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| Titel |
A new post-processing tool for the source-related element tracing in biogeochemical models: A case study for the North Sea |
| VerfasserIn |
Fabian Grosse, Markus Kreus, Johannes Pätsch |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105234
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| Publikation (Nr.) |
 EGU/EGU2015-4708.pdf |
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| Zusammenfassung |
| The mitigation of eutrophication and its concomitants, like harmful algal blooms
or deoxygenation of bottom waters, is one of the major aspects of the ecological
management of coastal marine ecosystems. In the past, biogeochemical models helped to
significantly improve the understanding of the interaction of the physical and biological
processes behind eutrophication. Nevertheless, the quantification of the influence
of source-related nutrient inputs to eutrophication in a specific region remains an
important issue, since it is as crucial for an efficient management as it is difficult to
obtain.
About a decade ago, a method applicable to biogeochemical models had been developed
allowing for the tracing of elements from different sources, e.g. phosphorus and/or nitrogen
from two different rivers, throughout the whole process chain of the applied model. This
tracing method – often referred to as ‘trans-boundary nutrient transport’ (TBNT) – provides
additional information about the contributions from different sources to the overall amount
(‘bulk’) of an element in each part of the model domain. This information constitutes the
basis for the quantification, evaluation and optimisation of nutrient reduction targets for the
tributaries of a marine ecosystem. In the meantime, the TBNT method has been applied to a
variety of different biogeochemical models, e.g. to quantify the influence of nutrient loads
from different rivers or atmospheric deposition on phytoplankton blooms or to determine the
source-related composition of total nitrogen in different parts of an ecosystem.
However, for all of these applications the method was directly implemented into
the considered model, and thus was model-dependent and required an individual
solution to deal with the model specifics like grid structure, programming language
etc.
For the application of the TBNT method to the ECOHAM model (ECOlogical model
HAMburg), we further developed the approach by creating a post-processing software which
uses the standard ‘bulk’ output of a regular model simulation for the TBNT calculation. This
output includes the 3D fields of all state variables containing the traced element and all fluxes
transforming these state variables into each other. Besides this the tool only requires
standardised information about the model grid and the involved state variables and fluxes.
Thereby, the new software avoids direct changes in the model code, and therefore provides a
model-independent tool for the application of the TBNT method. The basic functioning and
the main features of the new software are presented in a North Sea case study using
ECOHAM. |
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