Ponds on ice- What I do and why (I think!) it matters

Melt ponds, which are exactly what the name implies – ponds of melted water formed on ice – have been observed in recent years on the Antarctic Peninsula, the most northern part of Antarctica. Previously this area had been too cold for melting to occur but, due to a 2.5 degrees Centigrade warming trend on the Peninsula over the last 50 years (several times the global average), this has begun to change.[1]

Melt ponds on Arctic sea ice such as those initially modelled by CPOM, copyright NASA Goddard Space Flight Center

Melt ponds on Arctic sea ice such as those initially modelled by CPOM, copyright NASA Goddard Space Flight Center

The Larsen B ice shelf on the Antarctic Peninsula hit the headlines in 2002 when it spectacularly (see image below- definitely a justified use of the word spectacular!) collapsed and an area of ice larger than Rhode Island was lost in a matter of weeks.[2] This collapse occurred during record warm air temperatures when both the length and extent of the melt season reached a new high. Areas of the ice shelf with melt ponds collapsed whereas adjacent areas with few or no melt ponds did not. This suggests that melt ponds may be playing a role in triggering ice shelf collapse. However, there are many other processes – such as rising ocean temperatures – which may also play a role and so a greater understanding of ice-shelves and the mechanisms affecting them is essential in predicting their future.

A common misconception is that when ice shelves collapse they contribute to sea level rise. This is not strictly true; ice shelves are already floating on the water and in the same way that when ice cubes in your glass of water melt the water level in the glass doesn’t go up, ice shelf break-up (and subsequent melting) won’t add to global sea level. By Archimedes’ Principle (that’s the one from the ‘jumping out of the bath shouting “Eureka”’ story) the floating ice has already displaced a volume of water that is virtually the same as the amount that would be added to the sea if the ice shelf were to melt.*

However, the fact that ice shelf break-up doesn’t contribute to sea level directly doesn’t mean that it doesn’t have an effect on it. When Larsen B broke up it was observed that the glaciers which fed into the ice sheet accelerated, possibly because there was no longer any force from the ice sheet blocking their flow. The ice coming from these glaciers is coming from the land and going into the sea so does contribute to sea level rise. This acceleration can continue for several years after the ice shelf has collapsed,[3] so the effect of a large collapse can actually be quite significant. On top of this, there is also the loss of habitat and the effect that large amounts of cold fresh water from the melted ice shelves have on ocean circulation and chemical make-up to be considered.

The break up of Larsen B in early 2002. The dark marks on the ice shelf you can see are melt ponds or drained melt ponds. Copyright NASA.

The break up of Larsen B in early 2002. The dark marks on the ice shelf you can see are melt ponds or drained melt ponds. Copyright NASA.

So what is it about these ponds makes them so key in understanding what will happen to the ice shelves? Firstly, it’s important to note that ‘pond’ is quite a deceptive term – on the Antarctic Peninsula we’re talking about something that can cover several square kilometers as oppose to something that would be found in your back garden, so these ponds are actually a fairly significant feature of the ice shelf.

One of the crucial things that melt ponds affect is albedo. Albedo is the proportion of incoming radiation that a surface reflects back. Ice, being white, has a high albedo whereas a melt pond is darker and has a lower albedo: it will reflect less energy and thus absorb more energy. Absorbing more energy means more heat is absorbed, more ice melts, ponds grow, albedo is further decreased, more energy is absorbed and so on in a positive feedback loop that results in greater and greater amounts of ice melting.

Meltwater is also thought to influence ice shelf break up when it fills crevasses in the ice. The forces that act on crevasses that open in the ice sheet tend to close them but meltwater filling existing surface crevasses provides an outward pressure that can allow them to remain open. Additionally, meltwater can cause the crevasses to penetrate further through the ice shelf, possibly far enough for them to reach the ice shelf’s base and impact on its structural integrity.[1]

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A melt pond on the Greenland ice sheet- very similar to those I’m looking at and hopefully a lot of my work can be applied to Greenland too. Copyright NASA Earth Observatory.

