I work in the field of land-atmosphere interaction, which is centered on the connection of surface hydrology and meteorology through terrestrial ecosystems. The discipline is organized toward development of a comprehensive theory to describe the exchange of mass (e.g. water and CO2), energy, and momentum between the land and atmosphere over a wide range of spatial and temporal scales. The ultimate goal is to provide the theoretical framework and tools needed to quantify spatially integrated land surface fluxes over large regions of complex terrain from a parsimonious representation of the land surface state. The intended practical outcomes of this effort are: (i) marked improvement in medium-to-long range hydrological and meteorological forecasting, and (ii) improved ability to assess impacts from changing land use or changing atmospheric composition on the water and carbon cycles.
Examples of active projects in my lab include:
Optimal Dynamic Predictions of Semi-Arid Land Cover Change and Implication for Ecosystem Goods and Services,
Funded by NASA's Land Cover Land Use Change Program (2008-2011)
PI: John D. Albertson, Civil and Environmental Engineering, Duke University
Co-I: Silvia Ferrari, Mechanical Engineering and Materials Science, Duke University
Co-I: H. H. (Hank) Shugart, Environmental Sciences, University of Virginia
Co-I: Eric F. Wood, Civil and Environmental Engineering, Princeton University
Project Summary:
This project addresses the sensitivity and adaptability of the African savannas to climate and population changes. The project combines large-scale process models with remotely sensed data to understand past changes and to project future changes. Novel aspects include a large-scale coupling of a hydrological model with a mechanistic vegetation dynamics model, and the assimilation of multiple remote sensing data products for optimal estimates of soil moisture, tree cover, and grass cover. The study is focused on a region with a remarkable range of mean annual precipitation (200 mm to > 1000 mm) and distributions of grass and trees, thus enabling analysis of sensitivity of the savanna structure to climate and human disturbances over a wide range of conditions. The study domain is approximately 7o wide (E-W) and 28o long, running southwest from the Ethiopia-Kenya border (4o N) to the Botswana-South Africa (24o S) border, and covers a total area of approximately 2.4 million km2 (including large parts of Kenya, Tanzania, Malawi, Zambia, Zimbabwe, and Botswana).
Implications of Vegetation Dynamics for Semi-Arid Hydrology:
A Basis for Predicting Climate Impacts on Water Resources
Funding Pending from NSF Hydrologic Sciences (2008-2011)
PI: John D. Albertson, Duke University
Collaborator: Nicola Montaldo, University of Cagliari, Italy
Project Summary:
This project addresses the coupled eco-hydrologic dynamics of semi-arid Mediterranean watersheds, where the surface drinking-water reservoirs depend almost exclusively on overland flow in the rainy season and where the vegetation growth is water limited. The motivation centers on the observed and projected decreases in winter rainfall, stemming from shifts in circulation patterns. Presently, the ability to predict future hydrologic behavior of these systems is limited by gaps in understanding of how changes in the vegetation cover interact with precipitation dynamics to control the hydrological response. This project builds on experimental and modeling studies that the PI and Italian collaborator have been conducting for the past several years on Sardinia, the second largest island in the Mediterranean. This project will expand the existing experimental facilitates to include overland flow experiments to capture the effect of variable grass cover on infiltration and runoff generation. Analysis will be conducted over three overlapping time periods, representing: 1) the intensive field experiment record (~ 5+ years), 2) the satellite record (~ 20+ years), and 3) the streamflow and precipitation record (~ 80 years).
Designing Forest Warming Experiments and Other Interacting Factors
Funded by DOE NICCR (2007-2009)
PI: John D. Albertson
Co-I: Robert Jackson
Project Summary:
Efforts to design and plan so-called warming experiments are frustrated by subtle questions, both with respect to the technical complications of achieving a controlled warming of the free-air column, and with respect to scientific issues of corresponding changes to the humidity regime (e.g. relative humidity and vapor pressure deficit). This project examines the key technological issues related to straight warming experiments and jointly controlled warming-humidity experiments. The project consists of a set of simulated experiments using a state-of-the-art numerical model of turbulent flow and transport in plant canopies. This Large Eddy Simulation (LES) code was developed through DOE support to the PI and has been used extensively at the Duke forest. The project will evaluate a range of technologies for releasing heat (and moisture), related power needs, heat source geometries, and the resulting structure of the modified space-time field of air temperature, relative humidity and vapor-pressure deficit. The project will also examine the impact of the temperature changes on the stability of the local atmosphere and the ultimate impact of this on the turbulent transport characteristics.
I have support for graduate student assistants and for post-docs. Please send an email to me if you are interested in applying for a position.
Last modified: 10 Oct 2008