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1.
A. V. Vivchar K. B. Moiseenko N. V. Pankratova 《Izvestiya Atmospheric and Oceanic Physics》2010,46(3):281-293
The emissions from fires in the boreal zone of northern Eurasia significantly contribute to the global emissions of greenhouse
gases, their precursors, and aerosols. These emissions are an important component of the global carbon balance, and they significantly
affect both seasonal and long-term variations in the chemical composition and radiation properties of the atmosphere on both
regional and global scales. The atmospheric emissions of carbon monoxide (CO) from biomass burning have systematically been
estimated for the entire territory of northern Eurasia over the period of 2000–2008 on the basis of satellite (MODIS MCD45A1)
data on burned vegetation and the Seiler-Crutzen emission model with consideration for both regional and seasonal features.
On the whole, for Russia, the annual emissions of CO from biomass burning ranged from 10.6 to 88.2 Mt/y over the indicated
period. Depending on fire activity, the atmospheric emissions of CO from natural fires and agricultural work may yield from
25 to 200% of the total technogenic emissions according to the EDGAR-2000 model. In this case, the dominant contribution is
made by boreal forest fires (8–57 Mt/y), whose portion amounts to 63–76% of the total emissions from biomass burning. This
relatively short observational series does not allow one to reliably estimate long-term variations; however, on the whole,
a stable increase in burned areas has been observed in forest, steppe, and agricultural regions over the last decade. Our
analysis suggests significant spatial and seasonal variations in the large-scale fields of fire emissions, which are determined
by the physical, geographic, and climatic features of individual regions. The calculated fields of emissions can be used in
transport-chemical models, studies of the regional transport and quality of air, and climate models. 相似文献
2.
V. G. Bondur 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1039-1048
We describe the specific features of the summer 2010 emergency conditions in the European part of the Russian Federation,
when an anomalous heat wave (the monthly mean temperatures in the summer months were 5–9°C higher than those for 2002–2009)
and prolonged blocking anticyclones led to large wildfires. We analyze their causes and consequences. The features of the
satellite system for operational fire monitoring (constructed at the Aerospace Scientific Center) and examples of its application
in summer 2010 are presented. On the basis of the results of processing of satellite images of low (250–1000 m), medium (∼30–50
m), and high (∼6 m) resolutions, we found that the total area covered by fire from March to November of 2010 amounted to approximately
10.9 million hectares for the entire territory of the country and and 2.2 million hectares for its European part. Daily histograms
of areas covered by fire in the summer months of 2010 were constructed. On the basis of these data and empirical models, we
estimate the daily emissions of carbon monoxide (CO) from wildfires in the summer months of 2010 for the European part of
Russia and Moscow oblast. On some days in August 2010, these emissions reached 15000–27000 t for the European part of Russia
and 3000–7500 t for Moscow oblast. On the basis of analysis of data from the AIRS spectrometer (Aqua satellite), we derived
the spatial distribution of CO concentrations at heights of 2 to 10 km above the territory of the Eastern and Central Europe.
Moscow was shown to have been most severely affected by smoke from wildfires occurring on August 6–9, 2010, when the concentrations
of harmful gases (CO2, CO, CH4, and O3) and aerosols in the air significantly exceeded both the daily and the one-hour maximum allowable concentrations. 相似文献
3.
The shortwave radiative forcings of smoke aerosol in the cloudless atmosphere during the summer fires of 2010 in European
Russia were quantitatively estimated for the land surface and the atmospheric upper boundary from measurement data obtained
at the Zvenigorod Scientific Station of the Obukhov Institute of Atmospheric Physics (OIAP ZSS), Russian Academy of Sciences.
Variations in the temperature of the surface air layer due to the smoke-induced attenuation of incoming solar radiation were
estimated. The most intensive smoke generation in the atmosphere was observed on August 7–9, 2010, when the maximum aerosol
optical thickness amounted to more than 4.0 at a wavelength of 550 nm. In this case, the albedo of single aerosol scattering
amounted to ∼0.95–0.96 and the asymmetry factor amounted to ∼0.69–0.70. The maximum shortwave radiative forcing of aerosol
amounted to about −360 W/m2 for the land surface and almost −150 W/m2 for the atmospheric upper boundary. During the period of intensive smoke generation, the cooling of the atmospheric surface
layer over daylight hours (12 h) amounted, on average, to ∼6°C. The power character of the dependence of the shortwave radiative
forcing of aerosol for the land surface on aerosol optical thickness up to its values exceeding 4.0, which was revealed earlier
on the basis of data on aerosol optical thickness (up to 1.5) obtained at the OIAP ZSS during the summer forest and peatbog
fires of 2002 in the region of Moscow, was supported. 相似文献
4.
