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Global atmospheric CO2 inverse models converging on neutral tropical land exchange, but disagreeing on fossil fuel and atmospheric growth rate
Gaubert, Benjamin ; Stephens, Britton B. ; Basu, Sourish ; Chevallier, Frédéric ; Deng, Feng ; Kort, Eric A. ; Patra, Prabir K. ; Peters, Wouter ; Rödenbeck, Christian ; Saeki, Tazu ; Schimel, David ; Laan-Luijkx, Ingrid van der; Wofsy, Steven ; Yin, Yi - \ 2019
Biogeosciences 16 (2019)1. - ISSN 1726-4170 - p. 117 - 134.
We have compared a suite of recent global CO2 atmospheric inversion results to independent airborne observations and to each other, to assess their dependence on differences in northern extratropical (NET) vertical transport and to identify some of the drivers of model spread. We evaluate posterior CO2 concentration profiles against observations from the High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-To-Pole Observations (HIPPO) aircraft campaigns over the mid-Pacific in 2009-2011. Although the models differ in inverse approaches, assimilated observations, prior fluxes, and transport models, their broad latitudinal separation of land fluxes has converged significantly since the Atmospheric Carbon Cycle Inversion Intercomparison (TransCom 3) and the REgional Carbon Cycle Assessment and Processes (RECCAP) projects, with model spread reduced by 80% since TransCom 3 and 70% since RECCAP. Most modeled CO2 fields agree reasonably well with the HIPPO observations, specifically for the annual mean vertical gradients in the Northern Hemisphere. Northern Hemisphere vertical mixing no longer appears to be a dominant driver of northern versus tropical (T) annual flux differences. Our newer suite of models still gives northern extratropical land uptake that is modest relative to previous estimates (Gurney et al., 2002; Peylin et al., 2013) and near-neutral tropical land uptake for 2009- 2011. Given estimates of emissions from deforestation, this implies a continued uptake in intact tropical forests that is strong relative to historical estimates (Gurney et al., 2002; Peylin et al., 2013). The results from these models for other time periods (2004-2014, 2001-2004, 1992-1996) and reevaluation of the TransCom 3 Level 2 and RECCAP results confirm that tropical land carbon fluxes including deforestation have been near neutral for several decades. However, models still have large disagreements on ocean-land partitioning. The fossil fuel (FF) and the atmospheric growth rate terms have been thought to be the best-known terms in the global carbon budget, but we show that they currently limit our ability to assess regional-scale terrestrial fluxes and ocean-land partitioning from the model ensemble.
Constraints and biases in a tropospheric two-box model of OH
Naus, Stijn ; Montzka, Stephen A. ; Pandey, Sudhanshu ; Basu, Sourish ; Dlugokencky, Ed J. ; Krol, Maarten - \ 2019
Atmospheric Chemistry and Physics 19 (2019)1. - ISSN 1680-7316 - p. 407 - 424.
The hydroxyl radical (OH) is the main atmospheric oxidant and the primary sink of the greenhouse gas CH4. In an attempt to constrain atmospheric levels of OH, two recent studies combined a tropospheric two-box model with hemispheric-mean observations of methyl chloroform (MCF) and CH4. These studies reached different conclusions concerning the most likely explanation of the renewed CH4 growth rate, which reflects the uncertain and underdetermined nature of the problem. Here, we investigated how the use of a tropospheric two-box model can affect the derived constraints on OH due to simplifying assumptions inherent to a two-box model. To this end, we derived species- A nd timedependent quantities from a full 3-D transport model to drive two-box model simulations. Furthermore, we quantified differences between the 3-D simulated tropospheric burden and the burden seen by the surface measurement network of the National Oceanic and Atmospheric Administration (NOAA). Compared to commonly used parameters in two-box models, we found significant deviations in the magnitude and timedependence of the interhemispheric exchange rate, exposure to OH, and stratospheric loss rate. For MCF these deviations can be large due to changes in the balance of its sources and sinks over time. We also found that changes in the yearly averaged tropospheric burden of CH4 and MCF can be obtained within 0.96 ppb yr-1 and 0.14%yr-1 by the NOAA surface network, but that substantial systematic biases exist in the interhemispheric mixing ratio gradients that are input to two-box model inversions. To investigate the impact of the identified biases on constraints on OH, we accounted for these biases in a two-box model inversion of MCF and CH4. We found that the sensitivity of interannual OH anomalies to the biases is modest (1 %-2 %), relative to the uncertainties on derived OH (3 %-4 %). However, in an inversion where we implemented all four bias corrections simultaneously, we found a shift to a positive trend in OH concentrations over the 1994-2015 period, compared to the standard inversion. Moreover, the absolute magnitude of derived global mean OH, and by extent, that of global CH4 emissions, was affected much more strongly by the bias corrections than their anomalies (∼ 10 %). Through our analysis, we identified and quantified limitations in the two-box model approach as well as an opportunity for full 3-D simulations to address these limitations. However, we also found that this derivation is an extensive and species-dependent exercise and that the biases were not always entirely resolvable. In future attempts to improve constraints on the atmospheric oxidative capacity through the use of simple models, a crucial first step is to consider and account for biases similar to those we have identified for the two-box model.
