ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2013-01-03
    Description: [1]  CMIP5 multimodel ensemble projection of midlatitude storm track changes has been examined. Storm track activity is quantified by temporal variance of meridional wind and sea level pressure (psl), as well as cyclone track statistics. For the Southern Hemisphere (SH), CMIP5 models project clear poleward migration, upward expansion, and intensification of the storm track. For the Northern Hemisphere (NH), the models also project some poleward shift and upward expansion of the storm track in the upper troposphere/lower stratosphere, but mainly weakening of the storm track toward its equatorward flank in the troposphere. Consistent with these, CMIP5 models project significant increase in the frequency of extreme cyclones during the SH cool season, but significant decrease in such events in the NH. Comparisons with CMIP3 projections indicate high degrees of consistency for SH projections, but significant differences are found in the NH. Overall, CMIP5 models project larger decrease in storm track activity in the NH troposphere, especially over North America in winter, where psl variance as well as cyclone frequency and amplitude are all projected to decrease significantly. In terms of climatology, similar to CMIP3, most CMIP5 models simulate storm tracks that are too weak and display equatorward biases in their latitude. These biases have also been related to future projections. In the NH, the strength of a model's climatological storm track is negatively correlated with its projected amplitude change under global warming, while in the SH, models with large equatorward biases in storm track latitude tend to project larger poleward shifts.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2013-12-11
    Description: [1]  Cyclones are responsible for much of the high impact weather in the extratropics, thus how they will change under global warming is of great concern. Several studies have used the multi-model climate simulations conducted under Phase 5 of the Coupled Model Intercomparison Project (CMIP5) to examine such changes. One study suggested that the frequency of strong cyclones is projected to decrease over the North Pacific, while another concluded that this frequency will increase. [2]  A single tracking algorithm has been used to derive cyclone statistics from 23 CMIP5 simulations using two different definitions of cyclones: cyclones as minima in total sea level pressure (SLP), or cyclones as minima in SLP perturbations about a large scale, low frequency background. When cyclones are defined by total SLP, the frequency of deep cyclones over the Pacific is projected to increase, while if cyclones are defined as perturbations, this frequency is projected to decrease. These differences are shown to be due to a projected deepening of the climatological mean Aleutian low. [3]  In view of these results, it is important to critically assess how cyclones should be defined. Preliminary results suggest that among CMIP5 simulations, over the Pacific, both the projected changes in the frequency of high wind events and mean available potential energy are better correlated with the projected changes in the frequency of cyclones defined as perturbations. It is concluded that more research should be done to quantify and understand the impacts of the different definitions of cyclones.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2012-12-15
    Description: CMIP5 multimodel ensemble projection of midlatitude storm track changes has been examined. Storm track activity is quantified by temporal variance of meridional wind and sea level pressure (psl), as well as cyclone track statistics. For the Southern Hemisphere (SH), CMIP5 models project clear poleward migration, upward expansion, and intensification of the storm track. For the Northern Hemisphere (NH), the models also project some poleward shift and upward expansion of the storm track in the upper troposphere/lower stratosphere, but mainly weakening of the storm track toward its equatorward flank in the troposphere. Consistent with these, CMIP5 models project significant increase in the frequency of extreme cyclones during the SH cool season, but significant decrease in such events in the NH. Comparisons with CMIP3 projections indicate high degrees of consistency for SH projections, but significant differences are found in the NH. Overall, CMIP5 models project larger decrease in storm track activity in the NH troposphere, especially over North America in winter, where psl variance as well as cyclone frequency and amplitude are all projected to decrease significantly. In terms of climatology, similar to CMIP3, most CMIP5 models simulate storm tracks that are too weak and display equatorward biases in their latitude. These biases have also been related to future projections. In the NH, the strength of a model's climatological storm track is negatively correlated with its projected amplitude change under global warming, while in the SH, models with large equatorward biases in storm track latitude tend to project larger poleward shifts.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2014-07-13
    Description: A 12-m diameter radio telescope will be deployed to the Summit Station in Greenland to provide direct confirmation of a Super Massive Black Hole (SMBH) by observing its shadow image in the active galaxy M87. The telescope (Greenland Telescope: GLT) is to become one of the Very Long Baseline Interferometry (VLBI) stations at sub-millimeter (submm) regime, providing the longest baseline 〉 9,000 km to achieve an exceptional angular resolution of 20 µas at 350 GHz, which will enable us to resolve the shadow size of ~40 µas. The triangle with the longest baselines formed by the GLT, the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, and the Submillimeter Array (SMA) in Hawaii will play a key role for the M87 observations. We have been working on the image simulations based on realistic conditions for a better understanding of the possible observed images. In parallel, retrofitting of the telescope and the site developments are in progress. Based on three years of opacity monitoring at 225 GHz, our measurements indicate that the site is excellent for submm observations, comparable to the ALMA site. The GLT is also expected to make single-dish observations up to 1.5 THz.
