CARRYING CAPACITY ON TIKOPIA ISLAND     

KIRSTEN HERVAD-JØRGENSEN M.Sc. 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):88-95

Hervad-Jørgensen, Kirsten: Carrying Capacity on Tikopia Island. Geografisk tidsskrift 76: 88–95. København, juni 1, 1977.

On the basis of two aerial photographs of the island of Tikopia, information on population, standard energy consumption, knowledge of the food pattern, the agricultural system and yields/ha it has been attempted to estimate the areas necessary for food production. To verify the assessed values, they have been put into various formulas for estimation of carrying capacity. The consistency of the values turns out very well and the used methodology might be a possible way to estimate carrying capacity with limited means.  相似文献   

ET FORSØG PÅ EN KLIMATISK- HYDROLOGISK REGIONSINDDELING AF HOLSTEINSBORG KOMMUNE (SISIMIUT)     

BENT HASHOLT  HENRIK SØGAARD 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):72-92

Hasholt, B. & H. Søgaard 1978: Et forsøg på en klimatisk-hydrologisk regionsinddeling af Holsteinsborg kommune (Sisimut). Geografisk Tidsskrift 77: 72–92. København juni 1,1978.

The Holsteinsborg municipality (Sisimut) has been divided into climatic and hydrological regions. The investigation is of a preliminary character due to the limited possibilities for field work.

The regionalization is based upon selected climatological and hydrological parameters; these were primarily snow cover (precipitation), potential evapotranspiration, run-off, and temperature. Measurements of water quality have been used as indicator of the aridity in the area.  相似文献   

Vertebrate remains in Holocene limestone cave sediments: faunal succession in the Sirijorda Cave, northern Norway     

EIVIND ØSTBYE  STEIN-ERIK LAURITZEN  DAGFINN MOE  KJARTAN ØSTBYE 《Boreas: An International Journal of Quaternary Research》2006,35(1):142-158

The faunal composition and temporal species succession dynamics during the Holocene are poorly known in Norway, and interpretations are often biased because of the potential overrepresentation of game species in the archaeological finds. Pitfall traps in limestone caves represent less biased long-term records of fauna, often being excellently preserved for thousands of years and thus providing an opportunity for reconstruction of the postglacial distribution history. We excavated fossiliferous sediments at the bottom of a 40-m entrance shaft, functioning as a pitfall trap, in the Sirijorda Cave, northern Norway, comprising 3467 identified vertebrate bone fragments. Radiocarbon-dating of mammalian bones at stratigraphic levels in excavated trenches was used for calibrating the time scale during the last 8000 ¹⁴C years BP, with a reconstruction of local vegetation history from a pollen profile in the cave deposits. At least 20 species were identified: one frog, two birds (plus 1-2 to genus level) and 17 mammals. Most of the species appeared more or less continuously during the covered time periods of the Atlantic, Subboreal and Subatlantic chronozones. With the exception of one species, Sorex isodon, which seems to have disappeared during the past 2000 years, all the registered species in the time profile are present in the area today. The possible immigration routes and time periods for (re)colonization of the recorded species are discussed.  相似文献   

Counterstreaming in a Large Polar Crown Filament   总被引：1，自引：0，他引：1  

Lin  Yong  Engvold  OddbjØ rn  Wiik  Jun Elin 《Solar physics》2003,216(1-2):109-120

The motion of small-scale structures is well resolved in high-resolution filament images that were observed on 19 June 1998 with the Swedish Vacuum Solar Telescope, La Palma. The filament was between 80 000 and 100 000 km high. The study is based on two hours of narrow-band observations at three wavelength positions in Hα. Velocities along the line of sight and in the transverse direction, respectively, V _los and V _tr, were measured for a large number of individual small-scale filament structures. Small features are all moving along nearly parallel threads, some in one direction along the threads and the remainder in the other direction, a pattern of motion known as counterstreaming. The net flow velocities in the two directions are about 8 km s⁻¹ and both are tilted by an angle δ≃16° relative to the plane of the sky. This angle is less than expected, by factors between 2.0 and 2.5, relative to the local horizontal plane. We believe that V _los is underestimated by these factors due to a line-shift reducing effect by the underlying Hα absorption line of the chromosphere. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1026150809598  相似文献   

The Subdwarf Database     

Roy H. ØStensen 《Astrophysics and Space Science》2004,291(3-4):263-266

An interactive database interface to the subdwarf catalogue has been designed and prototyped. The implementation is still under development, but is already fully functional. More than 2300 stars from an updated edition of the subdwarf catalogue have been loaded into the database, and additional photometric data from many other sources have been included. The database tools include advanced search capabilities in coordinate, magnitude and colour space. Output tables can be generated in HTML with hyperlinks to automatically generated finding charts, the SIMBAD database, the Aladin viewer, as well as an internal data sheet generated for each database entry. Search results can be visualised automatically as interactive position, magnitude or colour diagrams. Access to the database is currently restricted to those who wish to contribute to the development of the project.  相似文献   

