A Method to Assess the Impact of High Tides, Storms and Storm Surges as Vital Elements in Climatic History the Case of Stormy Weather and Dikes in the Northern Part of Flanders, 1488 to 1609

In this paper a new method is introduced to assess the impact of storminess during the pre-instrumental period. The method is based on written sources. For this purpose Flemish documentary sources are taken as an example originating from a polder region between Ghent and Antwerp dating from the period 1488 to 1609. These documentary sources are continuous and homogeneous. The polders were protected by dikes, which had had to be maintained regularly. The annual upkeep was answered for in the annual dikes accounts in which nearly each storm that caused damage to the dikes was recorded. In order to assess the impact of storminess, these storms have been categorised, based on the following three principles: (a) the exact wording in the text, (b) the circumstances in which a storm appeared, (c) the consequences to which a storm has led, e.g. number of acres flooded. Accordingly eight separate categories are distinguished with storms ranging from one point to eight points. So in the first category the least important storms are given only one point. In category eight the storm surges appear, that have led to the flooding of large areas. These storms are given eight points. As the method enables us to assess the impact of storminess throughout the period, it shows only a small increase of storminess during the first quarter of the sixteenth century and a large increase in storminess during the second half of that century. Finally, looking at the storm pattern at Flushing between 1848 and 1990, there also appears to be a relative strong increase in storminess beginning around the 1950s. Whereas such a similarity in increase in storminess between these two quite different periods can hardly be coincidental, there must be some common cause. Could it be that periods of a relative strong increase of storminess precede periods of climatic change?     

Eddy-induced upwelling off Cape São Tomé (22°S,Brazil)

The regional ocean off southeast Brazil (20°S–28°S) is known as a current-eddy-upwelling region. The proximity of the Brazil Current to the coast in the Cape São Tomé vicinities, as well as of its quasi-stationary unstable meanders, suggests the possibility of background eddy-induced upwelling. Such phenomenon can intensify the prevalent coastal upwelling due to wind and topographic effects. In this paper, with the help of a numerical simulation, we provide evidence that eddy-induced upwelling in the absence of wind is possible in this region. The simulation was conducted with a regional configuration of the 3-D Princeton Ocean Model initialized by a feature-based implementation of the Brazil Current and Cape Frio eddy, blended with climatology.     

von Liebig's law of the minimum and plankton ecology (1899–1991)

The Law of the Minimum was originally formulated by Justus von Liebig, as one of the 50 interlinked laws concerned with agriculture. The original writings of J. von Liebig often were misinterpreted by his successors. Brandt (1899) took this one law out of its context and proposed that limitation by nitrogen is a dominant factor in plankton ecology, far beyond its original application to agriculture. This was opposed by Nathansohn (1908) who suggested instead a dynamic balance of growth and loss terms. Towards validating, or eventually falsifying Brandt's hypothesis, Atkins, Harvey, Cooper and others developed the chemical methods necessary for re-defining ocean nutrient cycling and growth limitation. The major exception to these modern perspectives was the Antarctic Paradox of high nutrients and low chlorophyll which inspired Gran, Atkins, Harvey and Cooper to pioneer the concept of iron limitation. An exhaustive overview is given of efforts to define Fe in seawater and its controlling effect on in situ plankton growth, for the 1920–1984 period. Somewhat parallel work in the laboratory on single species of algae in chelation-controlled media has provided much insight, but is sketched only briefly. Martin and contemporaries developed the chemical methods necessary for defining the ocean chemistry of Fe and its role for in situ growth. These developments are sketched for the 1982–1991 period. Once again the Law of the Minimum and associated bold hypotheses served, albeit briefly, to bring a nutrient element in the forefront of research. This, and the recent awareness of CO₂ as rate limiting factor, underline the conclusion that advances in sciences often hinge on advances in technology, confirming Kuhn (1962). In this case the new analytical techniques developed by Atkins, Harvey, Cooper, Martin and their associates have proven revolutionary for plankton ecology. Some observations in plankton ecology may be reminiscent of the agricultural Law of the Minimum, but this would not warrant its direct application, beyond its original context and agriculture, to plankton ecology. Rather the net rate of increase of phytoplankton is the dynamic balance of multiple growth and loss terms, together also determining the biomass at given time and space.     

