scholarly journals Global marine plankton functional type biomass distributions: coccolithophores

2012 ◽  
Vol 5 (2) ◽  
pp. 491-520 ◽  
Author(s):  
C. J. O'Brien ◽  
J. A. Peloquin ◽  
M. Vogt ◽  
M. Heinle ◽  
N. Gruber ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Seasonal Cycle ◽  
Marine Phytoplankton ◽  
The North ◽  
Carbon Biomass ◽  
Time Period ◽  
The Pacific ◽  
Individual Contributions ◽  
June July

Abstract. Coccolithophores are calcifying marine phytoplankton of the class Prymnesiophyceae. They are considered to play an import role in the global carbon cycle through the production and export of organic carbon and calcite. We have compiled observations of global coccolithophore abundance from several existing databases as well as individual contributions of published and unpublished datasets. We estimate carbon biomass using standardised conversion methods and provide estimates of uncertainty associated with these values. The database contains 58 384 individual observations at various taxonomic levels. This corresponds to 12 391 observations of total coccolithophore abundance and biomass. The data span a time period of 1929–2008, with observations from all ocean basins and all seasons, and at depths ranging from the surface to 500 m. Highest biomass values are reported in the North Atlantic, with a maximum of 501.7 μg C l−1. Lower values are reported for the Pacific (maximum of 79.4 μg C l−1) and Indian Ocean (up to 178.3 μg C l−1). Coccolithophores are reported across all latitudes in the Northern Hemisphere, from the Equator to 89° N, although biomass values fall below 3 μg C l−1 north of 70° N. In the Southern Hemisphere, biomass values fall rapidly south of 50° S, with only a single non-zero observation south of 60° S. Biomass values show a clear seasonal cycle in the Northern Hemisphere, reaching a maximum in the summer months (June–July). In the Southern Hemisphere the seasonal cycle is less evident, possibly due to a greater proportion of low-latitude data. The original and gridded datasets can be downloaded from Pangaea (http://doi.pangaea.de/10.1594/PANGAEA.785092).

scholarly journals Global marine plankton functional type biomass distributions: coccolithophores

2013 ◽  
Vol 5 (2) ◽  
pp. 259-276 ◽  
Author(s):  
C. J. O'Brien ◽  
J. A. Peloquin ◽  
M. Vogt ◽  
M. Heinle ◽  
N. Gruber ◽  
...  
Keyword(s):  
Seasonal Cycle ◽  
Marine Phytoplankton ◽  
Low Latitude ◽  
The North ◽  
Carbon Biomass ◽  
Time Period ◽  
The Pacific ◽  
Individual Contributions ◽  
June July ◽  
Global Carbon

Abstract. Coccolithophores are calcifying marine phytoplankton of the class Prymnesiophyceae. They are considered to play an import role in the global carbon cycle through the production and export of organic carbon and calcite. We have compiled observations of global coccolithophore abundance from several existing databases as well as individual contributions of published and unpublished datasets. We make conservative estimates of carbon biomass using standardised conversion methods and provide estimates of uncertainty associated with these values. The quality-controlled database contains 57 321 individual observations at various taxonomic levels. This corresponds to 11 503 observations of total coccolithophore abundance and biomass. The data span a time period of 1929–2008, with observations from all ocean basins and all seasons, and at depths ranging from the surface to 500 m. Highest biomass values are reported in the North Atlantic, with a maximum of 127.2 μg C L−1. Lower values are reported for the Pacific (maximum of 20.0 μg C L−1) and Indian Ocean (up to 45.2 μg C L−1). Maximum biomass values show peaks around 60° N and between 40 and 20° S, with declines towards both the equator and the poles. Biomass estimates between the equator and 40° N are below 5 μg C L−1. Biomass values show a clear seasonal cycle in the Northern Hemisphere, reaching a maximum in the summer months (June–July). In the Southern Hemisphere the seasonal cycle is less evident, possibly due to a greater proportion of low-latitude data. The original and gridded datasets can be downloaded from Pangaea (doi:10.1594/PANGAEA.785092).

scholarly journals Global marine plankton functional type biomass distributions: <i>Phaeocystis</i> sp.

