scholarly journals Oceanic Rossby waves drive inter-annual predictability of net primary production in the central tropical Pacific

2021 ◽  
Author(s):  
Sebastian Brune ◽  
Maria Esther Caballero Espejo ◽  
David Marcolino Nielsen ◽  
Hongmei Li ◽  
Tatiana Ilyina ◽  
...  
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Rossby Waves ◽  
Net Primary Productivity ◽  
Net Primary Production ◽  
Tropical Pacific ◽  
Prediction System ◽  
Decadal Prediction ◽  
Near Surface ◽  
Equatorial Rossby Waves

Abstract In the Pacific Ocean, off-equatorial Rossby waves, initiated by atmosphere-ocean interaction, modulate the inter-annual variability of the thermocline. In this study, we explore the resulting potential gain in predictability of central tropical Pacific primary production, which in this region strongly depends on the supply of macronutrients from below the thermocline. We use a decadal prediction system based on the Max Planck Institute Earth system model (MPI-ESM) to demonstrate that for the time period 1998-2014 properly initialized Rossby waves explain an increase in predictability of net primary productivity in the off-equatorial central tropical Pacific. We show that, for up to 5 years in advance, predictability of net primary productivity derived from the decadal prediction system is significantly larger than that derived from persistence alone, or an uninitialized historical simulation. The predicted signal can be explained by the following mechanism: off-equatorial Rossby waves are initiated in the eastern Pacific and travel towards the central tropical Pacific on a time scale of 2 to 6 years. On their arrival the Rossby waves modify the depths of both thermocline and nutricline, which is fundamental to the availability of nutrients in the euphotic layer. Local upwelling transports nutrients from below the nutricline into the euphotic zone, effectively transferring the Rossby wave signal to the near-surface ocean. While we show that skillful prediction of central off-equatorial tropical Pacific net primary productivity is possible, we open the door for establishing predictive systems for food web and ecosystem services in that region.

Inter-annual predictability of net primary productivity in the central equatorial Pacific

2020 ◽  
Author(s):  
Sebastian Brune ◽  
Maria Caballero Espejo ◽  
Hongmei Li ◽  
Tatiana Ilyina ◽  
Johanna Baehr
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Time Scale ◽  
Rossby Waves ◽  
Net Primary Productivity ◽  
Tropical Pacific ◽  
Equatorial Pacific ◽  
Prediction Skill ◽  
Central Equatorial Pacific ◽  
Equatorial Rossby Waves

<p>We analyse central equatorial Pacific inter-annual prediction skill of sea surface temperature (SST) and net primary productivity (NPP) using initialized retrospective forecasts with the Max Planck Institute Earth system model over the time period 1998-2014. We find significant NPP predictability for up to 5 lead years, which is far beyond the SST predictability of less than 1 year in this area. While El-Nino-Southern-Oscillation (ENSO) limits SST predictability, we find the origin of the high NPP prediction skill to be in the tropical upwelling zones of the eastern Pacific, i.e., the Peru-Chile current system offshore South America. Off-equatorial Rossby waves are initiated off the coast of Chile and travel towards the central tropical Pacific on a time scale of 4 to 5 years. On their arrival, the Rossby waves modify the depth of the nutricline, which is fundamental to the availability of nutrients in the euphotic layer in the central tropical Pacific.</p><p>We further demonstrate that the seasonal upwelling in the central equatorial Pacific, which is mainly driven by ENSO, transports nutrients, i.e. nitrate and phosphate, from below the nutricline into the euphotic zone, effectively transferring the Rossby wave signal from depth to the near-surface ocean. A shallower than normal nutricline leads to larger primary production, and vice versa, a deeper than normal nutricline to smaller primary production. The Rossby waves also modulate the SST, however, these changes are damped on the daily to weekly time scale due to surface heat fluxes at the atmosphere-ocean boundary. Therefore, the off-equatorial Rossby waves maintain the high predictability of NPP but not the SST. We conclude that NPP predictions in the central equatorial Pacific benefit from the memory contained in properly simulated off-equatorial Rossby waves.</p>

scholarly journals Global patterns and climatic controls of belowground net carbon fixation

2020 ◽  
Vol 117 (33) ◽  
pp. 20038-20043 ◽  
Author(s):  
Laureano A. Gherardi ◽  
Osvaldo E. Sala
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Primary Production ◽  
Primary Productivity ◽  
Carbon Fixation ◽  
Net Primary Productivity ◽  
Net Primary Production ◽  
Belowground Carbon ◽  
Belowground Productivity ◽  
Carbon Productivity