DeepGlobe 2018: A Challenge to Parse the Earth through Satellite Images
Demir, I. ; Koperski, K. ; Lindenbaum, D. ; Pang, G. ; Huang, J. ; Basu, S. ; Hughes, F. ; Tuia, D. ; Raska, R. - \ 2018
In: Proceedings 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops CVPRW 2018. - IEEE - ISBN 9781538661017 - p. 17200 - 17209.
We present the DeepGlobe 2018 Satellite Image Understanding Challenge, which includes three public competitions for segmentation, detection, and classification tasks on satellite images (Figure 1). Similar to other challenges in computer vision domain such as DAVIS and COCO, DeepGlobe proposes three datasets and corresponding evaluation methodologies, coherently bundled in three competitions with a dedicated workshop co-located with CVPR 2018. We observed that satellite imagery is a rich and structured source of information, yet it is less investigated than everyday images by computer vision researchers. However, bridging modern computer vision with remote sensing data analysis could have critical impact to the way we understand our environment and lead to major breakthroughs in global urban planning or climate change research. Keeping such bridging objective in mind, DeepGlobe aims to bring together researchers from different domains to raise awareness of remote sensing in the computer vision community and vice-versa. We aim to improve and evaluate state-of-the-art satellite image understanding approaches, which can hopefully serve as reference benchmarks for future research in the same topic. In this paper, we analyze characteristics of each dataset, define the evaluation criteria of the competitions, and provide baselines for each task.
Understanding the emergence of a hybrid knowledge production discourse : The case of the Generation Challenge Programme (GCP) drought tolerant rice research in India
Basu, S. ; Jongerden, J.P. ; Ruivenkamp, Martin - \ 2018
NJAS Wageningen Journal of Life Sciences 85 (2018). - ISSN 1573-5214 - p. 21 - 31.
The Generation Challenge Programme (GCP) is an international platform for agrarian knowledge production for a complex scientific problem, namely, Drought. The GCP ushered in a new form of knowledge production that reconciles both the upstream laboratorial research and its downstream delivery at the farmer's field. This paper aims at understanding the knowledge production process of the GCP. More precisely, it explores the following three research questions: how three processes such as research partnership, transdisciplinary and inclusion of end-user in research manifested within the knowledge production process of the GCP drought-tolerant rice research; what type of knowledge production emerged within the GCP drought-tolerant rice research; and what implications can be discerned for agricultural research and development. Through a qualitative case study method, this paper explores empirically the case of GCP drought-tolerant rice research in the Indian context to elucidate the knowledge production process of GCP to sketch a theoretical as well as a practical position on the agrarian knowledge production discourse. This paper argues that a hybrid knowledge production discourse has emerged within the GCP rice research that has elements from different knowledge production paradigms. Further, this paper also illustrates the implications of such hybrid knowledge production discourse for agricultural research and development.
Mercury associated neurochemical response in Arctic barnacle goslings (Branta leucopsis)
Brink, Nico W. van den; Scheiber, Isabella B.R. ; Jong, Margje E. de; Braun, Anna ; Arini, Adeline ; Basu, Niladri ; Berg, Hans van den; Komdeur, Jan ; Loonen, Maarten J.J.E. - \ 2018
Science of the Total Environment 624 (2018). - ISSN 0048-9697 - p. 1052 - 1058.