THE ROLE OF ATMOSPHERIC CIRCULATION PATTERNS IN AGROCLIMATE VARIABILITY IN FINLAND, 1961–2011          下载免费PDF全文

MASOUD IRANNEZHAD  DELIANG CHEN  BJØRN KLØVE 《Geografiska Annaler: Series A, Physical Geography》2016,98(4):287-301

This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year^–1 and 1.39 ± 0.91 mm year^–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south‐western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north‐western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north‐east of Finland. The overall agroclimatic year‐to‐year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns.  相似文献   

Dimensional reduction of a fractured medium for a polymer EOR model     

Dugstad  Martin  Kumar  Kundan  Pettersen  Øystein 《Computational Geosciences》2021,25(5):1753-1773

Computational Geosciences - Dimensional reduction strategy is an effective approach to derive reliable conceptual models to describe flow in fractured porous media. The fracture aperture is several...  相似文献   

Adaptive lives. Navigating the global food crisis in a changing climate     

Jonas Østergaard Nielsen  Henrik Vigh 《Global Environmental Change》2012,22(3):659-669

Human adaptation to climate change is gaining increasing academic as well as political attention. Understanding how and what people around the world adapt to is, however, difficult. Climate change is often, if not always, only one of a multiplicity of exposures perforating local communities. In Biidi 2, a small Sahelian village in northern Burkina Faso, climate variability have had a great influence on inhabitants’ lives since the major droughts of the early 1970s and 1980s. Tracing the intertwinement of drought, diminishing agricultural production and the need to buy food, this article explores how villagers attempt to attract development projects and negotiate with political parties in order to negate the impact of the global food crisis on their livelihoods. In doing so the article attempts to show how adaptation to climate variability is related to multiple, intersecting processes, and in this specific case is a matter of navigating changing socioeconomic factors. Using recent theory from social anthropology, adaptation is explored as a matter of social navigation. It is suggested that this theoretical approach might help nuance and elucidate how, and to what, local people around the world adapt.  相似文献   

Hot subdwarfs in binary systems and the nature of their unseen companions     

S. Geier  U. Heber  A. Tillich  H. Hirsch  H. Edelmann  V. Schaffenroth  T. Kupfer  S. Müller  P. F. L. Maxted  R. Østensen  P. Podsiadlowski  T. Marsh  B. Gänsicke  L. Morales-Rueda  G. Nelemans  R. Napiwotzki  E. W. Günther  L. Carone 《Astrophysics and Space Science》2010,329(1-2):91-99

A large fraction of the sdB stars reside in short period binaries. It is therefore clear that binary evolution plays an important role in the still unsolved problem of hot subdwarf formation. Here we present new results from different projects devoted to the analysis of sdBs in close binaries. The nature and masses of the unseen companions of 31 sdBs have been constrained by an analysis of high resolution spectra. In the course of this study candidate systems with massive compact companions have been discovered. The HYPERMUCHFUSS project aims at finding such systems making use of the huge spectral database of SDSS. A multi-site follow-up campaign of promising radial velocity variable sdBs started in 2009 and preliminary results are shown here. The most recent discovery of a substellar companion to the bright sdB HD?149382 may provide new evidence for the decisive role of low mass companions for sdB formation in general. A mysterious IR-excess has been detected, which may be caused by this otherwise invisible companion. Another low mass companion has been found to orbit the sdB star EGB?5 within 16.5 days. The space mission CoRoT is performing wide field and high precision photometry. First preliminary results from a spectroscopic survey of the COROT fields are also reported.  相似文献   

Multicolour photometry of EO Ceti (PB 8783)     

M. Vučković  R. H. Østensen  C. Aerts  V. S. Dhillon  T. R. Marsh 《Astrophysics and Space Science》2010,329(1-2):183-187

We present the first-look analysis of the high-speed multicolour photometry of the bright V361 Hya-type star EO?Ceti (m _V=12.3). The observations were gathered with the three-channel ULTRACAM instrument attached to the 4.2-m William Herschel Telescope. The data set has a total time span of 6.2?d and consists of 31 h simultaneous three colour photometry. The main power regions in all three colours are the same as previously reported in the white light photometric campaigns on EO?Ceti. We calculate the frequencies, amplitudes and phases of the significant modes in three colours of the SDSS system, r′, g′ and u′. The amplitudes of the detected modes are the highest in the u′ lightcurve, and the phases are the same in all three colours within the measurement accuracy. The amplitudes of the highest signal-to-noise modes show time variability in all three colours. We analyse the amplitude and phase variations of the five highest signal-to-noise modes in different colours. Even though the amplitudes show variations from night to night, the amplitude ratios are found to be constant to within 2σ level. This result is promising as it allows us to compare the observed amplitude ratios with theoretically calculated amplitude ratios. This may further constrain the mode identification of the highest amplitude modes in EO?Ceti and let us test the proposed seismic and binary evolution models.  相似文献