Lequ ´er ´e, C., Lewis, M., Perry, M.-J., Platt, T., Roemmich, D., Testor, P., Sathyendranath, S., Send, U., and Yoder, J.: Guidelines towards an integrated ocean observation system for ecosystems and biogeochemical cycles, in: Proceedings of OceanObs’09: Sustained Ocean Observations and Information for Society (Vol. 2), Venice, Italy, 21–25 September 2009, edited by: Hall, J., Harrison, D. E., and Stammer, D., ESA Publication WPP-306,
The main consequence of this situation is that fluores- cence data are underused. The constraints of calibration hin- der any combination of the different fluorescence data sets and also prevent their merging with other data sources. No fluorescence profile has been integrated, for example, in ex- isting Chl a C climatologies (Conkright et al., 2002), which are exclusively based on Chl a C estimations obtained from water sample data (HPLC or spectrofluorometer measure- ments). Consequently, climatologies are strongly interpo- lated, as the initial data density is generally low (Conkright et al., 2002). Furthermore, existing methods to generate blended Chl a C products combining data derived from differ- ent methods generally exclude fluorescence data. They have been limited to the merging of ocean colour satellite observa- tions with water sample-derived estimations. A pure blend- ing method (Gregg and Conkright, 2001) was developed to directly merge satelliteandinsitu data. A more indirect ap- proach used satelliteandinsitu data to establish empirical relationships between the surface Chl a C and its vertical sig- nature (Morel and Berthon, 1989; Uitz et al., 2006), in order to reconstruct a vertical profile for each available satellite pixel. Surprisingly, no attempt yet has been made to merge fluorescence profiles with alternative Chl a C measurement approaches.
The compiled global set of bio-optical insitu data de- scribed in this work has an emphasis, though not exclu- sive, on open-ocean data. It comprises the following vari- ables: remote-sensing reflectance (rrs), chlorophyll a con- centration (chla), algal pigment absorption coefficient (aph), detrital and coloured dissolved organic matter absorption co- efficient (adg), particle backscattering coefficient (bbp), dif- fuse attenuation coefficient for downward irradiance (kd) and total suspended matter (tsm). The variables rrs, aph, adg, bbp and kd are spectrally dependent, and this depen- dence is, hereafter, implied. The data were compiled from 27 sources (MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GeP&CO, AWI, ARCSSPP, BARENTSSEA, BATS, BIOCHEM, BODC, CALCOFI, CCELTER, CIMT, COASTCOLOUR, ESTOC, IMOS, MAREDAT, PALMER, SEADATANET, TPSS and TARA): each one described in Sect. 2.2. The data sources in this work should also be viewed as groups of data that were acquired from a specific source, standardized with a specific method and later merged into the compilation. The compiled insitu observations have a global distribution and cover the period 1997 to 2018. The listed variables, with the excep- tion of total suspended matter, were chosen as they are the operational satelliteocean-colour products of the ESA OC- CCI project, which currently focuses on the merging of four ocean-colour satellite sensors: the Medium Resolution Imag- ing Spectrometer (MERIS) of ESA, the Moderate Resolution Imaging Spectroradiometer (MODIS) of NASA, the Sea- viewing Wide Field-of-view Sensor (SeaWiFS) of NASA, and the Visible Infrared Imaging Radiometer Suite (VIIRS) of NASA and the National Oceanic and Atmospheric Admin- istration (NOAA) to create a time series of satellite data.
