159 results on '"Pak, B"'
Search Results
2. Amazon forest response to CO2 fertilization dependent on plant phosphorus acquisition
- Author
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Fleischer, K, Rammig, A, De Kauwe, MG, Walker, AP, Domingues, TF, Fuchslueger, L, Garcia, S, Goll, DS, Grandis, A, Jiang, M, Haverd, V, Hofhansl, F, Holm, JA, Kruijt, B, Leung, F, Medlyn, BE, Mercado, LM, Norby, RJ, Pak, B, von Randow, C, Quesada, CA, Schaap, KJ, Valverde-Barrantes, OJ, Wang, YP, Yang, X, Zaehle, S, Zhu, Q, and Lapola, DM
- Subjects
MD Multidisciplinary ,Meteorology & Atmospheric Sciences - Abstract
Global terrestrial models currently predict that the Amazon rainforest will continue to act as a carbon sink in the future, primarily owing to the rising atmospheric carbon dioxide (CO2) concentration. Soil phosphorus impoverishment in parts of the Amazon basin largely controls its functioning, but the role of phosphorus availability has not been considered in global model ensembles—for example, during the Fifth Climate Model Intercomparison Project. Here we simulate the planned free-air CO2 enrichment experiment AmazonFACE with an ensemble of 14 terrestrial ecosystem models. We show that phosphorus availability reduces the projected CO2-induced biomass carbon growth by about 50% to 79 ± 63 g C m−2 yr−1 over 15 years compared to estimates from carbon and carbon–nitrogen models. Our results suggest that the resilience of the region to climate change may be much less than previously assumed. Variation in the biomass carbon response among the phosphorus-enabled models is considerable, ranging from 5 to 140 g C m−2 yr−1, owing to the contrasting plant phosphorus use and acquisition strategies considered among the models. The Amazon forest response thus depends on the interactions and relative contributions of the phosphorus acquisition and use strategies across individuals, and to what extent these processes can be upregulated under elevated CO2.
- Published
- 2019
3. A systematic literature review for contextualizing participation in circular design.
- Author
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Rocha, V S B, Pak, B, and Piccardo, C
- Published
- 2024
- Full Text
- View/download PDF
4. TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO 2 fluxes, 1988-2003
- Author
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Baker, D. F, Law, R. M, Gurney, K. R, Rayner, P., Peylin, P., Denning, A. S, Bousquet, P., Bruhwiler, L., Chen, Y.-H., Ciais, P., Fung, I. Y, Heimann, M., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Taguchi, S., and Zhu, Z.
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annual variation ,atmospheric transport ,carbon cycle ,carbon dioxide ,carbon emission - Abstract
Monthly CO2 fluxes are estimated across 1988–2003 for 22 emission regions using data from 78 CO2 measurement sites. The same inversion (method, priors, data) is performed with 13 different atmospheric transport models, and the spread in the results is taken as a measure of transport model error. Interannual variability (IAV) in the winds is not modeled, so any IAV in the measurements is attributed to IAV in the fluxes. When both this transport error and the random estimation errors are considered, the flux IAV obtained is statistically significant at P ≤ 0.05 when the fluxes are grouped into land and ocean components for three broad latitude bands, but is much less so when grouped into continents and basins. The transport errors have the largest impact in the extratropical northern latitudes. A third of the 22 emission regions have significant IAV, including the Tropical East Pacific (with physically plausible uptake/release across the 1997–2000 El Niño/La Niña) and Tropical Asia (with strong release in 1997/1998 coinciding with large-scale fires there). Most of the global IAV is attributed robustly to the tropical/southern land biosphere, including both the large release during the 1997/1998 El Niño and the post-Pinatubo uptake.
- Published
- 2006
5. Impact of Fraserdale CO 2 observations on annual flux inversion of the North American boreal region
- Author
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Yuen, C.-W., Higuchi, K., Baker, D., Bousquet, P, Bruhwiler, L., Chen, Y.-H., Ciais, P., Denning, A. S., Fan, S., Fung, L., Gloor, M., Gurney, K. R., Heimann, M., John, J., Law, R. M., Maki, T,, Maksyutov, S., Pak, B., Peylin, P., Prather, M., Rayner, P., Sarmiento, J,, Taguchi, S., and Takahashi, T.
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boreal forest ,carbon dioxide ,carbon flux ,monitoring system - Abstract
In TransCom-3 (Level 1), atmospheric CO2 measurements from 76 monitoring stations for the period 1992–1996 and 16 atmospheric transport models were used to constrain annual mean CO2 fluxes over 11 land and 11 ocean regions. The tower measurements of atmospheric CO2 from Fraserdale, a continental site in northern Ontario, Canada are now available and processed for use in the TransCom-3 inverse modelling framework. In this short study, we show that by including this set of continental CO2 data, the estimated flux for the North American boreal region becomes nearly zero, a reduction of about 0.26 Pg C yr−1 from the previous estimate. The uncertainty of the estimated flux for this region is also reduced by ∼30%. All transport models show negative changes for boreal North America, with the strongest responses (∼−0.5 Pg C yr−1) shown by NIRE, NIES, CSU and SKYHI. Furthermore, models showing a strong response in boreal North America tend to show strong sensitivity in middle- and high-latitude Asian regions.
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- 2005
6. On error estimation in atmospheric CO 2 inversions
- Author
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Engelen, Richard J, Denning, A S, Gurney, K R, Law, R M, Rayner, P J, Baker, D, Bousquet, P, Bruhwiler, L, Chen, Y H, Ciais, P, Fan, S, Fung, I Y, Gloor, M, Heimann, M, Higuchi, K, John, J, Maki, T, Maksyutov, S, Masarie, K, Peylin, P, Prather, M, Pak, B C, Sarmiento, J, Taguchi, S, Takahashi, T, and Yuen, C W
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atmospheric movements ,carbon dioxide ,earth atmosphere ,error analysis ,inverse problems ,problem solving ,transport properties ,error ,fluxes ,model inversion - Abstract
This paper explores various sources of error in atmospheric CO2 synthesis inversions using global circulation models. The estimation of prior, observation, model transport, and representation errors is described, and the latter two error sources are explored in more detail. Not accounting for these errors will act as a hard constraint on the inversion and will produce incorrect solutions to the problem as is shown in some example inversions. The magnitude of these errors falls generally between about 10% and 100% in the retrieved fluxes but can be even larger. This makes it highly desirable to avoid hard constraints and apply any prior information we have about the surface fluxes as a weak constraint to the inversion problem.
- Published
- 2002
7. The Plumbing of Land Surface Models : Benchmarking Model Performance
- Author
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Best, M. J., Abramowitz, G., Johnson, H. R., Pitman, A. J., Balsamo, G., Boone, A., Cuntz, M., Decharme, B., Dirmeyer, P. A., Dong, J., Ek, M., Guo, Z., Haverd, V., van den Hurk, B. J. J., Nearing, G. S., Pak, B., Peters-Lidard, C., Santanello, J. A., Stevens, L., and Vuichard, N.