The seasonal climatic circulation of the sea reconstructed on the basis of assimilation of new arrays of many-year average
hydrological data in a model is analyzed. Five layers are discovered in the structure of climatic currents in the sea in depth:
the surface Ekman layer (∼ 10 m), a layer with small vertical gradients of the kinetic energy (∼ 10–60 m), a layer with relatively
high vertical gradients of the kinetic energy (∼ 60–150 m), a layer with gradual decrease in the kinetic energy and intensification
(from 250–350 m) of the east cyclonic gyre and Batumi anticyclonic eddy (∼ 150–1000 m), and an abyssal layer characterized
by an almost barotropic velocity (∼ 1000–2000 m). The specific features of the seasonal evolution of currents at these depths
are investigated. It is shown that the key role in the formation of deep-water circulation of the sea is played by the south
east flow, east cyclonic gyre, and Batumi anticyclonic eddy.
__________
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 28–45, November–December, 2005. 相似文献
5.
O. B. Dmitrenko 《Oceanology》2012,52(1):101-111
The nannofosssil assemblages have been analyzed in five cores taken from the Titanic area of the northwestern Atlantic (∼41°–42°
N, ∼47°–50° W, water depths >3500 m) during cruises 41 and 43 of the R/V Akademik Mstislav Keldysh in 1998 and 2000. They correlate the host sediments with the upper Pleistocene-Holocene Emiliania huxleyi zone. The changes in the structure of the nannofossil assemblages and the lithological characteristics such as the content
of biogenic CaCO3, the abundance of ice-rafted debris, and the grain-size composition were used for the high-resolution stratigraphy of sections
with defining marine isotopic stages 1–3 of the last 24 kyr. A characteristic feature of the nannofossil assemblages from
this area is their enrichment with the cold-resistant species Coccolthus pelagicus during the warm climatic stages and the lack of allochthonous coccolitophorid remains. 相似文献
6.
We analyze the space-and-time variability of the meridional heat transport in the North Atlantic. The contribution of various
mechanisms to the integral meridional heat transport (MHT) is estimated. The key role played by the drift transport of the
Tropical Atlantic in the formation of the meridional oceanic heat transport is confirmed. On the basis of the general analysis
of estimations obtained by various authors according to the data accumulated for 1870–2008 and the results of numerical analyses
based on the data of NCEP/NCAR reanalysis, we show that the long-term average meridional drift heat (mass) transport attains its maximum values equal to (1.6 ± 0.1)
PW [(17.4 ± 1.5) Sv] in the vicinity of 12.5°N in the Tropical Atlantic. The contribution of the heat transport caused by
the horizontal Sverdrup circulation to the integral meridional heat transport is maximum in the vicinity of 30° N. On the
average, it is equal to ∼ 40%. In the Subtropical Atlantic, the meridional heat transport varies with a period of ∼ 50–70 yr.
The minimum value of the integral meridional heat transport was attained in the mid-1960s and its maximum value was at attained
at the beginning of the 1990s. The location of the center of Azores pressure maximum makes it possible to conclude that the
intensification of the total meridional heat transport in the Subtropical Atlantic on these time scales is accompanied by
the displacement of the center of the North Subtropical anticyclonic gyre in the southwest direction. 相似文献
7.
The spatial distribution of the primary production (PP) and the chlorophyll a concentration (Chl) were investigated during two research cruises in the Drake Passage area in October–November of 2007 and
2008. The algorithm evaluating the integral PP (PPint) for the water column in this area was developed based on the data on the surface chlorophyll (Chls) and the incident solar irradiance obtained in 2004–2008 in the Atlantic Sector of the Southern Ocean. The results obtained
both by the experimental and model approaches suggested that the Polar Front (PF) region of the Drake Passage was characterized
by low values of both the PPint (<100 mg C/m2 per day) and Chls (0.08–0.20 mg/m3) in October–November. Low values of the Chls and relatively high phaeophytine a concentrations indicated the winter succession state of the phytoplankton community in the Antarctic Ocean and the southern
Polar Frontal Zone (PFZ). The seasonal warming of the surface water layers and the developing pycnocline resulted in a phytoplankton
bloom and a Chls concentration of more than 1 mg/m3 in mid-November in this area and the Subantarctic waters. 相似文献
8.
