Aerosol impacts: It is all a bit hazy!

Aerosols can have a range of impacts in the Arctic. Most people associate aerosols with having cooling properties. These pollutants are accountable for causing disruption to the radiative budget; reflecting light particles and preventing solar radiation reaching the surface, thus lowering temperatures (Law and Stohl, 2007).Pumping aerosols into the atmosphere has even been suggested as a mitigation method for climate change!

However their properties do not stop there... It is important to remember that many pollutants fall under this blanket of aerosols, some causing warming (black carbon) and others cooling (sulphates). 

Sources of aerosol pollutants

Arctic air is considered to be very clean, thus the assumption can be made practically all atmospheric pollutants (especially in the higher latitudes of the Arctic) have originated from sources south of the region. Local pollution sources are very limited mostly including volcanic emissions (in Alaska), industrial pollutants (mostly from northern Russia) and emissions from shipping tankers (Fisher, 2011).

An atmospheric dome forms above (the higher latitudes of) the Arctic, isolating the lower troposphere. During winter months the dome can move as far south as 40 degrees over Eurasia, thus allowing us to conclude northern Eurasia is a major source of many of the aerosol pollutants found in the Arctic. Pollutants, sourced from Asia and North America, are too warm and moist to penetrate the cool temperatures creating the dome, however these areas can contribute to pollutants found in the lower latitudes of the Arctic (ie Greenland) (Law and Stohl, 2007). 

Arctic haze: a consequence of aerosol pollution

Variability in Arctic Haze concentration (Law and Stohl, 2007)

Arctic Haze consists of a mixture of Sulphates, Nitrates, Black Carbon and dust aerosols. Haze, containing a high concentration of aerosols, very effectively scatter solar radiation (Scnell, 1984). This haze demonstrates seasonal variability. Maximum levels of haze are witnessed in late winter and early spring, as removal processes recede in the dry season. Figure one shows the long term (A) and seasonal variation (B) in Arctic haze concentrations. The main impact of this Haze is the reduction is visibility, mostly effecting planes and shipping vessels travelling through the area. Furthermore the haze can deposit particulates on the snowy surface which absorb radiation and reduce Arctic Albedo (Rink et al., 2004). Albedo is the ability of a surface to reflect radiation. Snow has a high albedo but the deposition of particulates lower this and cause this snow to melt at a faster rate than it otherwise naturally would.

Enjoy this post? GOOD, as there are plenty more to come!  Long range pollution, and the threats associated, are not as widely discussed as the threats of climate change, because of this i feel this would be a very engaging topic to continue to focus on.

Until next time!  

Aerosols: GHG's forgotten cousin

There are several types of long range pollutants the Arctic including: Mercury, PCBs and Toxaphene. Aerosols, in particular sulphates, are also very dominant in the region. Many of these aerosols, are generated by smelting and mining, within the Russian Arctic, generating large amounts of pollutants, which have been transported to remote regions. Industrialization isn't the only source tough! Another, more common source of aerosols can be found within your deodorant cans…

Now, I was asked recently asked how I would define an aerosol and honestly I couldn’t! So before I get into the depths of the influence of aerosols on cloud properties (the topic of my next post!) I thought I would take a step back and explain what an aerosol is.

An aerosol is defined as a gas containing suspended solid particulates. These can occur in either man-made or natural forms (due to the nature of man-made aerosols they will be the focus). 90% of aerosols are occur naturally including volcanoes, dust and even sea salt; yet it is the remaining 10% which I am interested in. These aerosols can have direct (reflect or absorb sunlight) and indirect (modify cloud properties) to alter the earth's energy budget. Examples of these harmful man-made aerosols can include CFCs, Black Carbon, Nitrates and sulphates and are often found to dominate downwind of urban or industrial regions.

Aerosols can cause a range of direct and indirect effects. A direct effect refers to the influence aerosols have on climate by reflecting or absorbing radiation. Aerosols can have both direct warming and cooling effects dependent on the composition and colour. Broadly speaking lighter and translucent aerosols (such as sulphates and nitrates) reflect solar radiation back into space causing cooling, and darker particles (for example black carbon) absorb radiation and cause warming. "scientists believe the cooling from sulphates and other reflective aerosols overwhelms the warming effects of black carbon and other absorbing aerosols on the planet". This has been taken as far as stating aerosols have counteracted about half the warming caused by green house gases since emissions began in the 1800s. However in the Arctic these warming aerosols have a more prominent impact. Indirect effects (which will be discussed in my next blog post so stick tight!) alter the the size of cloud particles, consequently changing the total amount of radiation reflected and absorbed. 

So now you know what an aerosol is you are completely prepared for next week’s blog! I know leave you with this final thought (below)…

Move over Greenhouse Gases...

After trawling through many academic journals, and trying not to get too distracted by the live COP21 debates, I have found a budding interest in Long range pollution in the Arctic region. Over the rest of my blogging experience I hope to explore this issue in greater detail.

I have several reasons for this focus:

Firstly, to provide a crevice for my blog to sit in, within the blogging community. I mean do you know any other blogs focusing on long range pollution?

Secondly, I feel like there are many threats to the Arctic which are brushed under the metaphorical carpet to make room for the almighty climate change. Now don’t get me wrong, I am not denying climate change isn't having (and will have) catastrophic effects on the polar regions (The Arctic in particular) but other issues such as pollutants cannot be ignored as a result.

Long range pollution can have equally as catastrophic implications to these regions and even contribute to global warming. A major consequence of long range pollutants is their integration into the Arctic food web (Kent Kwan et al., 2015). Pollutants often enter at the bottom of the food chain (through algae or terrestrial plants). This becomes a concern when pollutants are passed up to animals at the top of the food chain including Polar Bears, Orcas and even humans. These pollutants can act as a poison and contribute to the extinction of these already vulnerable species (International Polar Foundation, 2011). This is just a quick overview on one of the reasons long range pollutants should be more widely discussed. 

Now I promise there will be more to come but I am currently crying over a hydrological model for my undergraduate dissertations (a thing I expect many of you third years can relate to…) so in the mean time I will leave you with this video to keep you busy…. 

Whilstle stop tour of long range pollution

One of my main aims, when i started blogging was to explore some of the potential threats to the Polar Regiions. So far I have covered many scintillating topics such as oil exploitation (in posts 2 and 3),  the reactions of the individual poles to climate change and the global impacts of sea ice reduction (in posts 5 and 6) however I am yet to touch upon the influence of pollutants in the polar regions. Within this post I aim to introduce the topic of long range pollution in the Arctic. So here goes…

Green house gases (causing global warming) are often seen as one of the largest threats to the Polar Regions, but it is important not to forget other pollutants, which can be equally detrimental. These pollutants can be accountable for causing similar warming effects by altering the disruption the radiative budget (Law and Stohl, 2007).

After deciding to focus my blog on long range pollution I thought I would just provide a quick definition of what long range pollution actually is. Long range pollution consists of the transportation of atmospheric pollutants, over a distance over 100 KM. Simple!

I thought this diagram perfectly expresses the issues of long range pollution and the transportation of pollutants such as black carbon, sulphates and hydrocarbons, to remote areas (such as the Arctic, where pollution is not produced locally). 

Recently, I have been finding lots of literature surrounding the impacts of aerosols in the Arctic, so over the next few blogs they will be taking center stage of the long range pollution show. Until next time people!