The Impact of Saharan Dust on the North Atlantic Circulation

Inhaltsverzeichnis (Table of Contents)

• Introduction
  • Aims
  • Structure
• Response of the eastern subtropical North Atlantic sea surface temperature to Saharan dust
  • Introduction
  • Data and Methodology
    • MODIS AOD
    • TMI SST
  • Aerosol Radiative Forcing during AEROSE-I
  • Observed SST and AOD anomalies
  • Simulated SST anomalies in the ocean mixed layer
  • Isolating dust-induced SST anomalies
    • Model description
    • Model setup
    • Results from 3D eddy-permitting simulation
  • Concluding remarks
• Impact of Saharan Dust on the North Atlantic Circulation
  • Introduction
  • Methods
    • The experimental setup
    • Construction of a realistic perturbation
  • Mean ocean circulation
  • Perturbed response
    • Large-scale response
    • Sub-basin and local response
    • Vertical structure of temperature anomalies
    • Meridional Overturning and Heat Transport in the Atlantic
  • Discussion and Conclusions
• Conclusions
  • Summary
  • Outlook

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This dissertation investigates the impact of Saharan dust on the North Atlantic Ocean, focusing on its effects on the local sea surface temperature and the larger scale circulation. The primary aim is to understand how dust-induced changes in the ocean interact with other existing dynamical features, and to determine the magnitude and extent of these impacts.

• Impact of Saharan dust on sea surface temperature (SST)
• Influence of dust on ocean circulation and transport properties
• Role of dust-induced buoyancy anomalies on the Atlantic Meridional Overturning Circulation (AMOC)
• Effect of dust on the meridional heat transport in the Atlantic Ocean
• Relationship between dust variability and the propagation of Rossby waves

Zusammenfassung der Kapitel (Chapter Summaries)

• Chapter 2: This chapter examines the relationship between Saharan dust and sea surface temperature in the eastern subtropical North Atlantic. It analyzes satellite data from MODIS and TMI sensors, as well as in-situ measurements from the AEROSE campaign. The chapter also presents the results of simulations using a one-dimensional mixed layer model and a three-dimensional eddy-permitting general circulation model.
• Chapter 3: This chapter investigates the impact of Saharan dust on the North Atlantic circulation using an eddy-permitting ocean general circulation model (OGCM). The chapter focuses on the response of the ocean circulation to a realistic dust-induced buoyancy perturbation in the eastern subtropical North Atlantic. It analyzes the changes in simulated sea surface temperatures and heights, as well as the impact on the AMOC and meridional heat transport.

Schlüsselwörter (Keywords)

The primary keywords and focus topics of this dissertation include Saharan dust, sea surface temperature (SST), sea surface height (SSH), aerosol radiative forcing, North Atlantic circulation, Rossby waves, AMOC, meridional heat transport, and ocean modeling.