Validity of the Fossil Fuel Production Outlooks in the IPCC Emission Scenarios

Anthropogenic global warming caused by CO₂ emissions is strongly and fundamentally linked to future energy production. The Special Report on Emission Scenarios (SRES) from 2000 contains 40 scenarios for future fossil fuel production and is used by the IPCC to assess future climate change. Previous scenarios were withdrawn after exaggerating one or several trends. This study investigates underlying assumptions on resource availability and future production expectations to determine whether exaggerations can be found in the present set of emission scenarios as well. It is found that the SRES unnecessarily takes an overoptimistic stance and that future production expectations are leaning toward spectacular increases from present output levels. In summary, we can only encourage the IPCC to involve more resource experts and natural science in future emission scenarios. The current set, SRES, is biased toward exaggerated resource availability and unrealistic expectations on future production outputs from fossil fuels.     

Inter-annual and seasonal variations in the air–sea CO2 balance in the central Baltic Sea and the Kattegat

We estimated the net annual air–sea exchange of carbon dioxide (CO₂) using monitoring data from the East Gotland Sea, Bornholm Sea, and Kattegat for the 1993–2009 period. Wind speed and the sea surface partial pressure of CO₂ (pCO₂^w), calculated from pH, total alkalinity, temperature, and salinity, were used for the flux calculations. We demonstrate that regions in the central Baltic Sea and the Kattegat alternate between being sinks (−) and sources (+) of CO₂ within the −4.2 to +5.2 mol m⁻² yr⁻¹ range. On average, for the 1994–2008 period, the East Gotland Sea was a source of CO₂ (1.64 mol m⁻² yr⁻¹), the Bornholm Sea was a source (2.34 mol m⁻² yr⁻¹), and the Kattegat was a sink (−1.16 mol m⁻² yr⁻¹). Large inter-annual and regional variations in the air–sea balance were observed. We used two parameterizations for the gas transfer velocity (k) and the choice varied the air–sea exchange by a factor of two. Inter-annual variations in pCO₂^w between summers were controlled by the maximum concentration of phosphate in winter. Inter-annual variations in the CO₂ flux and gas transfer velocity were larger between winters than between summers. This indicates that the inter-annual variability in the total flux was controlled by winter conditions. The large differences between the central Baltic Sea and Kattegat were considered to depend partly on the differences in the mixed layer depth.     

Homogeneous nucleation of amorphous solid water particles in the upper mesosphere

Condensed water particles are known to exist in the high latitude upper mesosphere during the summer months. However, the mechanism or mechanisms through which they nucleate remains uncertain. It is postulated here that particles of amorphous solid water (ASW, condensed water with a non-crystalline structure) may nucleate homogeneously in the summer mesosphere. Using classical nucleation theory and a one-dimensional model, it is shown that more than 10⁵ cm^?3 amorphous solid water particles can nucleate homogeneously under mesopause conditions. Furthermore, it is shown that homogeneous nucleation competes with heterogeneous nucleation on meteoric smoke particles when the cooling rate is >0.5 K/h. The homogeneous nucleation of amorphous solid water could provide an explanation for the high density of ice particles (many thousands per cm³) thought to be required for electron depletions in the upper mesosphere. A parameterisation for homogeneous nucleation is presented which can be used in other mesospheric cloud models.     

Integrated Interpretation of Interwell Connectivity Using Injection and Production Fluctuations

A method to characterize reservoirs, based on matching temporal fluctuations in injection and production rates, has recently been developed. The method produces two coefficients for each injector–producer pair; one parameter, λ, quantifies the connectivity and the other, τ, quantifies the fluid storage in the vicinity of the pair. Previous analyses used λ and τ separately to infer the presence of transmissibility barriers and conduits in the reservoir, but several common conditions could not be easily distinguished. This paper describes how λ and τ can be jointly interpreted to enhance inference about preferential transmissibility trends and barriers. Two different combinations are useful: one is a plot of log (λ) versus log (τ) for a producer and nearby injectors, and the second is a Lorenz-style flow capacity (F) versus storativity (C) plot. These techniques were tested against the results of a numerical simulator and applied to data from the North Buck Draw field. Using the simulated data, we find that the F–C plots and the λ–τ plots are capable of identifying whether the connectivity of an injector–producer well pair is through fractures, a high-permeability layer, multiple-layers or through partially completed wells. Analysis of data from the North Buck Draw field shows a reasonable correspondence between τ and the tracer breakthrough times. Of two possible geological models for Buck Draw, the F–C and λ–τ plots support the model that has less connectivity in the field. The wells in fluvial deposits show better communication than those wells in more estuarine-dominated regions.     

Kandidater udgået fra Københavns Universitets Geografiske Institut 1966–71

Christensen, Leif: Faststående og omlejrede Saale-morånelersaflejringer. Et eksempel fra Szdding-området, Vestjylland. Geografisk Tidsskrift 82: 91–94. Copenhagen, Dec. 1, 1982.

In situ clayey till materials on the Skovbjerg Bakkea, western Jutland can be recognized by crop-marks revealing pseudomorphs of ice-wedge polygons in orthogonal, random orthogonal and hexagonal patterns. The tills inside these polygonal patterns have high shear-strength values as measured by vane tests. Remoulded fossil solifluction deposits of till origin reveal stripes and deformed polygonal patterns in the crops. High strength as measured by vane are encountered below fossil solifluction deposits 4 meters below ground.     