We utilized 234Th, a naturally occurring radionuclide, to quantify the particulate organic carbon (POC) export rates in the northern South
China Sea (SCS) based on data collected in July 2000 (summer), May 2001 (spring) and November 2002 (autumn). Th-234 deficit
was enhanced with depth in the euphotic zone, reaching a subsurface maximum at the Chl-a maximum in most cases, as commonly
observed in many oceanic regimes. Th-234 was in general in equilibrium with 238U at a depth of ∼100 m, the bottom of the euphotic zone. In this study the 234Th deficit appeared to be less significant in November than in July and May. A surface excess of 234Th relative to 238U was found in the summer over the shelf of the northern SCS, most likely due to the accumulation of suspended particles entrapped
by a salinity front. Comparison of the 234Th fluxes from the upper 10 m water column between 2-D and traditional 1-D models revealed agreement within the errors of
estimation, suggesting the applicability of the 1-D model to this particular shelf region. 1-D model-based 234Th fluxes were converted to POC export rates using the ratios of bottle POC to 234Th. The values ranged from 5.3 to 26.6 mmol C m−2d−1 and were slightly higher than those in the southern SCS and other oligotrophic areas. POC export overall showed larger values
in spring and summer than in autumn, the seasonality of which was, however, not significant. The highest POC export rate (26.6
mmol C m−2d−1) appeared at the shelf break in spring (May), when Chl-a increased and the community structure changed from pico-phytoplankton
(<2 μm) dominated to nano-phytoplankton (2–20 μm) and micro-phytoplankton (20–200 μm) dominated. 相似文献
9.
To date, only a few coral proxy studies have investigated coral growth as an indicator of climate variability. This study
presents the first extension-rate record (Porites lutea) from the Maldives (NW Indian Ocean), inferred from skeletal δ18O chronology for the lagoon of Rasdhoo Atoll (4°N/73°W) in the central area of the Maldives, influenced by the Indian monsoon.
The record spans 90 years over the period 1917–2007. The mean annual extension over this period was 9.9 mm/year, and an increase
of annual extension rates until 1990 by 3 mm/year can be explained by a rise of 0.7°C in sea surface temperature (SST) in
this region. After 1990, the extension rates do no continue increasing, possibly due to ecological stress caused by progressive
ocean warming and acidification. The correlation between annual extension rates and SSTs is thus significant and strong in
the lower part of the record until 1955 (r = +0.69, p < 0.0001), but weaker thereafter (r = +0.44, p < 0.001). The extension rates yield a distinct interannual variability of 3–4 years, caused by interannual SST fluctuations
driven by the El Ni?o-Southern Oscillation. A variability of 8–9 years is likely driven by SST variations endemic to the Indian
Ocean. Spectral peaks between 18–19 years and 6–7 years cannot be explained by SST fluctuations, but by variations in the
strength of the SW monsoon currents. It is suggested that during phases of stronger monsoon activity, the coral sacrificed
coral extension in favor of a denser, more robust skeleton. The geomorphology of the atoll may strengthen the potential of
this new coral archive to track climate variability. 相似文献
10.
To date, coral proxy studies have proved largely unsuccessful in reconstructing temporal variability of the Indian monsoon
system in the NW Indian Ocean. In a recent publication in this journal, Storz and Gischler demonstrated that extension rates
in corals can be used to fill this gap. Those authors found a link between decadal and interannual variations of the SW monsoon
current velocities and Porites lutea extension rates in the lagoon of Rasdhoo Atoll (4°N/73°W) in the central Maldives for the period 1917–2007. This sister paper
shows that this extension-rate record can be used to reconstruct decadal variations of summer monsoon rainfall over peninsular
India and adjacent areas. The amount of monsoon rainfall and current velocities during summer are both affected by the strength
of the Indian monsoon system. Assessments of coral extension rates and the mean May–September All India Monsoon Rainfall index,
a measure of monsoon strength over the Indian subcontinent, revealed a significant spectral coherence within periods of 18–19
and 6–7 years. Almost 92% of variance is shared between both time series in the former band, and 85% in the latter. A correlation
between the 5-year running mean extension rate and rainfall records from the Western Ghats (grid of 73–76°E/13–15°N) is significant
especially for 1958–2006 (r = −0.82, p < 0.05). These findings imply that coral growth characteristics can serve as a new marine archive to reconstruct past variations
of the Indian monsoon system on interannual to decadal timescales. 相似文献
11.
