Jacqueline J. Shinker

Visualizing Spatial Heterogeneity of Western U.S. Climate Variability

Abstract Monthly climatologies (1971–2000 monthly averages) for stations in the western United States, obtained from the NOAA/National Climatic Data Center (NCDC), are used to illustrate the spatial variations in the annual cycle of climate. Animated map sequences of temperature and precipitation, their average, intermonthly changes, and the local timing of annual maxima or minima provide a comprehensive spatiotemporal baseline of regional climate. The animated maps illustrate three scales of variation: 1) broadscale patterns related to the annual cycle of insolation and hemispheric-scale atmospheric circulation features; 2) mesoscale patterns related to location on the continent and the influence of specific regional circulation features like those associated with the North American monsoon; and 3) smaller-scale spatial variations, related to the mediation by local physiography of the influence of large-scale circulation. Although most western U.S. stations have temperature maxima in July, a delay occurs...

Climatic Shifts in the Availability of Contested Waters: A Long-Term Perspective from the Headwaters of the North Platte River

Early summer snowmelt from mountains in northern Colorado and southeastern Wyoming supplies the North Platte River, supporting nationally important agriculture, energy production, and urban development. Repeated decisions from the U.S. Supreme Court have fully apportioned Platte River waters among Colorado, Wyoming, and Nebraska, underscoring societal strains on this system. Now, climate change threatens the regional allocation of water. Tree-ring records indicate that past centuries contained multidecadal “megadroughts” far more severe than those of the historic period. However, the potential for even more persistent droughts, as the result of climate change, is poorly known. We document and evaluate the severity of recent and prehistoric droughts via a combination of data sources: modern temperature, precipitation, and stream gauge data; evidence of low lake-level stands; and related estimates of past hydroclimate change. Modern climate and stream data show an increase in spring temperatures of 2.21°C since 1916, an increase in the frequency of peak spring runoff before 1 May, and a reduction in winter precipitation. Lakes, however, that have only experienced minor hydrologic changes historically were desiccated during prehistoric dry periods during the past 12,000 years. Prehistoric lake shorelines indicate that water supplies were substantially reduced over centuries and millennia, such as from > 8,000 to < 5,000 years before present. The magnitude of these droughts likely also resulted in ephemeral river flows and thus indicates the potential for persistent shifts in regional hydrology. Such shifts should, therefore, be considered as part of long-term economic and legal planning.

Visualizing the Large-Scale Patterns of ENSO-Related Climate Anomalies in North America

Abstract The variations of large-scale climatic controls and surface responses through the annual cycle during strong positive (El Nino) and negative (La Nina) phase ENSO events are analyzed to assess the within-year and among-year variations of climate anomalies. Data from the NCEP–NCAR reanalysis project are presented as small-multiple maps to illustrate the spatial and temporal variability in North American climate associated with extreme phases of ENSO. Temperature, mean sea level pressure, 500-mb geopotential heights, and 850-mb specific humidity have composite-anomaly patterns that exhibit the greatest degree of spatial and temporal coherence. In general, the composite-anomaly patterns for El Nino and La Nina events are of opposite sign, with stronger, more spatially coherent anomalies occurring during El Nino events than during La Nina events. However, the strength and coherency of the precipitation anomaly patterns are reduced in the interior intermountain west during both positive and negative ph...

Using High-Resolution Reanalysis Data to Explore Localized Western North America Hydroclimate Relationships with ENSO

AbstractMany studies have used observational data to explore associations between El Nino–Southern Oscillation (ENSO) and western North America (NA) hydroclimate at regional spatial scales. However, relationships between tropical Pacific sea surface temperature (SST) variability and western NA hydroclimate at local scales using reanalysis data are less understood. Here, the current understanding of relationships between large-scale tropical Pacific SST variability and western NA hydroclimate is extended to localized headwaters. To accomplish this, high-resolution reanalysis data (i.e., monthly mean surface precipitation rate, 2-m temperature, 850-mb specific humidity, and 500-mb omega) were used for gridpoint correlation analyses with Nino-3.4 SST and El Nino Modoki indices. Reanalysis time series data were provided by the National Centers for Environmental Prediction North American Regional Reanalysis (NARR) product. To validate the accuracy of NARR surface data, observational Livneh precipitation and te...

Investigation of interaction modalities designed for immersive visualizations using commodity devices in the classroom

In this paper we present initial research of the investigation in the design collaborative interaction modalities for classroom-based immersive visualizations of 3D spatial data, with an initial implementation for geo-spatial applications. Additionally we allowed some pilot testing to gain a sense of our design decisions and where user error might occur. Valuable feedback will allow us to redesign and refine implementation for a much more formal long-term evaluation of the system. Initial results give indications that our interaction modalities may facilitate teaching and learning, but the use of devices should be different for user type.