The merged dataset was compiled from 10 sets of insitu data, which were obtained individually either from archives that incorporate data from multiple contributors (SeaBASS, NOMAD, MERMAID and ICES) or from par- ticular measurement programs or projects (MOBY, BOUS- SOLE, AERONET-OC, HOT, GeP&CO, AMT) and were subsequently homogenised andmerged. Data contributors are listed in Table 2. There were methodological differences between datasets. Therefore, after acquisition, and prior to any merging, each set of data was preprocessed for qual- ity control and conversion to a common format. During this process, data were discarded if they had (1) unrealistic or missing date, time and geographic coordinate fields; (2) poor quality (e.g. original flags) or a method of observation that did not meet the criteria for the dataset (e.g. insitu fluo- rescence for chlorophyll concentration); and (3) spuriously high or low data. For the latter, the following limits were imposed: for chla_fluor and chla_hplc [0.001–100] mg m −3 ; for rrs [0–0.15] sr −1 ; for aph, adg and bbp [0.0001–10] m −1 ; for kd [aw(λ)–10] m −1 , where aw is the pure water absorp- tion coefficients derived from Pope and Fry (1997). Also dur- ing this stage, three metadata strings were attributed to each observation: dataset, subdataset and pi. The dataset contains the name of the original set of data, and can only be one of the following: “aoc”, “boussole”, “mermaid”, “moby”, “nomad”, “seabass”, “hot”, “ices”, “amt” or “gepco”. The subdataset starts with the dataset identifier and is followed by additional information about the data, in the format <dataset>_<cruise/station/site>) (e.g. seabass_car71). The pi contains the name of the principal investigator(s). An effort was made to homogenise the names of principal investigators from the different sets of data. These three metadata are the link to trace each observation to its origin and were prop- agated throughout the processing. Finally, this processing
Former examples clearly show the importance to understand how various algorithms perform in the different conditions (here represented by the considered datasets), also revealing how the overall statistics may be affected by poor performance in a speci ﬁc environmental regime. Besides, this analysis gives indication of the areas of interest, where insitu sampling and analysis efforts should be directed. For instance, the different cruises conducted in the Nazaré canyon region, which displays a strong dynamical variability, revealed differences in the data product accuracy. The natural variability of this area challenges the algorithm performance, allowing for assessing the data product quality under different environmental conditions. A recent study (Mélin & Vantrepotte, 2015) has reported that intermediate regions between the coastal domain and open ocean waters, can be characterized by a high optical diversity through time. The Iberian coastal region is therein cited as an example of the bio-optical variability due to the dynamics of water masses and upwelling events. For validation purposes, these regions where temporal or spatial optical variability throughout the year is high, are preferable to obtain a validation dataset conveying the widest dynamic range of the optical variability (IOCCG, 2009).
The physical model was initialised from rest with salin- ity and temperature climatologies of the World Ocean At- las 2001 (Boyer et al., 2005). The biogeochemical model was initialised from outputs of the simulation described by Aumont and Bopp (2006). Thereafter a 7 yr spin-up period was performed on the coupled model and the simulation was run over the period 1958–2001. Surface boundary conditions were applied to the OGCM as follows: daily surface wind stresses were specified from the ERA40 re-analysis (Uppala et al., 2005). Radiation fluxes were based on the CORE v1 data set, using the International Satellite Cloud Climatol- ogy Project’s radiation product (Zhang et al., 2004), avail- able from 1984 onwards. Prior to 1984 a climatology of the radiation fluxes was imposed, which leads to better results than the use of reanalysis data. Precipitation was taken from the Climate Prediction Center Merged Analysis of Precipi- tation (CMAP; Xie and Arkin, 1997), available from 1979 onwards, while a CMAP climatology was applied before then. Evaporation and turbulent heat fluxes were computed using empirical bulk formulae by Goosse (1997), which em- ployed ERA40 daily wind speed and air temperatures, as well as climatological relative humidity fields from Trenberth et al. (1989). To avoid artificial model drift, sea surface salin- ity was restored towards monthly mean climatological val- ues from the World Ocean Atlas (Boyer et al., 2005), with a timescale of 300 days for a typical 50 m-thick mixed layer. Outputs were generated on a temporal resolution of 5 days.