2012 ◽  
Vol 5 (1) ◽  
pp. 405-443
Author(s):  
M. Vogt ◽  
C. O'Brien ◽  
J. Peloquin ◽  
V. Schoemann ◽  
E. Breton ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Spherical Geometry ◽  
Specific Cell ◽  
Carbon Conversion ◽  
Latitude Range ◽  
Abundance Data ◽  
The North ◽  
Carbon Biomass ◽  
Cell Biomass

Abstract. The planktonic haptophyte Phaeocystis has been suggested to play a fundamental role in the global biogeochemical cycling of carbon and sulphur, but little is known about its global biomass distribution. We have collected global microscopy data of the genus Phaeocystis and converted abundance data to carbon biomass using species-specific carbon conversion factors. Microscopic counts of single-celled and colonial Phaeocystis were obtained both through the mining of online databases and by accepting direct submissions (both published and unpublished) from Phaeocystis specialists. We recorded abundance data from a total of 1595 depth-resolved stations sampled between 1955–2009. The quality-controlled dataset includes 5057 counts of individual Phaeocystis cells resolved to species level and information regarding life-stages from 3526 samples. 83% of stations were located in the Northern Hemisphere while 17% were located in the Southern Hemisphere. Most data were located in the latitude range of 50–70° N. While the seasonal distribution of Northern Hemisphere data was well-balanced, Southern Hemisphere data was biased towards summer months. Mean species- and form-specific cell diameters were determined from previously published studies. Cell diameters were used to calculate the cellular biovolume of Phaeocystis cells, assuming spherical geometry. Cell biomass was calculated using a carbon conversion factor for Prymnesiophytes (Menden-Deuer and Lessard, 2000). For colonies, the number of cells per colony was derived from the colony volume. Cell numbers were then converted to carbon concentrations. An estimation of colonial mucus carbon was included a posteriori, assuming a mean colony size for each species. Carbon content per cell ranged from 9 pg (single-celled Phaeocystis antarctica) to 29 pg (colonial Phaeocystis globosa). Non-zero Phaeocystis cell biomasses (without mucus carbon) range from 2.9 × 10−5 μg l−1 to 5.4 × 103 μg l−1, with a mean of 45.7 μg l−1 and a median of 3.0 μg l−1. Highest biomasses occur in the Southern Ocean below 70° S (up to 783.9 μg l−1), and in the North Atlantic around 50° N (up to 5.4 × 103 μg l−1). The original and gridded data can be downloaded from PANGAEA, http://doi.pangaea.de/10.1594/PANGAEA.779101.

scholarly journals Global marine plankton functional type biomass distributions: <i>Phaeocystis</i> spp.

2012 ◽  
Vol 4 (1) ◽  
pp. 107-120 ◽  
Author(s):  
M. Vogt ◽  
C. O'Brien ◽  
J. Peloquin ◽  
V. Schoemann ◽  
E. Breton ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Spherical Geometry ◽  
Specific Cell ◽  
Carbon Conversion ◽  
Latitude Range ◽  
Abundance Data ◽  
The North ◽  
Carbon Biomass ◽  
C Cell

