Dynamic features in the western Baltic Sea investigated using NOAA-AVHRR data

Summary The western part of the Baltic Sea is a shallow transition area which is characterized by the water exchange between the Baltic and the North Sea. The dynamic processes in this area are forced by sea-level differences between the North Sea and Baltic Sea as well as by local wind and freshwater input. The response patterns are modified by Earth's rotation, bathymetric structures and the alignment of the coast. Series of satellite images permit synoptical views of these pattern and their temporal and spatial development.Sea surface temperature maps derived from infrared data supplied by the National Oceanic and Atmospheric Administration (NOAA) satellite-borne Advanced Very High Resolution Radiometer (AVHRR) are used to show various features like upwelling filaments and eddies.The River Oder discharges into the Pomeranian Bight is the main source of freshwater input into the western Baltic. The variability of this inflow and of the affected coastal seas is being presented in relation to the prevailing meteorological conditions.

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Dynamische Besonderheiten in der westlichen Ostsee untersucht anhand von NOAA-AVHRR-Daten

Zusammenfassung Die westliche Ostsee ist ein flaches Übergangsgebiet, das durch den Wasseraustausch zwischen Nord- und Ostsee charakterisiert ist. Die dynamischen Prozesse werden in diesem Gebiet durch Wasserstandsdifferenzen zwischen Nord- und Ostsee, durch den lokalen Wind und die Süßwasserzufuhr getrieben. Die Reaktionsmuster werden modifiziert durch die Erdrotation, die Bathymetrie und den Küstenverlauf.Serien von Satellitendaten gestatten die synoptische Betrachtung dieser Muster und ihrer zeitlichen und räumlichen Entwicklung.Karten der Wasseroberflächentemperatur (SST), abgeleitet aus Infrarotdaten des Advanced Very High Resolution Radiometer (AVHRR), werden genutzt, um verschiedene Strukturen wie Auftrieb, Filamente und Wirbel zu präsentieren. Das Radiometer wird durch die National Oceanic and Atmospheric Administration (NOAA) auf Wettersatelliten betrieben.Der Flußeintrag der Oder in die Pommersche Bucht ist die bedeutendste Süßwasserzufuhr in die westliche Ostsee. Die Veränderlichkeit des Einstroms und die beeinflußten Gebiete sind in Abhängigkeit von den meteorologischen Bedingungen dargestellt.

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Recherche du caractéristiques dynamiques en mer Baltique ouest á l'aide de données NOAA-AVHRR

Résumé La partie ouest de la mer Baltique est une zone de transition de profondeur réduite, caractérisée par un échange des eaux entre la mer du Nord et la mer Baltique.Dans cette zone, les processus dynamiques proviennent des différences de niveau de la mer du Nord et de la mer Baltique, des vents locaux et de l'apport en eau douce. Les modèles créés sont modifiés à partir de la rotation terrestre, de la bathymétrie et de la morphologie côtière.Les données satellite permettent d'établir une étude synoptique de ces processus dans l'ensemble de la zone ainsi que leur développement spatio-temporel au moyen de séries.Des cartes de température superficielle (SST) obtenues à partir des données radiométriques infrarouges AVHRR (Advanced Very High Resolution Radiometer) sont utilisées pour présenter des exemples SST caractéristiques de résultats de processus dynamiques de l'ouest de la mer Baltique. Les données radiométriques proviennent du National Oceanic and Atmospheric Administration (NOAA) à partir de satellites météorologiques.La dépendance des développements spatio-temporels de modèles en fonction des conditions météorologiques est discutée à partir de scènes et de séries particulières.Des exemples d'upwelling devant les côtes allemandes, suédoises et polonaises ainsi que des fronts, des filaments et des tourbillons sont présentés.La plus grande partie de l'apport en eau douce à l'ouest de la mer Baltique provient du fleuve Oder, en baie de Poméranie. L'influence des facteurs météorologiques sur la variation de ce déversement et sur les zones influencées est présentée.