Exposure and effect - Neurotoxicity - Polar - Terrestrial - Tundra
There remains great concern over mercury pollution in the Arctic, though relatively little is known about impacts on biota that inhabit Arctic terrestrial systems. To help address this, the current study was performed with barnacle goslings (Branta leucopsis) from a coal mine-impacted site and a control site near Ny-Ålesund, Spitsbergen (Svalbard). The works focused mainly on mercury, as coal contains trace levels of this element. Total mercury concentrations were quantified in soil and vegetation from the two sites, as well as feces and liver from the goslings. Next, the mercury exposures were related to dopamine 2 (D2)- and NMDA-receptors in the brain, given that mercury is a proven neurotoxicant. Soil and vegetation in the mining area contained mercury levels that were approximately 3- and 2.2-times higher than in the control site. Despite a significant difference between the sites, the soil and vegetation mercury levels where were within ranges found at other Arctic locations. Goslings grazing in the mine-impacted area contained significantly higher hepatic mercury levels than those sampled from the control site. Compared to other species, the hepatic concentrations were relatively low possibly due to dilution of the mercury in growing goslings (growth dilution) and deposition of mercury in the growing feathers. Hepatic mercury concentrations were positively related to D2-neuroreceptor levels but not to NMDA-receptor levels thus suggesting a possible subtle neurological effect. To our knowledge, this is among the first studies on mercury exposure in Arctic terrestrial organisms, and one of the first to document potential subtle neurological responses associated with exposure to low, environmentally relevant mercury levels, which also can be found at other locations in the Arctic. However, as a pilot effort, the results here need to be examined in additional studies that include, for example, lager study designs, different geographic sites and other terrestrial species.
The emergence of a hybrid mode of knowledge production in the Generation Challenge Programme Rice Research Network (GCP-RRN) in India : Exploring the concept of Commons-Based Peer Production (CBPP)
Basu, S. ; Jongerden, J.P. ; Ruivenkamp, G.T.P. - \ 2017
Geoforum 84 (2017). - ISSN 0016-7185 - p. 107 - 116.
The Generation Challenge Programme (GCP) was an international agrarian knowledge-production programme created in 2003 by the CGIAR. GCP aims at developing drought tolerant varieties by reconciling upstream biotechnology based advanced research with the downstream development at the farmer's field. The objective of this paper is to apply the theory of Commons Based Peer Production (CBPP) to analyse the knowledge production process of GCP, especially the case of drought tolerant rice research network in Indian context (GCP-RRN). CBPP represents the theorisation of a mode of production that can be distinguished from market (private) and state (public) knowledge-production systems that was developed by observing the phenomena of Free and Open Source Software (FOSS). The organisational attributes of the CBPP mode applied in computer software production include the modulation of work, small-size granularity of components, and mechanisms that integrate these modules into an end product. Socio-economically, this form of production is based on cooperation, collaboration and collective action rather than property, contract and managerial hierarchies. This paper argues that GCP-RRN knowledge production is basically a hybridised one in which there are certain inclinations towards CBPP within certain larger context, and there are other attributes too that do not fall within CBPP theorisation. Further, this paper elaborates on the implications of this hybridised model for agrarian knowledge production discourse and institutions.
Beyond the dichotomy of instrumentality and non-instrumentality of knowledge production : The case of generation challenge programme
Basu, S. ; Jongerden, J.P. ; Ruivenkamp, G.T.P. - \ 2017
Science and Public Policy 44 (2017)4. - ISSN 0302-3427 - p. 583 - 597.
(non) instrumentality - knowledge production - discourse - Science policy
A change in the discourse on knowledge production as a shift from the non-instrumentality to the instrumentality approach has been identified and, moreover, generally been regarded as an inevitable, unilinear transition. In this article, we question this assumption by questioning some of the key features of the instrumentality paradigm, particularly in relation to a specific organisation geared towards international agrarian knowledge production, the Generation Challenge Programme (GCP). We first provide an account of the non-instrumentality approach to knowledge production and of the gradual shift towards instrumentality. Then, different theories of instrumental knowledge production are analysed for patterns that holistically indicate the essence of instrumental knowledge production. Finally, by providing a descriptive analysis of the GCP, we argue against the idea of a unilinear transition towards the instrumental paradigm insofar as, within GCP, several non-instrumental patterns are emerging that seem to go beyond the dichotomous (instrumental versus non-instrumental) understanding of knowledge production discourse.