Abstract. The planktonic haptophyte Phaeocystis has been suggested to play a fundamental role in the global biogeochemical cycling of carbon and sulphur, but little is known about its global biomass distribution. We have collected global microscopy data of the genus Phaeocystis and converted abundance data to carbon biomass using species-specific carbon conversion factors. Microscopic counts of single-celled and colonial Phaeocystis were obtained both through the mining of online databases and by accepting direct submissions (both published and unpublished) from Phaeocystis specialists. We recorded abundance data from a total of 1595 depth-resolved stations sampled between 1955–2009. The quality-controlled dataset includes 5057 counts of individual Phaeocystis cells resolved to species level and information regarding life-stages from 3526 samples. 83% of stations were located in the Northern Hemisphere while 17% were located in the Southern Hemisphere. Most data were located in the latitude range of 50–70° N. While the seasonal distribution of Northern Hemisphere data was well-balanced, Southern Hemisphere data was biased towards summer months. Mean species- and form-specific cell diameters were determined from previously published studies. Cell diameters were used to calculate the cellular biovolume of Phaeocystis cells, assuming spherical geometry. Cell biomass was calculated using a carbon conversion factor for prymnesiophytes. For colonies, the number of cells per colony was derived from the colony volume. Cell numbers were then converted to carbon concentrations. An estimation of colonial mucus carbon was included a posteriori, assuming a mean colony size for each species. Carbon content per cell ranged from 9 pg C cell−1 (single-celled Phaeocystis antarctica) to 29 pg C cell−1 (colonial Phaeocystis globosa). Non-zero Phaeocystis cell biomasses (without mucus carbon) range from 2.9 × 10−5 to 5.4 × 103 μg C l−1, with a mean of 45.7 μg C l−1 and a median of 3.0 μg C l−1. The highest biomasses occur in the Southern Ocean below 70° S (up to 783.9 μg C l−1) and in the North Atlantic around 50° N (up to 5.4 × 103 μg C l−1). The original and gridded data can be downloaded from PANGAEA, doi:10.1594/PANGAEA.779101.

scholarly journals Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand 1954–2014

2016 ◽  
Author(s):  
Jocelyn C. Turnbull ◽  
Sara E. Mikaloff Fletcher ◽  
India Ansell ◽  
Gordon Brailsford ◽  
Rowena Moss ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Co2 Emissions ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Seasonal Cycle ◽  
Fossil Fuel ◽  
Anthropogenic Sources ◽  
Deep Waters ◽  
Cape Grim

Abstract. We present 60 years of Δ14CO2 measurements from Wellington, New Zealand (41° S, 175° E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest atmospheric Δ14CO2 record and records the rise of the 14C "bomb spike", the subsequent decline in Δ14CO2 as bomb 14C moved throughout the carbon cycle and increasing fossil fuel CO2 emissions further decreased atmospheric Δ14CO2. The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2 ‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport, and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. Δ14CO2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, Northern Hemisphere clean air sites show a higher and earlier bomb 14C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ14CO2 were quite similar, apparently due to the balance of 14C-free fossil fuel CO2 emissions in the north and 14C-depleted ocean upwelling in the south. The Southern Hemisphere sites show a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14C-depleted and carbon-rich deep waters in the Southern Ocean. This developing Δ14CO2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s, and suggests that upwelling of deep waters plays an important role in this change.

scholarly journals In situ observations of aerosol particles remaining from evaporated cirrus crystals: Comparing clean and polluted air masses

2002 ◽  
Vol 2 (5) ◽  
pp. 1599-1633 ◽  
Author(s):  
M. Seifert ◽  
J. Ström ◽  
R. Krejci ◽  
A. Minikin ◽  
A. Petzold ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Aerosol Particles ◽  
Pollution Level ◽  
Size Distributions ◽  
Number Density ◽  
Particle Volume ◽  
The North ◽  
In Situ Observations

Abstract. In situ observations of aerosol particles contained in cirrus crystals are presented and compared to interstitial aerosol size distributions (non-activated particles in between the cirrus crystals). The observations were conducted in cirrus clouds in the Southern and Northern Hemisphere mid-latitudes during the INCA project. The first campaign in March and April 2000 was performed from Punta Arenas, Chile (54° S) in pristine air. The second campaign in September and October 2000 was performed from Prestwick, Scotland (53° N) in the vicinity of the North Atlantic flight corridor. Size distribution measurements of crystal residuals (particles remaining after evaporation of the crystals) show that small aerosol particles (Dp < 0.1µm) dominate the number density of residuals. The crystal residual size distributions were significantly different in the two campaigns. On average the residual size distributions were shifted towards larger sizes in the Southern Hemisphere. For a given integral residual number density, the calculated particle volume was on average three times larger in the Southern Hemisphere. This may be of significance to the vertical redistribution of aerosol mass by clouds in the tropopause region. In both campaigns the mean residual size increased with increasing crystal number density. The observations of ambient aerosol particles were consistent with the expected higher pollution level in the Northern Hemisphere. The fraction of residual particles only contributes to approximately a percent or less of the total number of particles, which is the sum of the residual and interstitial particles.