Carbon allocated underground through belowground net primary production represents the main input to soil organic carbon. This is of significant importance, because soil organic carbon is the third-largest carbon stock after oceanic and geological pools. However, drivers and controls of belowground productivity and the fraction of total carbon fixation allocated belowground remain uncertain. Here we estimate global belowground net primary productivity as the difference between satellite-based total net primary productivity and field observations of aboveground net primary production and assess climatic controls among biomes. On average, belowground carbon productivity is estimated as 24.7 Pg y−1, accounting for 46% of total terrestrial carbon fixation. Across biomes, belowground productivity increases with mean annual precipitation, although the rate of increase diminishes with increasing precipitation. The fraction of total net productivity allocated belowground exceeds 50% in a large fraction of terrestrial ecosystems and decreases from arid to humid ecosystems. This work adds to our understanding of the belowground carbon productivity response to climate change and provides a comprehensive global quantification of root/belowground productivity that will aid the budgeting and modeling of the global carbon cycle.

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

<p>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 Gießen, and the TR32 measuring site at Selhausen close to Jülich 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 (> 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.</p><p> </p><p>Ackowledgement:</p><p>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.</p><p>Literature:</p><p>Knorr, W. et al., 2010. Carbon cycle data assimilation with a generic phenology model. Journal of Geophysical Research: Biogeosciences, 115(G4).</p><p>Schulz, J.-P., Vogel, G. & 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.</p>

A critical overview of model estimates of net primary productivity for the Australian continent

2004 ◽  
Vol 31 (11) ◽  
pp. 1043 ◽  
Author(s):  
Stephen H. Roxburgh ◽  
Damian J. Barrett ◽  
Sandra L. Berry ◽  
John O. Carter ◽  
Ian D. Davies ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Formal Model ◽  
Arid Zone ◽  
Net Primary Production ◽  
Climate System ◽  
Arid Ecosystems ◽  
Detailed Model ◽  
Spatial Coverage ◽  
Australian Continent

Net primary production links the biosphere and the climate system through the global cycling of carbon, water and nutrients. Accurate quantification of net primary productivity (NPP) is therefore critical in understanding the response of the world’s ecosystems to global climate change, and how changes in ecosystems might themselves feed back to the climate system. Twelve model estimates of long-term annual NPP for the Australian continent were reviewed. These models varied considerably in the approaches adopted and the inputs required. The model estimates ranged 5-fold, from 0.67 to 3.31 Gt C y–1. Within-continent variation was similarly large, with most of the discrepancies occurring in the arid zone of Australia, which comprises most of the continent. It is also within this zone that empirical NPP data are most lacking. Comparison with a recent global-scale analysis of six dynamic global vegetation models showed a similar level of variability in continental total NPP, 0.38 to 2.85 Gt C y–1, and similar within-continent spatial variability. As a first tentative step towards model validation the twelve NPP estimates were compared with existing field measurements, although the ability to reach definitive conclusions was limited by insufficient data, and incompatibilities between the field-based observations and the model predictions. It was concluded that the current NPP-modelling capability falls short of the accuracy required for effective application in understanding the terrestrial biospheric implications of global atmospheric / climatic change. Potential methods that could be used in future work for improving modelled estimates of Australian continental NPP and their validation are discussed. These include increasing the spatial coverage of empirical NPP estimates within arid ecosystems, the use of existing high quality site data for more detailed model exploration, and a formal model inter-comparison using uniform driver datasets to investigate more intensively differences in model behaviour and assumptions.

scholarly journals Prioritising Carbon Sequestration Areas in Southern Queensland using Time Series MODIS Net Primary Productivity (NPP) Imagery

2014 ◽  
Vol XL-8 ◽  
pp. 549-553
Author(s):  
A. Apan ◽  
L. A. Suarez Cadavid ◽  
L. Richardson ◽  
T. Maraseni
Keyword(s):  
Carbon Sequestration ◽  
Primary Production ◽  
Net Primary Productivity ◽  
Net Primary Production ◽  
Climate Scenario ◽  
Forest Growth ◽  
Tree Canopy ◽  
Annual Rainfall ◽  
Primary Input ◽  
Tree Canopy Cover