Development of the drought tolerant variety Sahbhagi Dhan : exploring the concepts commons and community building
Basu, S. ; Jongerden, J.P. ; Ruivenkamp, G.T.P. - \ 2017
International Journal of the Commons 11 (2017)1. - ISSN 1875-0281 - p. 144 - 170.
The concept of commons is often understood to refer to resources shared among a group of people. The resources are typically classified by binaries such as (non-)natural, (non-)rival and (non-)substractable, and the analytical focus is placed on governance for sustainable management. Another approach to the idea of commons emphasises social relations. This concentrates on production resulting from human-human and human-nature interactions. Here, we focus on the latter and investigate the relationship between these two conceptualisations. This is enabled through an empirical study of the development process of a drought-tolerant rice variety, Sahbhagi Dhan, which was the result of a twelveyear long collaboration between the International Rice Research Institute (IRRI) and other different Indian institutions. We argue that the concept of the common as a production system can be characterised as an interwoven process of community building involved in the production of resource commons, and we indicate several features of the community-building process that are essential to an understanding of commons as a socially specified system of production.
A multidisciplinary research agenda for the acceptance of Golden Rice
Bongoni, Radhika ; Basu, Soutrik - \ 2016
Nutrition & Food Science 46 (2016)5. - ISSN 0034-6659 - p. 717 - 728.
Consumer acceptance - GM foods - Golden Rice - Vitamin A - β-carotene
Purpose: The world is facing serious global food security challenges such as the need for sufficient food for a growing population and an exponential growth in nutrient deficiency disorders. Agricultural biotechnology, such as genetically modified (GM) crops, offers itself as a promising solution to address one or more of these issues. Golden Rice (GR) is an example of a GM crop which contains high amount of β-carotene, a compound which is an antioxidant and a precursor of vitamin A. In spite of GR’s promised potential benefits in combating vitamin A deficiency (VAD) disorders it is still not cultivated. This viewpoint paper aims to present the reader with a need for multidisciplinary research agenda, the outcomes of which can contribute towards the acceptance of GR. Design/methodology/approach: This viewpoint paper is based on an extensive literature review to identify the “gaps” which contributed to low acceptance of GR. This paper presents a systematic discussion on the importance of GR in tackling VAD and discusses controversies around GR and a scientific approach to tackle them. Findings: The literature review clearly indicates that there is a huge gap in information substantiating the potential of GR for consumers as well as for the farming community. Addressing these issues can substantially increase the acceptance and cultivation of GR. This viewpoint paper proposes food technologists’ and social scientists’ research agenda for GR and further indicates how the involvement of other research disciplines can improve the acceptance of GR. Originality/value: The literature review indicates the potential of GR in tackling VAD disorders but clearly lacks information to substantiate these arguments. This paper presents authors’ opinions, urging scientists to take up a multidisciplinary research approach to emancipate GR from the clutches of GM food controversies.
LES results of the GABLS4 exercice : an intercomparison of models in extremely stable conditions over Antarctica
Couvreux, F. ; Bazile, E. ; Canut, G. ; Moigne, P. Le; Maronga, B. ; Stratum, Bart van; Basu, S. ; Fuka, V. ; Moene, A.F. ; Edwards, J.M. ; Matheou, G. ; Vignon, E. ; Maurel Sr, W. ; Traullé, O. - \ 2016
Knowledge production, agriculture and commons : the case of generation challenge programme
Basu, S. - \ 2016
Wageningen University. Promotor(en): Guido Ruivenkamp; Han Wiskerke, co-promotor(en): Joost Jongerden. - Wageningen : Wageningen University - ISBN 9789462576773 - 148
Keywords: Knowledge Production; Agrarian Research; Research Networks; Research Policy; (non)-instrumentality; CBPP; Commons; GCP; Drought; Sahbhagi Dhan; India
Knowledge Production, Agriculture and Commons: The Case of Generation Challenge Programme
The discourse on knowledge production is in constant transformation: on the one hand, there is the emergence of instrumental knowledge production based on scientific utility and socio-economic relevance and marked by property regimes, while on the other hand, there is another form of knowledge production based on cooperation, communication and the sharing of knowledge often entitled the open-source production or commons-based peer production (CBPP) mode. Both these trends are reflected partially or in full measure within the agrarian knowledge production programme called Generation Challenge Programme (GCP) of the Consultative Group of International Agricultural Research (CGIAR). GCP is an international knowledge production platform that aims to use plant genetic diversity to develop technologies to support plant breeders in developing countries. This research aims at understanding the dynamics of the knowledge production in the GCP drought-tolerant rice research network in Indian context to reflect on the ways in which its knowledge production evolves and the implications of this for agrarian knowledge production and agrarian knowledge producing institutions. This research applied a critical-constructivist research methodology to analyse the GCP knowledge production (drought tolerant rice research in Indian context) in which the three different paradigms of knowledge production (non-instrumental and instrumental, CBPP and Commons) come together. This research shows that an alternative hybrid discourse of knowledge production has emerged within the knowledge production process of GCP drought tolerant rice research in India that has elements from all the three paradigms (mentioned above) alongside some elements that belongs to neither of these paradigms. Further, this research also reflects on the broader implications of this hybrid discourse of knowledge production for agrarian knowledge production and agrarian knowledge producing institutions such as CGIAR, NARS, and ICAR.
