New Article!

Examples of wind flow steering over a foredune for three incident wind approaches

Chuffed to announce that my first article in collaboration with Patrick Hesp, Flow deflection over a foredune, is now available in press from Geomorphology. Patrick was the most cited author in my PhD thesis and its a real pleasure to be working with him here at Flinders. Here's to many more!

10 Reasons why geomorphology is important!

Be sure to check out the British Society for Geomorphology's new publication here.

Spray Day

I've been fortunate to be involved in lots of different fieldwork the last few years but today was the first that involved taking to the air! 

In conjunction with Airborne Research Australia two planes were flown along the Young Husband and Sir Richard Peninsula's here in South Australia measuring salt spray along the coast.

Both planes in flight along one of the sites. 

Another 'action' shot.

Dr Graziela Miot Da Silva as part of the ground based team.

ICAR 8 and the Badain Jaran Desert

In July the International Society for Aeolian Research held its biennial conference in Lanzhou, China. As part of the conference we were fortunate to visit the Badain Jaran desert which hosts some of the tallest dunes of earth.

As well as some massive dunes, over 140 lakes can be found between the dunes in Badain Jaran desert. 

A trip to Minqin desert control experiment station was also organised. Checkerboarding from the bus!

Chinese hospitality after a long day on the road, Inner Mongolia. 

Chinese Nebkha

Yours truly rolling the prayer wheels in Ta'er Monastry

Online seminar: Sand dunes, Shipwrecks and Space

I recently gave a presentation as part of Flinders University 'Environment Matters!' seminar series.

The seminar and presentation slides can be viewed online or downloaded here. 

NEW PUBLICATION : Sediment transport patterns in a trough blowout

The trough blowout investigated in the study. (County Donegal, Ireland.)

This study examines the variability of sediment flux and its relationship with near surface wind in a trough blowout. Results demonstrated that sediment flux rates were highly variable even over distances of less than 0.5 m. Where wind flow was steadiest, flux was greatest, consequently highest rates of sediment transport were measured on the erosional walls of the blowout. Interestingly however, correlation between sediment flux and wind parameters was best in the centre of the blowout and poorest on the erosional wall crest.

Authors: Thomas Smyth, Derek Jackson and Andrew Cooper

Published in Earth Surface Processes and Landforms

Fieldwork - Northern California 2014

Unloading the gear. Thankfully we didn't have to bring all this from Australia!

Calibration time. Ian Walker and Michael Grilliot from the University of Victoria check the instruments

Dunes, glorious dunes.

Making use of all that drift wood

Yours truly enjoying the west coast sunshine!

The Coorong

Patrick, Stefano (a visiting PhD student from Italy) and I took a trip down to the Coorong National Park at the weekend. This was my first visit and I was blown away by the coastline. So much variety in wave energy and dune types all on one beach. From no energy in Lacepede Bay in the South to a very high energy environment at the Murray Mouth.  Hopefully it will make the perfect laboratory!

The Granites. The only rock on 194 km of continuous beach.

It's hard to fully appreciate the scale of the landforms here and the processes that drive their evolution.

Australia's second longest continuous beach.

My first foray into marine archaeology

Shortly after completing my PhD last year I was presented the opportunity to use the computational fluid dynamics (CFD) techniques I've been predominantly applying over coastal dunes, to the marine environment.

In collaboration with Dr Rory Quinn, from the University of Ulster, we simulated the fluid dynamics around a shipwreck on the Arklow Bank, Ireland. The simulations confirmed that flow velocity and turbulence are both amplified by the presence of the wreck, causing changes in the morphology of the flow regime, causing changes in the morphology of the flow regime.

The study has recently been published in the Journal or Archaeological Science. Please click here for the full article.

Sand dune migration in an arid coastal dune field

Maspalomas is a coastal dune field situated on the south coast of Gran Canaria. With an annual precipitation of less than 100 mm, the area is very arid with sparse vegetation. Predominant winds blow from the northeast, forcing the dunes to migrate toward the south west. Mapping of dune migration has found that those closest to the shoreline, move faster than those further inland.

Simulated wind speed 0.5 m above the surface of the study site. Vectors on the map represent wind speed and direction at 61 dune crests within the study area. 

To explore why dune migration is faster near the beach, a 3D computational fluid dynamics (CFD) simulation was applied over the surface of the dunes. The results found that although flow was faster on the taller, landward dunes, those dunes also created large zones of flow re-circulation which will cause sediment, transported from the windward slope and crest, to be deposited. Conversely wind in lee of the lower dunes created little to no flow reversal allowing sediment eroded from the dune to be transported further landward into the dune field.

Top image represents flow across a 640 m cross sectional profile of the study area. The middle image shows flow in lee of a large inland dune. note the large zone of flow separation and re-circulation. The bottom image is of a smaller dune close to the shoreline behind which flow slows, but remains attached.

This post is a summary of an article published by Jackson et al., 2013 in the Journal of Coastal Research. Please click the link below to view the full article:

Jackson, D.W.T., N., Cruz Avero, T.A.G., Smyth, L. Hernández Calvento (2013) 3D airflow modelling and dune migration patterns in an arid coastal environment, Journal of Coastal Research SI 65, 1301 - 1306

How do patterns of wind flow change with wind speed?

Complex blowout that wind flow was measured and simulated over. Each point denotes the location of a 3D ultrasonic anemometer

It is sometimes perceived that patterns of wind direction over dunes, including zones of flow reversal and acceleration, change with wind speed. A recent paper by Smyth et al., 2013 published in Aeolian Research found that that patterns of flow steering remained constant even during hurricane force winds.

Measured wind direction at 15 points 

Measurements made by 15 ultrasonic anemometers of wind flow at 1 m above the surface at 15 locations in a complex blowout during from fresh breeze to strong gale found that wind flow steering remained remarkably constant. A validated computational fluid dynamics (CFD) model was then used to simulate flow during hurricane force winds. Wind direction at the 15 points during hurricane force winds also did not vary from those at lower incident velocities.

Simulated wind direction in a blowout during fresh breeze to hurricane force winds

Full Article
Smyth, T.A.G., D.W.T., Jackson, J.A.G. Cooper (2013), Three dimensional airflow patterns within a coastal blowout during fresh breeze to hurricane force winds, Aeolian Research, 9, 111 - 123