In-Line Combustion System for the Measurement of δC-CH in Gas Reference Materials Using Optical Isotope Ratio Spectroscopy.

Measurements of the stable carbon isotope ratio in methane (δC-CH) are used in determining the source of CH emissions on local, regional, and global scales. To achieve the required level of data comparability for atmospheric monitoring networks, accurate gas reference materials of δC-CH in air are required with high levels of reproducibility. We describe a method to determine the δC-CH of CH in synthetic air reference materials reported against the Vienna Pee Dee Belemnite (VPDB) scale.

The Ronne Ice Shelf survived the last interglacial.

The fate of the West Antarctic Ice Sheet (WAIS) is the largest cause of uncertainty in long-term sea-level projections. In the last interglacial (LIG) around 125,000 years ago, data suggest that sea level was several metres higher than today, and required a significant contribution from Antarctic ice loss, with WAIS usually implicated. Antarctica and the Southern Ocean were warmer than today, by amounts comparable to those expected by 2100 under moderate to high future warming scenarios.

Southern Ocean drives multidecadal atmospheric CO rise during Heinrich Stadials.

The last glacial period was punctuated by cold intervals in the North Atlantic region that culminated in extensive iceberg discharge events. These cold intervals, known as Heinrich Stadials, are associated with abrupt climate shifts worldwide. Here, we present CO measurements from the West Antarctic Ice Sheet Divide ice core across Heinrich Stadials 2 to 5 at decadal-scale resolution.

Reconciling ice core CO and land-use change following New World-Old World contact.

Ice core records of carbon dioxide (CO) throughout the last 2000 years provide context for the unprecedented anthropogenic rise in atmospheric CO and insights into global carbon cycle dynamics. Yet the atmospheric history of CO remains uncertain in some time intervals. Here we present measurements of CO and methane (CH) in the Skytrain ice core from 1450 to 1700 CE.

The influence of sampling design on tree-ring-based quantification of forest growth.

Tree-rings offer one of the few possibilities to empirically quantify and reconstruct forest growth dynamics over years to millennia. Contemporaneously with the growing scientific community employing tree-ring parameters, recent research has suggested that commonly applied sampling designs (i.e.