- Published
- 2015
8. Impact of Maternal Severe Acute Respiratory Syndrome Coronavirus 2 Detection on Breastfeeding Due to Infant Separation at Birth
- Author
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Popofsky, S, Noor, A, Leavens-Maurer, J, Quintos-Alagheband, ML, Mock, A, Vinci, A, Magri, E, Akerman, M, Noyola, E, Rigaud, M, Pak, B, Lighter, J, Ratner, AJ, Hanna, N, Krilov, L, Popofsky, S, Noor, A, Leavens-Maurer, J, Quintos-Alagheband, ML, Mock, A, Vinci, A, Magri, E, Akerman, M, Noyola, E, Rigaud, M, Pak, B, Lighter, J, Ratner, AJ, Hanna, N, and Krilov, L
- Abstract
OBJECTIVE: To assess the impact of separation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR)-positive mother-newborn dyads on breastfeeding outcomes. STUDY DESIGN: This observational longitudinal cohort study of mothers with SARS-CoV-2 PCR-and their infants at 3 NYU Langone Health hospitals was conducted between March 25, 2020, and May 30, 2020. Mothers were surveyed by telephone regarding predelivery feeding plans, in-hospital feeding, and home feeding of their neonates. Any change prompted an additional question to determine whether this change was due to coronavirus disease-2019 (COVID-19). RESULTS: Of the 160 mother-newborn dyads, 103 mothers were reached by telephone, and 85 consented to participate. There was no significant difference in the predelivery feeding plan between the separated and unseparated dyads (P = .268). Higher rates of breastfeeding were observed in the unseparated dyads compared with the separated dyads both in the hospital (P < .001) and at home (P = .012). Only 2 mothers in each group reported expressed breast milk as the hospital feeding source (5.6% of unseparated vs 4.1% of separated). COVID-19 was more commonly cited as the reason for change in the separated group (49.0% vs 16.7%; P < .001). When the dyads were further stratified by symptom status into 4 groups-asymptomatic separated, asymptomatic unseparated, symptomatic separated, and symptomatic unseparated-the results remained unchanged. CONCLUSIONS: In the setting of COVID-19, separation of mother-newborn dyads impacts breastfeeding outcomes, with lower rates of breastfeeding both during hospitalization and at home following discharge compared with unseparated mothers and infants. No evidence of vertical transmission was observed; 1 case of postnatal transmission occurred from an unmasked symptomatic mother who held her infant at birth.
- Published
- 2020
9. SIMILARITY ANALYSIS WITH RESPECT TO SOME QUALITY INDICATORS AND QUALITY
- Author
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Aydin, I, Algan, D, Pak, B, and Ocak, N
- Subjects
evaluation ,Feed value ,Quality grade ,Principle component ,Cluster analysis ,Forage - Abstract
One of factors to take into consideration to improve the rangeland quality is forage quality indicators (FQI) such as neutral detergent fiber (NDF), acid detergent fiber (ADF), digestible dry matter (DDM), dry matter intake (DMI), crude protein (CP), metabolizable energy (ME), relative feed value (RFV) and relative forage quality (RFQ). To study the relations among these indicators and to evaluate the sources of relationships and variations among the rangeland forages, 45 different desirable forage species were collected from Akdag rangelands in Samsun province of Turkey in 2015 and 2016. All FQI were analysed using the restricted maximum likelihood and a multivariate approach. The legume, grass and the other plant family species exhibited generally the highest, the lowest and intermediate FQI, respectively. The quality score based on RFQ was higher for the other family species than those for the legume and grass species. The NDF and ADF contents of species showed negative relationship with ME, RFV and RFQ, while the CP was positively and negatively correlated with these variables. The DDM, ME, RFV, RFQ and DMI components accounted for 86.68% of total variation of species. The first cluster composed of, in general, the legume and the other family species, whereas second cluster included all grass species. In conclusion, the legume and the other family species showed higher quality than grass species. The FQI appeared mainly botanical family dependent rather than single species. The ME, RFV and RFQ rather than the CP should be mainly considered for evaluation of species. C1 [Aydin, Ibrahim; Algan, Duygu] Univ Ondokuz Mayis, Fac Agr, Dept Field Crops, TR-55139 Kurupelit, Samsun, Turkey. [Pak, Betul] Univ Pamukkale, Tavas Vocat High Sch, Dept Crop & Anim Prod, TR-20500 Denizli, Turkey. [Ocak, Nuh] Univ Ondokuz Mayis, Fac Agr, Dept Anim Sci, TR-55139 Kurupelit, Samsun, Turkey.
- Published
- 2019
10. In Vitro hydrodynamic evaluation of prosthetic polymer heart valves in steady flow
- Author
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Pak, B. C., Cho, B. S., Baek, B. J., Kim, C. S., and Min, B. G.
- Published
- 1993
- Full Text
- View/download PDF
11. Amazon forest response to CO2 fertilization dependent on plant phosphorus acquisition
- Author
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Fleischer, K., Rammig, A., De Kauwe, M.G., Walker, A.P., Domingues, T.F., Fuchslueger, L., Garcia, S., Goll, D.S., Grandis, A., Jiang, M., Haverd, V., Hofhansl, F., Holm, J.A., Kruijt, B., Leung, F., Medlyn, B.E., Mercado, L.M., Norby, R.J., Pak, B., von Randow, C., Quesada, C.A., Schaap, K.J., Valverde-Barrantes, O.J., Wang, Y.-P., Yang, X., Zaehle, S., Zhu, Q., Lapola, D.M., Fleischer, K., Rammig, A., De Kauwe, M.G., Walker, A.P., Domingues, T.F., Fuchslueger, L., Garcia, S., Goll, D.S., Grandis, A., Jiang, M., Haverd, V., Hofhansl, F., Holm, J.A., Kruijt, B., Leung, F., Medlyn, B.E., Mercado, L.M., Norby, R.J., Pak, B., von Randow, C., Quesada, C.A., Schaap, K.J., Valverde-Barrantes, O.J., Wang, Y.-P., Yang, X., Zaehle, S., Zhu, Q., and Lapola, D.M.
- Abstract
Global terrestrial models currently predict that the Amazon rainforest will continue to act as a carbon sink in the future, primarily owing to the rising atmospheric carbon dioxide (CO2) concentration. Soil phosphorus impoverishment in parts of the Amazon basin largely controls its functioning, but the role of phosphorus availability has not been considered in global model ensembles—for example, during the Fifth Climate Model Intercomparison Project. Here we simulate the planned free-air CO2 enrichment experiment AmazonFACE with an ensemble of 14 terrestrial ecosystem models. We show that phosphorus availability reduces the projected CO2-induced biomass carbon growth by about 50% to 79 ± 63 g C m−2 yr−1 over 15 years compared to estimates from carbon and carbon–nitrogen models. Our results suggest that the resilience of the region to climate change may be much less than previously assumed. Variation in the biomass carbon response among the phosphorus-enabled models is considerable, ranging from 5 to 140 g C m−2 yr−1, owing to the contrasting plant phosphorus use and acquisition strategies considered among the models. The Amazon forest response thus depends on the interactions and relative contributions of the phosphorus acquisition and use strategies across individuals, and to what extent these processes can be upregulated under elevated CO2.
- Published
- 2019
12. Participation-based parametric design in early stages: A participative design process for spatial planning in office building
- Author
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Daher, E., Sylvain Kubicki, Pak, B., KepczynskaWalczak, A, and Bialkowski, S
- Abstract
The term participation has been used to define different activities, such as civil debate, communication, consultation, delegation, self-help construction, political decisions. However, participation in design started from the idea that individuals whom being affected by a design project must contribute to the design process. Recently, designers have been moving closer to the future users and developing new ways to empower them to get involved in the design process. In this paper we rethink the way the early design process is developed in a participatory approach thanks to parametric methods. A use case is proposed showing the potential of parametric design methods to empower the participation of users in the design of their facilities. The use case is dealing in particular with the spatial planning of an office building where the users together with the spatial planning team are able to design the layout spatial configuration by 1) fixing the objectives, 2) manipulating the model, 3)modifying some parameters, 4) visualizing the iterations and evaluating in a real-time each solution in an interactive 3D environment and together with facility managers 5) choosing the configuration of the spatial layout. no ISSN ispartof: pages:429-438 ispartof: Proceedings of the 36th eCAADe Conference - Volume 1 vol:1 pages:429-438 ispartof: the 36th eCAADe Conference: Computing for a better tomorrow location:Lodz University of Technology, Lodz, Poland, 19-21 September 2018 date:17 Sep - 21 Sep 2018 status: published
- Published
- 2018
13. Electrophilic reactions of group six element halides. 11. Synthesis of the condensed system selen (tellur) azino-[2, 3-g, h] carbazole
- Author
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Lendel, V. G., Pak, B. I., Balog, I. M., Kiyak, M. V., and Migalina, Yu. V.
- Published
- 1990
- Full Text
- View/download PDF
14. Modulation of Endothelial Bone Morphogenetic Protein Receptor Type 2 Activity by Vascular Endothelial Growth Factor Receptor 3 in Pulmonary Arterial Hypertension
- Author
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Peterson, L., Kang, H., Chun, H.J., Jin, S.-W., Hu, X., Lee, H.-W., Hwang, E.M., Park, J.-Y., Bautch, V.L., Lee, S., Sofer, A., Kim, J.-D., Pak, B., Papangeli, I., El-Hely, O., Hwangbo, C., Han, J., Wiley, D.S., Comhair, S., Ju, H., Dunworth, W.P., Erzurum, S.C., and Thomas, J.-L.
- Abstract
Background: Bone morphogenetic protein (BMP) signaling has multiple roles in the development and function of the blood vessels. In humans, mutations in BMP receptor type 2 (BMPR2), a key component of BMP signaling, have been identified in the majority of patients with familial pulmonary arterial hypertension (PAH). However, only a small subset of individuals with BMPR2 mutation develops PAH, suggesting that additional modifiers of BMPR2 function play an important role in the onset and progression of PAH. Methods: We used a combination of studies in zebrafish embryos and genetically engineered mice lacking endothelial expression of Vegfr3 to determine the interaction between vascular endothelial growth factor receptor 3 (VEGFR3) and BMPR2. Additional in vitro studies were performed by using human endothelial cells, including primary lung endothelial cells from subjects with PAH. Results: Attenuation of Vegfr3 in zebrafish embryos abrogated Bmp2b-induced ectopic angiogenesis. Endothelial cells with disrupted VEGFR3 expression failed to respond to exogenous BMP stimulation. Mechanistically, VEGFR3 is physically associated with BMPR2 and facilitates ligand-induced endocytosis of BMPR2 to promote phosphorylation of SMADs and transcription of ID genes. Conditional, endothelial-specific deletion of Vegfr3 in mice resulted in impaired BMP signaling responses, and significantly worsened hypoxia-induced pulmonary hypertension. Consistent with these data, we found significant decrease in VEGFR3 expression in pulmonary arterial endothelial cells from human PAH subjects, and reconstitution of VEGFR3 expression in PAH pulmonary arterial endothelial cells restored BMP signaling responses. Conclusions: Our findings identify VEGFR3 as a key regulator of endothelial BMPR2 signaling and a potential determinant of PAH penetrance in humans.
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- 2017
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15. The role of representations in architectural design learning
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Aydemir, A, primary, Pak, B, additional, and Scheerlinck, K, additional
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- 2017
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16. Project Arrivée: Countermapping Super-diversity in Brussels and Ghent with Architecture Students
- Author
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Pak, B, Meeus, B, Grasl, T, Martens, B, Wurzer, G, Grasl, Thomas, Martens, Bob, and Wurzer, Gabriel
- Abstract
In this paper we report on a research study in Brussels and Ghent on the affordances of geographic web platforms for countermapping. We use the term “affordance” to describe the “action possibilities latent in the environment in relation to agents and their capabilities” as introduced by Gibson (1986). Countermapping is a practice that actively challenges the dominant images of particular places (Peluso, 1995; Hodgson & Schroeder, 2002). Maps and visualizations with themes such as high densities of crime, poverty, foreigners and immigration reinforce these dominant discourses and the presumed isomorphism of particular Belgian urban neighbourhoods and crime, poverty and foreigners. Our countermapping project in this context aims at challenging dominant discourses that describe particular Belgian immigrant neighbourhoods as ‘no-go areas’, ‘ghetto’s’, ‘disadvantaged’ or ‘a foreign country’ (Schuermans et al., 2014). In order to develop a deeper understanding of these neighborhoods, there is a need for developing and testing alternative analysis and mapping strategies and tools. A new generation of geographical web (Geoweb 2.0) applications emerged during the last decade as a strong alternative to expert-led top-down production and analysis practices. Their availability and ease of use enabled novel modes of counter-mapping (Leszczynski, 2012: 544). Through these technologies, a large number of people became potential ‘sensors’ as well as ‘produsers’ of geographic information (Haklay et al. 2010)(Bruns, 2010). The possibility of facilitating collective production at a historically unprecedented scale enabled harnessing the power of masses or ‘crowdsourcing’ location-based intersubjective information (Goodchild, 2009). In this sense, Geoweb 2.0 is well-positioned for the collective countermapping of the particular urban ‘arrival neighborhoods’. In line with the aims above the research questions of our study are: • Can Geoweb 2.0 applications afford the countermapping of urban ‘arrival neighborhoods’? • What can we learn from countermaps created as a result? • What are the key factors to be considered for the facilitation of better Geoweb 2.0 supported countermapping practices? no issn publicationstatus: published ispartof: pages:369-378 ispartof: eCAADe 2015 - 33rd Annual Conference 16th-18th September 2015 pages:369-378 ispartof: International Conference on Education and Research in Computer Aided Architectural Design in Europe (eCAADe) location:Vienna date:16 Sep - 18 Sep 2015 status: published
- Published
- 2015
17. Collective city-making in Brussels
- Author
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Van Reusel, H, Pak, B, van Meerbeek, P, and Verbeke, J
- Subjects
action research ,collective city-making ,civic making ,design empowerment - Abstract
This paper is the result of a joint study emerging from a practice-based PhD and the Brussels Selfcityproject. Through the PhD an urban practice is developing – action-research - that aims at gaining a better understanding of collective tactical and grassroots city-making processes. For this, a constructive research collaboration with Piet Van Meerbeek and his Selfcityproject has been set up. Together we aimed to unravel, develop and empower collective city-making initiatives in the Brussels context. A case study has been made of five carefully selected projects – amongst which the action-case of the PhD. This has been done through a framework for ‘features of civic making’ which focuses on the critical aspects of the role and position of the actors, activism, ad hoc/organisation, openness and commoning,. In this paper, followed by a brief review of the growing movement of citizen initiatives, we will describe the outlined framework and give an overview of the studied cases using this structure. In the final chapter we will present our conclusions and speculate on how these findings can inspire the making and advancement of the own practice and similar future initiatives. publicationstatus: published ispartof: pages:364-378 ispartof: A publication by ADAPT-r for the Creative Practice Conference ‘Making Research | Researching Making’ (10-12 September 2015) pages:364-378 ispartof: International Conference for Creative Practice Research location:Aarhus status: published
- Published
- 2015
18. The Plumbing of Land Surface Models: Benchmarking Model Performance
- Author
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Vuichard, And, Best, M., Abramowitz, G., Johnson, H., Pitman, A., Balsamo, G., Boone, A., Cuntz, M., Decharme, B., Dirmeyer, P., Dong, J., EK, M., Guo, Z., Haverd, V., Van Den Hurk, B., Nearing, G., Pak, B., Peters-Lidard, C., Santanello, J., Stevens, L., Vuichard, N., Department Computational Hydrosystems [UFZ Leipzig], Helmholtz Centre for Environmental Research (UFZ), Joint DECC/Defra Met Office Hadley Centre Climate Programme CA01101Australian Research CouncilCE110001028United States Department of Energy (DOE)DE-FG02-04ER63917DE-FG02-04ER63911CFCAS Natural Sciences and Engineering Research Council of Canada (NSERC) BIOCAP CGIAR Natural Resources Canada European Commission FAO-GTOS-TCO iLEAPS Max Planck Institute for Biogeochemistry National Science Foundation (NSF) Tuscia University Universite Laval and Environment Canada United States Department of Energy (DOE, United Kingdom Met Office [Exeter], University of New South Wales [Sydney] (UNSW), European Centre for Medium-Range Weather Forecasts (ECMWF), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), George Mason University [Fairfax], Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), NASA Goddard Space Flight Center (GSFC), GSFC Hydrospheric and Biospheric Sciences Laboratory, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Water and Climate Risk, Amsterdam Global Change Institute, Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Climate Change Research Centre [Sydney] (CCRC), Météo France-Centre National de la Recherche Scientifique (CNRS), and Royal Netherlands Meteorological Institute (KNMI)
- Subjects
Surface (mathematics) ,Atmospheric Science ,Meteorology ,Climate Models ,Parameterization ,Project ,Sensible heat ,[SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology ,[SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems ,Latent heat ,Range (statistics) ,Energy partitioning ,Shortwave radiation ,SDG 7 - Affordable and Clean Energy ,[SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,Energy ,Water ,Model comparison ,Benchmarking ,Model evaluation/performance ,Impact ,Phase ,[SDE]Environmental Sciences ,Environmental science ,Soil-moisture ,Land surface model ,Hydrology ,Atmosphere Coupling Experiment ,Nonlinear regression ,Simulation - Abstract
The Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) was designed to be a land surface model (LSM) benchmarking intercomparison. Unlike the traditional methods of LSM evaluation or comparison, benchmarking uses a fundamentally different approach in that it sets expectations of performance in a range of metrics a priori—before model simulations are performed. This can lead to very different conclusions about LSM performance. For this study, both simple physically based models and empirical relationships were used as the benchmarks. Simulations were performed with 13 LSMs using atmospheric forcing for 20 sites, and then model performance relative to these benchmarks was examined. Results show that even for commonly used statistical metrics, the LSMs’ performance varies considerably when compared to the different benchmarks. All models outperform the simple physically based benchmarks, but for sensible heat flux the LSMs are themselves outperformed by an out-of-sample linear regression against downward shortwave radiation. While moisture information is clearly central to latent heat flux prediction, the LSMs are still outperformed by a three-variable nonlinear regression that uses instantaneous atmospheric humidity and temperature in addition to downward shortwave radiation. These results highlight the limitations of the prevailing paradigm of LSM evaluation that simply compares an LSM to observations and to other LSMs without a mechanism to objectively quantify the expectations of performance. The authors conclude that their results challenge the conceptual view of energy partitioning at the land surface.
- Published
- 2015
19. The plumbing of land surface models: Is poor performance a result of methodology or data quality?
- Author
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Haughton, N, Abramowitz, G, Pitman, AJ, Or, D, Best, MJ, Johnson, HR, Balsamo, G, Boone, A, Cuntz, M, Decharme, B, Dirmeyer, PA, Dong, J, Ek, M, Guo, Z, Haverd, V, van den Hurk, BJJ, Nearing, GS, Pak, B, Santanello, JA, Stevens, LE, Vuichard, N, Haughton, N, Abramowitz, G, Pitman, AJ, Or, D, Best, MJ, Johnson, HR, Balsamo, G, Boone, A, Cuntz, M, Decharme, B, Dirmeyer, PA, Dong, J, Ek, M, Guo, Z, Haverd, V, van den Hurk, BJJ, Nearing, GS, Pak, B, Santanello, JA, Stevens, LE, and Vuichard, N
- Abstract
The Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) illustrated the value of prescribing a priori performance targets in model intercomparisons. It showed that the performance of turbulent energy flux predictions from different land surface models, at a broad range of flux tower sites using common evaluation metrics, was on average worse than relatively simple empirical models. For sensible heat fluxes, all land surface models were outperformed by a linear regression against downward shortwave radiation. For latent heat flux, all land surface models were outperformed by a regression against downward shortwave radiation, surface air temperature, and relative humidity. These results are explored here in greater detail and possible causes are investigated. It is examined whether particular metrics or sites unduly influence the collated results, whether results change according to time-scale aggregation, and whether a lack of energy conservation in flux tower data gives the empirical models an unfair advantage in the intercomparison. It is demonstrated that energy conservation in the observational data is not responsible for these results. It is also shown that the partitioning between sensible and latent heat fluxes in LSMs, rather than the calculation of available energy, is the cause of the original findings. Finally, evidence is presented that suggests that the nature of this partitioning problem is likely shared among all contributing LSMs. While a single candidate explanation for why land surface models perform poorly relative to empirical benchmarks in PLUMBER could not be found, multiple possible explanations are excluded and guidance is provided on where future research should focus.
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- 2016
20. Linear and nonlinear effects of dominant drivers on the trends in global and regional land carbon uptake: 1959 to 2013
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Zhang, X, Rayner, PJ, Wang, Y-P, Silver, JD, Lu, X, Pak, B, Zheng, X, Zhang, X, Rayner, PJ, Wang, Y-P, Silver, JD, Lu, X, Pak, B, and Zheng, X
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- 2016
21. The plumbing of land surface models: Is poor performance a result of methodology or data quality?
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Haughton, N., Abramowitz, G., Pitman, A.J., Or, D., Best, M.J., Johnson, H.R., Balsamo, G., Boone, A., Cuntz, Matthias, Decharme, B., Dirmeyer, P.A., Dong, J., Ek, M., Guo, Z., Haverd, V., van den Hurk, B.J.J., Nearing, G.S., Pak, B., Santanello, J.A., Stevens, L.E., Vuichard, N., Haughton, N., Abramowitz, G., Pitman, A.J., Or, D., Best, M.J., Johnson, H.R., Balsamo, G., Boone, A., Cuntz, Matthias, Decharme, B., Dirmeyer, P.A., Dong, J., Ek, M., Guo, Z., Haverd, V., van den Hurk, B.J.J., Nearing, G.S., Pak, B., Santanello, J.A., Stevens, L.E., and Vuichard, N.