The aim of this study was to develop a method that will use satellite imagery to identify areas of high forest growth and productivity, as a primary input in prioritising revegetation sites for carbon sequestration. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data, this study analysed the annual net primary production (NPP) values (gC/m<sup>2</sup>) of images acquired from 2000 to 2013, covering the Condamine Catchment in southeast Queensland, Australia. With the analysis of annual rainfall data during the same period, three transitions of "normal to dry" years were identified to represent the future climate scenario considered in this study. The difference in the corresponding NPP values for each year was calculated, and subsequently averaged to the get the "<i>Mean of Annual NPP Difference</i>" (MAND) map. This layer identified the areas with increased net primary production despite the drought condition in those years. Combined with key thematic maps (i.e. regional ecosystems, land use, and tree canopy cover), the priority areas were mapped. The results have shown that there are over 42 regional ecosystem (RE) types in the study area that exhibited positive vegetation growth and productivity despite the decrease in annual rainfall. However, seven (7) of these RE types represents the majority (79 %) of the total high productivity area. A total of 10,736 ha were mapped as priority revegetation areas. This study demonstrated the use of MODIS-NPP imagery to map vegetation with high carbon sequestration rates necessary in prioritising revegetation sites.

scholarly journals Variation in Primary Production in Relation to Physico-Chemical Parameters of Kadwai Reservoir, Ratnagiri, Maharashtra, India.

2016 ◽  
Vol 11 (1) ◽  
pp. 228-232 ◽  
Author(s):  
Rahul Rathod ◽  
Balasaheb R. Chavan ◽  
Raghuvendra Pai
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Monsoon Season ◽  
Total Alkalinity ◽  
Organic Load ◽  
Total Hardness ◽  
Post Monsoon ◽  
Physiochemical Parameters ◽  
Post Monsoon Season

The present study has been carried out to study the status of primary productivity in relation to physiochemical parameters of the Kadwai reservoir of Ratnagiri district, Maharashtra. The primary productivity was determined by estimating gross and net primary productivity. The experiment was conducted during the monsoon and post monsoon seasons from 1st June to 30th Nov 2015 to know the effect of organic run off on primary production of Kadwai reservoir. The physiochemical parameters such as temperature, pH, dissolved oxygen, total hardness, total alkalinity and transparency ranged from 27oC-30.5oC, 7.5-8.6, 3.2-7.0 mg/l, 46-75 mg/l, 56-95 mg/l, and 118-130 cm, respectively. The gross primary productivity (GPP) during monsoon was 0.07-0.11 gC/m3/hr in June, July and August 2015, respectively, which was very low, whereas GPP were increased during post monsoon season. The values were recorded as 0.12-0.48 gC/m3/hr in the months of September, October, and November 2015, respectively. The results indicated that during monsoon season, organic load is coming along with water in to the reservoir, but phytoplankton growth is minimum due to the heavy rain and flushing rate were high from the downstream of the reservoir. During post monsoon, primary productivity was increased. The results indicate that Kadwai reservoir is more productive during post monsoon season suitable for stocking fish seed.

scholarly journals Primary Productivity of Phytoplankton of Mahakali River, Nepal

BIBECHANA ◽  
2016 ◽  
Vol 14 ◽  
pp. 98-102
Author(s):  
Vinod Kumar Mahasetha
Keyword(s):  
Primary Production ◽  
Water Temperature ◽  
Primary Productivity ◽  
Net Primary Production ◽  
Gross Primary Production ◽  
Mean Value ◽  
Production Value ◽  
Lentic Water

Present paper describes primary productivity of Mahakali river at four stations. The two years mean of net primary production was 96.80 mgC/m3/day. The  net primary production value of Mahakali river was less due to the low water temperature and less phytoplanktonic growth. Two years mean value of gross primary production of Mahakali river was 176.29 mgC/m3/day, which is less than lentic water. It shows that the river is oligotrophic but developing a tendency as going towards mesotrophic.BIBECHANA 14 (2017) 98-102

scholarly journals Twenty-first century ocean warming, acidification, deoxygenation, and upper-ocean nutrient and primary production decline from CMIP6 model projections

2020 ◽  
Vol 17 (13) ◽  
pp. 3439-3470 ◽  
Author(s):  
Lester Kwiatkowski ◽  
Olivier Torres ◽  
Laurent Bopp ◽  
Olivier Aumont ◽  
Matthew Chamberlain ◽  
...  
Keyword(s):  
Primary Production ◽  
Radiative Forcing ◽  
Net Primary Production ◽  
Ocean Warming ◽  
First Century ◽  
Upper Ocean ◽  
Global Changes ◽  
Model Uncertainties ◽  
Near Surface ◽  
Twenty First Century

