Role of land-ocean interactions in stepwise Northern Hemisphere Glaciation.

The investigation of triggers causing the onset and intensification of Northern Hemisphere Glaciation (NHG) during the late Pliocene is essential for understanding the global climate system, with important implications for projecting future climate changes. Despite their critical roles in the global climate system, influences of land-ocean interactions on high-latitude ice sheets remain largely unexplored. Here, we present a high-resolution Asian dust record from Ocean Drilling Program Site 1208 in the North Pacific, which lies along the main route of the westerlies.

Global climate forcing on late Miocene establishment of the Pampean aeolian system in South America.

Wind-blown dust from southern South America links the terrestrial, marine, atmospheric, and biological components of Earth's climate system. The Pampas of central Argentina (~33°-39° S) contain a Miocene to Holocene aeolian record that spans an important interval of global cooling. Upper Miocene sediment provenance based on n = 3299 detrital-zircon U-Pb ages is consistent with the provenance of Pleistocene-Holocene deposits, indicating the Pampas are the site of a long-lived fluvial-aeolian system that has been operating since the late Miocene.

A westerly wind dominated Puna Plateau during deposition of upper Pleistocene loessic sediments in the subtropical Andes, South America.

The Tafí del Valle depression (~27° S) in the eastern Andes of Argentina provides a record of late Pleistocene dust deposition in the subtropics of South America. We present large-n U-Pb geochronology data for detrital zircons from upper Pleistocene loess-paleosol deposits. When compared to regional data, the age spectra from the Tafí del Valle samples are most like the southern Puna Plateau, supporting derivation largely from the west and northwest.

Eccentricity forcing of East Asian monsoonal systems over the past 3 million years.

The East Asian summer monsoon and the precipitation it brings are relevant for millions of people. Because of the monsoon's importance, there has been a substantial amount of work attempting to describe the driving mechanisms behind its past variability. However, discrepancies exist, with speleothem-based East Asian monsoon reconstructions differing from those based on loess records from the Chinese Loess Plateau during the late Quaternary.

Poleward and weakened westerlies during Pliocene warmth.

The prevailing mid-latitude westerly winds, known as the westerlies, are a fundamental component of the climate system because they have a crucial role in driving surface ocean circulation and modulating air-sea heat, momentum and carbon exchange. Recent work suggests that westerly wind belts are migrating polewards in response to anthropogenic forcing. Reconstructing the westerlies during past warm periods such as the Pliocene epoch, in which atmospheric carbon dioxide (CO) was about 350 to 450 parts per million and temperatures were about 2 to 4 degrees Celsius higher than today, can improve our understanding of changes in the position and strength of these wind systems as the climate continues to warm.

A wind-albedo-wind feedback driven by landscape evolution.

The accurate characterization of near-surface winds is critical to our understanding of past and modern climate. Dust lofted by these winds has the potential to modify surface and atmospheric conditions as well as ocean biogeochemistry. Stony deserts, low dust emitting regions today, represent expansive areas where variations in surficial geology through time may drastically impact near-surface conditions.