Models and theoretical predictions suggest that subtropical continents will dry as a result of anthropogenic warming, with impacts on water resources and ecosystems. However, geologic evidence from past warm periods like the Pliocene document wetter conditions across the subtropics, at odds with theoretical expectations. In this talk, I show…

Ocean warming is considered the most severe threat to coral reefs. Increasing duration and frequency of marine heat waves over the last few decades have led to large-scale coral bleaching and death, and hence the loss of diverse and productive coral reefs around the world. However, not all corals are equally susceptible to heat stress and it is…

Interfacial water structure is key to diverse chemical and physical processes, including many of environmental and geochemical relevance.  It can be probed by vibrational sum-frequency generation (vSFG) spectroscopy as well as ultrafast time-resolved vSFG.  However, a more complete microscopic understanding requires additional…

Abstract

Metals such as Fe, Mn, Co, and Cu are critical micronutrients for life, yet exist at trace concentrations in modern, oxygenated seawater. Low availability of these trace metals in the illuminated surface ocean can limit the growth of phytoplankton, which serve as the base of the marine food chain. As a result…

Cancer cells have the ability to use 15N-depleted N by-products as ammonium (NH4) as a source of N [1]. This recycling of a normally toxic waste product has been hypothesized to result in a measurably lower 15N/14N of tumors relative to the surrounding heathy tissue, in which low-15N metabolic N is not recycled but rather released to the…

Abstract:

Carbonate minerals formed in ancient lakes are a key archive of terrestrial climate and atmospheric chemistry. However, many carbonate facies form in alkaline lakes, and each encode unique formation processes in their textures, chemistry, and isotopic signatures. Which carbonate facies best reconstruct hydroclimate? Which…

The study of organism-scale dynamics allows for more accurate estimates of key ecological processes. For instance, predator-prey interactions drive energy and material transfer through intermediate levels of food webs. Predators such as cnidarian jellyfishes act as trophic links between primary productivity and large marine animals, and…

The ocean modulates the response of Earth’s climate to forcing by transporting and storing large quantities of heat and carbon. Because the ocean’s transport pathways are dependent upon the position of the continents, it is thought that past changes in ocean gateways may have had an outsize impact on Earth’s climate evolution. However, pinning…

Microbes play a major role in the ocean carbon cycle. Understanding their metabolism will be critical for improving our capacity to predict ocean processes as global temperatures rise and the climate changes. Theory predicts that respiration is more sensitive to increases in temperature than photosynthesis and that cell size tends to decrease…

Glaciers have covered ~10-30 % of land surface over the past 100,000 years and are sensitive barometers of climatic change, yet are rarely considering in conceptual models of global biogeochemical cycles. For example, textbooks illustrating river catchment fluxes of solute and sediment to the ocean regularly display ice sheets (continental…