Extending the EBM: the effect of deep ocean temperature on climate with applications to the cretaceous

Three types of models are frequently applied to problems of present or past climates: (1) the energy balance model (EBM), which can be solved for the mean thermal state of the climate system based only on thermodynamical considerations, (2) the statistical dynamical model (SDM), which includes momentum considerations from which one can solve for climate statistics on a monthly or seasonal time scale including mean poloidal motions and the hydrologic cycle, and (3) the general circulation model (GCM), which can be solved for the evolving daily weather patterns that are then post-processed to yield all the climate statistics in much the same manner as synoptic data are processed. One major drawback of nearly all these models is that they typically do not consider the subsurface vertical heat fluxes (e.g., the effect of deep ocean temperatures and circulation). We present results froman SDM developed in the late 1960's that includes the parameterized effects of subsurface heat fluxes, and then use these results to demonstrate the importance that deep ocean temperatures can have in determining the climatic state. In this SDM, the ratio of the surface short wave absorption to the surface conductive capacity emerges as a quantity that competes with the subsurface (e.g., deep ocean) temperature in determining surface temperatures. For land, the conductive capacity is small and short wave absorption plays an important role; however, for the ocean the conductive capacity is large and the subsurface (deep ocean) temperature is the dominant influence on the surface temperature for the time scale over which the model is valid. This SDM also includes several of the most important features absent in an EBM, namely, an explicit dependence on the intrinsic physical nature of the earth's surface, the mean poloidal motions in the atmosphere that lead to the climate zonation, and a representation of the hydrologic cycle.When deep ocean temperatures in the model are increased to levels suggested by geologic data for the Cretaceous, surface temperatures at mid to high latitudes become much warmer and the circulation of the atmosphere becomes much subdued, especially as indicated by eddy statistics. These results hold for both present-day and Cretaceous land-ocean distributions, indicating that deep ocean temperature, not geography, is the key model boundary condition. The results also agree with interpretations of geologic data, but disagree in part with earlier interpretations of GCM studies of the Cretaceous. Removal of sea ice (with resultant change from a land-like to an ocean surface) accounts for much of the high latitude warming.     

Perturbation equations for the time-average state of the atmosphere including the effects of transient disturbances

Summary The time-average, or «stationary», state of the atmosphere can be regarded as a forced response to large-scale transient eddy transports of heat and momentum, as well as to fixed sources and sinks of heat and momentum resulting from small-scale transient eddy processes, non-adiabatic processes (e. g., radiation and phase transformations), topography, and friction. Perturbation equations governing this response are derived and a program of research based on the equations is proposed.     

Parameterization of hemispheric heating and temperature variance fields in the lower troposphere

Summary Indirect observational estimates are obtained of the covariance of diabatic heating and temperature at 850 mb, and of the implied value of the Newtonian cooling coefficient, for winter and summer mean conditions over the Northern Hemisphere. Combining the Newtonian approximation for heating and the Austausch approximation for the horizontal transient eddy heat transport we obtain a simple formula for the variance of the temperature at 850 mb in terms of the climatological mean temperature field at that level. Hemispheric fields computed from this formula seem to be an acceptable first approximation to the observations     

夏季自然水体与大气界面间气态总汞的交换通量

利用动力学通量箱法与高时间分辨率大气测汞仪的联用技术, 在瑞典西南的Kristineberg海洋观测站(KMRS)和Knobesholm的Hovgårdsån河分别测定了夏季海水和河水表面与大气间汞的交换通量. 在夏季, 河水和海水都是大气汞的源. 河水和海水表面与大气间汞的交换通量在夏季具有一致的昼夜变化规律, 白天由水体向大气排汞且在正午达到最大值; 夜间排汞量相对较小且有时会出现大气汞向水体沉降. 河水与大气间汞的交换通量与光照强度呈线性正相关关系, 与大气相对湿度呈线性负相关性, 同时还与水体温度存在指数相关性. 海水与大气间汞交换通量只与光照强度存在良好的线性正相关关系. 水体中溶解态气汞的过饱和是水体汞向大气释放的驱动力.     

Adsorption of monocarboxylates at the water/goethite interface: The importance of hydrogen bonding

The adsorption of monocarboxylates (acetate, benzoate, and cyclohexanecarboxylate) at the water/goethite interface was studied as a function of pH and ionic strength by means of quantitative adsorption measurements and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. ATR-FTIR spectra were obtained of suspensions prepared in both H₂O and D₂O. In order to identify the number of predominating surface complexes and to improve the resolution of overlapping peaks the ATR-FTIR spectra were subjected to a 2D correlation spectroscopic analysis. The adsorption envelopes of acetate, benzoate, and cyclohexanecarboxylate are similar and depend strongly on pH and ionic strength, but the pH dependence is also correlated to the slightly different pK_a values of the monocarboxylic acids. At the molecular level, the ATR-FTIR spectroscopic results reveal two surface complexes: one solvent-surface hydration-separated ion pair and one surface hydration-shared ion pair. The former predominates at circumneutral pH values while the latter forms mainly in the acidic pH range. We find no evidence for direct inner-sphere coordination between the carboxylic oxygens and the Fe(III) ions present at the surface. The identification of surface hydration-shared ion pairs emphasizes the importance of comparatively strong ionic hydrogen-bonding interactions for adsorption processes at the water/goethite interface.     

