SITES
Observatories & Infrastructure
Southern Sierra (CA) | Jemez River-Catalina Mtns (NM/AZ) | Boulder Creek (CO)
Shale Hills (PA & more) | Christina River (DE/PA) | Luquillo (PR)
SIX CRITICAL ZONE OBSERVATORIES
The U.S. National CZO Program is centered on six observatories located in differing climatic and physiographic environments, from California to Puerto Rico. These CZOs work with their European counterpart observatories funded by the European Commission (see SoilTrEC).
Each U.S. CZO is working toward a common infrastructure while also establishing additional resources that advance their unique strengths. All are supported by the US National Science Foundation (NSF), Geoscience Directorate, Earth Science Division. And all work together with partnering organizations to share existing infrastructure built with other programs.
WHAT IS A CZO?
The U.S. CZOs are working together to help determine how the Critical Zone operates and evolves - including a predictive ability for how it will respond to projected changes in climate and land use.
Each Critical Zone Observatory works on overarching shared CZO goals but also focuses on aspects of Critical Zone science that fit the strengths of its investigators and its physical setting. Each CZO consists of a series of field sites within a watershed-scale field area. The sites are instrumented for a variety of hydrogeochemical measurements as well as sampled for soil, canopy and bedrock materials.
Each CZO is run by a team of cross-disciplinary scientists who have expertise in fields including hydrology, geochemistry, geomorphology, pedology, ecology and climatology. Participants also include postdocs, grad students, undergrad students, and interested members of the general public.
The research at each CZO includes field and theoretical approaches, including modeling studies. Each CZO also emphasizes education and outreach, including students from K-12 to undergraduate and graduate levels.
A COMMON INFRASTRUCTURE
The U.S. National CZO program is working toward a common infrastructure that enables measurement of whole-watershed energy and mass balances for a variety of climatic and geologic settings. Such an integrated data/measurement system allows us to further our theoretical framework, constrain our conceptual and coupled systems models, and test model-generated hypotheses across the CZO Network.
Such infrastructure permits measurement of:
1) Fluxes across the watershed boundary.
2) Fluxes between major reservoirs and changes in their storage.
With a focus on Energy, Water, Carbon, Sediments, Nutrients, and Other Materials.
The resources required to deploy and manage such an integrated sensor and data system are substantial, with the consequence that very few watersheds have a complete data suite to close the mass and energy balances. Fortunately, the CZO program can feasibly close the balances of multiple watersheds through incremental additions to existing CZO infrastructure.
Such infrastructure can enable better predictions of how the Critical Zone will respond to climate and land-use changes as well as help answer key scientific questions such as the missing continental carbon sink.
For more details,
read "Future Directions for Critical Zone Observatory (CZO) Science" (PDF)>>
For further information on infrastructure planning, email Tim White >>
THE OBSERVATORIES
BOULDER CREEK CZO
Colorado
"We study how EROSION and WEATHERING control Critical Zone architecture and evolution, concentrating on slope, climate, ecosystems, and rock properties."
- What is the legacy of climate and geologic history in critical zone architecture?
- How are the dynamics of key interfaces within critical zone governed?
- What are the feedbacks between hydrologic and ecological processes and critical zone evolution?
- How do landscape position, slope aspect, microclimate and rock properties control the evolution of the critical zone?
University of Colorado at Boulder and Institute of Arctic & Alpine Research (INSTAAR).
PI: Suzanne Anderson.
Our CZO spans from the Continental Divide (4120 m) in the Front Range of the Rockies to the western edge of the Plains (1480 m). Our research sites have large differences in elevation, climate, geologic history, and weathering regime.
CHRISTINA RIVER BASIN CZO
Delaware/Pennsylvania
"We integrate knowledge of mineral and carbon cycles to quantify human impact on Critical Zone CARBON SEQUESTRATION - from uplands to coastal zone."
- Are mineral and carbon mixing processes rate-limiting to watershed-scale carbon sequestration, chemical weathering and soil production?
- Do humans accelerate carbon-mineral mixing rates, and is this significant to local, regional and global budgets?
University of Delaware, Delaware Environmental Institute, Stroud Water Research Center.
PIs: Donald Sparks & Anthony Aufdenkamp.
Our CZO is located in the Piedmont and Atlantic Coastal Plain which provides drinking water to a million people in Delaware and Pennsylvania. Our CZO coastal component explores the effects of salinity and redox gradients of carbon mineralization and iron mobilization.
JEMEZ RIVER & SANTA CATALINA MTNS CZO
New Mexico/Arizona
"We focus on CRITICAL ZONE INTERACTIONS that help drive models of carbon/water cycling, arid/semi-arid ecohydrology, and landscape evolution."
- How does variability in energy input and related mass flux influence critical zone structure and function?
- How do feedbacks between critical zone structure and the cycling of water and carbon alter short-term hydrologic response and long-term landscape evolution?
University of Arizona, Biosphere 2.
PIs: Jon Chorover and Peter Troch.
Our CZO comprises elevation (climate) gradients on rhyolite, granite and schist in northern New Mexico and Southern Arizona. Our research is especially pertinent to climate variations of arid and semi-arid systems.
LUQUILLO CZO
Puerto Rico
"We study how Critical Zone processes and water balances differ in landscapes with CONTRASTING BEDROCK but similar climatic and environmental histories."
- How does saprolite advance vary with regolith thickness and landscape position?
- How are soil carbon, surface redox, and plant nutrient cycling affected by bedrock lithology, landscape position, and climate?
- How does bedrock lithology influence delivery of sediment, water and solutes across the landscapes?
- How do riparian zones and the stratigraphy of coastal sediments vary with lithology, climate, and basin size?
University of Pennsylvania.
PI: Fred Scatena.
SOUTHERN SIERRA CZO
California
"We investigate how the WATER CYCLE drives Critical Zone processes, focusing on water balance, nutrient cycling, and weathering across the rain-snow transition."
- How does landscape variability control how soil moisture, evapotranspiration and streamflow respond to snowmelt and rainfall?
- How is soil moisture linked to topographic variability, soil formation and weathering?
- What physiological mechanisms are controlling how vegetation distribution and function vary with climate?
- How do vegetation attributes influence cycling of water, energy, and CO2?
- What is the link between soil heterogeneity, water fluxes and nutrient availability?
University of California, Merced. Sierra Nevada Research Institute.
PI: Roger Bales.
SUSQUEHANNA SHALE HILLS CZO
Pennsylvania & more
"We emphasize QUANTITATIVE PREDICTION of Critical Zone creation and structure, focusing on pathways and rates of water, solutes, and sediments."
- How does water sculpt a landscape on shale bedrock?
- What controls the hydrologic and elemental budgets of the catchment?
- What are the rates and mechanisms of important hydrological, ecological, and geochemical processes?
Penn State.
PI: Christopher Duffy.
Our CZO is a forested, first-order catchment on shale bedrock in a temperate climate. Our research promotes understanding of how the forested catchment evolves over multiple timescales ranging from the meteorological to the geological.
INTERACTIVE MAP
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View National CZO sites in a larger map