was drawn through the sampling inlets at 90 SLPM under fully turbulent flow conditions (Re > 10 000). Analog signals from all of these instruments were filtered at 15 Hz and then logged at 50 Hz (National Instruments SCXI-1143). The ship’s compass and GPS systems were digitally logged at 1 Hz. The mast configuration was similar to that used during the Knorr_11 North Atlantic cruise (Bell et al., 2013), with the following two
ABSTRACT: Chlorophyllfluorescence of the testa of seeds is proposed as a non-invasive method for the determination of maturity and quality of seeds. In this study cabbage seeds (Brassica oleracea) were sorted individually based on the chlorophyllfluorescence signals into four subsamples labeled with respect to their chlorophyllfluorescence signal (low, medium, high and very high). The results show that the magnitude of the chlorophyllfluorescence signal was inversely related to the quality of the seeds, expressed as germination %, normal seedling %, germination rate (T50) and uniformity of germination (T75-T25). The seed lot could be improved from 90 to 97% normal seedlings by sorting out 13% of the seeds with very high chlorophyllfluorescence signals. Advantages of the chlorophyllfluorescence method for sorting seeds are the high sensitivity, the method being fully non-destructive, the high speed at which the fluorescence is generated and measured and the specificity for only chlorophyll. Other pigments or substances which can influence seed colour but do not fluoresce at the specific wavelengths of excitation and emission of chlorophyll, will not contribute to the fluorescence signal. These characteristics make chlorophyllfluorescence highly suitable as a new sorting technique. Key Words: maturation, chlorophyllfluorescence, cabbage seed, sorting, quality
In the present study Cr was the only metal detected only in roots. However, Cr was already found in shoots of water hyacinth (Klumpp et al., 2002; Soltan and Rashed, 2003; Mangabeira et al., 2004; Paiva et al., 2009). According to Table 2, the higher concentrations of Cr were observed in water hyacinth roots from the middle PSR, in some cases with values inferior to concentrations detected in plants from other polluted rivers (Table 4). In this study, other elements with lower concentrations than plants inhabiting other world rivers were Pb, Ni, Cu, and Zn. The tolerance of this species to several metals was analyzed under experimental conditions by Odjegba and Fasidi (2007), the authors detected that the order of tolerance was Zn>Cr>Ag>Pb>Cd>Cu>Ni>Hg. Thus, it is possible that the Zn and Cr concentrations of this study may not be considered detrimental to water hyacinth development. Hu et al. (2007), suggest that this species can tolerate moderate concentrations of Cu (with approximately 30 mg kg -1 DW) without significant changes in photosynthetic
The resulting mergedand deseasonalized time series is shown as a function of altitude and time for several latitude bins in Fig. 4. Missing data due to lack of sufficient sampling or screening of the data for contamination from the large vol- canic eruptions is shown in white. Particularly in the tropics there is the clear signature of the downward propagating sig- nal of the QBO. Note the approximate change in phase of this signal above ∼ 27 km, which is related to the change from dynamical to chemical control of stratospheric ozone around this altitude level as reported by several other studies in the past (for example, Randel and Thompson, 2011; Chipperfield et al., 1994). In this figure, the beginning and end of the in- strument overlap period is marked with vertical black lines; however, the consistency of the observed structures across these time periods fosters confidence in the quality of the merged data set. Note that even by eye, a broad minimum in ozone can be seen in each latitude bin between 1994 and 2005, particularly in the upper stratosphere.