Hajime Kawakami Makio C. Honda Masahide Wakita Shuichi Watanabe 《Journal of Oceanography》2007,63(6):967-982
Time-series measurements of dissolved inorganic carbon (DIC) and nutrient concentrations were conducted in the northwestern
North Pacific from October 2002 to August 2004. Assuming that data obtained in different years represented time-series seasonal
data for a single year, vertical distributions of DIC and nutrients showed large seasonal variabilities in the surface layer
(∼100 m). Seasonal variabilities in normalized DIC (nDIC) and nitrate concentrations at the sea surface were estimated to
be 81–113 μmol kg−1 and 12.7–15.7 μmol kg−1, respectively, in the Western Subarctic Gyre. The variability in nutrients between May and July was generally at least double
that in other seasons. In the Western Subarctic Gyre, estimations based on statistical analyses revealed that seasonal new
production was 39–61 gC m−2 and tended to be higher in the southwestern regions or coastal regions. The seasonal new productions in the northwestern
North Pacific were two or more times higher than in the North Pacific subtropical gyre and the northeastern North Pacific.
It is likely that this difference is due to spatial variations in the concentrations of trace metals and the species of phytoplankton
present. In addition, from estimations of surface pCO2 it was verified that the Western Subarctic Gyre is a source of atmospheric CO2 between February and May and a sink for CO2 between July and October. 相似文献
12.
E. I. Ponomarev E. G. Shvetsov V. I. Kharuk 《Izvestiya Atmospheric and Oceanic Physics》2016,52(7):725-736
Spatial and temporal patterns of vegetation fires in the Russian part of Altai-Sayan region over the period of instrumental satellite observations (1996–2014) have been studied. The distribution of fires by landscape categories, natural zones, altitudinal belts, and terrain profile forms is presented. We estimate the confinement of fire development in forests dominated by dark coniferous, light coniferous, and deciduous forest stands. The results are standardized taking into account the ratio between plant-cover areas of the selected categories, classes, and zones in the region. We have found an exponential decrease in the number of fires in the area of transition from plains and lowlands to highlands. Middle mountains are characterized by the largest burnt areas. Up to 50% of all fires are observed in the northern and adjacent slopes. The fire occurrence on concave slopes is 40% higher than that on convex slopes. The logarithmic growth in the number of burnt areas and fire frequency was found for all natural zones (forest, steppe, and forest steppe); the greatest seasonal variability in fire frequency and fire statistics is observed in the forest-steppe zone of the region. It is shown that the spatial distribution of fires is in agreement with the selected climatic facies. On the whole, the long-term dynamics of forest burning in the Altai-Sayan region and Siberia is strongly related to the variation of meteorological parameters characterizing climatic changes. 相似文献
13.
Using time series of hydrographic data in the wintertime and summertime obtained along 137°E from 1971 to 2000, we found that
the average contents of nutrients in the surface mixed layer showed linear decreasing trends of 0.001∼0.004 μmol-PO4 l−1 yr−1 and 0.01∼0.04 μmol-NO3 l−1 yr−1 with the decrease of density. The water column Chl-a (CHL) and the net community production (NCP) had also declined by 0.27∼0.48
mg-Chl m−2 yr−1 and 0.08∼0.47 g-C-NCP m−2 yr−1 with a clear oscillation of 20.8±0.8 years. These changes showed a strong negative correlation with the Pacific Decadal Oscillation
Index (PDO) with a time lag of 2 years (R = 0.89 ± 0.02). Considering the recent significant decrease of O2 over the North Pacific subsurface water, these findings suggest that the long-term decreasing trend of surface-deep water
mixing has caused the decrease of marine biological activity in the surface mixed layer with a bidecadal oscillation over
the western North Pacific. 相似文献
14.
Motohiko Kashima Shin-Ichi Ito Kaoru Ichikawa Shiro Imawaki Shin-Ichiro Umatani Hiroshi Uchida Takashi Setou 《Journal of Oceanography》2009,65(1):73-80
A quasiperiodic variation of 100–110 days in the Kuroshio path off Cape Ashizuri, resulting from the passage of small meanders,
was detected by observation with moored current meters during 1993–1995. TOPEX/POSEIDON altimeter data covering 9 years showed
that the quasiperiodic variation period was not persistent and modulated twice, with a ∼110-day period from mid-1993 to late
1996, a ∼150-day period from late 1996 to mid-1999, and a ∼110-day period from mid-1999 to late 2001. The quasiperiodic variations
of the Kuroshio path migration were contemporaneous with the quasiperiodic arrivals of mesoscale eddies from the east along
27–32°N over the same ∼110- and ∼150-day period quasiperiodic variations. The periodic arrivals of the eddies configure the
periodic variations of the Kuroshio path and its inter-annual modulation. 相似文献
15.
