Climate Science

studies and investigations pertaining to climate science in the most general sense

Robust direct effect of carbon dioxide on tropical circulation and regional precipitation

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.

When Crocodiles Roamed the Poles

(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 gyres at the end of the 21st century

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.

400 ppm of CO2: How will sea-level respond?

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.

Detecting ozone- and greenhouse gas-driven wind trends with observational data

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.

Increase in the range between wet and dry season precipitation

A simple thermodynamic argument suggests that as the water vapor content of the atmosphere increases with global warming dry regions may become drier and wet regions wetter. This enhanced hydrological contrast with global warming can be attributed to changes in the atmospheric water vapor concentration being comparatively larger than those of the moisture advecting winds in the lower atmosphere.

Fungi, not plants, drive long-term carbon sequestration in boreal forest

Soils contain two-thirds of the world’s terrestrial carbon (3,000 Pg C). The total annual soil CO2 efflux yearly exceeds the current rate of anthropogenic CO2 emissions from deforestation and burning of fossil fuels by a factor of 10. Subtle changes in soil organic carbon (SOC) processing (formation and decomposition) are, therefore, highly relevant to the global carbon cycle as soils have the potential to enhance or mitigate current increases in atmospheric CO2.

Climate-Ecosystem Carbon Feedbacks

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.

Unusual Southern Hemisphere Tree Growth Induced by Ozone Depletion

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.


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