Global warming simulations suggest that wet regions (where precipitation exceeds evaporation) will become wetter and dry regions drier by the end of the 21st century (e.g., Held and Soden 2006), with larger contrasts expected between dry and wet seasons (Chou et al., 2013). This ‘rich-get-richer’ behavior is consistent with a large increase in the moisture content of atmosphere, leading to enhanced horizontal moisture fluxes across regions.
(CNN) Most of us can appreciate that the world is an ancient place and that a lot has changed in the almost 4.6 billion years since it took its shape.
It’s not easy to have a feel for the amount of time that has passed, but grappling with deep time helps you understand why an atmospheric carbon dioxide concentration (CO2) of 400 parts per million (ppm) is meaningful.
Deep time is geologic time and the scale needed to fathom the evolution of life, mountains, oceans, and Earth’s climate.
Subpolar ocean gyres (large systems of rotating ocean currents) in the Southern Hemisphere are found poleward of the Antarctic Circumpolar Current near the Weddell and Ross Sea. They play a key role in the global energy and water budgets. These gyres are crucial for the transport of heat around the planet, as well as the distribution of nutrients and marine species. Thus, the subpolar gyres are important in the mixing and transformation of water masses. In a recent study, Dr.
We are currently on the eve of a world with ~400 parts per million (ppm) of atmospheric carbon dioxide (398.35 ppm as of May 2nd, Mauna Loa Observatory). How global climate, sea-level and ecosystems will respond to this level of CO2 level is a key question for global change research. Recently, Foster and Rohling (2013) looked back into Earth’s geological history to explore the relationship between atmospheric CO2 and global sea-level.
Pearson and colleagues (2013) recently showed how the expansion of shrubs and trees in the Arctic could promote even further warming through a series of postive feedbacks. Their modeling study that estimates the future composition and distribution of vegetation across the Arctic indicated shrubs and trees could expand by as much as 50% over current levels by 2050.
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.
Venkatachalam Ramaswamy, Director, Geophysical Fluids Laboratory, Princeton University, delivers a lecture entitled, “Understanding Trends and Extremes in Climate”.