Researchers in the group that I’m part of- Centre for Polar Observation and Modelling (CPOM) [4] at the University of Reading are looking at improving climate models by incorporating a better understanding of the processes affecting melt pond formation into the models. Initially, work was done on modelling melt ponds on Arctic sea ice [5]; one of the greatest uncertainties in predicting future global temperature changes is sea ice level fluctuations and this is something the level of melt ponds will play a role in. Now they have successfully incorporated a physically based melt pond scheme into the CICE sea ice model in order to simulate the stages of melt pond development.[6]

So where do I come into this? I’m going to be adapting a physical model of Arctic sea ice melt ponds to look at the Antarctic, focussing on the Larsen C ice shelf as melt ponds have appeared there and it is thought to be a potential candidate for future collapse. The ponds found on Antarctica are much larger and over a greater scale than the Arctic sea ice ones and, unlike sea ice, the ice-shelves do not contain salt, adding an extra challenge in modifying previous work. If successful this model will help to provide new insights into the role of meltwater in the collapse of ice shelves and help to improve future versions of ice sheet models and climate predictions. I’ll keep you updated.

*Technically, a very small amount of sea level rise would occur on melting as ice shelves are made of fresh water and sea water is salty (and therefore more dense than fresh water) so slightly less water is displaced than the total melted amount would add but the effect is so small it is negligible: the equivalent of less than 4cm of sea level rise if all floating ice (ice shelves and sea ice) were to melt.

References:

[1] Scambos et al. (2000), The link between climate warming and break-up of ice shelves in the Antarctic Peninsula, Journal of Glaciology, Vol. 46, No. 154, pg 516-529

[2] http://nsidc.org/news/press/larsen_B/2002.html

[3] Scambos et al. (2004), Glacier acceleration and thinning after ice shelf collapse in the Larsen B embayment Antarctica, Geophys. Res. Lett., 31, L18402, doi:10.1029/2006GL020670

[4] http://www.cpom.org/research.html

[5] Scott and Feltham (2010), A model of the three-dimensional evolution of Arctic melt ponds on first-year and multiyear sea ice, J. Geophys. Res., Vol.115, C12064, doi:10.1029/2010JC006156

[6] Flocco et al. (2010), Incorporation of a physically based melt pond scheme into the sea ice component of a climate model,  J. Geophys. Res., Vol.115, C08012, doi:10.1029/2009JC005568

An interesting thought on solar energy

So this one’s not technically ice related but as what I do is mot likely only relevant due to global warming then climate change and renewable energy may be things that feature occasionally. This image floats around the internet and appears from time to time but I think it’s such a good visual piece of information it’s worth promoting.

This image shows how much space would be needed for solar power plants to power the World. Now obviously we can’t just go bunging huge great solar panels all over the Algerian/Libyan desert- there are issues with storage and transportation before you even get on to the intermittent nature of solar energy. Solar is definitely not a complete solution, but the relative area here is certainly worth thinking about.

Countries like Germany are way ahead of us here in the UK in terms of solar and even though we may not be the best candidates for solar power plants there are plenty of places that are.

 

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Theoretical space needed for solar power plants to generate sufficient electric power in order to meet the electricity demand of the World, Europe (EU-25) and Germany (De) respectively. (Data by the German Center of Aerospace (DLR), 2005)

 

 

 

 

 

 

Image source:

Diploma Thesis of Nadine May,pg 26

Technical University of Braunschweig, Faculty for Physics and Geological Sciences, in collaboration with the Institute of Technical Thermodynamics at the DLR, Stuttgart, Germany

http://www.dlr.de/tt/Portaldata/41/Resources/dokumente/institut/system/projects/Ecobalance_of_a_Solar_Electricity_Transmission.pdf

Rationing Recipes- Fruity Potato Cakes

Tasty wartime treats

Tasty wartime treats

I recently acquired a wartime recipes book so here is my first experiment on cooking from the 40′s. The first two things I tried, these potato cakes and some carrot cookies, both use veg to bulk out the standard ingredients and it really is surprising how far things go with just small amounts of sugar and marge.

These are fried or cooked on a hot plate or griddle and reminded me a lot of Welshcakes.

Makes 10-12

Ingredients:

Cakes

Ingredients ready to go

Ingredients ready to go

4 oz cooked potatoes (I found just over 5 oz will reduced to 4 when peeled and cooked)
2 oz self raising flour (or use plain and double the baking powder)
1/2 tsp baking powder
1 oz sugar
1 oz margarine
1 tbsp marmalade
1 oz dried fruit

Topping

sugar
mixed spice

My resident historian using a more authentic mixing method than my Kenwood.

My resident historian using a more authentic mixing method than my Kenwood.

1. Mash the potatoes, or better still use a potato ricer to ensure no lumps (I thought this might be cheating but having just seen Mary Berry using her mother’s it is definitely authentic).

2. Cream the margarine, sugar and marmalade together. It might be easier to add the marmalade after so you can see the colour of the margarine to make sure it has gone pale and mixed in properly.

3. Mix in the flour, potato and dried fruit. The mixture should be quite stiff.

4. Flour your worksurface and shape into rounds. Add more flour if they’re too sticky to shape.

Ready to cook. Plenty of flour required to prevent sticking.

Ready to cook. Plenty of flour required to prevent sticking.

5. Grease a heavy frying pan/ solid electric hotplate or griddle. Heat for a few minutes- you will know if it’s ready when a pinch of flour will turn golden brown within a minute.

6. Add the cakes to the pan, cooking for 2 minutes on each side.

7. Lower the heat and cook for a further 5-6 minutes, keep turning to avoid burning.

Cooked on one side.

Cooked on one side.

8. Sprinkle with sugar and mixed spice. Can be eaten hot or cold but are best fresh out of the pan.

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To make up for the lack of a white Christmas…

Snowflakes; micro-photographic images from nature: A.Sigson: Rybinsk

Snowflakes; micro-photographic images from nature: A.Sigson: Rybinsk

These snowflakes photos were taken at the end of the 19th century by Russian photographer A. Sigson (1839-1907). His advanced photographic techniques won him several prizes at the time (including a gold medal at the Exposition Universelle of 1900 in Paris) and were widely used in the scientific community.

Of course these days there are much clearer photos available and with a bit of effort anyone can take their own (see the link below which uses a similar method to the ‘web-cam microscope’ that has been doing the rounds on the internet recently, a very good example of which is shown here) but I still prefer Sigson’s, there’s something about the clarity of capturing an object that normally disappears so quickly in a time long before digital photography.

Saying that, this guy is still very much worth checking out:

http://www.extremetech.com/extreme/172357-the-most-beautiful-snowflake-photos-youll-ever-see-captured-with-a-cheap-diy-camera

Alexey Kljatov, 18/12/13.

Alexey Kljatov, 18/12/13.

References:

The Russian contribution to snow science, S. Sokratov, ICE no.162.

Images:

Sigson image obtained from http://upload.wikimedia.org/wikipedia/commons/f/f4/Photos_of_Snowflakes_01_%28Sigson%29.JPG

Kljatov image obtained from http://www.flickr.com/photos/chaoticmind75/11432202444/

Vegan cupcakes- an update

An actual properly made vegan cupcake, courtesy of the Vegan Cakery.

An actual properly made vegan cupcake, courtesy of the Vegan Cakery.

I feel that vegan cupcakes may have got a bit of bad press from my previous post about them, but let’s be honest they weren’t great at a first attempt. However, this week a very lovely person sent me some of the real thing,  provided by the Vegan Cakery (www.vegancakery.com – check them out they are really rather good) and I’m pleased to say they were very tasty. The office approved too and they are cake experts after all.

They very good and moist- there’s still something about them that’s different to your standard cupcake but not in a bad way. These were much lighter than mine (see here, the main issue with them was that they were too dense), but didn’t have the same springyness you would expect a cake to, they were more crumbly. This isn’t a criticism, they’re just different. Not massively different (I doubt most people would even notice to be honest) and definitely a very good alternative. So I’ve been convinced to try and make my own again, I just might take them to the office next time as I’m not sure my other half’s lovely carnivore family will be so ready to try a second batch…

To be continued…

Nice, moist, and cake like. What's not to like.

Nice, moist, and cake like. What’s not to like.

A happy delivery of chai flavoured goodness.

A happy delivery of chai flavoured goodness.

They didn’t last long in cake office.

Banana and Lime Cake

Doesn’t sound like it should work but it really really does…

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Ingredients:

Cake

300g self raising flour
175g brown sugar (caster is also ok, cake will just be slightly lighter/sweeter/ less rich and fruit cake like)
1 large lime (zest & juice)
100g cream cheese (full or low fat work :) )
50g softened butter
1 ripe banana
120g sultanas/ mixed fruit
1 large egg (beaten)

Icing

120g icing sugar (icing is to taste, use more the sweeter you want it!)
1-2 tsp lime juice (you should be able to get this out of the lime used for the cake)
Lime zest (also from the same lime)

1. Grease and line an 18cm cake tin. (Double ingredients for a 22cm tin, will make a slightly taller cake but this is the easiest way so you don’t get odd bits of egg/ lime left over). Preheat the oven to 180 degrees centigrade.

2. Sieve the flour into a large mixing bowl. Stir in the sugar and about 2/3 of the lime zest (aim for about 1tsp full, the more the better) putting the remaining lime zest to one side for use later in the icing-  save the best looking bits!

3. Mash the banana with 1 tbsp of the lime juice.

4. Thoroughly mix the cream cheese and butter,

4. Make a well in the centre of the flour. Add the egg, banana, cream cheese-butter mix and sultanas. Incorporate gradually and mix well. It will get really tough, make sure to keep turning over, crafty pockets of flour will keep hiding from you.

The mixture will get really thick and stick to the spoon as I'm attempting to demonstrate here.

The mixture will get really thick and stick to the spoon as I’m attempting to demonstrate here.

5. Bake for 40-45 minutes. A skewer/ flat knife will come out clean when it’s done. If making double sized it will need about an hour.

6. Allow to cool before icing. Make up the glacé icing using the remaining lime juice instead of water. You want it to be fairly thick so you can pipe/ drizzle it over the cake. As the photos show there’s no need to be neat.

7. Decorate with the remaining lime zest, will stick best if you add it straight after the icing while the icing is still wet.

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When Scientists Go Back To School- or the missing link between glaciers and sheep

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Karthaus town square. It really is worth the 5 trains, 1 plane and 1 bus it took to get there.

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View from the corner of the lecture theatre. It takes some keen scientist to ignore this and learn about numerical modelling.

Doing research means that you’re learning all the time, whether that be reading someone else’s work or looking up a concept that you don’t understand, but sometimes that learning is something more formal- taking a relevant Master’s module or a Summer School for example. This the reason I’ve spent part of my September up in the mountains in Italy, on the Karthaus Summer School on Ice Sheets and Glaciers in the Climate System.

So what does this actually involve? A typical day looks something like this:

8am: Breakfast
8.30am-12.45 pm: Lectures (with coffee and cake break of course)
1-2pm: 3 course lunch
2-3.30pm: Problem class
3.30-4pm: Coffee and more cake
4-5.30pm: Work on group projects
5.30-7.30pm: Hiking, football, running, sauna, or catching up on much needed sleep if you’re lucky
7.30-9.30pm: 5 course dinner
9.30pm-??: Socialising in the bar, potential tango dancing/ general music making.

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Sometimes it even got too much for the lecturers.

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Enjoying the hiking around Karthaus. Every way leads up…

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One of the more noisy local residents.

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The intrepid group of brave explorers who made it all the way up Kruezspitze.

The group projects were especially useful, there was enough time to properly get stuck into a problem that, although in the same area as our PhDs was not related to them. It forces you to think in a different way and you get something completely new out of it- although I look at what is happening on top of ice shelves I now know a bit about what’s going on underneath them too which can only be a good thing.

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Field trip day. Bonus marks go to Frank’s hat. Trust the lecturers to try and outdo the students.

The planned field trip to a glacier had to be cancelled due to the weather but the trip leaders still managed to take us up to a rock glacier nearby, maybe less exciting to look at but really interesting to learn about all the same. Rock glaciers are insulated by (as the name suggests) a layer of rock debris allowing them to survive in warmer climates than they would otherwise. They can move up to several meters a year which suddenly sounds quite impressive when you see the size of one.

Karthaus students being shown a rock glacier.

Karthaus students being shown a rock glacier.

Not only was the science training great as I’ve been able to learn about so many relevant things to my PhD that often won’t be taught in more general university courses, the social aspect was, surprisingly for me, just as important. Glaciology isn’t a huge community and often departments at individual universities are small so it’s easy to feel quite isolated. I love Meteorology at Reading but sometimes when there is a talk on rainfall or the jet stream I’m thinking “but I just want to hear about ice!”, and now I have a whole network of people to discuss things with or just have a chat about PhD life in general. PhD imposter syndrome (the worry that at some point someone will realise it’s all a big mistake and you’re not clever and shouldn’t be doing a PhD) or worries that you’re not progressing fast enough or know enough are pretty much endemic and it’s good to hear that nearly everyone else has them at some point- and the fact that I got bonus hiking, football and sauna time with them all can only help to ensure our continuing, productive professional relationships !