Short-term stimulation in photosynthetic rate was detected under mid-level nitrate during the first 2 d (Figure 2), a trend which could be considered a short-term response to nitrate stress because of the increase of photosynthetic pigment content (Figure 3A), increases in the following samplings were hardly significant due to the recovery of photosynthetic pigment content (Figure 3A). High-level nitrate resulted in substantial decrease of photosynthetic rate over treatment course (Figure 2). High nitrate concentration can impose both ionic and osmotic stresses on cucumbers. Stomatal closure, which increases the diffusive resistance to the entry of CO 2 into the
Effects of low temperature on changes in energy dissipation - It is well known that effective heat dissipation prevents chilling-induced inhibition of photosynthesis (Wang & Guo, 2005). Cold stress can cause irreversible damages in the photosynthetic apparatus with reduced efficiency in the utilization of energy (Xie et al., 2008). In this work, the changes in energy dissipation of leaves were evaluated in cultivar Longjiao 2 as well as cultivar Zhejiao 911 at different temperatures and the results are summarized in Figure 3. We found that the portion of energy dissipation by antenna pigments of the light energy captured by PSII reaction centers (D) was increased in both cvs. The portion of absorbed light energy utilized in the PSII photochemistry (P) decreased in the two cvs. as well although the patterns of change were different in both varieties (Figure 3). Interestingly, 87.8% of light energy was utilized in the photochemical reaction at first day of 5°C and then sharply decreased to 47.4% in ‘Zhejiao 911’. These findings are consistent with many studies and indicate that an increase in the thermal dissipation in the PSII antennae competes with the excitation energy transfer from the PSII antennae to PSII reactions centers, thus resulting in a decrease in the efficiency with the excitation energy captured by “open” PSII reaction centers (P). The component of absorbed light not going into either P or D is labelled as “excess energy” (Ex). Ex includes not only “excess” energy but also reflects non-light induced quenching processes. This portion of energy has the greatest potential to cause PSII photoinactivation because it represents light energy that is trapped by closed PSII reaction centers. Indeed, there was an increase in the excess energy in the photosynthetic apparatus during the reduction of photosynthetic rate. While the excess of light energy (Ex) increased only in the ‘Zhejiao 911’ at first day of 5°C and ‘Longjiao 2’ at third day of 10°C when treated with
ABSTRACT: The use of nitrogen fertilizers is an effective resource to increase the coffee yield, so that the improvement and /or generation of new techniques that assist in the management of nitrogen fertilization are essential, as will contribute to increase nitrogen use efficiency (N). Thus, this study aimed to determine the chlorophyll a fluorescence transient and vegetative growth in Conilon coffee under different nitrogen sources. The experiment was carried out in Nova Venécia - ES - Brazil, on coffee plantation Conilon cultivar “Vitória Incaper 8142”. Were evaluated five sources of nitrogen fertilizers: urea common, urea + NBPT, urea + Cu and B, urea + S, and ammonia nitrate. The chlorophyll a fluorescence maximum did not differ in any of the times examined. The values of relative chlorophyll index (RCI) alternated their significance with respect to treatments throughout the evaluation dates. The N sources were not responsible, singly, with changes to the RCI. The sources of nitrogen fertilizers with increased efficiency exhibited low influence on transient fluorescence of chlorophyll a and do not influence the vegetative growth of the coffee.
RESUMO - A fluorescência da clorofila tem sido utilizada como um método diagnóstico rápido e não destrutivo para detectar e quantificar danos no aparato fotossintético das folhas em plantas daninhas, culturas e árvores ornamentais/coníferas em resposta ao estresse ambiental, assim como em resposta aos herbicidas. O objetivo do presente trabalho foi avaliar a fluorescência de clorofila em guanandi (Calophyllum brasiliense) após aplicação de diferentes herbicidas em pós-emergência. O experimento foi realizado em delineamento inteiramente casualizado, com seis tratamentos (controle, bentazon, sulfentrazone, isoxaflutole, atrazine e glyphosate) e cinco repetições. Os tratamentos herbicidas foram aplicados em pulverizador estacionário, para posterior análise da taxa de transporte de elétrons (ETR) com o aparelho Multi-Mode Chlorophyll Fluorometer OS5p. No período monitorado, as plantas de guanandi apresentaram maior sensibilidade ao atrazine que aos demais tratamentos, em relação à fluorescência da clorofila. O bentazon, inibidor do fotossistema II, não ocasionou maiores alterações no transporte de elétrons na espécie e nos períodos avaliados. Em síntese, a ETR mostrou- se um bom parâmetro para avaliar o efeito de herbicidas na espécie arbórea estudada.
