TY - JOUR
T1 - Barchan swarm dynamics from a Two-Flank Agent-Based Model
AU - Robson, Dominic T.
AU - Baas, Andreas C.W.
N1 - Publisher Copyright:
© 2024 Dominic T. Robson.
PY - 2024/10/22
Y1 - 2024/10/22
N2 - In this work, we simulate barchan swarms using the Two-Flank Agent-Based Model and investigate how changes to model parameters and environmental drivers lead to different swarm dynamics. In particular, we explore how the parameter qshift, which controls the rate of equilibration between the flanks of an asymmetric dune and thereby the stability of an asymmetric morphology, influences the frequencies of different collision types in the swarm and can be adjusted to produce swarms with dune sizes that are longitudinally homogeneous. Such size stability has been observed in real-world swarms but has not been obtained by previous agent-based models. We also find that, for certain densities of newly added barchans, the dune number density remains constant with downwind distance, something which has also been reported in nature but not in previous agent-based models. We also investigated how boundary condition changes propagate through swarms, something which will become increasingly important in the face of human infrastructure expansion and anthropogenic climate change. Finally, we are able to investigate how asymmetry and spatially patterning in the swarms are influenced by bimodal wind regimes. Since these simulations produce many more realistic phenomena than previous models, this work represents a significant step forward in the our understanding of the interplay between environmental conditions and dune interactions in shaping the dynamics of barchan swarms.
AB - In this work, we simulate barchan swarms using the Two-Flank Agent-Based Model and investigate how changes to model parameters and environmental drivers lead to different swarm dynamics. In particular, we explore how the parameter qshift, which controls the rate of equilibration between the flanks of an asymmetric dune and thereby the stability of an asymmetric morphology, influences the frequencies of different collision types in the swarm and can be adjusted to produce swarms with dune sizes that are longitudinally homogeneous. Such size stability has been observed in real-world swarms but has not been obtained by previous agent-based models. We also find that, for certain densities of newly added barchans, the dune number density remains constant with downwind distance, something which has also been reported in nature but not in previous agent-based models. We also investigated how boundary condition changes propagate through swarms, something which will become increasingly important in the face of human infrastructure expansion and anthropogenic climate change. Finally, we are able to investigate how asymmetry and spatially patterning in the swarms are influenced by bimodal wind regimes. Since these simulations produce many more realistic phenomena than previous models, this work represents a significant step forward in the our understanding of the interplay between environmental conditions and dune interactions in shaping the dynamics of barchan swarms.
UR - http://www.scopus.com/inward/record.url?scp=85207630016&partnerID=8YFLogxK
U2 - 10.5194/esurf-12-1205-2024
DO - 10.5194/esurf-12-1205-2024
M3 - Article
AN - SCOPUS:85207630016
SN - 2196-6311
VL - 12
SP - 1205
EP - 1226
JO - Earth Surface Dynamics
JF - Earth Surface Dynamics
IS - 5
ER -
