Charting and Knowledge in Enlightened Empires: The Case of Tierra del Fuego in Anson’s Voyage Round the World (1748)

2021 ◽  
pp. 1-13
Author(s):  
Katherine Parker
Keyword(s):  
Tierra Del Fuego ◽  
The World

Four Centuries of Summer Temperature Changes in Tierra Del Fuego: Atmospheric Drivers and Tree-Ring Reconstruction From the Southernmost Forests of the World

2021 ◽  
Author(s):  
Vladimir Matskovsky ◽  
Fidel A. Roig ◽  
Mauricio Fuentes ◽  
Irina Korneva ◽  
Diego Araneo ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Temperature Reconstruction ◽  
Summer Temperature ◽  
Temperature Variability ◽  
Tierra Del Fuego ◽  
Climate Modelling ◽  
Least Squares Regression ◽  
Nothofagus Pumilio ◽  
The World

Abstract Proxy climate records, such as those derived from tree rings, are necessary to extend relatively short instrumental meteorological observations into the past. Tierra del Fuego is the most austral territory with forests in the world, situated close to the Antarctic Peninsula, which makes this region especially interesting for paleoclimatic research. However, high-quality, high-resolution summer temperature reconstruction are lacking in the region. In this study we used 63 tree-ring width chronologies of Nothofagus pumilio and Nothofagus betuloides and partial least squares regression (PLSR) to produce annually resolved December-to-February temperature reconstruction since AD 1600 which explains up to 65% of instrumental temperature variability. We also found that observed summer temperature variability in Tierra del Fuego is primarily driven by the fluctuations of atmospheric pressure systems both in the South Atlantic and South Pacific, while it is insignificantly correlated to major hemispheric modes: ENSO and SAM. This fact makes our reconstruction important for climate modelling experiments, as it represents specific regional variability. Our reconstruction can be used for direct comparison with model outputs to better understand model limitations or to tune a model or contribute to larger scale reconstructions based on paleoclimatic data assimilation. Moreover, we showed that PLSR has improved performance over principal component regression (PCR) in the case of multiple tree-ring predictors. According to these results, PLSR may be a preferable method over PCR for the use in automated tree-ring based reconstruction approaches, akin widely used point-by-point regression.

First airborne gravity wave observations at the world’s hotspot in Southern Argentina

2020 ◽  
Author(s):  
Markus Rapp ◽  
Bernd Kaifler ◽  
Andreas Dörnbrack ◽  
Sonja Gisinger ◽  
Tyler Mixa ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Antarctic Peninsula ◽  
Wave Activity ◽  
Airborne Lidar ◽  
Tierra Del Fuego ◽  
Mountain Waves ◽  
The Andes ◽  
Chemistry Research ◽  
The World ◽  
The Antarctic

<p>The region around Southern Argentina and the Antarctic peninsula is known as the world’s strongest hotspot of stratospheric gravity wave activity. In this region, large tropospheric winds are perturbed by the orography of the Andes and the Antarctic peninsula resulting in the excitation of mountain waves which might propagate all the way up into the upper mesosphere when the polar night jet is intact. In addition, satellite observations also show large stratospheric wave activity in the region of the Drake passage, i.e., in between the Andes and the Antarctic peninsula, and along the corresponding latitudinal circle of 60°S. The origin of these waves is currently not entirely understood. Several hypotheses are currently being investigated, like for example the idea that the mountain waves that were originally excited over the Andes and the Antarctic peninsula propagate horizontally to 60°S and along the latitudinal circle. In order to investigate this and other hypotheses the German research aircraft HALO was deployed to Rio Grande, Tierra del Fuego, at the Southern Tip of Argentina in September and November 2019 in the frame of the SOUTHTRAC (Southern hemisphere Transport, Dynamics, and Chemistry) research mission. A total of 6 dedicated research flights with a typical length of 7000km were conducted to obtain gravity wave observations with the newly developed ALIMA (ALIMA=Airborne LIdar for Middle Atmosphere research)-instrument and the GLORIA (GLORIA=Gimballed Limb Observer for Radiance Imaging of the Atmosphere) limb sounder. While ALIMA measures temperatures and temperature perturbations in the altitude range from 20-90 km, GLORIA observations allow to characterize wave perturbations in temperatures and trace gas concentrations below flight level (<~14 km). This paper gives an overview of the mission objectives, the prevailing atmospheric conditions during the HALO deployment, and highlights some outstanding initial results of the gravity wave observations.</p>

scholarly journals Language in the Americas: Out of Beringia

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Norbert Francis
Keyword(s):  
Language Change ◽  
Western Hemisphere ◽  
Tierra Del Fuego ◽  
Language Research ◽  
The World ◽  
Made In

Linguistically, the Western Hemisphere harbors a great typologicaldiversity, by some estimates, the greatest in the world. Controversyregarding classification aside, much work lies ahead to identify themovements up through to include the final leg of the journey ofmodern humans, in terms of distance travelled from our continent oforigin, to Tierra del Fuego. This article will briefly summarize theadvances that the language sciences have made in describing thesemigrations and the languages that accompanied them, to then discussviable proposals for collaboration with other fields. Such an interdisciplinaryprogram of study is necessary because the tools of linguisticsdo not suffice. Continuing work on the processes of origin, dispersionand convergence will help us better understand fundamentalproperties of language. Research on the description of individuallanguages and how they can be classified will contribute to thisunderstanding. For speakers and students of the American languages,these advances will also contribute to the recovery of the culturalheritage that is associated with historical language change.

Sign in / Sign up

Export Citation Format

Share Document