- Abstract
The Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) illustrated the value of prescribing a priori performance targets in model intercomparisons. It showed that the performance of turbulent energy flux predictions from different land surface models, at a broad range of flux tower sites using common evaluation metrics, was on average worse than relatively simple empirical models. For sensible heat fluxes, all land surface models were outperformed by a linear regression against downward shortwave radiation. For latent heat flux, all land surface models were outperformed by a regression against downward shortwave radiation, surface air temperature, and relative humidity. These results are explored here in greater detail and possible causes are investigated. It is examined whether particular metrics or sites unduly influence the collated results, whether results change according to time-scale aggregation, and whether a lack of energy conservation in flux tower data gives the empirical models an unfair advantage in the intercomparison. It is demonstrated that energy conservation in the observational data is not responsible for these results. It is also shown that the partitioning between sensible and latent heat fluxes in LSMs, rather than the calculation of available energy, is the cause of the original findings. Finally, evidence is presented that suggests that the nature of this partitioning problem is likely shared among all contributing LSMs. While a single candidate explanation for why land surface models perform poorly relative to empirical benchmarks in PLUMBER could not be found, multiple possible explanations are excluded and guidance is provided on where future research should focus.
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- 2016
22. Interactive Design: Designing Sensorial, Dialogical Spaces
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Maier, C, Pak, B, and Verbeke, J
- Abstract
In this paper, we describe an ongoing research project which is mainly based on the realization of several installations using interaction design as an essential quality. In Arts, the digital art, which is part of the so called new media art, represents a topic of actuality together while raising issues regarding its curation. Interactive installations, mainly artistic endeavors with intriguing outcomes and some using artificial lighting as a tool, introduce a different kind of experience than artworks exhibited and forbidden to be touched. Thanks to their interactive aspects, the user becomes a participant either willingly or unwillingly and influences the overall scene. These immersive installations have the potential to challenge the notions and perception of space, as well as to enrich any activity within that space. The interactive space becomes a place with intriguing qualities, an icon of human interaction and one that has the ability to adapt to our needs, while at the same time shaping our experiences. This interaction is not only with the installation itself, but also between individuals, thus fulfilling the evolving individual and social demands or intentions. publicationstatus: published ispartof: Acta Technica Napocensis: Civil Engineering & Architecture vol:57 pages:233-241 status: published
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- 2014
23. Using Social-Geograpic Web Platforms to Enhance Design Learning
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Pak, B, Verbeke, J, Schnabel, MA, and Schnabel, M. A.
- Abstract
publicationstatus: published ispartof: pages:61-70 ispartof: Cutting Edge: 47th International Conference of the Architectural Science Association pages:61-70 ispartof: Cutting Edge location:Hong Kong date:13 Nov - 16 Nov 2013 status: published
- Published
- 2013
24. Prince Lobanov-Rostovsky and Russia's Greater Role in the Far East.
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Pak, B.
- Subjects
- *
FOREIGN ministers (Cabinet officers) , *CHINESE-Japanese War, 1894-1895 - Published
- 2017
- Full Text
- View/download PDF
25. Improving the responses of the Australian community land surface model (CABLE) to seasonal drought
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Li, L, Wang, YP, Yu, Q, Pak, B, Eamus, D, Yan, J, Van Gorsel, E, and Baker, IT
- Abstract
Correct representations of root functioning, such as root water uptake and hydraulic redistribution, are critically important for modeling the responses of vegetation to droughts and seasonal changes in soil moisture content. However, these processes are poorly represented in global land surface models. In this study, we incorporated two root functions: a root water uptake function which assumes root water uptake efficiency varies with rooting depth, and a hydraulic redistribution function into a global land surface model, CABLE. The water uptake function developed by Lai and Katul (2000) was also compared with the default one (see Wang et al., 2010) that assumes that efficiency of water uptake per unit root length is constant. Using eddy flux measurements of CO 2 and water vapor fluxes at three sites experiencing different patterns of seasonal changes in soil water content, we showed that the two root functions significantly improved the agreement between the simulated fluxes of net ecosystem exchange and latent heat flux and soil moisture dynamics with those observed during the dry season while having little impact on the model simulation during the wet seasons at all three sites. Sensitivity analysis showed that varying several model parameters influencing soil water dynamics in CABLE did not significantly affect the model's performance. We conclude that these root functions represent a valuable improvement for land surface modeling and should be implemented into CABLE and other land surface models for studying carbon and water dynamics where rainfall varies seasonally or interannually. © 2012. American Geophysical Union. All Rights Reserved.
- Published
- 2012
26. Sensitivity of optimal extension of CO2 observation networks to model transport
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Patra, P., Maksyutov, S., Baker, D., Bousquet, P., Bruhwiler, L., Chen, Y., Ciais, P., Denning, A., Fan, S., Fung, I., Gloor, M., Gurney, K., Heimann, M., Higuchi, K., John, J., Law, R., Maki, T., Peylin, P., Prather, M., Pak, B., Rayner, P., Sarmiento, J., Taguchi, S., Takahashi, T., and Yuen, C.
- Subjects
Network planning and design ,Reduction (complexity) ,Atmospheric Science ,Meteorology ,Ensemble forecasting ,Flux ,Inverse ,Environmental science ,Spatial variability ,Sensitivity (control systems) ,Uncertainty reduction theory - Abstract
Optimal extensions of the surface CO 2 observation network have been determined using 15 global transport models and a time-independent inverse model. The regional average CO 2 flux estimate uncertainty is minimized based on the TransCom-3 (level 1) framework. An ensemble model calculation shows that the regional average CO 2 flux uncertainties could be reduced to about 0.36, 0.32, 0.28 or 0.26 Gt C yr −1 per region, from about 0.53 Gt C yr −1 per region corresponding to the basic network, after adding 5, 10, 15 or 20 optimally located stations, respectively. The additional station locations are mostly found in continental South America and Africa. The distribution of the efficiency in estimation of flux uncertainty reduction per station tends to become more uniform with the extension of the network. We show that the multimodel approach to network design converges if a large enough extension is considered; about 20 stations in this inverse model framework. The reduction in the flux uncertainty for the first few stations depends on the model of atmospheric transport, and is nearly proportional to the simulated signal from local emissions in the surface layer. In addition, it is seen that the simulated spatial and temporal variability of CO 2 concentration has significant influence on the distribution of the additional stations as well as determining the regional flux estimate uncertainty. DOI: 10.1034/j.1600-0889.2003.00056.x
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- 2011
27. The plumbing of land surface models: benchmarking model performance
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Best, M.J., Abramowitz, G., Johnson, H.R., Pitman, A.J., Balsamo, G., Boone, A., Cuntz, Matthias, Decharme, B., Dirmeyer, P.A., Dong, J., Ek, M., Guo, Z., Haverd, V., van den Hurk, B.J.J., Nearing, G.S., Pak, B., Peters-Lidard, C., Santanello Jr., J.A., Stevens, L., Vuichard, N., Best, M.J., Abramowitz, G., Johnson, H.R., Pitman, A.J., Balsamo, G., Boone, A., Cuntz, Matthias, Decharme, B., Dirmeyer, P.A., Dong, J., Ek, M., Guo, Z., Haverd, V., van den Hurk, B.J.J., Nearing, G.S., Pak, B., Peters-Lidard, C., Santanello Jr., J.A., Stevens, L., and Vuichard, N.