Community, conflict and land: exploring the strategic partnership model of South African land restitution
Basu, Soutrik - \ 2016
Journal of International Development 28 (2016)5. - ISSN 0954-1748 - p. 733 - 748.
The Strategic Partnership (SP) model was implemented in the South African land restitution programme. The model prematurely ended in a fiasco that left the community with huge debts and intractable conflicts. This paper aims at understanding the implementation process by taking up the issue of how conflict emerged, resolved and sustained around the SP model. This paper suggests that conflict emerged because of the following reasons: the policy framework failed to address the heterogeneity of the community; community value was undermined as a business partner; and the state placed unprecedented trust, power, and authority on strategic partners.
Comparing the CarbonTracker and M5-4DVar data assimilation systems for CO2 surface flux inversions
Babenhauserheide, A. ; Basu, S. ; Houweling, S. ; Peters, W. ; Butz, A. - \ 2015
Atmospheric Chemistry and Physics 15 (2015)17. - ISSN 1680-7316 - p. 9747 - 9763.
Data assimilation systems allow for estimating surface fluxes of greenhouse gases from atmospheric concentration measurements. Good knowledge about fluxes is essential to understand how climate change affects ecosystems and to characterize feedback mechanisms. Based on the assimilation of more than 1 year of atmospheric in situ concentration measurements, we compare the performance of two established data assimilation models, CarbonTracker and TM5-4DVar (Transport Model 5 - Four-Dimensional Variational model), for CO2 flux estimation. CarbonTracker uses an ensemble Kalman filter method to optimize fluxes on ecoregions. TM5-4DVar employs a 4-D variational method and optimizes fluxes on a 6° x 4° longitude-latitude grid. Harmonizing the input data allows for analyzing the strengths and weaknesses of the two approaches by direct comparison of the modeled concentrations and the estimated fluxes. We further assess the sensitivity of the two approaches to the density of observations and operational parameters such as the length of the assimilation time window. Our results show that both models provide optimized CO2 concentration fields of similar quality. In Antarctica CarbonTracker underestimates the wintertime CO2 concentrations, since its 5-week assimilation window does not allow for adjusting the distant surface fluxes in response to the detected concentration mismatch. Flux estimates by CarbonTracker and TM5-4DVar are consistent and robust for regions with good observation coverage, regions with low observation coverage reveal significant differences. In South America, the fluxes estimated by TM5-4DVar suffer from limited representativeness of the few observations. For the North American continent, mimicking the historical increase of the measurement network density shows improving agreement between CarbonTracker and TM5-4DVar flux estimates for increasing observation density.
Response of the Amazon carbon balance to the 2010 drought derived with CarbonTracker South America
Laan-Luijkx, I.T. van der; Velde, I.R. van der; Krol, M.C. ; Gatti, L.V. ; Domingues, L.G. ; Correia, C.S.C. ; Miller, J.B. ; Gloor, M. ; Leeuwen, T.T. van; Kaiser, J.W. ; Wiedinmyer, C. ; Basu, S. ; Clerbaux, C. ; Peters, W. - \ 2015
Global Biogeochemical Cycles 29 (2015)7. - ISSN 0886-6236 - p. 1092 - 1108.
