The goals of our research are twofold.

First,we seek to understand why the ¹⁴C age of marine dissolved organic carbon (DOC) is thousands of years old, despite evidence that most of it is produced in the surface ocean during photosynthesis. Is black carbon, produced on land, a significant source of old oceanic DOC?

The Hydrology & Climate Research Group is focused on modeling and remote sensing of the terrestrial and global water cycles. The work has implications for hydrologic and Earth system modeling, for characterizing water cycle variability across multiple scales, for understanding its interactions in the land-ocean-atmosphere-ice system, and for monitoring changes in freshwater availability in the context of global environmental change. The hydrology group is composed of Ph.D. students, postdoctoral researchers, and occasionally, highly motivated undergraduates.

My research primarily involves the use of geochemical variations preserved in cave-calcite deposits (speleothems) to reconstruct time-series of past environmental changes. A major goal of my research is to improve our understanding of what fundamentally controls speleothem stable isotopic composition and trace-element composition at both short and long timescales (seasonal to glacial-interglacial scale). These proxies are primarily controlled by variations in temperature and/or rainfall at a particular study area, but the specific mechanisms are complicated, incorporating a range of atmospheric, hydrologic, biologic, pedologic, kinetic, crystallographic, and thermodynamic controls. To understand these controls, I combine detailed studies of modern cave systems with studies of fossil speleothems, utilizing a wide range of analytical techniques (e.g. microsampling, analytical chemistry, mass spectrometry, laser ablation, etc.) along with laboratory experiments, rigorous data analysis, and geochemical modeling. Speleothem records can be dated much more precisely than most other paleoclimate archives using U-series methods, and therefore, often provide important information about the relative timing and mechanisms of abrupt climate change. The ultimate goal of my research is to obtain precisely dated, high-resolution, quantitative reconstructions of past variations in rainfall and temperature at a wide range of timescales.

Professor Gudrun Magnusdottir is interested in atmospheric and climate dynamics. In her work she uses observations as well as a hierarchy of numerical models to study dynamical processes in the atmosphere, and climate variability.

One focus of her research centers on investigating feedback mechanisms influencing the unprecedented high-latitude trends in several climate variables over recent decades.

Another focus of her research centers on tropical-extratropical as well as troposphere-stratosphere dynamical interactions.

A third focus centers on the Intertropical Convergence Zone (ITCZ), its variability on different timescales, and what controls it in the climate system.

I am an oceanographer interested in the role of marine biota in global biogeochemical cycles and Earth's climate system. My research focuses on understanding how marine phytoplankton and other ocean biota influence the cycling of key elements (carbon, nitrogen, phosphorus, silicon, iron) in the oceans, and on the biogeochemical links between the ocean, atmosphere, and land through atmospheric transport and riverine runoff.

We are interested in the ocean's role in the climate of the Earth. The ocean plays a determining role in the variability of the climate system on inter-annual to millennial timescales. We use global observations and a hierarchy of ocean models together with advanced computational and mathematical techniques to study the ocean. Our current research is directed in three broad areas:

1. the surface-to-surface transport and ventilation of ocean water masses
2. inter-annual to decadal variability of the ocean's wind-driven circulation
3. global ocean biogeochemical cycles

We seek to improve our understanding of global change in terrestrial ecosystems. We use remote sensing data, atmospheric trace gas observations, field measurements, and models in new ways to study feedbacks between terrestrial ecosystems and climate.

The oceans produce a diverse array of trace gases that affect the chemistry of the atmosphere and the climate system. Our goal is to understand what controls the production, emissions, and atmospheric chemistry of oceanic trace gases. We develop trace gas detectors, collect field data from islands and ships and use computer models to simulate natural processes.

Trumbore uses stable and radioisotopes (especially 14C) to study how the Earth's natural exchanges of carbon among ocean, land and atmosphere are altered by human activity.She is a founding member of the Earth System Science Department at UC Irvine, and a co-director of the WM Keck Carbon Cycle Accelerator Mass Spectrometry Facility at UC Irvine.

In 2001, ESS/CGECR researchers Ellen Druffel, John Southon and Susan Trumbore were awarded $2 million by the W.M. Keck Foundation for the development of an accelerator mass spectrometry (AMS) facility – the Keck-Carbon Cycle AMS facility - for radiocarbon measurements in support of carbon cycle research at University of California, Irvine.

Related Research Group: Santos Research Group