Earth’s climate is characterized by persistent westerly jets (eastward flow) in the upper troposphere, located in the mid-latitudes of the Northern and Southern Hemisphere, which are associated locally with strong weather systems. The location of these jets is of paramount importance to human societies, as these are collocated with maximum in precipitation rates and surface winds in the extratropical regions.
In their recent Science article, Marcott and colleagues present a reconstruction of Earth’s mean surface temperature over the last 11,300 years – the Holocene. Why is this important? It is the most comprehensive and inclusive reconstruction to date from which to assess how novel our current temperatures are compared with those in the recent geologic past. In other words, are we experiencing average temperatures that are essentially unprecedented over this timeframe?
Respiration by plants and microorganisms is primarily responsible for mediating carbon exchanges between the biosphere and atmosphere. Climate warming has the potential to influence the activity of these organisms, altering the exchanges between carbon pools. Traditionally, the respiratory release of CO2 into the atmosphere is thought to be more temperature-sensitive than photosynthesis (carbon fixation), generating a positive climate-ecosystem carbon feedback with the potential to accelerate climate warming by up to 1.4 times.
Earth’s climate system includes several patterns of climate variability at the hemispheric scale. One of the best known of these is the El-Nino/Southern Oscillation, which influences weather across much of the globe. Another important feature of the climate system is the Southern Annular Mode (also known as the Antarctic Ocean Oscillation), which is an index of the pressure gradient between the mid- and high-latitudes in the Southern Hemisphere. Over the last few decades, the dominance of the positive phase of the Southern Annular Mode has been increasing.
Methane, a greenhouse gas second in importance only to carbon dioxide, has built up rapidly in the atmosphere since the Industrial Revolution due to human emissions. It was believed that prior to the 19th century,
YCEI develops interdisciplinary Research Initiatives that integrate faculty, postdoctoral fellows, and graduate students to address pressing issues in Climate and Energy. Each Research Initiative is organized by a team of faculty and promotes solutions through the funding of collaborative research, as well as workshops and symposia that feature national and international experts. Our Research Initiatives include: