Black and Bloom

Progress since returning from the field

It’s been about six weeks since we returned from the field, and time has flown. Most of us caught up on holiday, and Ewa top trumped all of us by getting married. Congratulations to her and her very lucky husband, and best wishes for a long and happy marriage.

The cost and timing of moving equipment around Greenland means that one of the first things we had to do was to make a preliminary decision about where and when we want to be in the field next year. We have quickly examined the likely gaps in the data sets we obtained, reflected on the processes we observed in the field and decided the big science questions we want to address next field season. The post docs have been driving the process, and we are very likely to return to the Dark Snow camp again, but this time being there prior to snowmelt, and following the snow-slush-ice transition. We will firm up this decision when we have our first full project science meeting in Potsdam 16th-18th January, 2017.This will give us a couple of months to work up our data sets and further reflect on how to plug any gaps and further define the big science issues.

Andrew, Chris, Joe and Tris have had their offer of presenting talks at the December AGU in San Fransisco accepted, so they are particularly busy.

A brief summary of work in progress/work completed in each of the four Work Packages follows.

Microbiology: Chris, Marian and the team are beginning their counts of the microbes collected from the ice and the measurement of their pigments. Experiments on the photophysiology of the ice algae, and preparations for nutrient and DOC analysis are also ongoing.

Steffi is conducting genomic work on snow and ice algae, collected around the camp and on the dashes.

Particulates: Jenine has just returned to Australia, and is finishing the papers for her thesis, prior to joining us full time in January. However, she, Jim and Liane have been busy. All aqueous analyses of the collected snow, ice and meltwater samples are already in the pipeline (cations, trace metals, nutrients and DOC). Furthermore, the analysis of Black Carbon on some aerosol filters, as well as carbon speciation and isotopic analyses on selected surface samples, have already been completed and data processing is ongoing.

Albedo measurements and modelling: the first project paper on a new Radiative Transfer Model of snow, which includes particulates and microbes, has been revised and resubmitted to Journal of Geophysical Research. The code will be openly available once the paper is accepted, and Joe will post details of how to get it on this website.

Collation and exploration of the large spectral reflectance data sets gathered on the ground is well underway, and Tris has begun analysing data gathered from a UAV platform. Processing and analysing this data will give us a detailed picture of how albedo varies between different surface types, and will also guide our data collection scheme for next season.

Remote sensing: Andrew is currently establishing the processes that drive significant differences in dark ice extent between consecutive melt seasons, which cause strong intra-seasonal variability in ablation zone albedo. He is exploring a combination of in-situ measurements of spectral albedo, surface contaminants and meterology collected during the 2016 melt season together with remotely-sensed measurements of surface reflectance and broadband albedo, and surface mass balance estimates derived from the state of the science surface mass balance energy model, MAR.

The whole team benefitted from being in the field and seeing the profound changes in the surface albedo during the summer, and reflecting on the feedbacks between the biological, chemical and physical processes that combine to produce the variability and the rate of change of albedo. I am very confident that we will be able to make fundamental contributions to the science of surface albedo, and the prediction of albedo change into the coming century. Keep watching this space for developments.

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