Reconstructing past climatic impacts on hydrologic and soil systems
To formulate rational environmental policies for the future we must understand the past. Linking conditions in modern and ancient systems allows us to assess future and paleoenvironmental responses to climate.
Jay Banner’s laboratory explores: (1) the application of modern hydrologic, geologic and soil conditions, determined by monitoring, to Pleistocene and Holocene mineral deposits in caves (speleothems; Pape et al. 2010); and (2) the impacts of urbanization on streamwater quality through novel tracers (Christian et al., 2011). Speleothems can be precisely dated and incorporate tracers that preserve decadal to millennial-scale records of water quality and quantity (Banner et al., 2007). REU researchers can investigate: (1) the physical and chemical parameters of cave hydrology and meteorology and how speleothems reflect past climate, or (2) the natural and anthropogenic sources of dissolved ions to streams. They will learn methods for low-contamination field and clean-room sampling and mass spectrometer analysis of water, soil, and rock. Speleothem studies in Texas afford a regional analysis of paleorainfall across abrupt climate change events during the late Pleistocene, in a region of particular climate sensitivity (Feng et al., 2014a). Studies on Guam can help define paleorainfall and present aquifer conditions near a growing U.S. military base on a water-limited (although not arid) Pacific island.
Climate Change Impacts on Ecosystems, Hydrologic Systems & Public Health
Earth’s biological systems are changing in response to shifts in temperature and precipitation patterns and amounts. REU researchers will study the ecological interplay of symbionts, natural and invasive species, and fire with changes or gradients in climate.
Joshua Apte’s research group focuses on the intersection of cities, air quality, human health, and climate change mitigation. REU students will be mentored on one of several projects that explore the relationship between urban form, energy, and human air pollution exposures. Current research projects in the Apte group include high-resolution mapping of urban air quality using low-cost sensors and highly instrumented vehicles, interpretation of satellite remote sensing datasets on regional air quality, and field-based investigations of the relationship between urban form and human air pollution exposures.
Bayani Cardenas’ research group studies hydrologic processes. His group will mentor an REU student interested in the interactions of groundwater with surface water and how these interactions are impacted by warming or human activities. A first potential project is focused on laboratory flume experiments designed to analyze the effects of warming of rivers and their underlying sediment on biogeochemical processes. Another potential project will involve extensive field work on the Lower Colorado River where there are various on-going projects analyzing the downstream effects of dams on river and groundwater quality.
Kerry Cook’s project objective is to use observations of the developing global warming signal to better understand sensitivity and resilience within the climate system to climate forcing. The project will focus on the tropical and subtropical climate system’s response to tropical/subtropical forcing, and on regional-scale climate processes. Are some regions more resilient to change under greenhouse gas forcing, while other regions more vulnerable to the same forcing? If so, why? What regional physical processes operate to produce or resist change? Research activities will combine analysis of observations and existing global and/or regional climate model output to improve our fundamental understanding of how the tropical/subtropical climate responds to tropical forcing for a specified region identified as being resilient and/or vulnerable.
Norma Fowler’s research group studies the effects of wildfire and the use of prescribed fires to reduce the risk of wildfires. As the climate of the Western US warms, plant transpiration rates will rise, which by itself will increase drought stress and lower plant moisture content. It is now thought likely that annual rainfall will decrease in this region. Both warming and precipitation decreases will increase the likelihood and intensity of wildfire. REU students may participate in one or both of two projects. (1) A study of recovery trajectories after 2011 wildfires in the Lost Pines region of central Texas. Of particular interest is the post-fire balance between loblolly pine (Pinus taeda), the former dominant, and sand post oak (Quercus margaretta), which may become dominant. (2) A study of prescribed fire to control an invasive grass, King Ranch bluestem (Bothriochloa ischaemum) and reduce the danger of wildfires.
Rob Plowes at Brackenridge Field Laboratory (BFL) mentors students either working in the Invasive Species Research Program or on climate related ecological studies at the field station. The Invasive Species lab researches the causes and consequences of biological invasions, and tests opportunities for biological control of pest species applicable to the arid western and southern parts of Texas where climate plays a limiting role in species distributions. In other studies at the BFL field station, we follow several biological systems across time to determine relationships with weather patterns and environmental gradients. We also have two DroughtNet installations, part of a global group that studies vegetation responses to climate change.
Energy-water nexus and infrastructure adaptations
Climate change and increasing demand combine to exert pressure on hydrologic systems, many of which are already regulated for human needs such as drinking water supply, agriculture, energy production and energy use.
Mary Jo Kirisits’ research group will mentor REU students in one of several ongoing drinking-water projects. The first investigates the effect of climate change on water treatment practice at small drinking-water systems. The objective is to develop guidelines for small-system operators to account for temperature changes in their treatment systems. The second project involves rainwater harvesting (where rainwater is collected and treated for potable or non-potable use), which is becoming common practice in semi-arid regions. Our aim is to understand the role of the storage cistern in changing harvested rainwater quality. The third project involves emerging biological drinking water treatment systems and the goal is to decrease the energy and associated greenhouse gas footprint of centralized water treatment.
Lynn Katz, Kerry Kinney, Jay Banner, and Daniel Breecker are engaged in two research projects focused on the reuse of water in semi-arid regions that are suitable for REU researchers. The first project is on the reuse of water from hydraulic fracking and oil production. This project involves the further development of a patented hydrophobic membrane technology for oil/water separation from produced, frac, oil spill and biofuel production waters. REU students will evaluate the membrane operation for a particular set of waters and operating parameters to support the development of a predictive model for this system. The second project is a collaboration with Pecan Street, a 501(c)(3) research and development organization focused on collecting data on consumer energy and water consumption. Students will be sampling and analyzing rainwater and air conditioning condensate at Pecan Street metered homes to assess the reuse of this water in semi-arid to arid climates.
Michael Webber’s research group analyzes energy and environmental problems at the intersection of engineering, science and public policy. The group emphasizes interdisciplinary issues by recognizing that sustainable solutions must also address environmental and public policy issues. Students in the Webber group complete research on the energy-water nexus, energy systems modeling, and alternative transportation fuels. Each of these topics can be linked to the impact of climate change and its effect on arid regions. As an example, researchers recently investigated the impact that rising water temperatures and water scarcity will have on power plants to maintain cooling performance. Undergraduate students will collaborate closely with mentors, attend group meetings, collect data, complete technical analysis, and possibly work on scientific communication projects such as educational videos.
Charlie Werth’s research group will mentor REU students on research related to geological carbon sequestration. This technology is used to capture carbon dioxide emissions from stationary power sources and inject it into deep geological formations for long-term storage and climate change mitigation. The objectives of the project are to determine in what phase carbon dioxide is stored after injection, what chemical reactions the injected carbon dioxide promotes in the formation, and how these reactions affect formation permeability and geomechanical properties. Formation permeability is important because it controls the ability to inject carbon dioxide over long time periods. Formation geomechanical properties are important because they determine whether carbon dioxide injection is more or less likely to induce seismic activity (i.e., earthquakes). REU students will work with and be mentored by a graduate student. They will work in the laboratory to perform experiments to quantify the aforementioned reservoir characteristics, and analyze their results using cutting edge analytical models.