Anmeldelser

Meyer, Marlene: Settlement Patterns and Land-use in Northern Ghana—A Study of the Changes during the period 1963–1991 based on Historical Surveys and recent SPOT-images. Geografisk Tidsskrift 92:101–104. Copenhagen 1992.

A study by Hunter (1966) describes how large areas along the Red Volta River bank, have been abandoned due to river blindness. The mapping of current land-use status and settlements patterns, using multispectral SPOT-satellite images, shows how the border of settlements continue to retreat, whereas new land is being reclaimed for bush fields in the abandoned areas.     

Methods for locating the proper position of a planned fishway entrance near a hydropower tailrace

The spatial distribution of upstream migrating Atlantic salmon (Salmo salar) spawners was studied in 2008 and 2009 in the surroundings of the tailrace from a hydropower station in the River Umeälven. This area is problematic because the fish have difficulties finding their way into the original riverbed, which prompted an investigation on the feasibility of adding a fishway in the area. Echo sounding was used in 2008 to investigate the spatial use of fish in the tailrace channel during the time of salmon migration. Presence of other fish species was so low that all echo sounding detections were assumed to be salmon. In 2009, data on wild radio-tagged salmon (n = 94) was collected in the same tailrace by an array of underwater antennas with a detection radius of approximately 10 m, to validate the results from the echo sounding. Both types of surveys showed aggregations of fish in one part of the tailrace. As a final step, Computational Fluid Dynamics (CFD) modeling was performed to analyze hydrodynamics. This CFD modeling showed a coincidence of fish detections in areas with turbulence intensities between 0.6 and 0.8, which may be an indication that the fish are holding in these areas to reduce energy expenditure during migration. A high proportion of the radio-tagged salmon were observed in the tailrace area (a median of 21 days between their first and last detection), indicating that the salmon are delayed in their upstream migration by the attraction to the tailrace in this area. The overall data on fish behavior in the tailrace led us to suggest a location for a new fishway where the fish aggregation was most pronounced. The number of detections from either technology had similar distributions over the tailrace, suggesting that the results are comparable. Thus, the split beam echo sounder can preferably be used to investigate which location is most appropriate for locations of entrances to new fishways since many more individual fishes are covered by this method compared to telemetry. Furthermore, there is no need to handle the fish in the echo sounding studies as is required in telemetry studies.     

Land acquisition: a means to mitigate water scarcity and reduce conflict?

ABSTRACT

In recent years there has been a surge in land investments, primarily in the African continent, but also in Asia and Latin America. This increase in land investment was driven by the food pricing crisis of 2007–2008. Land investors can be identified from a variety of sectors, with actors ranging from hedge funds to national companies. Many water-scarce countries in the Middle East and North Africa (MENA) are among these financiers, and primarily invest in Africa. Recognizing the potential for “outsourcing” their food security (and thereby also partly their water security), Middle Eastern countries such as Jordan, Qatar and the United Arab Emirates have invested in land for food production in Africa. The extent to which this is happening is still unclear, as many contracts are not yet official and the extent of the leases is vague. This paper investigates the land investments and acquisitions by Middle Eastern countries. It also seeks to analyse what effect, if any, these investments can have on the potential for conflict reduction and subsequent peacebuilding in the Middle East region as the activity removes pressure from transboundary water resources.

EDITOR D. Koutsoyiannis ASSOCIATE EDITOR K. Aggestam     

Integrating lysimeter drainage and eddy covariance flux measurements in a groundwater recharge model

Abstract

Field-scale water balance is difficult to characterize because controls exerted by soils and vegetation are mostly inferred from local-scale measurements with relatively small support volumes. Eddy covariance flux and lysimeters have been used to infer and evaluate field-scale water balances because they have larger footprint areas than local soil moisture measurements. This study quantifies heterogeneity of soil deep drainage (D) in four 12.5-m² repacked lysimeters, compares evapotranspiration from eddy covariance (ET_EC) and mass balance residuals of lysimeters (ETwb_Lys), and models D to estimate groundwater recharge. Variation in measured D was attributed to redirection of snowmelt infiltration and differences in lysimeter hydraulic properties caused by surface soil treatment. During the growing seasons of 2010, 2011 and 2012, ETwb_Lys (278, 289 and 269 mm, respectively) was in good agreement with ET_EC (298, 301 and 335 mm). Annual recharge estimated from modelled D was 486, 624 and 613 mm for three calendar years 2010, 2011 and 2012, respectively. In summary, lysimeter D and ET_EC can be integrated to estimate and model groundwater recharge.

Editor D. Koutsoyiannis     

Hyperspectral remote sensing analysis of short rotation woody crops grown with controlled nutrient and irrigation treatments

Hyperspectral remote sensing research was conducted to document the biophysical and biochemical characteristics of controlled forest plots subjected to various nutrient and irrigation treatments. The experimental plots were located on the Savannah River Site near Aiken, SC. AISA hyperspectral imagery were analysed using three approaches, including: (1) normalized difference vegetation index based simple linear regression (NSLR), (2) partial least squares regression (PLSR) and (3) machine-learning regression trees (MLRT) to predict the biophysical and biochemical characteristics of the crops (leaf area index, stem biomass and five leaf nutrients concentrations). The calibration and cross-validation results were compared between the three techniques. The PLSR approach generally resulted in good predictive performance. The MLRT approach appeared to be a useful method to predict characteristics in a complex environment (i.e. many tree species and numerous fertilization and/or irrigation treatments) due to its powerful adaptability.