News & Events
Atmospheric mercury measurements in California: evaluations of point source emissions, speciation, and wet deposition through fog
Atmospheric mercury fluxes to the the earth's surface through wet and dry deposition are important in determining the availability of mercury (Hg) to aquatic and terrestrial ecosystems, where mercury can be bioconcentrated in the food web and poses a health risk for humans who consume fish. Hg can exist in several forms in the atmosphere, including gaseous elemental, gaseous oxidized, airborne particulate, dissolved aqueous, particulate aqueous, and monomethyl Hg in both gaseous and aqueous phases. Quantifying the wet and dry deposition fluxes of Hg has important implication
Providing realistic projections of ice sheet response in a warming climate and estimating their contribution to sea level rise is a major challenge for the glaciology community. To better explain the ongoing changes observed on the polar ice sheets and be able to project their evolution, treatment of grounding line and ice front dynamics, coupling with other components of the Earth system and numerical ice sheet models should be improved.
In situ observations, remote sensing and numerical models all indicate that the Southern Ocean is populated by many coherent structures. In particular, variations in water mass properties within the Antarctic Circumpolar Current (ACC) are concentrated in multiple coherent fronts, which are associated with strong zonal flows, or jets. Temporal and spatial variations in these fronts play a key role in regulating the Southern Ocean's meridional overturning circulation.
The characteristic of El Niño-Southern Oscillation (ENSO) has been changing since it was appeared in the earth. In particular, the modulation of ENSO was believed to relate to decadal-to-interdecadal changes in the mean climate state of the tropical Pacific. The mean state can modify ENSO amplitude, especially when the mean state changes near the Hopf-bifurcation. This indeed occurred between the pre-1980s and the post-1980s. Here, we introduce both the linear and the nonlinearity processes that give birth to the decadal modulation of ENSO.
It is known for a long time that the free water surface is deformed by underlying density anomalies. Measurements of these anomalies, done by means of gravimeters and more recently by observing perturbations of geodetic satellites, give access to the geoid surface from which altitudes are defined.
The common belief that trees are efficient filters of airborne particulates has played a prominent role in determining the ecosystem service value of trees and has led to policies encouraging urban tree planting to improve human health. In order to develop a rigorous understanding of deposition kinetics that could inform the design of vegetative buffers, we developed a wind tunnel method to quantify real time deposition while varying species, leaf area, wind speed, and particle size under controlled, replicated experiments.
The Greenland and Antarctic ice sheets are losing mass at an accelerating pace, according to a new NASA-funded satellite study. The findings of the study -- the longest to date of changes in polar ice sheet mass -- suggest these ice sheets are overtaking ice loss from Earth's mountain glaciers and ice caps to become the dominant contributor to global sea level rise, much sooner than model forecasts have predicted.
The results of the study will be published this month in Geophysical Research Letters, a journal of the American Geophysical Union.
The Dean of the Division of Undergraduate Education, the TLTC, and the Senate Council on Student Experience come together annually to recognize teaching excellence in undergraduate teaching at the annual Celebration of Teaching.
The event takes place each year during the last week in May and serves to acknowledge the teaching excellence of Senate faculty, lecturers, and teaching assistants. There are two categories of awards: Campuswide Awards (competitive) and School Honorees.
In many ways, the human species is unique, but in others entirely predictable. On the one hand, the human species is clearly the most ecologically dominant in Earth history, but on the other, our internal biology is quite unremarkable. So, how did we get to be where we are? To understand how the human species came to be so dominant requires understanding how human ecology evolved from subsistence-level hunting and gathering societies, to industrialized market economies.