The Drake Silver Maps are 68-mm-diameter silver disks with maps of the sixteenth-century known world featuring Drake’s route of circumnavigation. They were probably stamped with dies. The nine ...existing medallions have weights from 260 to 424 grains (the heaviest one weighs about 28 g). Each of these medallions has a diameter that is about the same as that of a tennis ball. The lightest one is as thin as a thumbnail, and the heaviest one is as thick as a credit card. This article shows that they were most likely created in 1588–89: the strongest evidence for this is that they used the double-hemisphere equatorial stereographic map projection that was first used by Rumold Mercator in 1587.
A new companion for Mercator Tobler, Waldo
Cartography and geographic information science,
05/2018, Letnik:
45, Številka:
3
Journal Article
Recenzirano
The inappropriate use of the Mercator projection has declined but still occasionally occurs. One method of contrasting the Mercator projection is to present an alternative in the form of an equal ...area projection. The map projection derived here is thus not simply a pretty Christmas tree ornament: it is instead a complement to Mercator's conformal navigation anamorphose and can be displayed as an alternative. The equations for the new map projection preserve the latitudinal stretching of the Mercator while adjusting the longitudinal spacing. This allows placement of the new map adjacent to that of Mercator. The surface area, while drastically warped, maintains the correct magnitude.
Abstract The ability of the Weather Research and Forecasting (WRF-ARW) model to simulate precipitation variability throughout the Middle East, especially Iraq, is evaluated in this study. The Weather ...Research and Forecasting model (WRF v 4.2.1) was used. Using a two-way nesting technique and Mercator projection, the WRF model was set up with two nested grids with high regional resolution at 30 km (WRF30km) and 10 km (WRF10km) horizontal grid spacing. From the surface to 50 hPa, both domains have 41 vertical levels. The outer domain covers the Middle East region and the smaller one covers the Iraq region. The ARW supports horizontal nesting, allowing higher resolution over a region of interest, by introducing additional grids, which is available only for horizontal refinement. The nested grids are rectangular and are aligned with the parent (coarser) grid within which they are nested. To predict many atmospheric parameters WRF-ARW model was used based on the initial conditions taken from National Centre for Atmospheric Research (NCAR) records for the period from 23 to 25 of march 2019. The study area is essentially an area bounded by longitudes 35°-55° and latitudes 29°-38° typically including the area of Iraq. The WRF-ARW model was set up on a Linux platform with a 10 km grid size in the zonal and meridional directions. The aim of this study is to evaluate the two WRF tools dynamical downscaling and nesting) at high resolution (30 and 10 km), for simulating rainfall and temperature over Iraq.
Low‐salinity waters in the upper Arctic Ocean, referred to as “freshwaters”, are cold and play a major role in isolating the sea ice cover from the heat stored in the salty Atlantic Waters (AW) ...underneath. We examined changes in Arctic freshwater distribution and circulation since 2007 using the 1/12° global Mercator Ocean operational model. We first evaluated model simulations over the upper water column in the Arctic Ocean, using nearly 20,000 independent in situ temperature‐salinity profiles over the 2007–2020 period. Simulated hydrographic properties and water mass distributions were in good agreement with observations. Comparison with long‐term mooring data in the Bering Strait and Beaufort Gyre highlighted the model's capabilities for reproducing the interannual evolution of Pacific Water properties. Taking advantage of the good performance of the model, we examined the interannual evolution of the freshwater distribution and circulation over 2007–2020. The Beaufort Gyre is the major freshwater reservoir across the full Arctic Ocean. After 2012 the gyre extended northward and increased the freshwater content in the Makarov Basin, near the North Pole. Coincidentally, the freshwater content decreased along the East Siberian slope, along with the AW shoaling, and the Transpolar Drift moved from the Lomonosov Ridge to align with the Mendeleev Ridge. We found that these changes in freshwater distribution were followed in 2015 by a marked change in the export of freshwater from the Arctic Ocean with a reduction in Fram Strait (−30%) and an increase in the western Canadian Archipelago (+16%).
Plain Language Summary
We evaluated 14 years of simulations from a high‐resolution ocean model to identify changes in the upper water column of the Arctic Ocean since 2007. Comparisons of simulations with observations highlighted the model's capabilities for reproducing the properties of the Arctic Ocean. We then examined how the freshwaters, which isolate the sea‐ice from the heat stored at depth, have seen their distribution and pathways changed over the last 14 years in the model. The freshwater content increased near the North Pole after 2012, while one of the largest reservoirs of freshwater in the Arctic Ocean retreated to the northeast. We also documented changes in the freshwater pathway exiting the Arctic with more freshwater outflow through the western Canadian Archipelago after 2015.
