Phytoplankton standing crop, primary productivity, and near-surface nitrogenous nutrient fields in the Ross Sea, Antarctica

1983 ◽  
Vol 30 (8) ◽  
pp. 871-886 ◽  
Author(s):  
Sayed Z. El-Sayed ◽  
Douglas C. Biggs ◽  
Osmund Holm-Hansen
Keyword(s):  
Primary Productivity ◽  
Standing Crop ◽  
Ross Sea ◽  
Near Surface

scholarly journals Ground ice in the Northern Foothills, northern Victoria Land, Antarctica

2004 ◽  
Vol 39 ◽  
pp. 495-500 ◽  
Author(s):  
Mauro Guglielmin ◽  
Hugh M. French
Keyword(s):  
Oxygen Isotope ◽  
Ross Sea ◽  
Progress Report ◽  
Ground Ice ◽  
Lake Ice ◽  
Near Surface ◽  
Victoria Land ◽  
Different Types ◽  
Glacier Ice ◽  
Surface Ice

AbstractThis progress report classifies the different types of ground-ice bodies that occur in the Northern Foothills, northern Victoria Land, Antarctica. Oxygen isotope variations are presented, but interpretation is kept to a minimum pending further investigations. Surface ice, as distinct from moving glacier ice, occurs in the form of widespread buried (‘dead’) glacier ice lying beneath ablation (sublimation) till, together with perennial lake ice, snow banks and icing-blister ice.’Dry’ permafrost is uncommon, and interstitial ice is usually present at the base of the active layer and in the near-surface permafrost. This probably reflects the supply of moisture from the Ross Sea and limited sublimation under today’s climate. Intrusive ice occurs as layers within perennial lake-ice covers and gives rise to small icing blisters. Small ice wedges found beneath the furrows of high-centered polygons appear to agree with the model of sublimation-till development proposed by Marchant and others (2002).

Thermohaline structure and variability in the Terra Nova Bay polynya, Ross Sea

2000 ◽  
Vol 12 (4) ◽  
pp. 493-508 ◽  
Author(s):  
G. Budillon ◽  
G. Spezie
Keyword(s):  
Surface Layer ◽  
Cold Water ◽  
Ross Sea ◽  
Heat Budget ◽  
Salt Content ◽  
Heat Fluxes ◽  
Local Source ◽  
Near Surface ◽  
Terra Nova Bay ◽  
Terra Nova

Hydrological measurements from three cruises during the summers 1994/95, 1995/96 and 1997/98 in the western sector of the Ross Sea allow summer and year to year changes in heat and salt content in the Terra Nova Bay polynya to be analysed. Changes in the surface layer (upper pycnocline) followed the expected seasonal pattern of warming and freshening from the beginning to the end of the summer. These near-surface changes, expressed as net heating and salting rate, were about 11 W m−2 and -6 mg salt m−2 s−1. The heating changes were substantially lower than the estimated heat supplied by the atmosphere during the summer, which underlines the importance for this season of the advective component carried by the currents in the total heat budget. The year to year differences were about one or two orders of magnitude smaller than the seasonal changes in the surface layer. In the intermediate and deep layers, the summer heat and salt variability were of the same order as or one order higher than from one summer to the next. The differences in sign and magnitude for the heat change in the upper and in the lower pycnocline indicate a weak connection in the summer period between the surface heat fluxes and the deep waters. A local source of very cold water (with temperatures below the surface freezing point) of about 0.3 Sv has been detected close to the Terra Nova Bay coast. It arose out of the interaction of the shallow–intermediate layers of High Salinity Shelf Water with the coastal glaciers. The presence and the variability of this cold water point to the significant role of the thermohaline properties of Terra Nova Bay waters in controlling the floating glacier by governing the basal melting processes.

Pelagic primary production in the Coral and southern Solomon Seas

1996 ◽  
Vol 47 (5) ◽  
pp. 695 ◽  
Author(s):  
MJ Furnas ◽  
AW Mitchell
Keyword(s):  
Primary Production ◽  
Mixed Layer ◽  
Standing Crop ◽  
Central Basin ◽  
Strong Wind ◽  
Surface Mixed Layer ◽  
Barrier Reef ◽  
Near Surface ◽  
Western Margin ◽  
Coral Sea

