All posts by Louise

Antarctic Fieldwork Support

We regularly provide geospatial support to scientists who are heading out into the deep field in Antarctica.

Recently, we’ve helped one particular research team plan their trip into the field, scheduled for the end of this year.

Funded by NERC, Dr Joanne Johnson is leading an international team aiming to deliver a high-resolution record of past changes in the West Antarctic Ice Sheet. Specifically, it will use glacially-transported rocks and novel isotopic measurements to study changes in the Smith, Kohler and Pope Glaciers since the peak of the last glacial period, approximately 20,000 years ago.

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At present, these glaciers are amongst the most rapidly thinning and retreating of all Antarctic glaciers, and yet we hardly know anything about their history.

Johnson and her BAS colleague Dr Stephen Roberts will undertake fieldwork in extremely remote mountain ranges in Marie Byrd land. Being so remote and seldom-visited, terrestrial geographic data available for this region is sparse, and of variable quality.

Having the best possible information in advance of a field campaign is invaluable for planning the most appropriate aircraft landing sites, safe overland travel, and for prioritising sampling sites.

Setting up GPS receivers at Turtle Rock
Setting up GPS receivers at Turtle Rock. Credit: JS Johnson, BAS.

With the use of high resolution satellite imagery captured in stereo, we are able to produce geospatial data of the region at a scale and level of detail previously not available.

We use data from the satellite Worldview-2, which collects full colour imagery at 2m resolution, and black and white imagery at 50cm. This is powerful stuff when it comes to helping out the field teams.

The imagery  allows us to create elevation models, terrain corrected imagery, 3D visualisations and mapping products.

Here’s a photo Jo took of Hedin Nunatak on her last trip to the field.

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Hedin Nunatak from the air. Credit: JS Johnson, BAS

Compare this photo, to this georeferenced 3D visualisation created with stereo satellite imagery.

With our help, Johnson’s team will be using the same imagery, combined with outputs from smaller UAVs, to produce highly-detailed geomorphological data and maps when they return from the field. These will in turn inform interpretation of the isotopic analyses they will make on the rock samples. Together all these data will help to build a detailed picture of changes in the West Antarctic Ice sheet over the past 20,000 years across the whole Amundsen Sea Embayment.

New QGIS plugin for Oceancolor Data

We have released a new plugin for QGIS which allows easy download of oceancolor and sea surface temperature data from NASA Oceancolor.

It downloads either global level 3 mapped chlorophyll-a concentrations or sea surface temperatures within a defined time range, and resolution. The data is saved in GeoTiff format and can be added to the QGIS canvas once downloaded. The plugin is available via the official QGIS plugins repository.

interface
 
The plugin provides access to three datasets:
  • MODIS AQUA CHL-a concentration
  • SeaWiFS CHL-a concentration
  • MODIS AQUA Night Sea Surface Temperatures
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We are currently developing new features and working to improve existing ones. A selection of features we are looking to include in a future release are:
  • Alternative output file formats
  • Options to subset output data to a lat/long bounding box
  • Other datasets, such as Net Primary Production
  • Progress bar
Louise Ireland et al.. (2015) oceancolor_downloader: v1.1.1. Zenodo.10.5281/zenodo.160