On the Role of Atmospheric Teleconnections in Climate

2008 ◽  
Vol 21 (12) ◽  
pp. 2990-3001 ◽  
Author(s):  
Anastasios A. Tsonis ◽  
Kyle L. Swanson ◽  
Geli Wang
Keyword(s):  
Northern Hemisphere ◽  
North Atlantic ◽  
Recent Application ◽  
The North ◽  
The Pacific ◽  
Atmospheric Teleconnections ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
The Tropics

Abstract In a recent application of networks to 500-hPa data, it was found that supernodes in the network correspond to major teleconnection. More specifically, in the Northern Hemisphere a set of supernodes coincides with the North Atlantic Oscillation (NAO) and another set is located in the area where the Pacific–North American (PNA) and the tropical Northern Hemisphere (TNH) patterns are found. It was subsequently suggested that the presence of atmospheric teleconnections make climate more stable and more efficient in transferring information. Here this hypothesis is tested by examining the topology of the complete network as well as of the networks without teleconnections. It is found that indeed without teleconnections the network becomes less stable and less efficient in transferring information. It was also found that the pattern chiefly responsible for this mechanism in the extratropics is the NAO. The other patterns are simply a linear response of the activity in the tropics and their role in this mechanism is inconsequential.

Atmospheric short-chain-chlorinated paraffins in Melbourne, Australia – first extensive Southern Hemisphere observations

2017 ◽  
Vol 14 (2) ◽  
pp. 106 ◽  
Author(s):  
Robert W. Gillett ◽  
Ian E. Galbally ◽  
Melita D. Keywood ◽  
Jennifer C. Powell ◽  
Gavin Stevenson ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Seasonal Cycle ◽  
Metal Cutting ◽  
Short Chain ◽  
Ambient Atmosphere ◽  
Industrial Chemicals ◽  
Chlorinated Paraffins ◽  
Atmospheric Concentrations

Environmental contextThis study presents the first comprehensive set of ambient atmospheric concentrations of short-chain-chlorinated paraffins in the Southern Hemisphere. The data show a seasonal cycle with a summer maximum and a winter minimum. The seasonal cycle is consistent with temperature dependence of the vapour pressure of the short-chain-chlorinated paraffins resulting in partitioning between the atmosphere and other reservoirs with a secondary modulation by soil moisture. AbstractThe first extensive measurements of short-chain chlorinated paraffins (SCCPs) in the atmosphere of the Southern Hemisphere are presented. The analytical and sampling methodologies used in this Australian study were verified by systematic testing along with two inter-comparisons with Northern Hemisphere laboratories with established SCCP programs. In the ambient atmosphere of Melbourne, Australia, in 2013–14, there was a clear seasonal cycle in SCCP monthly averaged concentrations, these ranging from 28.4ng m–3 in summer to 1.8ng m–3 in winter. Air temperature was the factor most closely related to the seasonal cycle in SCCPs in Melbourne. The average SCCP concentrations observed indoors were less than those observed outdoors. Atmospheric concentrations of SCCPs in Melbourne are more than two orders of magnitude higher than concentrations in the background atmosphere. Surprisingly, the SCCP concentrations in Melbourne are similar to those observed in cities in Japan, South Korea and the United Kingdom, and less than those observed in China. Direct transport of SCCPs in the atmosphere from the Northern Hemisphere emissions to Melbourne is ruled out. Instead elevated concentrations in the Melbourne air-shed are most likely a result of the long-term import of SCCPs as industrial chemicals and within manufactured materials from the Northern Hemisphere so that the use of SCCPs in Melbourne and their consequent release to the environment has produced environmental reservoirs of SCCPs in Melbourne that are comparable with those in some Northern Hemisphere cities. The increase in SCCP concentrations from winter to summer is consistent with the temperature dependence of partitioning of SCCPs between the atmosphere and other reservoirs. Insufficient information exists on SCCP use and its presence in soils and sediments in Australia to indicate whether the atmospheric presence of SCCPs in Melbourne is a legacy issue due to its import and use as a metal cutting agent in past decades or due to ongoing imports of manufactured materials containing SCCPs today.

