Current and ongoing:

Colorado River near San Luis Bridge

Colorado River near San Luis Bridge

CO-PI NSF-RAPID: Colorado River Pulse 2014

Collaborators:  Tom Bianchi, (Lead-University of Florida); Peter Raymond (Yale School of Forestry and Environmental Studies), Karl Flessa (University of Arizona)

A new addition to the 1944 U.S.-Mexico Water Treaty between the United States and Mexico (Minute 319) was signed in late 2012. (International Boundary and Water Commission, 2012) that will allow for greater sharing of water from the Colorado River (Flessa et al., 2013). This agreement also calls for a flooding event, planned for from March 2014 to May 2014, whereby 130 m3 of water will be released into the dry Colorado River channel in Mexico. While only small amounts of water have entered the delta since 2000, and some moderate flooding events occurred in the late 1990s, this region has not experienced natural flow rates and spring floods since prior to dam building in the 1930s. While there have been a few pulse release experiments of this type (e.g., Rio Grande and Truckee Rivers) much of the previous post-pulse research to date has focused on sediment transport and the response of riparian zone communities. Here will examine how rapid mobilization of carbon and greenhouse gasses in newly flooded sediments and soils, affect river-carbon composition and fluxes (land/ocean and land/atmosphere), after being isolated from an active floodplain. Here we posit that during a flow restoration pulse, dissolved organic and inorganic carbon (DOC/DIC) and greenhouse gasses (CH4, CO2, N2O), previously stored as inactive pools in the dry floodplain will enter the modern carbon and greenhouse gas cycles. This is particularly important in light of possible increases in the occurrence of natural flooding events associated with climate change. It is also an important study in terms of understanding the unintended consequences of such ecosystem restoration efforts.

 

The Dalles - Tailwater site, Oregon

The Dalles - Tailwater site, Oregon

Lead - U.S. Geological Survey Greenhouse gas monitoring  - Columbia River, US

Collaborators: Rob Striegl (USGS-NRP, Boulder), Mark Dornblaser (NRP), John Crawford (NRP).

Partners: Chauncey Anderson and Heather Bragg, USGS Oregon Water Science Center, (OR-WSC)

There is a need for systematic field measurements that concentrate on direct measurement of the spatial and temporal distributions of gas transfer velocity (k) and gas concentration gradient (ΔC), for dissolved carbon dioxide (CO2) and methane (CH4) in natural waters.  Previous research as part of the USGS LandCarbon program has identified the Pacific Northwest (PNW) as a critical region within the conterminous US to address this information gap. Current LandCarbon estimates suggest that the PNW has the largest areal fluxes of CO2 from streams and rivers, driven largely by the high CO2 exchange velocities due to the steep terrain.  Additionally, the Western Cascades have been identified as vulnerable to climate change.  Earlier snowmelt is predicted to shift peak river discharge to occur 20-40 days earlier, in additional to significantly more rain on snow events – altering the biogeochemistry of local alpine watersheds with the consequences on both terrestrial and aquatic carbon cycling largely unknown.  This research will lead to the development of a comprehensive assessment of the seasonality of aquatic carbon biogeochemistry within the Columbia River Basin

 

Aquatic Carbon Efflux for the conterminous US

Aquatic Carbon Efflux for the conterminous US

USGS - LandCarbon Program

Collaborators: Rob Striegl (Lead - USGS - NRP), Sarah Stackpoole (USGS - NRP), David Clow (USGS - Colorado Water Science Center), Edward Stets (USGS-NRP), Zhiliang Zhu (USGS - NRP), David D'Amore (USFS - PNW Research Station), David McGuire (USGS/UA Fairbanks) among many others.

With the U.S. Geological Survey, and the national ‘LandCarbon’ program, we are running a first of its kind large-scale field campaign to physically take measurements of organic and inorganic carbon, methane, and nitrous oxide fluxes from streams and rivers across the US.  The LandCarbon program is designed to assess the carbon sequestration potential and greenhouse gas fluxes from natural ecosystems across the US.  Field data from the summer of 2012 suggests that CO2 and CH4 fluxes from aquatic systems are extremely variable and are influenced by short-term events, where streams can release large fluxes of carbon after intense precipitation. Field measurements will critically improve the results of the national assessment of streams and river carbon fluxes that I have previously completed, as well as provide modern data that matches with the current suite of remote sensing data products.  

Currently, we are developing the first integration of aquatic carbon cycling with terrestrial ecosystem modeling for the state of Alaska under the LandCarbon program. We are  working collaboratively with universities and research institutions, to predict the effects of climate change on regional water and carbon cycles in boreal and arctic systems through integrated remote sensing and ecosystem modeling.  This effort may be expanded across other biomes within the US to develop a unified approach to estimate US carbon and greenhouse fluxes from natural systems.