Key Points
The Mercator Ocean model was capable of reproducing observed spatial patterns of Arctic freshwater content and sea surface height
After 2012, waters in the Makarov Basin near the North Pole freshened and Atlantic‐origin waters shoaled along the East Siberian slope
After 2015, liquid freshwater outflow increased through the western Canadian Archipelago and decreased through Fram Strait
In view of the problem that the interpolated distance parameters and the plotting precision of the geodetic line cannot be quantitatively regulated and adaptively matched, this paper extends the ...application of the solution method for constant line segment by considering the angle of the constant line and the geodetic line to the quantitative evaluation and control process of the error of the geodetic line plotting. Using the strategy of limiting the overall length error of the geodetic line plotting by the local arch height error threshold limits, a quantitative control model of interpolated distance parameters within the geodetic line plotting arch height error threshold limits is also established. A rapid plotting algorithm of the geodetic line with arch height error threshold under Mercator projection is proposed in this paper. The experimental results show that the algorithm can realize the rapid plotting of geodetic lines in any length and any latitude and longitude range, and the precision is controlled within the specified threshold range.
Oryzaephilus mercator (Fauvel) (Coleoptera: Silvanidae) is a postharvest pest of stored peanuts (Arachis hypogea L.). Although it is only a secondary pest, this insect causes extensive damage and ...reduces the quantity and quality of peanut kernels. The objective of this research was to study whether host preference and development of O. mercator differ depending on the variety of peanut and/or on whether the peanut retains its seed coat or is bare. We used three varieties of peanut (Kelinci, Bison and Takar1) separating out each variety into groups with or without a seed coat. In the laboratory, we conducted two separate studies examining host preference and development of O. mercator. Host preference was studied using a preference cage consisting of six chambers for all peanut varieties with and without seed coat and each cage contained 15 mating pairs of O. mercator. The development study was conducted by placing 15 mating pairs of O. mercator into a treatment jar and allowing them to feed on different peanut varieties with and without a seed coat. Results from the host preference study indicated that O. mercator preferred bare kernels of the Kelinci variety over other peanut varieties both as a food source and for oviposition. During the development experiment, we observed that O. mercator experienced faster development time when exposed to bare kernels of all three varieties tested as opposed to those with intact seed coat. Results show that peanuts with a seed coat and variety with high kernel hardness (Bison variety) deters predation and inhibits host preference and development of O. mercator.
•O. mercator preferred bare kernels of the Kelinci variety of peanut.•O. mercator experienced faster development time when exposed to bare kernels.•Seed coat presence/absence had a significant influence on host preference and on development of O. mercator.•Peanuts with a thick seed coat inhibits feeding activity as well as increased mortality of O. mercator adults.
Nowadays Marine Geographical Information Systems (MGIS) play an essential role in several research activities, the most part of them related to solve Geoscience problems. The nautical maps, ...containing most of the information used by the marine navigators, are used as cartographic base of MGIS and widely referred to Mercator projection. Remotely sensed images can be introduced in MGIS to improve the study outcomes even if they are in a different cartographic representation (generally Universal Transverse of Mercator, UTM). The adaptation of already georeferred remotely sensed images to Mercator projection requires particular care, moreover when also geodetic data are different (i.e. local datum and global datum). This paper is aimed to offer an easy-to-use work-flow that could be adopted every time remotely sensed images are to be introduced in MGIS and overlaid to nautical maps. Particularly the work addresses the implementation and evaluation of reprojection of Landsat 8 imageries, regarding both the gulfs of Naples and Salerno (Italy): a transformation from UTM WGS84 to Mercator Roma40 is applied. The result accuracy encourages the adoption of the proposed work-flow.
Starting from the general equations for a viscous, incompressible fluid, written in rotating spherical coordinates, an asymptotic theory for steady flow is developed. This uses only the thin-shell ...approximation, by suitably defining the variables and parameters. The result is a consistent theory which produces an Ekman-type balance, expressed in spherical coordinates, at leading order. The correction terms, which are mainly the nonlinear contribution in the equations, can be accommodated by invoking the method of multiple scales and using a strained coordinate. The resulting leading order, with slow/weak corrections, provides the basis for a study of oceanic gyres. By choosing the velocity (and noting the vorticity) at the surface, some examples are presented. Various choices are made, for closed particle paths expressed in a simple form (using a transformation based on the Mercator projection): zero velocity and vorticity at the centre and on the periphery of the gyre; non-zero speed on the periphery; finite-strength line vortex at the centre. In addition, in one case, we describe how the slow-
z
variation affects the solution. This treatment of the problem shows that our extended version of the Ekman balance, valid in spherical coordinates over large regions, can be used to investigate the properties of gyres. Many analytical and numerical options are available for future study.
This paper is focused on Mercator's projection as a breakthrough in maritime navigation. In the paper, the principle and properties of Mercator's projection are described. The advantages, ...disadvantages and current utilization are mentioned.
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