scholarly journals A global climatology of tropospheric and stratospheric ozone derived from Aura OMI and MLS measurements

2011 ◽  
Vol 11 (17) ◽  
pp. 9237-9251 ◽  
Author(s):  
J. R. Ziemke ◽  
S. Chandra ◽  
G. J. Labow ◽  
P. K. Bhartia ◽  
L. Froidevaux ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Northern Hemisphere ◽  
Tropospheric Ozone ◽  
Stratospheric Ozone ◽  
Ozone Monitoring Instrument ◽  
Asian Continent ◽  
Nasa Goddard Space ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean

Abstract. A global climatology of tropospheric and stratospheric column ozone is derived by combining six years of Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone measurements for the period October 2004 through December 2010. The OMI/MLS tropospheric ozone climatology exhibits large temporal and spatial variability which includes ozone accumulation zones in the tropical south Atlantic year-round and in the subtropical Mediterranean/Asia region in summer months. High levels of tropospheric ozone in the Northern Hemisphere also persist in mid-latitudes over the eastern part of the North American continent extending across the Atlantic Ocean and the eastern part of the Asian continent extending across the Pacific Ocean. For stratospheric ozone climatology from MLS, largest column abundance is in the Northern Hemisphere in the latitude range 70° N–80° N in February–April and in the Southern Hemisphere around 40° S–50° S during August–October. Largest stratospheric ozone lies in the Northern Hemisphere and extends from the eastern Asian continent eastward across the Pacific Ocean and North America. With the advent of many newly developing 3-D chemistry and transport models it is advantageous to have such a dataset for evaluating the performance of the models in relation to dynamical and photochemical processes controlling the ozone distributions in the troposphere and stratosphere. The OMI/MLS gridded ozone climatology data are made available to the science community via the NASA Goddard Space Flight Center ozone and air quality website http://ozoneaq.gsfc.nasa.gov/.

Global Synoptic Maps *

1952 ◽  
Vol 33 (10) ◽  
pp. 435-437 ◽  
Author(s):  
Leo Alpert
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
North Pole ◽  
Weather Bureau ◽  
The North ◽  
The Earth ◽  
Antarctic Continent ◽  
Map Analysis ◽  
The Antarctic

Synoptic map analysis of the Earth from the North Pole to the shores of the Antarctic Continent is now attained by combining the Southern Hemisphere map analysis of the U. S. Weather Bureau-M.I.T. Southern Hemisphere Map Analysis Project, and the Northern Hemisphere map analysis of the published Daily Historical Weather Maps. Sample synoptic maps of the Earth for 19 and 20 March 1949 are presented.

scholarly journals Computation of Compilation Catalogs

1986 ◽  
Vol 109 ◽  
pp. 75-86
Author(s):  
Thomas E. Corbin
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Fundamental System ◽  
Proper Motions ◽  
The South ◽  
International Reference ◽  
The North ◽  
Naval Observatory ◽  
Made In

Currently the computation of mean positions and proper motions for the International Reference Stars (IRS) is hampered by large variations in the observational histories of the stars and lack of overlap between the magnitudes of the IRS and of the FK4. The poorest IRS observational histories are +60° to +80° in the north and −40° to −80° in the south. The much-needed extension of the fundamental system to the ninth magnitude will be made in the FK5. The Faint Fundamental Extension is currently being selected at the U. S. Naval Observatory. A proposed list of 1030 Faint Fundamental stars has been prepared for the Northern Hemisphere, and work has begun on the selection in the Southern Hemisphere.

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