The lecturers themselves are excellent and also inventive. Whoever could have thought a link could be made between the annual ‘sheep coming down the mountain’ party and glacier flow? Even after a night in the bar no-one can fail to wake up when a sheep appears on a slide mid lecture.

The sheep flow glacier model, Ng et al. 2013.

The sheep flow glacier model, Ng et al. 2013.

The sheep incidentally were also excellent. 2000 come down the mountain at once and are then sorted into pens by thier owners. It looks chaotic but somehow works. Photos at the bottom.

Finally, you can’t talk about Karthaus and not mention the food. It is never ending and always very very good. For example, a typical evening:

A typical evening's light refreshment at Hotel Goldene Rose.

A typical evening’s light refreshment at Hotel Goldene Rose.

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Advice for Karthaus 2014 participants:

- The journey is not as impossible as it looks but if you can find people to travel with it helps, although the closer you get the chances of finding another bemused looking glaciologist on a station platform increases exponentially. We gained 3.
- It gets pretty cold, especially inside the lecture room. Bring many layers.
- Just as importantly don’t bring much tight fitting clothing. You will have a permanent ‘food baby’, or more likely food twins.
- Don’t bring work. You just won’t have time.
- Sleep a lot before you come.
- Leave any British style sauna inhibitions at home. Maybe don’t go to the sauna if you’re supervisor is a lecturer on the   course though, some things once seen can never be erased.
- There is Wifi. Don’t panic.
- Be prepared to learn to tango…

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Cocktail cupcakes- raspberry & strawberry daiquiri and piña colada

Raspberry daquiri, piña colada, strawberry daquiri

Raspberry daquiri, piña colada, strawberry daiquiri

I bought the Hummingbird Bakery Cake Days book after being tempted in by their mini cocktail cupcakes.  They have some really good ideas of how to create the cocktails in cake form but with two major issues: too small and too sweet. As cute as the mini cupcakes are they’re just gone too quickly, and if they’re made into a full sized cupcake the sugariness and general Hummingbird overuse of complicted/ unhealthy ingredients is overwhelming. So here is a simple and less sweet version.

Important- These are best made on the day- they don’t keep well due ot the amount of wet fruit content. You can do steps 1 and 2 and leave overnight for an extra boozy experience though. Recommended.

Piña colada cupcakes

Piña colada cupcakes

Strawberry daiquiri cupcakes

Strawberry daiquiri cupcakes

Ingredients:

Cake

100 ml white rum (or malibu for piña colada cakes)
150g strawberries/ raspberries/ pineapple (tinned is ok)
1 large egg (beaten)
50g butter
130g caster sugar
100g self raising flour

Icing

50g butter
250g icing sugar (minimum- probably much more, up to double this!)
4 tsp whole milk
1 tsp lime zest  (daiquiri)/ 50 g dessicated coconunt (piña colada)
Pink/ yellow food colouring
Optional fresh fruit to decorate

1. In  a small saucepan add 30g of the sugar to the rum, bring to the boil and simmer until about half the original volume. Careful of the really quite alcoholic fumes. As fun as they may make stirring your rum chances are you’ll later fall asleep and burn your cakes. Or do something like get your finger stuck in a teapot…

2. Chop the fruit into small pieces (these will go into the cake so about raisin size works well) and once the rum has cooled a little add them to the mixture. Leave to soak for at least half an hour, the longer the better (I’d recommend overnight, depends how much rum flavour you want!).

3. Preheat the oven to 180 degrees centigrade.

4. Prepare 12 cupcake cases in a baking tray. Drain the fruit (keep the left over rum!) and split between the cake cases.

5. Mix together the butter and remaining sugar until soft and pale coloured, then slowly stir in the beaten egg.

6. Fold in the flour and distribute the mixture among the cake cases, covering the fruit.

7. Bake for 12-15 minutes until a light brown colour and a flat knife comes out of them clean.

8. Once the cakes are cooled mix together the icing sugar, butter, milk and as much of remaining rum as required. Add the lime zest if making daiquiri cakes and food colouring if desired.

9. Pipe on the icing and decorate with fresh fruit (daiquiri) or dessicated coconut (piña colada).

Strawberry daiquiri cupcakes

 

An alternative decoration if you're not a fan of piping.

An alternative easier decoration if you’re not a fan of piping.