Manfred A. Lange

Bio: Manfred A. Lange is an academic researcher from The Cyprus Institute. The author has contributed to research in topics: Sea ice & Arctic ice pack. The author has an hindex of 38, co-authored 92 publications receiving 4256 citations. Previous affiliations of Manfred A. Lange include California Institute of Technology & Alfred Wegener Institute for Polar and Marine Research.

Climate change and interconnected risks to sustainable development in the Mediterranean

Abstract: Recent accelerated climate change has exacerbated existing environmental problems in the Mediterranean Basin that are caused by the combination of changes in land use, increasing pollution and declining biodiversity. For five broad and interconnected impact domains (water, ecosystems, food, health and security), current change and future scenarios consistently point to significant and increasing risks during the coming decades. Policies for the sustainable development of Mediterranean countries need to mitigate these risks and consider adaptation options, but currently lack adequate information — particularly for the most vulnerable southern Mediterranean societies, where fewer systematic observations schemes and impact models are based. A dedicated effort to synthesize existing scientific knowledge across disciplines is underway and aims to provide a better understanding of the combined risks posed.

Climate change and impacts in the Eastern Mediterranean and the Middle East.

Abstract: The Eastern Mediterranean and the Middle East (EMME) are likely to be greatly affected by climate change, associated with increases in the frequency and intensity of droughts and hot weather conditions. Since the region is diverse and extreme climate conditions already common, the impacts will be disproportional. We have analyzed long-term meteorological datasets along with regional climate model projections for the 21st century, based on the intermediate IPCC SRES scenario A1B. This suggests a continual, gradual and relatively strong warming of about 3.5–7°C between the 1961–1990 reference period and the period 2070–2099. Daytime maximum temperatures appear to increase most rapidly in the northern part of the region, i.e. the Balkan Peninsula and Turkey. Hot summer conditions that rarely occurred in the reference period may become the norm by the middle and the end of the 21st century. Projected precipitation changes are quite variable. Annual precipitation is expected to decrease in the southern Europe – Turkey region and the Levant, whereas in the Arabian Gulf area it may increase. In the former region rainfall is actually expected to increase in winter, while decreasing in spring and summer, with a substantial increase of the number of days without rainfall. Anticipated regional impacts of climate change include heat stress, associated with poor air quality in the urban environment, and increasing scarcity of fresh water in the Levant.

The ice thickness distribution across the Atlantic sector of the Antarctic Ocean in midwinter

Abstract: During the first leg of the Winter Weddell Sea Project (Antarktis V/2) cruise of F.S. Polarstern the entire width of the Antarctic sea ice zone was traversed in the vicinity of 0° longitude in the period July 18 to September 10, 1986. Ice thicknesses were measured by direct drilling and by helicopter profiling using an Exstar 100-MHz impulse radar system. In addition, aerial photography of the ice cover was done from 100- to 2000-m altitude using a 70-mm aerial camera mounted in the helicopter. The results of the point measurements (drilling) are reported in this paper together with an indication of how the radar and photography data will be used to extend them so as to yield area-averaged ice thickness distributions. It was found that the main ice type across the entire width of the ice cover was consolidated pancake ice occurring in vast floes; this formed out of a 250-km-wide band at the advancing ice edge which comprised a concentrated field of individual pancakes in a matrix of frazil ice. Preferred thicknesses of undeformed floes were 40–60 cm of ice covered with 5–15 cm of snow. The individual pancakes attained almost all of this thickness before consolidation; subsequent congelation growth was slow, estimated at 0.4 cm d−1. The floes contained much small-scale roughness on the upper and lower surfaces due to rafting of pancakes at the time of consolidation, but pressure ridging was modest except in the far south. A few very thick (8–11 m) multiyear floes were observed embedded in the pack at latitudes beyond 66° S.

Impact of climate change on the water resources of the eastern Mediterranean and Middle East region: Modeled 21st century changes and implications

Abstract: [1] The likely effects of climate change on the water resources of the eastern Mediterranean and Middle East region are investigated using a high-resolution regional climate model (PRECIS) by comparing precipitation simulations of 2040–2069 and 2070–2099 with 1961–1990. The simulations show about a 10% decline in precipitation across the region by both the middle and the end of the century, with considerable variation between countries and international river basins. Results suggest that per capita water resources will not change particularly significantly in southeastern Europe, where they are relatively plentiful and population growth is minimal. However, in much of the Middle East, climate change coupled with population growth is likely to reduce per capita water resources considerably. This will inevitably result in major social, economic, and environmental change in the region. Countries where the required adaptation is likely to be particularly challenging include Turkey and Syria because of the large agricultural workforces, Iraq because of the magnitude of the change and its downstream location, and Jordan because of its meager per capita water resources coupled with limited options for desalination. If the internal water footprint of the region declines in line with precipitation but the total water footprint of the region increases in line with population, then by midcentury, as much as half the total water needs of the region may need to be provided through desalination and imported in the form of virtual water.

Development of sea ice in the Weddell Sea

Abstract: We report on the development and physical properties of sea ice in the central and eastern Weddell Sea. The investigations were part of the Winter Weddell Sea Project 1986, which extended over the months of July through December. Major elements of the glaciological part of this study included continuous shipborne observations of sea-ice conditions and occasional helicopter reconnaissance flights, extensive measurements of snow and ice thicknesses at daily ice stations, and detailed analyses of sampled ice cores from each ice station. Textural investigations of the sampled ice revealed the dominance of frazil ice in the central Weddell Sea and the occurrence of an additional ice class, called platelet ice, together with the commonly known frazil and congelation ice in the coastal region of the eastern Weddell Sea. These results, in combination with the visual ice observations, reveal two major mechanisms for sea-ice generation in the Antarctic, which were not sufficiently well accounted for in previous investigations. In the central Weddell Sea, a cycle of pancake-ice formation and its growth into consolidated floes seems to be the dominant process of the advancing sea-ice edge. In the coastal waters, the growing sea-ice cover consists, to a considerable degree, of ice platelets which are formed in the underlying water column in front of the ice-shelf edges. Thus, congelation-ice growth, which is mainly controlled by atmospheric, thermodynamic forcing, seems to be of less importance in the central and south-eastern Weddell Sea than, for example, in the Arctic Basin.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

Abstract: The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Earth's early atmosphere

Abstract: Ideas about atmospheric composition and climate on the early Earth have evolved considerably over the last 30 years, but many uncertainties still remain. It is generally agreed that the atmosphere contained little or no free oxygen initially and that oxygen concentrations increased markedly near 2.0 billion years ago, but the precise timing of and reasons for its rise remain unexplained. Likewise, it is usually conceded that the atmospheric greenhouse effect must have been higher in the past to offset reduced solar luminosity, but the levels of atmospheric carbon dioxide and other greenhouse gases required remain speculative. A better understanding of past atmospheric evolution is important to understanding the evolution of life and to predicting whether Earth-like planets might exist elsewhere in the galaxy.

Fractals and fragmentation

Abstract: The use of renormalization group techniques on fragmentation problems is examined. The equations which represent fractals and the size-frequency distributions of fragments are presented. Method for calculating the size distributions of asteriods and meteorites are described; the frequency-mass distribution for these interplanetary objects are due to fragmentation. The application of two renormalization group models to fragmentation is analyzed. It is observed that the models yield a fractal behavior for fragmentation; however, different values for the fractal dimension are produced . It is concluded that fragmentation is a scale invariant process and that the fractal dimension is a measure of the fragility of the fragmented material.