Population increase impacts the climate,using the sensitive Arctic as an example          下载免费PDF全文

Ola M. Johannessen  Elena V. Shalina 《大气和海洋科学快报》2022,15(2):100192

The global population during the last 100 years has increased from 2 to 7.7 billion, causing an increase in greenhouse gases in the atmosphere. In order to see how population increase is directly related to physical variables of the climate, this Perspective article places observations and scenarios of climate change into context and puts forth a statistical modeling study on how the sensitive Arctic climate responds to the increasing population. The relationships between population, Arctic sea-ice extent (SIE), and surface air temperature (SAT) are very strong, with the increasing population explaining 96% of the decreasing SIE and about 80% of the increasing SAT in the Arctic. Our projection for the SIE using the population as a “proxy predictor” for a projected population of 10 billion people on the Earth in 2100, yields a SIE of 9.30 and 8.21 million km² for a linear and squared relationship, respectively, indicating no “tipping point” for the annual ice extent in this century. This adds another dimension to climate understanding for the public at large using population as a proxy variable, instead of the more abstract CO₂ parameter. This also indicates that it is important to attempt to limit the ongoing increase in population, which is the main cause of the greenhouse gas emissions, in addition to reducing per capita emissions by an exponential increase in implementing renewable energy, a formidable challenge in this century.  相似文献   

Comet Hyakutake (C/1996 B2): Spectacular disconnection event and the latitudinal structure of the solar wind     

M Snow  J.C Brandt  C.C Petersen  H Mikuz 《Planetary and Space Science》2004,52(4):313-323

Images of comet Hyakutake (C/1996 B2) are analyzed in conjunction with solar wind data from spacecraft to determine the relationship between solar wind conditions and plasma tail morphology. The disconnection event (DE) on March 25, 1996 is analyzed with the aid of data from the IMP-8 and WIND Earth-orbiting spacecraft and the DE is found to be correlated with a crossing of the heliospheric current sheet. The comet was within of Earth at the time of the DE and data from IMP-8 and WIND show no high-speed streams, significant density enhancements or shocks.The latitudinal variation in the appearance and orientation of the plasma tail are interpreted based on results from the Ulysses spacecraft. In the polar solar wind region, the comet has a relatively undisturbed appearance, no DEs were observed, and the orientation of the plasma tail was consistent with a higher solar wind speed. In the equatorial solar wind region, the comet's plasma tail had a disturbed appearance, a major DE was observed, and the orientation of the plasma tail was consistent with a lower solar wind speed. The boundary between the equatorial and polar regions crossed by comet Hyakutake in April 1996 was near 30°N (ecliptic) or 24°N (solar) latitude.  相似文献   

Distributional effects of property rights: Transitions in the Atlantic Herring fishery     

Sylvia Brandt  David McEvoy   《Marine Policy》2006,30(6):659-670

A principal challenge in developing any fishery management plan is the allocation of benefits and costs among participants in the fishery. This process is further complicated by imperfect information about future market demand and limited ability to predict the consequences of regulatory change. This paper offers a new approach to policymakers, using econometric analysis to simulate the potential impact of individual tradable quotas (ITQs) in a fishery. We compare the distribution of harvest across participants in the Atlantic Herring fishery under the current open access regime and under a potential ITQ regime, assuming two different levels of future demand. Our results show that production efficiency varies by vessel gear, home-port and relationship with buyers. Some of the predicted consequences of ITQs are: vessels from Massachusetts will gain share relative to those from Maine; trawlers will gain share relative to purse seine vessels; and independent vessels will lose share relative to vessels that are primarily contracted to specific processors or bait companies. These results will help policymakers in developing future management plans for the herring fishery. More generally, this analytical approach can help regulators in any fishery assess the potential impact of alternative policy changes under alternative future demand scenarios.  相似文献   

On Novel Methods to Determine Areas of Sunspots from Photoheliograms     

Pettauer  T.  Brandt  P. N. 《Solar physics》1997,175(1):197-203

Two novel methods of measuring umbral and penumbral areas of sunspots and of complex sunspot groups are described. Both methods comprise the digitization of photoheliograms by a frame grabber and the computation of intensity histograms of selected areas of activity. The first method, called cumulative histogram method, in principle determines the intensity boundaries umbra–penumbra and penumbra–photosphere from the intersections of linear fits into the corresponding parts of the cumulative histograms of sunspots. The second method, called maximum gradient method, marks image pixels of a given intensity level ±2 units wide as a white isophote on a display. Interactive variation of this level makes it easy to visually select the contour line fitting the boundary penumbra–photosphere (or umbra–penumbra) best. At the same level usually the width of the contour line is smallest. In both cases the summation of the pixel numbers above the corresponding intensity levels yields the umbral and the total sunspot areas, respectively. Some limitations of the two methods are discussed.  相似文献   

Study of WATCH GRB error boxes     

J. Gorosabel  A. J. Castro-Tirado  N. Lund  S. Brandt  S. Guziy  A. Shlyapnikov 《Astrophysics and Space Science》1995,231(1-2):297-301

We have studied the first WATCH GRB Catalogue of-ray Bursts in order to find correlations between WATCH GRB error boxes and a great variety of celestial objects present in 33 different catalogues. No particular class of objects has been found to be significantly correlated with the WATCH GRBs.  相似文献   

Preface          下载免费PDF全文

Hui-Jun Wang  Ola M.Johannessen 《大气和海洋科学快报》2018,(2)