Two major droughts in the past decade had large impacts on carbon exchange in the Amazon. Recent analysis of vertical profile measurements of atmospheric CO2 and CO by Gatti et al. (2014) suggests that the 2010 drought turned the normally close-to-neutral annual Amazon carbon balance into a substantial source of nearly 0.5 PgC/yr, revealing a strong drought response. In this study, we revisit this hypothesis and interpret not only the same CO2/CO vertical profile measurements but also additional constraints on carbon exchange such as satellite observations of CO, burned area, and fire hot spots. The results from our CarbonTracker South America data assimilation system suggest that carbon uptake by vegetation was indeed reduced in 2010 but that the magnitude of the decrease strongly depends on the estimated 2010 and 2011 biomass burning emissions. We have used fire products based on burned area (Global Fire Emissions Database version 4), satellite-observed CO columns (Infrared Atmospheric Sounding Interferometer), fire radiative power (Global Fire Assimilation System version 1), and fire hot spots (Fire Inventory from NCAR version 1), and found an increase in biomass burning emissions in 2010 compared to 2011 of 0.16 to 0.24 PgC/yr. We derived a decrease of biospheric uptake ranging from 0.08 to 0.26 PgC/yr, with the range determined from a set of alternative inversions using different biomass burning estimates. Our numerical analysis of the 2010 Amazon drought results in a total reduction of carbon uptake of 0.24 to 0.50 PgC/yr and turns the balance from carbon sink to source. Our findings support the suggestion that the hydrological cycle will be an important driver of future changes in Amazonian carbon exchange.
Comparing the CarbonTracker and TM5-4DVar data assimilation systems for CO2 surface flux inversions
Babenhauserheide, A. ; Basu, S. ; Peters, W. - \ 2015
Atmospheric Chemistry and Physics Discussions 15 (2015)6. - ISSN 1680-7367 - p. 8883 - 8932.
Data assimilation systems allow for estimating surface fluxes of greenhouse gases from atmospheric concentration measurements. Good knowledge about fluxes is essential to understand how climate change affects ecosystems and to characterize feedback mechanisms. Based on assimilation of more than one year of atmospheric in-situ concentration measurements, we compare the performance of two established data assimilation models, CarbonTracker and TM5-4DVar, for CO2 flux estimation. CarbonTracker uses an Ensemble Kalman Filter method to optimize fluxes on ecoregions. TM5-4DVar employs a 4-D variational method and optimizes fluxes on a 6° × 4° longitude/latitude grid. Harmonizing the input data allows analyzing the strengths and weaknesses of the two approaches by direct comparison of the modelled concentrations and the estimated fluxes. We further assess the sensitivity of the two approaches to the density of observations and operational parameters such as temporal and spatial correlation lengths.
The seasonal variation of the CO2 flux over Tropical Asia estimated from GOSAT, CONTRAIL, and IASI
Basu, S. ; Krol, M.C. ; Butz, A. ; Clerbaux, C. ; Sawa, Y. ; Machida, T. ; Matsueda, H. ; Frankenberg, C. ; Hasekamp, O.P. ; Aben, I. - \ 2014
Geophysical Research Letters 41 (2014)5. - ISSN 0094-8276 - p. 1809 - 1815.
atmospheric co2 - carbon balance - emissions - gosat - retrievals - aerosol - fires
We estimate the CO2 flux over Tropical Asia in 2009, 2010, and 2011 using Greenhouse Gases Observing Satellite (GOSAT) total column CO2(XCO2) and in situ measurements of CO2. Compared to flux estimates from assimilating surface measurements of CO2, GOSAT XCO2 estimates a more dynamic seasonal cycle and a large source in March–May 2010. The more dynamic seasonal cycle is consistent with earlier work by Patra et al. (2011), and the enhanced 2010 source is supported by independent upper air CO2 measurements from the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project. Using Infrared Atmospheric Sounding Interferometer (IASI) measurements of total column CO (XCO), we show that biomass burning CO2 can explain neither the dynamic seasonal cycle nor the 2010 source. We conclude that both features must come from the terrestrial biosphere. In particular, the 2010 source points to biosphere response to above-average temperatures that year.
The spread of the system of rice intensification in a network in Andhra Pradesh, India
Basu, S. ; Leeuwis, C. - \ 2014
The spread of innovation is often understood in the context of farmers’ adoption and dis-adoption. In this paper we try to understand the spread of innovation at levels higher than that of the farmer, i.e. at the level of policy, academia and research. The system of rice intensification (SRI) (heavily contested among rice scientists) is used as a casestudy for this research. This paper seeks to examine the process of SRI in Andhra Pradesh, India. The data collection methods used consisted of interviews, discussions and a secondary literature review. Data were then analysed through life history analysis and content analysis. This paper suggests that the formation of a heterogeneous ‘support network’ which transcends the conventional agricultural networks played a crucial role in the spreading of SRI. Amongst others, this network seems to have strategically mobilised the mass media to represent SRI in a positive manner.
