Cosmos : a sketch of a physical description of the universe / By Alexander von Humboldt ; Translated from the German by E.C. Otté.

3

Cosmos : a sketch of a physical description of the universe / By Alexander von Humboldt ; Translated from the German by E.C. Otté.

4

Cosmos : a sketch of a physical description of the universe / By Alexander von Humboldt ; Translated from the German by E.C. Otté.

2

Cosmos : a sketch of a physical description of the universe / By Alexander von Humboldt ; Translated from the German by E.C. Otté.

1

Cosmos : a sketch of a physical description of the universe / By Alexander von Humboldt ; Translated from the German by E.C. Otté.

5

Residual delay maps unveil global patterns of atmospheric nonlinearity and produce improved local forecasts

We use residual-delay maps of observational field data for barometric pressure to demonstrate the structure of latitudinal gradients in nonlinearity in the atmosphere. Nonlinearity is weak and largely lacking in tropical and subtropical sites and increases rapidly into the temperate regions where the time series also appear to be much noisier. The degree of nonlinearity closely follows the meridional variation of midlatitude storm track frequency. We extract the specific functional form of this nonlinearity, a V shape in the lagged residuals that appears to be a basic feature of midlatitude synoptic weather systems associated with frontal passages. We present evidence that this form arises from the relative time scales of high-pressure versus low-pressure events. Finally, we show that this nonlinear feature is weaker in a well regarded numerical forecast model (European Centre for Medium-Range Forecasts) because small-scale temporal and spatial variation is smoothed out in the grided inputs. This is significant, in that it allows us to demonstrate how application of statistical corrections based on the residual-delay map may provide marked increases in local forecast accuracy, especially for severe weather systems.

Central Africa: on a scale of 1:10,000,000

by Dr. F. Boas.

(Table 1) Stable oxygen isotopic ratios and yearly snow accumulation of firn and ice cores from Svalbard

We analyse ice cores from Vestfonna ice cap (Nordaustlandet, Svalbard). Oxygen isotopic measurements were made on three firn cores (6.0, 11.0 and 15.5 m deep) from the two highest summits of the glacier located on the SW-NE and NW-SE central ridges. Sub-annual d18O cycles were preserved and could be counted visually in the uppermost parts of the cores, but deeper layers were affected by post-depositional smoothing. A pronounced d18O minimum was found near the bottom of the three cores. We consider candidates for this d18O signal to be a valuable reference horizon since it is also seen elsewhere in Nordaustlandet. We attribute it to isotopically depleted snow precipitation, which NCEP/NCAR reanalysis shows was unusual for Vestfonna, and came from northerly air during the cold winter of 1994/95. Finding the 1994/95 time marker allows establishment of a precise depth/age scale for the three cores. The derived annual accumulation rates indirectly fill a geographical gap in mass balance measurements and thus provide information on spatial and temporal variability of precipitation over the glacier for the period spanned by the cores (1992-2009). Comparing records at the two locations also reveals that the snow net accumulation at the easternmost part of Vestfonna was only half of that in the western part over the last 17 years.

Report on the geological survey of the State of Iowa, to the Thirteenth General Assembly, January, 1870, containing results of examinations and observations made within the years 1866, 1867, 1868, and 1869.

Photocopy. Iowa City, Iowa, University of Iowa Libraries, 1980.

The face of the earth =Das antlitz der erde /

Vol. 5: Indexes and maps.