Reactive monazite and robust zircon growth in diatexites and leucogranites from a hot,slowly cooled orogen: implications for the Palaeoproterozoic tectonic evolution of the central Fennoscandian Shield,Sweden

Monazite in melt-producing, poly-metamorphic terranes can grow, dissolve or reprecipitate at different stages during orogenic evolution particularly in hot, slowly cooling orogens such as the Svecofennian. Owing to the high heat flow in such orogens, small variations in pressure, temperature or deformation intensity may promote a mineral reaction. Monazite in diatexites and leucogranites from two Svecofennian domains yields older, coeval and younger U–Pb SIMS and EMP ages than zircon from the same rock. As zircon precipitated during the melt-bearing stage, its U–Pb ages reflect the timing of peak metamorphism, which is associated with partial melting and leucogranite formation. In one of the domains, the Granite and Diatexite Belt, zircon ages range between 1.87 and 1.86 Ga, whereas monazite yields two distinct double peaks at 1.87–1.86 and 1.82–1.80 Ga. The younger double peak is related to monazite growth or reprecipitation during subsolidus conditions associated with deformation along late-orogenic shear zones. Magmatic monazite in leucogranite records systematic variations in composition and age during growth that can be directly linked to Th/U ratios and preferential growth sites of zircon, reflecting the transition from melt to melt crystallisation of the magma. In the adjacent Ljusdal Domain, peak metamorphism in amphibolite facies occurred at 1.83–1.82 Ga as given by both zircon and monazite chronology. Pre-partial melting, 1.85 Ga contact metamorphic monazite is preserved, in spite of the high-grade overprint. By combining structural analysis, petrography and monazite and zircon geochronology, a metamorphic terrane boundary has been identified. It is concluded that the boundary formed by crustal shortening accommodated by major thrusting.     

Landscape care paradoxes: Swedish landscape care arrangements in a European context

Contemporary European agriculture has a number of additional aims beside of food production, such as safeguarding environmental services and conservation values. Substantial efforts at official levels are aimed towards sustainable development but also towards maintaining values of what may be termed vanishing landscapes. Selected areas and landscape features are set aside for protection or restoration. Individual efforts of this type have a long history in Sweden, and the issue has recently received increased attention, primarily due to more ambitious government goals concerning biodiversity conservation and Sweden’s ratification of the European Landscape Convention. This has resulted in an increased scientific and official interest in vanishing values in the rural landscape, where parts of Eastern Europe, such as the Maramures district in Romania, have been used as model examples of land use regimes which in the past was common in Sweden. In this context, the dilemma of romanticizing peasants’ use of land is highlighted and discussed more than has hitherto been done. This paper sheds light on some paradoxes inherent in official policies in relation to land use practices concerning the management of rural landscapes in Sweden, and relates the Swedish situation to a contrasting example of landscape practice in Romania. We discuss the concept of landscape care in relation to the construction and perception of landscape values and valuable landscapes through the lenses of rural realities and official policies. When Swedish authorities engage in the promotion of landscape care, they tend to work with slices of land, specific predefined values and individual farmers, and they often disregard the need to treat the landscape as a socio-ecological complex dynamic in space and time. We discuss how environmental policy generally could be improved through the adoption of a more inclusive and flexible approach towards aiding the different aims inherent in multifunctional rural landscapes.     

Hydrogen peroxide concentrations in the Peru upwelling area

The concentration of hydrogen peroxide was measured in waters off the coast of Peru during June and July 1983. The study period coincided with the end of the 1982/83 El Niño and the onset of coastal upwelling. Depth profiles of hydrogen peroxide concentration exhibit surface maxima and decrease with depth to the base of the mixed layer. Surface peroxide concentrations ranged from 0.8 to 5 × 10^?8 M. Below the mixed layer hydrogen peroxide was below the detection limit (5 × 10^?9 M). Diel variations were observed, with surface peroxide levels increasing during the day and decreasing at night. The nearshore station exhibited lower hydrogen peroxide concentrations than offshore stations, a reversal of the trend found in other coastal regions. This is attributed to the lack of coastal vegetation and runoff, and to active coastal upwelling of deeper water with low hydrogen peroxide concentrations.