Abstract. Anthropogenic climate change is projected to lead to ocean warming, acidification, deoxygenation, reductions in near-surface nutrients, and changes to primary production, all of which are expected to affect marine ecosystems. Here we assess projections of these drivers of environmental change over the twenty-first century from Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) that were forced under the CMIP6 Shared Socioeconomic Pathways (SSPs). Projections are compared to those from the previous generation (CMIP5) forced under the Representative Concentration Pathways (RCPs). A total of 10 CMIP5 and 13 CMIP6 models are used in the two multi-model ensembles. Under the high-emission scenario SSP5-8.5, the multi-model global mean change (2080–2099 mean values relative to 1870–1899) ± the inter-model SD in sea surface temperature, surface pH, subsurface (100–600 m) oxygen concentration, euphotic (0–100 m) nitrate concentration, and depth-integrated primary production is +3.47±0.78 ∘C, -0.44±0.005, -13.27±5.28, -1.06±0.45 mmol m−3 and -2.99±9.11 %, respectively. Under the low-emission, high-mitigation scenario SSP1-2.6, the corresponding global changes are +1.42±0.32 ∘C, -0.16±0.002, -6.36±2.92, -0.52±0.23 mmol m−3, and -0.56±4.12 %. Projected exposure of the marine ecosystem to these drivers of ocean change depends largely on the extent of future emissions, consistent with previous studies. The ESMs in CMIP6 generally project greater warming, acidification, deoxygenation, and nitrate reductions but lesser primary production declines than those from CMIP5 under comparable radiative forcing. The increased projected ocean warming results from a general increase in the climate sensitivity of CMIP6 models relative to those of CMIP5. This enhanced warming increases upper-ocean stratification in CMIP6 projections, which contributes to greater reductions in upper-ocean nitrate and subsurface oxygen ventilation. The greater surface acidification in CMIP6 is primarily a consequence of the SSPs having higher associated atmospheric CO2 concentrations than their RCP analogues for the same radiative forcing. We find no consistent reduction in inter-model uncertainties, and even an increase in net primary production inter-model uncertainties in CMIP6, as compared to CMIP5.

scholarly journals PRODUCTIVIDAD PRIMARIA EN LAGUNA LARGA, CAYO COCO, CUBA

2011 ◽  
Vol 3 ◽  
pp. 31 ◽  
Author(s):  
Mayrene Guimarais Bermejo ◽  
Roberto González de Zayas
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Net Primary Production ◽  
Ruppia Maritima ◽  
Halodule Wrightii ◽  
Phytoplankton Productivity ◽  
North Central ◽  
Net Production ◽  
The North ◽  
Total Productivity

Se determinó la productividad primaria en Laguna Larga, ubicada en la costa norte y central de Cayo Coco. La producción primaria del fitoplancton y la biomasa del macrofitobentos fueron medidas durante el 2008-2009 en dos sectores de la laguna. La producción primaria neta acuática del sector este fue de 4.32 ± 3.59 g C m-2 día-1 y en el sector oeste fue de 0.71 ± 0.41 g C m-2 día-1. Ambos sectores, atendiendo a la relación producción/respiración anual, fueron autotróficos para el oxígeno e hipertróficos para el carbono. Entre las especies más productivas del macrofitobentos estuvieron: Cladophoropsis sp., Halodule wrightii, Cladophora sp. y Ruppia maritima. La alta producción neta acuática registrada en el sector este, con respecto al oeste, se debe a la contribución del macrofitobentos a la productividad total. El fitoplancton en el sector este exhibió baja productividad (0.12 ± 0.07 g C m-2 día-1) con respecto al oeste (0.71 ± 0.41 g C m-2 día-1), lo que puede deberse a la competencia del macrofitobentos por los nutrientes.ABSTRACT Phytoplankton primary productivity and macrophyte biomass were determined during 2008-2009 for Laguna Larga, located on the north-central coast of Cayo Coco, Cuba. Aquatic net primary production was measured in two different sectors of the lagoon resulting in 4.32 ± 3.59 g C m-2 d-1 and 0.71 ± 0.41 g C m-2 d-1 in the eastern and western part, respectively. In regard to the annual production to respiration ratio, both sections showed autotrophic and hypertrophic levels for the oxygen and carbon metabolisms. The most productive species were Cladophoropsis sp., Halodule wrightii, Cladophora sp. and Ruppia maritima. Aquatic net production recorded for the eastern lobe was higher than the western lobe because of the macrophytobenthos contribution to total productivity. On the contrary, phytoplankton productivity in the eastern part was lower (0.12 ± 0.07 g C m-2 d-1) than the western lobe (0.71 ± 0.41 g C m-2 d-1), probably due to the macrophyte competition for nutrients.

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