- Abstract
The Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) was designed to be a land surface model (LSM) benchmarking intercomparison. Unlike the traditional methods of LSM evaluation or comparison, benchmarking uses a fundamentally different approach in that it sets expectations of performance in a range of metrics a priori—before model simulations are performed. This can lead to very different conclusions about LSM performance. For this study, both simple physically based models and empirical relationships were used as the benchmarks. Simulations were performed with 13 LSMs using atmospheric forcing for 20 sites, and then model performance relative to these benchmarks was examined. Results show that even for commonly used statistical metrics, the LSMs’ performance varies considerably when compared to the different benchmarks. All models outperform the simple physically based benchmarks, but for sensible heat flux the LSMs are themselves outperformed by an out-of-sample linear regression against downward shortwave radiation. While moisture information is clearly central to latent heat flux prediction, the LSMs are still outperformed by a three-variable nonlinear regression that uses instantaneous atmospheric humidity and temperature in addition to downward shortwave radiation. These results highlight the limitations of the prevailing paradigm of LSM evaluation that simply compares an LSM to observations and to other LSMs without a mechanism to objectively quantify the expectations of performance. The authors conclude that their results challenge the conceptual view of energy partitioning at the land surface.
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- 2014
28. On error estimation in atmospheric CO2 inversions
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Peylin, Philippe, Engelen, R., Denning, A., Gurney, K., Law, R., Rayner, P., Baker, D., Bousquet, P., Bruhwiler, L., Chen, Y., Ciais, P., Fan, S., Fung, I., Gloor, M., Heimann, M., Higuchi, K., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Sarmiento, J., Taguchi, S., Takahashi, T., Yuen, C., Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Biomolécules : synthèse, structure et mode d'action (UMR 8642) (BIOSYMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Department of Physics [Tokyo], and Gakushuin University
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[SDE.MCG]Environmental Sciences/Global Changes ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2006
29. TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO 2 fluxes, 1988-2003
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Baker, D., Law, R., Gurney, K., Rayner, P., Peylin, P., Denning, A., Bousquet, P., Bruhwiler, L., Chen, Y.-H., Ciais, P., Fung, I., Heimann, M., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Taguchi, S., Zhu, Z., Princeton University, CSIRO Marine and Atmospheric Research (CSIRO-MAR), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Purdue University [West Lafayette], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Colorado State University [Fort Collins] (CSU), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), National Oceanic and Atmospheric Administration (NOAA), Massachusetts Institute of Technology (MIT), ICOS-ATC (ICOS-ATC), University of California [Berkeley], University of California, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Japan Meteorological Agency (JMA), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), University of California [Irvine] (UCI), National Institute of Advanced Industrial Science and Technology (AIST), NASA Goddard Space Flight Center (GSFC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley] (UC Berkeley), University of California (UC), and University of California [Irvine] (UC Irvine)
- Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,annual variation ,atmospheric transport ,carbon cycle ,ATMOSPHERIC CARBON-DIOXIDE, SENSITIVITY, DELTA-C-13, SINKS, CYCLE ,Physical Sciences and Mathematics ,carbon dioxide ,carbon emission ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment - Abstract
International audience; [1] Monthly CO 2 fluxes are estimated across 1988-2003 for 22 emission regions using data from 78 CO 2 measurement sites. The same inversion (method, priors, data) is performed with 13 different atmospheric transport models, and the spread in the results is taken as a measure of transport model error. Interannual variability (IAV) in the winds is not modeled, so any IAV in the measurements is attributed to IAV in the fluxes. When both this transport error and the random estimation errors are considered, the flux IAV obtained is statistically significant at P 0.05 when the fluxes are grouped into land and ocean components for three broad latitude bands, but is much less so when grouped into continents and basins. The transport errors have the largest impact in the extratropical northern latitudes. A third of the 22 emission regions have significant IAV, including the Tropical East Pacific (with physically plausible uptake/release across the 1997-2000 El Niño/La Niña) and Tropical Asia (with strong release in 1997/1998 coinciding with large-scale fires there). Most of the global IAV is attributed robustly to the tropical/southern land biosphere, including both the large release during the 1997/1998 El Niño and the post-Pinatubo uptake.
- Published
- 2006
30. TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO2 fluxes, 1988-2003
- Author
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Peylin, Philippe, Baker, Df, Law, Rm, Gurney, Kr, Rayner, P., Denning, As, Bousquet, P., Bruhwiler, L., Chen, Yh, Ciais, P., Fung, Iy, Heimann, M., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Taguchi, S., Zhu, Z., Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Department of Medicine, National University of Singapore (NUS), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
- Subjects
DELTA-C-13 ,SINKS ,[SDE.MCG]Environmental Sciences/Global Changes ,ATMOSPHERIC CARBON-DIOXIDE ,CYCLE ,SENSITIVITY - Abstract
International audience; Monthly CO2 fluxes are estimated across 1988-2003 for 22 emission regions using data from 78 CO2 measurement sites. The same inversion (method, priors, data) is performed with 13 different atmospheric transport models, and the spread in the results is taken as a measure of transport model error. Interannual variability (IAV) in the winds is not modeled, so any IAV in the measurements is attributed to IAV in the fluxes. When both this transport error and the random estimation errors are considered, the flux IAV obtained is statistically significant at P
- Published
- 2006
31. TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO2 fluxes, 1988-2003
- Author
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Baker, D., Law, R., Gurney, K., Rayner, P., Peylin, P., Denning, A., Bousquet, P., Bruhwiler, L., Chen, Y., Ciais, P., Fung, I., Heimann, M., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Taguchi, S., and Zhu, Z.
- Abstract
Monthly CO2 fluxes are estimated across 1988-2003 for 22 emission regions using data from 78 CO2 measurement sites. The same inversion (method, priors, data) is performed with 13 different atmospheric transport models, and the spread in the results is taken as a measure of transport model error. Interannual variability (IAV) in the winds is not modeled, so any IAV in the measurements is attributed to IAV in the fluxes. When both this transport error and the random estimation errors are considered, the flux IAV obtained is statistically significant at P
- Published
- 2006
32. Publisher's correction to 'On error estimation in atmospheric CO2 inversions' (Journal of Geophysical Research, 107(D22), 4635, doi:10.1029/2002JD02195, 2002)
- Author
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Engelen, R., Denning, A., Gurney, K., Law, R., Rayner, P., Baker, D., Bousquet, P., Bruhwiler, L., Chen, Y., Ciais, P., Fan, S., Fung, I., Gloor, M., Heimann, M., Higuchi, K., John, J., Maki, T., Maksyutov, S., Masarie, K., Peylin, P., Prather, M., Pak, B., Sarmiento, J., Taguchi, S., Takahashi, T., and Yuen, C.