     

Calibration of regional pollen data to construct maps of former forest types in southern Sweden

A method was developed to construct maps of former forest types based on regional pollen data in southern Sweden. The considered species were Alnus, Betula, Carpinus, Corylus, Fagus, Fraxinus, Juniperus, Picea, Pinus, Populus, Quercus, Salix, Tilia and Ulmus. A network of 37 regional pollen sites with high data quality from lakes and peat deposits were selected from Sweden south of 60 ° N. Pollen percentage values were calculated and converted into estimates of tree composition. For controlling the reliability of the reconstruction, the estimates from the core-tops were compared with present day forest inventory data, and local pollen diagrams were compared with the regional pollen diagrams. An inverse distance weighted interpolation algorithm was used to generate maps for each tree species distribution at 2000 BP, 1500 BP, 1000 BP, 500 BP and 0 BP. A supervised classification routine was implemented to generate nine different forest types common to the five studied time intervals. The maps show that the amounts and patterns of distribution of the species and the forest types have varied in a significant but systematic manner through time. The changes are due to human activities, migrational patterns and changes in climate. These maps will be of value as a basis for future landscape planning, forestry and conservation of biodiversity.This is the 20th in a series of papers published in this special AMQUA issue. These papers were presented at the 1994 meeting of the American Quaternary Association held 19–22 June, 1994, at the University of Minnesota, Minneapolis, Minnesota, USA. Dr Linda C. K. Shane served as guest editor for these papers.     

Glacier fluctuations in the southern Peruvian Andes during the late‐glacial period,constrained with cosmogenic 3He

The occurrence of pronounced climate reversals during the last glacial termination has long been recognised in palaeoclimate records from both hemispheres and from high to low latitudes. Accurate constraint of both the timing and magnitude of events, such as the Younger Dryas and Antarctic Cold Reversal, is vital in order to test different hypotheses for the causes and propagation of abrupt climate change. However, in contrast to higher‐latitude regions, well‐dated records from the Tropics are rare and the structure of late‐glacial tropical climate remains uncertain. As a step toward addressing this problem, we present an in situ cosmogenic ³He surface exposure chronology from Nevado Coropuna, southern Peru, documenting a significant fluctuation of the ice margin during the late‐glacial period. Ten tightly clustered ages from a pair of moraines located halfway between the modern glacier and the Last Glacial Maximum terminus range from 11.9 to 13.9 ka and give an arithmetic mean age of 12.8 ± 0.7 ka (1σ). These data constitute direct evidence for a readvance, or prolonged stillstand, of glaciers in the arid Andes of southwestern Peru. Copyright © 2011 John Wiley & Sons, Ltd.     

Simultaneous determinations of U–Pb age,Hf isotopes and trace element compositions of zircon by excimer laser-ablation quadrupole and multiple-collector ICP-MS

We describe an in situ method for simultaneous measurement of U–Pb–Hf isotopes and trace element compositions of zircons using a quadrupole and multiple-collector inductively-coupled-plasma mass spectrometer (Q-ICP-MS and MC-ICP-MS, respectively) connected to a single excimer laser-ablation system. A laser-generated zircon aerosol was split behind the ablation cell into two transport tubes via a Y-shaped connector and simultaneously introduced into the two mass spectrometers. Hafnium isotopes were measured on the MC-ICP-MS instrument, while U–Pb ages and trace element compositions were determined using the Q-ICP-MS. The precision and accuracy of this method was evaluated using six well-known and widely used zircon standards (91500, Temora-2, GJ-1, Mud Tank, BR266 and Monastery). Analyses were carried out using spot sizes of 32, 44 and 60 μm. For the 44 and 60 μm spot, the resulting U–Pb ages, Hf isotopic and rare earth element (REE) compositions of these six zircons agree with recommended/reported values within 2σ error. The difference in relative standard deviations (RSD) of ²⁰⁶Pb/²³⁸U ages between split-flow measurements and those obtained separately on the Q-ICP-MS is within ～ 20% for 91500, Temora-2 and GJ-1, and ～ 60% for Mud Tank (due to its lower U and Pb concentrations). Our method provides a precise approach for determining the U–Pb age and the Hf isotopic and trace element compositions of zircon within a single ablation event. This is in particular important for analysis of zircons that are small or contain complicated zoning patterns. Finally, the REE composition of zircon BR266 is more homogeneous than other zircons and could be a suitable standard by which to benchmark new standards for microprobe analyses of zircons.     