Calibration of a CsI(Tl) crystal with nuclear recoils and pulse shape measurements for dark matter detection

The quenching factor of cesium and iodine nuclei recoiling in a CsI(Tl) scintillator is measured by scattering of 3 to 6 MeV neutrons. This factor increases when recoil energy decreases, from 7% at 150 keV to 15% at 25 keV. This relatively high efficiency could be useful in experiments dealing with very low recoil energies like the WIMP direct detection. These values are well explained by the Birks model. Pulse shape discrimination between electron and nuclei recoils is also investigated. Results are sufficiently good to allow a significant statistical rejection of radioactive background. This rejection capability is shown to be better than for NaI(Tl), at the same electron equivalent energy.     

Zooplankton responses to sandbar opening in a tropical eutrophic coastal lagoon

The effects of a disturbance by sandbar opening on the zooplankton community were evaluated through a long-term study in an eutrophic and oligohaline system, Imboassica Lagoon, Rio de Janeiro, Brazil. Zooplankton samples and limnological data were collected monthly from March 2000 to February 2003. Before the sandbar was opened in February 2001, the lagoon showed eutrophic conditions, with high mean nutrient concentrations and low salinity (total nitrogen – TN = 190.28 μM, chlorophyll a content – Chl. a = 104.60 μg/L and salinity = 0.87′). During this period, the zooplankton species present, such as the rotifers Brachionus calyciflorus and Brachionus havanaensis, were typical of freshwater to oligohaline and eutrophic environments. After the sandbar opening, the lagoon changed to a lower trophic status and increased salinity (TN = 55.11 μM, Chl. a = 27.56 μg/L and salinity = 19.64′). As a result, the zooplankton community came to consist largely of the rotifer Brachionus plicatilis, marine copepods and meroplanktonic larvae, mainly Gastropoda. Salinity was the main force structuring the zooplankton community after the sandbar opening. Two years after this episode, the prior zooplankton community had not reestablished itself, indicating a low resilience to this disturbance. The conditions developed prior to a sandbar opening can be crucial to the community responses in the face of this disturbance and for the capacity of the original zooplankton community to re-establish itself.     

Surface Fluxes and Characteristics of Drying Semi-Arid Terrain in West Africa

This study examines the seasonal cycle of the components of the surface energy balance in the Volta basin in West Africa as part of the GLOWA-Volta project. The regional climate is characterized by a strong north–south gradient of mean annual rainfall and the occurrence of pronounced dry and wet seasons within one annual cycle, causing a strong seasonal variation in the natural vegetation cover. The observations are conducted with a combined system, consisting of a Large Aperture Scintillometer (LAS) for areally averaged sensible heat flux, radiometers and sensors for soil heat flux. For comparisons the eddy-covariance (EC) method providing the fluxes of momentum, sensible and latent heat is utilized as well. The measurements of a seasonal cycle in 2002/2003 were gathered including the rapid wet-to-dry transition after the wet season at two locations in Ghana, one in the humid tropical southern region and one in the northern region. A direct comparison and the energy balance closure of the two methods are investigated for daytime and nighttime separately. An attempt is made to understand and explain the differences between the two methods and the closure of energy budget found for these. It is found that the two systems correspond well during daytime. During nighttime the LAS seems to perform more realistically than the EC system. Considering the fact that a LAS system is much easier to use in the climate conditions of the Volta basin, it is concluded that the LAS approach is very suitable in this type of climate conditions. Surface conductances are estimated by rearranging the Penman–Monteith equation and compared to a Jarvis-type model optimised for savannah conditions. It is found that temperature dependence should be included in the conductance formulation in contrast to earlier findings. Based on the findings the gathered dataset can be used for further model studies of the climate and environment of West Africa.     

Sky luminance distribution in the North of Iberian Peninsula during winter

This work is based on the study of outdoor daylight conditions during the winter period in Pamplona (the Iberian Peninsula). The 15 standard sky types proposed by the Commission Internationale de l’Eclairage (CIE) are used. The selected sky type in each moment is the one exhibiting the lowest root mean standard deviation (RMSD) when the theoretical and experimental luminance distributions in the sky hemisphere are compared. The selection was derived from luminance distribution data from 145 patches of the sky hemisphere and registered every 10 min from October to March from 2007 and 2008.The most frequent sky type observed in winter in Pamplona is V.5 (cloudless polluted with a broad solar corona), with a frequency of occurrence of 21%. Notwithstanding, the group of overcast skies exhibits a slightly higher frequency (40%) than the clear skies (37%). Seven out of the 15 standard sky types, i.e.V.5, I.1, III.4, II.1, IV.4, II.2 and III.3, are practically 80% of those under study. In order to provide a possible application in daylight climates studies, the frequency of occurrence of the 15 sky types is included in eleven intervals of solar elevation on the threshold corresponding to the time period and the location considered.