A very-small-aperture laser (VSAL) with a circular aperture has a trade-off between the spot size and the output power. A nanometric annular aperture is fabricated to overcome this difficulty. The advantages of the annular aperture are demonstrated by measuring and comparing its near-field intensity distribution with that of a circular aperture. These apertures are fabricated on the same VSAL t...

This study examines whether both the trend and the increase in variance of the Northern Hemisphere winter annular mode during the past 30 years arise from atmospheric internal variability. To address this question, a synthetic time series is generated that has the same intraseasonal stochastic properties as the annular mode. By generating a distribution of linear trend values for the synthetic ...

A theoretical investigation has been made of core-annular flow: the flow of a high-viscosity liquid core surrounded by a low-viscosity annular liquid layer through a horizontal pipe. Special attention is paid to the question how the buoyancy force on the core, caused by a possible density difference between the core and the annular layer, is counterbalanced. From earlier studies it is known tha...

Recap of project goals The principle goal of the research project is to bring together scientists with seemingly disparate expertise to systematically develop and test hypotheses regarding the impact of large scale climate variability on the carbon cycle. The research is largely focused on the dominant patterns of hemispheric scale variability, the so-called Northern and Southern Hemisphere ann...

24 Observed 850 hPa westerly wind trends over the Southern Ocean during 1979-2011 exhibit 25 strong regional and seasonal asymmetries. On an annual basis, trends in the Pacific Sector 26 (40°S-60°S; 70°W-160°W) are significant and three times larger than zonal-mean trends related 27 to the increase in the Southern Annular Mode (SAM). Seasonally, the SAM-related trend is 28 significant in austra...

Determining how climate fluctuations affect ocean ecosystems requires an understanding of how biological and physical processes interact across a wide range of scales. Here we examine the role of physical and biological processes in generating fluctuations in the ecosystem around South Georgia in the South Atlantic sector of the Southern Ocean. Anomalies in sea surface temperature (SST) in the ...