The Impact of Radiation on the GABLS3 Large-Eddy Simulation through the Night and during the Morning Transition
Edwards, J.M. ; Basu, S. ; Bosveld, F.C. ; Holtslag, A.A.M. - \ 2014
Boundary-Layer Meteorology 152 (2014)2. - ISSN 0006-8314 - p. 189 - 211.
nocturnal boundary-layer - model - entrainment - dynamics - weather - shear - flux
Large-eddy simulation in the GABLS3 intercomparison is concerned with the developed stable boundary layer (SBL) and the ensuing morning transition. The impact of radiative transfer on simulations of this case is assessed. By the time of the reversal of the surface buoyancy flux, a modest reduction of the lapse rate in the developed SBL is apparent in simulations that include longwave radiation. Subsequently, with radiation, the developing mixed layer grows significantly more quickly, so that four hours after the transition the mixed layer is roughly 40 % deeper; the resulting profiles of potential temperature and specific humidity are in better agreement with observations. The inclusion of radiation does not substantively alter the shape of turbulent spectra, but it does indirectly reduce the variance of temperature fluctuations in the mixed layer. The deepening of the mixed layer is interpreted as a response to the reduction of the strength of the capping inversion, resulting from cumulative radiative cooling in the residual layer and around the top of the former SBL. Sensitivity studies are performed to separate the two effects. Solar radiative heating of the atmosphere has a smaller impact on the development of the mixed layer than does longwave radiative cooling and slightly reduces its rate of growth, compared to simulations including longwave radiation alone. These simulations demonstrate that nocturnal radiative processes have an important effect on the morning transition and that they should be considered in future large-eddy simulations of the transition.
Observational Support for the Stability Dependence of the Bulk Richardson Number across the Stable Boundary Layer
Basu, S. ; Holtslag, A.A.M. ; Caporaso, L. ; Riccio, A. ; Steeneveld, G.J. - \ 2014
Boundary-Layer Meteorology 150 (2014)3. - ISSN 0006-8314 - p. 515 - 523.
self-correlation - resistance laws - surface fluxes - least-squares - model - height - regression - formulations - parameter - breakdown
The bulk Richardson number (Ri Bh ; defined over the entire stable boundary layer) is commonly utilized in observational and modelling studies for the estimation of the boundary-layer height. Traditionally, Ri Bh is assumed to be a quasi-universal constant. Recently, based on large-eddy simulation and wind-tunnel data, a stability-dependent relationship has been proposed for Ri Bh . In this study, we analyze extensive observational data from several field campaigns and provide further support for this newly proposed relationship.
Reduced carbon uptake during the 2010 Northern Hemisphere summer from GOSAT
Guerlet, S. ; Basu, S. ; Butz, A. ; Krol, M.C. ; Hahne, P. ; Houweling, S. ; Hasekamp, O.P. ; Aben, I. - \ 2013
Geophysical Research Letters 40 (2013)10. - ISSN 0094-8276 - p. 2378 - 2383.
column observing network - calibration - transport - dioxide - europe
Column-averaged dry air mole fractions of carbon dioxide (XCO2) measured by the Greenhouse Gases Observing Satellite (GOSAT) reveal significant interannual variation (IAV) of CO(2)uptake during the Northern Hemisphere summer between 2009 and 2010. The XCO(2)drawdown in 2010 is shallower than in 2009 by 2.4ppm and 3.0ppm over North America and Eurasia, respectively. Reduced carbon uptake in the summer of 2010 is most likely due to the heat wave in Eurasia driving biospheric fluxes and fire emissions. A joint inversion of GOSAT and surface data estimates an integrated biospheric and fire emission anomaly in April-September of 0.89 0.20 PgC over Eurasia. In contrast, inversions of surface measurements alone fail to replicate the observed XCO(2)IAV and underestimate emission IAV over Eurasia. This shows the value of GOSAT XCO(2)in constraining the response of land-atmosphere exchange of CO2 to climate events.