- Published
- 2006
33. Synthesis of perhydro-1,4-selenazines and perhydro-1,4-tellurazines containing a sulfamide group
- Author
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Lendel, V. G., Sani, A. Yu., Migalina, Yu. Yu., Pak, B. I., and Balog, I. M.
- Published
- 1989
- Full Text
- View/download PDF
34. Transcom 3 inversion intercomparison: Model mean results for the estimation of seasonal carbon sources and sinks
- Author
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Gurney, K. R., Law, R. M., Denning, A. S., Rayner, P. J., Pak, B. C., Baker, D., Philippe Bousquet, Bruhwiler, L., Chen, Y. -H, Ciais, P., Fung, I. Y., Heimann, M., John, J., Maki, T., Maksyutov, S., Peylin, P., Prather, M., Taguchi, S., Department of Atmospheric Science [Fort Collins], Colorado State University [Fort Collins] (CSU), CSIRO Marine and Atmospheric Research [Aspendale], Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Department of Earth System Science [Irvine] (ESS), University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), National Center for Atmospheric Research [Boulder] (NCAR), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), NOAA Climate Monitoring and Diagnostics Laboratory (CMDL), National Oceanic and Atmospheric Administration (NOAA), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), ICOS-ATC (ICOS-ATC), University of California [Berkeley] (UC Berkeley), University of California (UC), Max-Planck-Institut für Biogeochemie (MPI-BGC), Japan Meteorological Agency (JMA), Frontier Research System for Global Change (FRSGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), National Institute of Advanced Industrial Science and Technology (AIST), University of California [Irvine] (UCI), University of California-University of California, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of California [Berkeley], University of California, Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), CSIRO Marine and Atmospheric Research (CSIRO-MAR), School of Earth Sciences [Melbourne], Faculty of Science [Melbourne], University of Melbourne-University of Melbourne, NOAA Earth System Research Laboratory (ESRL), Department of Earth and Planetary Science [UC Berkeley] (EPS), and National Institute for Environmental Studies (NIES)
- Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,inversion ,annual variation ,carbon transport ,atmospheric transport ,[SDE.MCG]Environmental Sciences/Global Changes ,carbon cycle ,Physical Sciences and Mathematics ,carbon dioxide ,carbon emission ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience; The TransCom 3 experiment was begun to explore the estimation of carbon sources and sinks via the inversion of simulated tracer transport. We build upon previous TransCom work by presenting the seasonal inverse results which provide estimates of carbon flux for 11 land and 11 ocean regions using 12 atmospheric transport models. The monthly fluxes represent the mean seasonal cycle for the 1992 to 1996 time period. The spread among the model results is larger than the average of their estimated flux uncertainty in the northern extratropics and vice versa in the tropical regions. In the northern land regions, the model spread is largest during the growing season. Compared to a seasonally balanced biosphere prior flux generated by the CASA model, we find significant changes to the carbon exchange in the European region with greater growing season net uptake which persists into the fall months. Both Boreal North America and Boreal Asia show lessened net uptake at the onset of the growing season with Boreal Asia also exhibiting greater peak growing season net uptake. Temperate Asia shows a dramatic springward shift in the peak timing of growing season net uptake relative to the neutral CASA flux while Temperate North America exhibits a broad flattening of the seasonal cycle. In most of the ocean regions, the inverse fluxes exhibit much greater seasonality than that implied by the DeltapCO(2) derived fluxes though this may be due, in part, to misallocation of adjacent land flux. In the Southern Ocean, the austral spring and fall exhibits much less carbon uptake than implied by DeltapCO2 derived fluxes. Sensitivity testing indicates that the inverse estimates are not overly influenced by the prior flux choices. Considerable agreement exists between the model mean, annual mean results of this study and that of the previously published TransCom annual mean inversion. The differences that do exist are in poorly constrained regions and tend to exhibit compensatory fluxes in order to match the global mass constraint. The differences between the estimated fluxes and the prior model over the northern land regions could be due to the prior model respiration response to temperature. Significant phase differences, such as that in the Temperate Asia region, may be due to the limited observations for that region. Finally, differences in the boreal land regions between the prior model and the estimated fluxes may be a reflection of the timing of spring thaw and an imbalance in respiration versus photosynthesis.
- Published
- 2004
35. TransCom 3 CO2 inversion intercomparison: 2. Sensitivity of annual mean results to data choices
- Author
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Law, R., Chen, Y., Gurney, K., Baker, D., Bousquet, P., Bruhwiler, L., Ciais, P., Denning, A., Fan, S., Fung, I., Gloor, M., Heimann, M., Higuchi, K., John, J., Maki, T., Maksyutov, S., Pak, B., Peylin, P., Prather, M., Rayner, N., Sarmiento, J., Taguchi, S., Takahashi, T., and Yuen, C.
- Abstract
TransCom 3 is an intercomparison project for CO2 source inversions. Annual mean CO2 concentration data are used to estimate CO2 sources using 16 different atmospheric transport models. Here we test the sensitivity of the inversion to the concentration data. We examine data network choice, time period of data, baseline data selection and the choice of data uncertainty used. We find that in most cases regional source estimates lie within the source uncertainty range of the control inversion. This indicates that the estimated sources are relatively insensitive to the changes in data that were tested. In the data network tests, only the Australian region source estimates varied over a much larger range than that given by the control case uncertainty estimate. For the other regions, the sensitivity to data network was within or close to the uncertainty range. Most of the sensitivity was found to be associated with a small number of sites (e.g. Darwin, Easter Island). These sites are often identified by the inability of the inversion to fit the data at these locations. The model-mean inversion values are mostly insensitive to the time period of data used, with the exception of temperate North America and the tropical Indian ocean. Data selection has a small impact on source estimates for the mean across models, but individual model sensitivity can be large. The magnitude of data uncertainties controls the relative magnitude of the estimated source uncertainty and the spread in model source estimates. Smaller data uncertainties lead to larger differences in source estimates between models. Overall, the data sensitivity tests performed here support the robustness of the control inversion source estimates presented in Gurney et al. (2003. Tellus 55B, this issue). The test results also provide guidance in setting up and interpreting other inversions.
- Published
- 2003
36. Reflective Practice in Urban Design
- Author
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Verbeke, J, Pak, B, De Maeyer, G, Montague, LM, Verbeke, J, Pak, B, De Maeyer, G, and Montague, LM
- Abstract
This paper presents part of a PhD that explores the ways in which theories in urban design influence the process of urban design, and the extent to which they may inform design decisions. The focus of the paper is the empirical stage of the research; the execution of a site evaluation, urban design framework and masterplan design for Croydon in London, a commentary recording that process, and the subsequent analysis of it. Reflection on that process and product appears to indicate that theory’s influence in the creative process of urban design is distinctive but subservient to a variety of other influences. Apparently, the more conceptual and strategic the stage of design, the more extensive and explicit theory’s influence is. Conversely, the more spatial and detailed the stage of design, the more tacit and fragmented theory’s involvement seems to be. It is often implicit, embedded within the guiding principles that the individual designer exercises when generating and evaluating ideas, evidenced in the thought processes and decisions that are made.