Phytoplankton primary production was measured around the periphery of the Coral Sea during October 1985 and in the boundary current systems bordering the northern Australian Great Barrier Reef (GBR) and Papuan Barrier Reef (PBR) during October 1985 and June-July 1988. Under strong wind conditions (mean winds 8-12 m s-1), the north-western Papuan Barrier Reef region was characterized by a shallow surface mixed layer, shallow nutriclines (25-75 m) and shallow subsurface chlorophyll maxima. Under low wind stress conditions (mean winds <5 m s-1), the southern and western Coral Sea were also characterized by a shallow surface mixed layer and stable underlying density profiles but deep (>I00 m) nutriclines and deep (60-125 m) subsurface chlorophyll and primary production maxima. Regardless of location, most primary production occurred above the 20% mid-day isolume surface. Phytoplankton standing crop and primary production in all regions were dominated by picoplankton (<2 μm size fraction). Very high primary production rates (1-3 g C m-2 day-1) were measured at a number of stations adjacent to the western margin of the PBR and within the central basin of the Louisiade Archipelago. Evidence for upwelling along the western margin of the PBR was observed under both north-easterly (normal to the reef axis) and south-easterly (parallel to the reef axis) wind regimes; however, surface outcropping of upwelled water did not occur. Oceanic primary production in the Coral Sea is estimated to be between 100 and 200 g C m-2 year-1. Primary production in and around the Louisiade Archipelago appears to be on the order of 200-300 g C m-2 year-1. Near-surface chlorophyll standing crop was generally better correlated with near-surface primary production than was total chlorophyll with total areal primary production.

A Seasonally Varying Phenology for High Resolution Simulations with the COSMO-CLM Model

2020 ◽  
Author(s):  
Eva Nowatzki ◽  
Jan-Peter Schulz ◽  
Jean-Marie Bettems ◽  
Jürg Luterbacher ◽  
Merja Tölle
Keyword(s):  
Latent Heat ◽  
Primary Productivity ◽  
Water Availability ◽  
Net Primary Productivity ◽  
Regional Climate ◽  
Day Length ◽  
Geophysical Research ◽  
Near Surface ◽  
Meteorological Observatory ◽  
Measuring Site

&lt;p&gt;The energy and water cycle of the regional climate is influenced by the phenological development of the vegetation through albedo, sensible and latent heat flux changes. This influences near surface temperature, precipitation and ultimately the boundary layer structure. The phenological stages in turn depend on temperature, day length, water availability and net primary productivity variations. Therefore, vegetation should play an important role in climate simulations. The current implementation of the seasonal vegetation development in the regional climate model COSMO-CLM (CCLM, COSMO 5.0 clm15), represented in the model by the leaf area index (LAI), the root depth or plant coverage, assumes a static, annually recurring cycle. In reality, it varies from year to year depending on the environmental conditions. In particular, the phenology will change with climate change modifying the environment. In this study, we implement the approach of Knorr et al. (2010) to improve the representation of the phenology in CCLM with 3 km horizontal resolution by temperature, day length and water availability. Here, the tuning parameters of the growth rate for grass is adapted from Schulz et al. (2015). Convection-permitting single column simulations are performed over the Lindenberg Meteorological Observatory, the FACE measuring site at Linden close to Gie&amp;#223;en, and the TR32 measuring site at Selhausen close to J&amp;#252;lich in Germany. Comparisons of LAI results with observations show significantly improved correlations compared to simulations with the standard phenology over the period from 1999 to 2015. The reaction of the LAI due to years with extreme warm winter and spring or years with extreme dry summer is improved as well. A warmer beginning of the year causes an earlier start of the growing season, whereas a drier summer reduces the LAI due to water limitation. It is also shown, that lower LAI values lead to decreases of latent heat fluxes in the model. The mean amount of strong precipitation events (&gt; 20 mm) is closer to the observations with the new phenology compared to the standard phenology. Further seasonally varying phenology for different plant functional types and its net primary productivity will be implemented in future work.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Ackowledgement:&lt;/p&gt;&lt;p&gt;Computational resources were made available by the German Climate Computing Center (DKRZ) through support from the Federal Ministry of Education and Research in Germany (BMBF). We acknowledge the funding of the German Research Foundation (DFG) through grant nr. 401857120.&lt;/p&gt;&lt;p&gt;Literature:&lt;/p&gt;&lt;p&gt;Knorr, W. et al., 2010. Carbon cycle data assimilation with a generic phenology model. Journal of Geophysical Research: Biogeosciences, 115(G4).&lt;/p&gt;&lt;p&gt;Schulz, J.-P., Vogel, G. &amp; Ahrens, B., 2015. A new leaf phenology for the land surface scheme TERRA of the COSMO atmospheric model. COSMO Newsletter No. 15, p.21-29.&lt;/p&gt;

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