Habitat suitability index of Chub mackerel (<Emphasis Type="Italic">Scomber japonicus</Emphasis>) from July to September in the East China Sea 总被引:1,自引:0,他引:1
The habitat quality of Chub mackerel (Scomber japonicus) in the East China Sea has been a subject of concern in the last 10 years due to large fluctuations in annual catches of
this stock. For example, the Chinese light-purse seine fishery recorded 84000 tons in 1999 compared to 17000 tons in 2006.
The fluctuations have been attributed to variability in habitat quality. The habitat suitability Index (HSI) has been widely
used to describe fish habitat quality and in fishing ground forecasting. In this paper we use catch data and satellite derived
environmental variables to determine habitat suitability indices for Chub mackerel during July to September in the East China
Sea. More than 90% of the total catch was found to come from the areas with sea surface temperature of 28.0°–29.4°C, sea surface
salinity of 33.6–34.2 psu, chlorophyll-a concentration of 0.15–0.50 mg/m3 and sea surface height anomaly of −0.1–1.1 m. Of the four conventional models of HSI, the Arithmetic Mean Model (AMM) was
found to be most suitable according to Akaike Information Criterion analysis. Based on the estimation of AMM in 2004, the
monthly HSIs in the waters of 123°–125°E and 27°30′–28°00′ N were more than 0.6 during July to September, which coincides
with the catch distribution in the same time period. This implies that AMM can yield a reliable prediction of the Chub mackerel’s
habitat in the East China Sea. 相似文献
16.
On the basis of processing of the oceanographic data accumulated for the water area of the North Atlantic in 1950–1999 (∼500,000
stations), we study seasonal and interannual variations of the principal characteristics of pycnocline within the range of
σt = 25.5–27.5 conventional density units. It is shown that the interannual oscillations of these characteristics in the entire
analyzed layer can be regarded as a superposition of fluctuations with periods from 2–3 to 10–12 yr. The typical ranges of
these fluctuations for the depths of occurrence of isopycnic surfaces and the corresponding temperature and salinity are equal
to 20–25 m, 1–1.5°C, and 0.25‰, respectively. The intensification of atmospheric circulation at middle latitudes is accompanied
by the simultaneous deepening of the pycnocline and its heating in the central part of the North Subtropical Anticyclonic
Gyre. At the same time, the process of weakening of the atmospheric circulation leads to the rise of the pycnocline and its
cooling. The complete cycle of interaction of the North-Atlantic Oscillation with the anomalies of isopycnic characteristics
(with regard for the period of their advection) is equal to ∼6–8 yr.
__________
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 2, pp. 29–48, March–April, 2007. 相似文献
17.
O. S. Chauhan B. S. Sukhija A. R. Gujar P. Nagabhushanam A. L. Paropkari 《Geo-Marine Letters》2000,20(2):118-122
Down-core variations in illite, chlorite, smectite and kaolinite (the major clays) in two 14C-dated cores collected along the SW continental margin of India show that illite and chlorite have enhanced abundance during
20–17, 12.5, 11–9.5, and 5–4.8 ka b.p., whereas smectite accumulation is higher between 17 and 12.5, and after 9 ka b.p. The climate may have been predominantly arid at 17 (20–17), 12.5, 10.5 (11–9.5), and 4.8 ka b.p. The first three dates correspond to the last glacial maximum, Bolling-Allerod, and Younger Dryas events, respectively. The
SW monsoon was variable between 17 and 15 ka b.p., and it was more stable and intense after the Younger Dryas until about 6 ka b.p.
Received: 2 December 1999 / Revision accepted: 11 April 2000 相似文献
18.