- Published
- 2013
37. Walkability as a Performance Indicator for Urban Spaces Strategies and tools for the social construction of experiences
- Author
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Pak, B. (author), Verbeke, J. (author), Pak, B. (author), and Verbeke, J. (author)
- Abstract
s paper frames walkability as a performance indicator for urban spaces and critically addresses some of the existing evaluation methods. It introduces alternative strategies and tools for enabling the collective evaluation of walkability and discusses how experiences of the citizens can possibly lead to a social construct of walkability. This discussion is elaborated by a pilot study which includes exploratory research, social-geographic web services and heat maps. Using these tools and methods, it was possible to derive various experiential and environmental spatial qualities, extract problems and identify problematic areas. From these we have learned that walkability may serve as a fruitful conversation framework and a participatory research concept. Furthermore, we were able to develop ideas for solutions to design and planning problems.
- Published
- 2013
38. Interannual growth rate variations of atmospheric CO2 and its δ13C, H2, CH4, and CO between 1992 and 1999 linked to biomass burning
- Author
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Langenfelds, R., Francey, R., Pak, B., Steele, L., Lloyd, J., Trudinger, C., and Allison, C.
- Abstract
[1] High-precision, multispecies measurements of flask air samples since 1992 from CSIRO's global sampling network reveal strong correlation among interannual growth rate variations of CO2 and its delta(13)C, H-2,CH4, and CO. We show that a major fraction of the variability is consistent with two emission pulses coinciding with large biomass burning events in 1994/1995 and 1997/1998 in tropical and boreal regions, and observations of unusually high levels of combustion products in the overlying troposphere at these times. Implied pulse strengths and multispecies emission ratios are not consistent with any other single process, but do not exclude possible contributions from covarying processes that are linked through climatic forcing. Comparison of CO2 with its delta(13)C indicates that most of the CO2 variation is from terrestrial exchange, but does not distinguish forcing by biomass burning from imbalance in photosynthesis/respiration of terrestrial ecosystems. Partitioning of terrestrial CO2 fluxes is constrained by H-2,CH4, and CO, all of which are products of biomass burning but which have no direct link to net respiration of CO2. While CO is a strong indicator of biomass burning, its short lifetime prevents it from usefully constraining the magnitude of CO2 emissions. If the H-2 and CH4 variations were dominated by biomass burning, they would imply associated carbon emissions in excess of mean annual levels of other years, of 0.6-3.5 and 0.8-3.7 Pg C for 1994/1995 and 1997/1998, respectively. The large range in emission estimates mainly reflects uncertainty in H-2/CO2 and CH4/CO2 emission ratios of fires in these years.
- Published
- 2002
39. The land surface model component of ACCESS: description and impact on the simulated surface climatology
- Author
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Kowalczyk, E, primary, Stevens, L, additional, Law, R, additional, Dix, M, additional, Wang, Y, additional, Harman, I, additional, Haynes, K, additional, Srbinovsky, J, additional, Pak, B, additional, and Ziehn, T, additional
- Published
- 2013
- Full Text
- View/download PDF
40. A frequency to voltage converter based on an accurate pulse width modulator for frequency locked loops
- Author
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Gurleyuk, C., primary, Pak, B., additional, and Aksin, D. Y., additional
- Published
- 2013
- Full Text
- View/download PDF
41. The CSIRO Mk3L climate system model v1.0 coupled to the CABLE land surface scheme v1.4b: evaluation of the control climatology
- Author
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Mao, J., primary, Phipps, S. J., additional, Pitman, A. J., additional, Wang, Y. P., additional, Abramowitz, G., additional, and Pak, B., additional
- Published
- 2011
- Full Text
- View/download PDF
42. ChemInform Abstract: Electrophilic Reactions of Group 6 Element Halides. Part 13. Addition of Selenium Tetrabromide and Selenium Tetrachloride to Acetylene and Its Derivatives.
- Author
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LENDEL, V. G., primary, PAK, B. I., additional, MIGALINA, YU. V., additional, KUCHI, P., additional, DZURILLA, M., additional, and KRISTIAN, P., additional
- Published
- 2010
- Full Text
- View/download PDF
43. A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere
- Author
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Wang, Y. P., primary, Law, R. M., additional, and Pak, B., additional
- Published
- 2010
- Full Text
- View/download PDF
44. A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere
- Author
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Wang, Y. P., primary, Law, R. M., additional, and Pak, B., additional
- Published
- 2009
- Full Text
- View/download PDF
45. Heat-Treated Titanium Balls for the Mitigation of Mineral Fouling in Heat Exchangers
- Author
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Tijing, L. D., primary, Pak, B. C., additional, Lee, D. H., additional, and Cho, Y. I., additional
- Published
- 2008
- Full Text
- View/download PDF
46. TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO2fluxes, 1988-2003
- Author
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Baker, D. F., primary, Law, R. M., additional, Gurney, K. R., additional, Rayner, P., additional, Peylin, P., additional, Denning, A. S., additional, Bousquet, P., additional, Bruhwiler, L., additional, Chen, Y.-H., additional, Ciais, P., additional, Fung, I. Y., additional, Heimann, M., additional, John, J., additional, Maki, T., additional, Maksyutov, S., additional, Masarie, K., additional, Prather, M., additional, Pak, B., additional, Taguchi, S., additional, and Zhu, Z., additional
- Published
- 2006
- Full Text
- View/download PDF
47. A STUDY OF NEW ANTI-FOULING TECHNOLOGY USING THE CATALYTIC PROPERTIES OF TITANIUM IN MINERAL FOULING MITIGATION
- Author
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Tijing, L. D., primary, Pak, B. C., additional, Baek, B. J., additional, and Lee, D. H., additional
- Published
- 2006
- Full Text
- View/download PDF
48. Measurements of biomass burning influences in the troposphere over southeast Australia during the SAFARI 2000 dry season campaign
- Author
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Pak, B. C., primary, Langenfelds, R. L., additional, Young, S. A., additional, Francey, R. J., additional, Meyer, C. P., additional, Kivlighon, L. M., additional, Cooper, L. N., additional, Dunse, B. L., additional, Allison, C. E., additional, Steele, L. P., additional, Galbally, I. E., additional, and Weeks, I. A., additional
- Published
- 2003
- Full Text
- View/download PDF
49. Interannual growth rate variations of atmospheric CO2and its δ13C, H2, CH4, and CO between 1992 and 1999 linked to biomass burning
- Author
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Langenfelds, R. L., primary, Francey, R. J., additional, Pak, B. C., additional, Steele, L. P., additional, Lloyd, J., additional, Trudinger, C. M., additional, and Allison, C. E., additional
- Published
- 2002
- Full Text
- View/download PDF
50. TYRP2-mediated resistance to cis-diamminedichloroplatinum (II) in human melanoma cells is independent of tyrosinase and TYRP1 expression and melanin content
- Author
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Pak, B. J., primary, Li, Q., additional, Kerbel, R. S., additional, and Ben-David, Y., additional
- Published
- 2000
- Full Text
- View/download PDF
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