    Print ISSN: 0048-6604
    Electronic ISSN: 1944-799X
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2013-04-09
    Description: [1]  Many studies have attempted to estimate the equilibrium climate sensitivity (CS) to the doubling of CO 2 concentrations. One common methodology is to compare versions of Earth Models of Intermediate Complexity (EMICs) to spatially and/or temporally averaged historical observations. Despite the persistent efforts, CS remains uncertain. It is, thus far, unclear what is driving this uncertainty. Moreover, the effects of the internal climate variability on the CS estimates obtained using this method have not received thorough attention in the literature. [2]  Using a statistical approximator (“emulator”) of an EMIC, we show in an observation system simulation study, that unresolved internal climate variability appears to be a key driver of CS uncertainty (as measured by the 68% credible interval). We first simulate many realizations of pseudo-observations from an emulator at a “true” prescribed CS, and then re-estimate the CS using the pseudo-observations and an inverse parameter estimation method. [3]  We demonstrate that a single realization of the internal variability can result in a sizable discrepancy between the best CS estimate and the truth. Specifically, the average discrepancy is 0.84 °C, with the feasible range up to several °C. The results open the possibility that recent climate sensitivity estimates from global observations and EMICs are systematically considerably lower or higher than the truth, since they are typically based on the same realization of climate variability. This possibility should be investigated in future work. We also find that estimation uncertainties increase at higher climate sensitivities, suggesting that a high CS might be difficult to detect.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2013-08-02
    Print ISSN: 0930-7516
    Electronic ISSN: 1521-4125
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Published by Wiley
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2011-08-22
    Description: Background Porcine circovirus type 2 (PCV2) is associated with post-weaning multisystemic wasting syndrome (PMWS) in pigs. Currently, there is considerable interest in the immunology of PCV2; in particular, the immunological properties of the capsid protein. This protein is involved in PCV2 immunogenicity and is a potential target for vaccine development. In this study, we identified one critical amino acid that determines a conformational neutralizing epitope in the capsid protein of PCV2. Results One monoclonal antibody (mAb; 8E4), against the capsid protein of PCV2, was generated and characterized in this study. 8E4 reacted with the genotype PCV2a (CL, LG and JF2) strains but not PCV2b (YJ, SH and JF) strains by an immunoperoxidase monolayer assay (IPMA) and a capture ELISA. Furthermore, the mAb had the capacity to neutralize PCV2a (CL, LG and JF2) strains but not PCV2b (YJ, SH and JF) strains. One critical amino acid that determined a conformational neutralizing epitope was identified using mAb 8E4 and PCV2 infectious clone technique. Amino acid residues 47-72 in the capsid protein of PCV2a/CL were replaced with the corresponding region of PCV2b/YJ, and the reactivity of mAb 8E4 was lost. Further experiments demonstrated that one amino acid substitution, the alanine for arginine at position 59 (A59R) in the capsid protein of PCV2a (CL, LG and JF2) strains, inhibited completely the immunoreactivity of three PCV2a strains with mAb 8E4. Conclusions It is concluded that the alanine at position 59 in the capsid protein of PCV2a (CL, LG and JF2) strains is a critical amino acid, which determines one neutralizing epitope of PCV2a (CL, LG and JF2) strains. This study provides valuable information for further in-depth mapping of the conformational neutralizing epitope, understanding antigenic difference among PCV2 strains, and development of a useful vaccine for control of PCV2-associated disease.
    Electronic ISSN: 1471-2180
    Topics: Biology
    Published by BioMed Central
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...