terms of sampling and modeling) makes its use as a proxy for density an appealing possibility. I found that occupancy and density estimates were not consistent and led to significantly different inference about coyote and red fox populations. Coyotes and red fox occupancy probabilities were similar to each other (range: 0.34-0.48), but red fox density was nearly four times greater than coyote density. While both methods produced precise parameter estimates, top-ranking occupancy and density models were different. I suggest that managers use caution when using occupancy as a proxy for density. Occupancy is best used to address questions related to spatial use, while density should be used to assess population size. Together, these findings provide valuable information about the current status of a previously unstudied mesocarnivore community and provide managers with useful insight into study design and management actions that should be taken to best protect this guild.
• #### Non-linear dynamics of marine ecosystem models

Despite a rapid trend towards more realistic Nutrient-Phytoplankton-Zooplankton (NPZ) models, in which zooplankton are presented with multiple nutritional resources, investigations into the fundamental dynamics of these newer models have been limited. The objective of this dissertation was to explore the dynamical behavior of such NPZ models parameterized for the coastal Gulf of Alaska. With alternative stationary forcing regimes and zooplankton grazing functions, the dynamics of one-dimensional NPZ models were investigated for a range of specific predation rates (h) and predation exponents (q), which together define the form of the predation (model closure) function. Oscillations in state variables are shown to be an intrinsic property of the NPZ models, not dependent on variable seasonal forcing for their existence. Increasing mixed layer diffusivity or reducing mixed layer depth increased model excitability; it is hypothesized that this is due to the resultant increase in flux of utilizable nutrient. Model behavior was also strongly influenced by the form of both the grazing and predation functions. For all of the grazing functions implemented, Hopf bifurcations, where the form of the solution transitioned between steady equilibrium and periodic limit cycles, persisted across the q-h parameter space. Regardless of the values of h and q, with some forms of the grazing function steady equilibrium solutions that simultaneously comprised non-zero concentrations for all model components could not be found. The inclusion of sinking detritus in the model had important implications for the composition and excitability of model solutions, generally increasing the region of q-h space for which oscillatory solutions were found. Therefore, in order to correctly simulate the depth-explicit concentrations of model components, or to have an accurate understanding of the potential excitability of the system, inclusion of this component is valuable. This dissertation highlights the importance of understanding the potential impact that choice of functional response may have on the intrinsic oscillatory nature of a model prior to interpreting results from coupled bio-physical simulations. As we come to rely more on ecosystem models as a tool to interpret marine ecosystem functionality it will be important to improve our understanding of the non-linear behavior inherent in these models.
• #### Non-Normality In Scalar Delay Differential Equations

Analysis of stability for delay differential equations (DDEs) is a tool in a variety of fields such as nonlinear dynamics in physics, biology, and chemistry, engineering and pure mathematics. Stability analysis is based primarily on the eigenvalues of a discretized system. Situations exist in which practical and numerical results may not match expected stability inferred from such approaches. The reasons and mechanisms for this behavior can be related to the eigenvectors associated with the eigenvalues. When the operator associated to a linear (or linearized) DDE is significantly non-normal, the stability analysis must be adapted as demonstrated here. Example DDEs are shown to have solutions which exhibit transient growth not accounted for by eigenvalues alone. Pseudospectra are computed and related to transient growth.
• #### Nonlinear analysis of the ground-based magnetometer network

When the first magnetometer was created by Frederick Gauss in 1833, scientists gained a powerful tool for studying the structure, dynamics, and strength of the Earth's magnetic field: the magnetosphere. Since Gauss' time, the world's scientific community has established ground-based magnetometer stations around the globe in an effort to study local and global perturbations and patterns of the Earth's magnetic field. The main focus of this network has been monitoring the magnetic flux and impact from the Sun's constant outflow of radiation and particles known as the solar wind, as well as its more violent eruptive events. There has been little work, by comparison, into the signals and correlations within the network itself. Since the Earth's field can roughly be mapped to a dipole and disturbances often have a large scale structure, one can surmise there should be some correlation between stations based on their relative positions to one another. What that correlation is or represents is not clear. To investigate this possible correlation and its nature, a set of nonlinear analytic methods were conducted on magnetic data collected from stations scattered across North America over an 18 year period. The analysis was focused on searching for spatial and temporal correlations of nonperiodic signals in the magnetometer network. The findings from that analysis suggest there exist nonlocal correlations between stations that are dependent on position, which could be useful in the development of a space weather risk assessment.