O. V. Krivenko 《Physical Oceanography》2006,16(6):337-349
Based on the experimental data obtained in 1990–1993 by the method of isotopic tracers with the help of a stable isotope of
nitrogen (15N), we establish basic regularities of the formation of “new” and regeneration production in the Black Sea and reveal the
factors specifying their combination. It is shown that the rates of nitrate and ammonium uptake by microplankton vary from
the minimum values in winter to the maximum values in summer. In the surface layer, the uptake of nitrates corresponding to
the amount of “new” production in deep-water layers is equal to ∼ 50% (in winter) and ∼ 30% (in summer) of the total uptake
of inorganic nitrogen compounds by microplankton. In the zone of photosynthesis, the average fractions of nitrates are equal
to 31 ± 10% in winter and 41 ± 10% in summer. The minimum values of this parameter are attained in the middle of spring and
in autumn. The fraction of “new” production (f-ratio) and the integral content of nitrates in the zone of photosynthesis are connected by a hyperbolic dependence. The period
of cyclic transformations of nitrates in this zone decreases from several dozens of days at the beginning of winter to 12
h in the mid-spring. In summer, this period is equal, on the average, to one day. The average period of cyclic transformations
of ammonium is equal to 15 ± 4 h in winter and 5 ± 3 h in summer.
__________
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 29–43, November–December, 2006. 相似文献
19.
F. V. Kashin R. M. Akimenko V. N. Aref’ev Yu. I. Baranov G. I. Bugrim N. I. Sizov L. B. Upenek 《Izvestiya Atmospheric and Oceanic Physics》2010,46(1):45-54
The results of measurements of the concentration of carbon oxide (CO) in the atmospheric surface layer over the town of Obninsk
(in European Russia, 105 km to the southwest of Moscow) are presented. Air samples were analyzed with the aid of a measuring
system consisting of a Fourier-spectrometer and an optic multipass cell. The CO concentration was measured simultaneously
with the measurements of air temperature up to a height of 300 m. The measurement data obtained from February 1998 to January
2009 suggest the presence of variations within the range 100–450 ppb (∼80% of all the data) and nonperiodic relatively short-term
and anomalously high CO concentrations that reach several ppm. The highest concentrations are due to CO accumulated in the
surface air in the presence of temperature inversion and during forest fires. The measurements of the concentration of CO
throughout a day revealed its morning and evening maxima, which coincide in time with the increased traffic current. The maxima
and minima of seasonal variations in the monthly mean concentrations of CO, which are due to variations in the sources and
sinks of CO that happen within a year, are observed in January and June, respectively. The amplitudes of seasonal variations
amounted to (53 ± 10)% of the annual mean. The annual mean concentration of CO decreased by ∼12% over the measurement period.
A comparison was made with observational data obtained at five monitoring stations located in the latitudes that are close
to the latitude of Obninsk. Over the European continent, the concentration of CO tends to decrease with a longitude decrease
as it goes from east to west. 相似文献
20.
Hodaka Kawahata Mayuri Inoue Masato Nohara Atsushi Suzuki 《Journal of Oceanography》2006,62(4):405-412
The δ18O, δ13C and trace element composition of pearls collected from Ago Bay, Japan, were investigated in order to evaluate biomineralization
in the cultured pearl oyster (Pinctada fucata martensii). The oxygen isotopic data suggest that the pearls were produced around 23–24°C, mainly in June to early July, which is consistent
with their occurrence in the field. Therefore the pearls were produced under or close to isotopic equilibrium conditions,
although they showed high calcification rates (higher than 0.2–1.0 g cm− 2yr−1) under which, for example, coral skeletons (calcification rate ∼0.28 g cm− 2yr−1) often show non-equilibrium isotope partitioning. The δ13C values were ∼− 2.9‰ lower than those calculated for offshore waters under equilibrium conditions. This may be due to low-δ13C bottom waters resulting from the degradation of organic matter (OM) or to a contribution of low-δ 13C food. In the latter case, a simple mass balance calculation gives a respiration component of 14%. Twelve trace elements
of bulk pearl samples were classified into four groups on the basis of their enrichment/depletion patterns relative to seawater
and inter-element relationships: group 1, Co, Cr, Pb; group 2, Ba, Cs, U; group 3, Cu, Sn, V, and group 4, Mn, Rb, Mo. Comparison
with coral skeletons suggests that Ba and Mn (groups 2 and 4) were definitely much enriched in proteinaceous OM relative to
aragonite crystals in pearls and that V (group 3) in pearls showed only slight enrichment in the organicrich layer. By contrast,
the other elements showed small differences between both layers (enrichment factor of <3), suggesting that these elements
occur largely in aragonite crystals. 相似文献