正Special Issue to Commemorate the 10th Anniversary of Atmospheric and Oceanic Science Letters First published in late 2008 and currently in Volume 11(2018),Atmospheric and Oceanic Science Letters(AOSL)is unique in providing a rapid communication channel between academic communities concerned with the interdisciplinary research areas of atmospheric science and physical oceanography.This approach allows the journal to cover such critical issues as climate change,the cryosphere,water resources,  相似文献   

Climate change in the North- past, present and future     

Joern Thiede Ola M. Johannessen 《《幕》》2008,31(1):163-167

The Nordic countries have produced famous polar explorers and researchers who have generated climate research schools at a variety of locations. The dependence of these countries with respect to the lifelihood of their societies, of their use of lands and seas, the exploitation of marine living and non-living resources have made climate research an eminent topic, and many outstanding discoveries of longand short-term climate change have been made for the first time in Scandinavia. These include early contributions to our understanding of the geological effects of continent-wide glaciations during the ice ages, the complex postglacial history of the Baltic Sea and the varved sediment sequences preserved from lakes with an extraordinary seasonality in their sediment input, as well as the detailed records of temperature, ice texture and impurities and greenhouse gas variations of the last Glacial and of the Holocene preserved in the ice cores from Greenland. Iceland with its volcanic sequences and intercalated sediment layers not only preserved the history of this subaerial segment of the mid-Atlantic Ridge, but also easily datable paleoclimate records. The fate of the Vikings, who settled during the Medieval climate optimum on Iceland and later on Greenland and who lost their habitat on Greenland at the beginning of the Little Ice Age, illustrates vividly the climate-dependent subsistence of the indigenous and non-indigenous Scandinavian populations. Modern Scandinavian climate research institutions also include sophisticated modelling groups.  相似文献   

Benthic organic carbon flux and oxygen penetration reflect different plankton provinces in the Southern Ocean     

Oliver Sachs  Eberhard J. Sauter  Michael Schlüter  Michiel M. Rutgers van der Loeff  Kerstin Jerosch  Ola Holby 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(8):1319-1335

For the investigation of organic carbon fluxes reaching the seafloor, oxygen microprofiles were measured at 145 sites in different sub-regions of the Southern Ocean. At 11 sites, an in situ oxygen microprofiler was deployed for the measurement of oxygen profiles and the calculation of organic carbon fluxes. At four sites, both in situ and ex situ data were determined for high latitudes. Based on this data set as well as on previous published data, a relationship was established for the estimation of fluxes derived by ex situ measured O₂ profiles. The fluxes of labile organic matter range from 0.5 to 37.1 mg C m^?2 d^?1. The high values determined by in situ measurements were observed in the Polar Front region (water depth of more than 4290 m) and are comparable to organic matter fluxes observed for high-productivity, upwelling areas like off West Africa. The oxygen penetration depth, which reflects the long-term organic matter flux to the sediment, was correlated with assemblages of key diatom species. In the Scotia Sea (～3000 m water depth), oxygen penetration depths of less than 15 cm were observed, indicating high benthic organic carbon fluxes. In contrast, the oxic zone extends down to several decimeters in abyssal sediments of the Weddell Sea and the southeastern South Atlantic. The regional pattern of organic carbon fluxes derived from microsensor data suggests that episodic and seasonal sedimentation pulses are important for the carbon supply to the seafloor of the deep Southern Ocean.  相似文献   

PCB contamination from sampling equipment and packaging     

Malin Andersson  Rolf Tore Ottesen  Morten Jartun  Ola Eggen  Ann-Christine Enqvist 《Applied Geochemistry》2012

Work reported in this paper suggests that there are cases of contamination of soil and water samples by polychlorinated biphenyls (PCB) from paper and plastic packaging. Soil samples, which have been stored in paper bags for more than 20 years, share a similar congener distribution as the bags. Analyses showed a predominance of light congeners. PCB-analyses of water also indicate that water samples could be contaminated by plastic packaging. All analytical results of solid material packaging, as well as soil stored in the packaging, show a high relative amount of light weight PCB congeners. The paper bags that were analysed are made of strong paper and very popular among geochemists because of their watertight quality. These paper bags were manufactured more than 20 years ago. The plastic packaging that was analysed was produced in 1997 and 2008. The analyses of plastic and paper show that the raw material that has been used in the production at different times contains a wide concentration range of PCB. Re-sealable plastic bags, which contained the highest levels of PCB of the plastic material, are used by researchers world-wide as sampling bags for soils and sediments. This paper raises an important issue that packaging may potentially contaminate the samples that they hold.  相似文献   

First ENA observations at Mars: Charge exchange ENAs produced in the magnetosheath     

H. Gunell  K. Brinkfeldt  P. C:son Brandt  E. Kallio  Y. Futaana  H. Andersson  A. Grigoriev  R.A. Frahm  J.R. Scherrer  D.R. Linder  T. Säles  W. Schmidt  J. Kozyra  E. Roelof  S. Livi  K.C. Hsieh  M. Grande  J.-A. Sauvaud  J.-J. Thocaven  S. Orsini  M. Maggi  P. Bochsler  J. Woch  K. Asamura 《Icarus》2006,182(2):431-438

Measurements of energetic neutral atoms (ENA) generated in the magnetosheath at Mars are reported. These ENAs are the result of charge exchange collisions between solar wind protons and neutral oxygen and hydrogen in the exosphere of Mars. The peak of the observed ENA flux is . For the case studied here, i.e., the passage of Mars Express through the martian magnetosheath around 20:15 UT on 3 May 2004, the measurements agree with an analytical model of the ENA production at the planet. It is possible to find parameter values in the model such that the observed peak in the ENA count rate during the spacecraft passage through the magnetosheath is reproduced.  相似文献