Echo I: An experimental analysis of local effects and conjugate return echoes from an electron beam injected into the magnetosphere by a sounding rocket

On 13 August 1970, a sounding rocket carrying a high voltage electron accelerator and several electron detectors was launched from Wallops Island, Virginia. 16 msec long, 70 mA pulses were injected into the magnetosphere at pitch angles near 90°. In each pulse the electron energy was modulated between 35 and 43 keV. The electrons were trapped in the Earth's magnetic field and bounced between the northern and southern conjugate points with a period of ～0.65 sec and drifted eastward with a gradient-curvature drift velocity of ～765 m/sec. For about 90 seconds the rocket intercepted the returning echoes. Careful study of the rocket trajectory has allowed a partial space-time picture of an echo to be constructed. The bounce time and drift velocity observations are consistent with predictions based on internal magnetic field models with no electric fields. The flux has the spatial variations predicted by atmospheric scattering models at the southern conjugate point but is about a factor of 10 too low. After some injections delayed echoes are observed, apparently 40 keV electrons whose bounce time has been increased by ～75 msec, but with no change in their bounce averaged drift velocity. Study of detector response during gun pulses revealed three unexplained features: (1) a field aligned upward moving flux after downward injections; (2) a downward moving, time dependent, flux after injections at some upward pitch angles; (3) a lack of altitude (or atmospheric density) dependence on observed count rates.     

The resilience paradox: flooding experience,coping and climate change mitigation intentions

Climate change is projected to increase the frequency, intensity and unpredictability of extreme weather events across the globe and these events are likely to have significant mental health implications. The mental health literature broadly characterises negative emotional reactions to extreme weather experiences as undesirable impacts on wellbeing. Yet, other research in psychology suggests that negative emotional responses to extreme weather are an important motivation for personal action on climate change. This article addresses the intersection of mental health and functional perspectives on negative emotions, with a specific focus on the potential that reduced negative emotional responses to extreme weather may also translate to diminished motivation to undertake climate change mitigation actions – which we term the ‘resilience paradox’. Using survey data gathered in the aftermath of severe flooding across the UK in winter 2013/2014, we present new evidence indicating that self-appraised coping ability moderates the link between flooding experience and negative emotions and thereby attenuates the indirect link between flooding experience and climate change mitigation intentions. We conclude that support for flood victims should extend beyond addressing emotional, physical and financial stresses to include acknowledgement of the involvement of climate change and communication of the need for action to combat future climate risks.

Key policy insights

• Psychological resilience to flooding and other extreme weather events can translate to diminished motivation to mitigate climate change

• Negative emotional reactions need to occur at an optimal level to enable people to respond appropriately to climate risks.

• Flood victims’ subjective appraisal of their ability to cope does not necessarily encompass consideration of the role played by climate change. Therefore, support for victims of extreme weather should include explicit acknowledgement of the involvement of climate change and the need for action to mitigate future climate risks.

     

Ultra-High Resolution Nitrate in Polar Ice as Indicator of Past Solar Activity

Ionization in the polar atmosphere causes the formation of nitrate compounds, which are frozen out and incorporated into the layers of the polar ice sheets. From a 122-m ice core collected in 1992 on the central Greenland ice sheet, it has been possible to examine a solar signal in a ultra-high resolution record of nitrate concentrations. The sequence extends over a period of 415 years at a temporal resolution of no less than one analysis per month (total number of samples 7776 resulting from 1.5 cm sampling along the entire core). This type of measurement reveals major nitrate anomalies which are thought to result from the injection of individual solar proton events into the winter polar stratosphere. For this reason, the large nitrate anomalies provide the possibility to delineate a signal of solar activity well beyond the known geophysical records.