Atmospheric Research 3 CAPSS: Clean Air Policy Support System 4 REAS: Regional Emission inventory in Asia 5 GAINS: Greenhouse gas and Air pollution INteractions and Synergies 6 FINN: Fire Inventory from NCAR 7 MEGAN: Model of Emissions of Gases and Aerosols from Nature 8 MOHYCAN: MOdel for Hydrocarbon emissions by the CANopy 9 GEIA: Global Emissions Inventory Activity. a Emission increase (or decrease) rates from 2006 to 2011 for the air pollutants were obtained from the GAINS emission scenarios. b Mono-terpene emissions are not included in MEGAN+MOHYCAN emissions. Therefore, the ratios of mono-terpene to isoprene in the biogenic emissions were obtained from the GEIA emission inventory.
A chlorophyllfluorescenceproduct may also be feasible from Geostationary (GEO) orbit using instrumentation being proposed for the NASA decadal survey GEO-Coastal and Air Pollution Events (GEO-CAPE) mission. This would provide important informa- tion regarding the links between pollutants, such as tropospheric O 3 that can damage vegetation, and climate, through the uptake of CO 2 , the primary anthropogenic green-
In arid environments, the effects of drought and salinity must be overcome in the presence of excess radiation, which may affect the function of the photosynthetic apparatus. The fraction of the incident solar radiation absorbed by the leaf is directly proportional to the leaf absorptance (α) in the 400–00 (photosynthetically active radiation, PAR) and the 400–3,000 nm (PAR+IR) wavelength bands (Ehleringer, 1981). The seasonal reduction in α, from 0.81 to 0.29, due to drought-induced increase in pubescence of Encelia farinosa, represents an adaptation to arid environments characterized by low water availability and high temperatures (Ehleringer, 1981). The presence of a waxy epicuticular layer on the leaves of some arid species must have implications on the leaf energy balance. We can expect the epicuticular waxy layer in leaves of N. glauca to reduce the absorption of excess heat under stress conditions.
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energy absorbed will be dissipated as fluorescence thus giving maximal fluorescence (Krause and Weis, 1984, 1991; Govindjee, 1995). Other variables have been used with due interpretations, photochemical quenching (q p ) is associated with photosynthetic metabolism of carbon and varies numerically from 0 (closed PSII reaction centers, Q a complete reduced) to 1 (PSII reaction centers open, Q a completed oxidized). This variable represents, in general terms, the capacity of the photochemical/biochemical process to re-oxidize Q a , that is, the excitation energy dissipation in the form of electron transference (Bolhàr- Nordenkampf et al., 1989). Non-photochemical quenching (q N ) is directly related to the non photochemical reaction of excitation energy dissipation (Krause and Weis, 1991) and is constructed from some components. Of these, three are of major importance: 1) “q e ” quenching dependent on energy - results from energy dissipation in non-radiant heat form, which is related to the formation of the transthylacoid proton gradient (∆pH) (Krause and Weis, 1991); 2) “q t ” quenching dependent on the transition state - related to the phosphorylation of the light harvesting complex II (LHCII) (Allen, 1992) and 3) “q i ” photoinhibitory quenching - results from transformation of the PSII reaction center because of photoinhibitory processes (Schreiber and Bilger, 1992). There is another way of expressing non- photochemical quenching that is called NPQ (Bilger and Björkman, 1990). NPQ has been shown to be closely related to the excess light energy which is actively dissipated by plants into heat in order to avoid photodamage (Rohacek and Bartak, 1999).
experiments using nutrient solution specific for common bean. Plants were cultivated in 75% shade and with different concentrations of sodium chloride (0, 30, 60, 90 and 120 mM). Shaded and non-shaded plants were analyzed for the parameters gas exchanges andchlorophyll a fluorescence, as well as chlorophyll a and b, and carotenoids. In the second experiment, the shaded plants of cultivars Carioca and Cargamanto were transferred to sunlight at 24 and 26 days post-emergence, respectively. The effects of radiation and salinity on photoinhibition of the transferred plants were determined by measuring gas exchange andchlorophyll a fluorescence at 0, 2 and 5 days post-transfer. At the end of the experiment, pigment contents, osmotic potential (Ψ s ) and