Introduction

Hi there,

Let me start off with a few keywords: environment - change - humans - system earth - challenge. You will guess where this is headed: the global challenge of environmental change. It is one that affects all of us, whether we attempt to ignore it or not. It is present in the information we receive through the media, in what we study, and even in the (un)conscious choices we make, such as "Let's not go on holiday to Winterberg this year, as it might not have enough snow to ski properly."

The 'melting snowman' that will accompany you through these - granted - 
usually not very cheerful topics.

Other keywords for this particular blog are: snow - glacier - albedo - sea level - permafrost. I will discuss the effects of global environmental change on the arctic and on the winter season in various locations. The rationale behind this is not only my fondness of subzero temperatures, but mainly the ambition to explain how change in these different locations feeds into feedback cycles that concern system earth in its entirety. As we go along, I will have posts that concern changes on small spacial and temporal scales, as well as address how these are part of larger mechanisms that date back into the past and will impact the future.

To kickstart this blogging journey, I will address 'the big picture' with background on one of the most important feedback cycles concerning cold. This is referred to as the ice-albedo feedback cycle: the interaction between the cryosphere and global climate. The illustration below shows the very basics of this positive feedback cycle.

The most basic of illustrations of the Ice-Albedo Positive Feedback Cycle

Snow covered ice has an albedo of ca. 0.8, meaning it reflects the majority of incoming solar radiation, as opposed to melting ice with an albedo of ca. 0.6 and water, which has an albedo of merely 0.06. (Andreas et al. 2011) With the melting of snow and ice, the surface albedo changes, absorbing more solar radiation and hereby increasing the surface temperature. This again triggers further melting. The feedback cycle also functions in the opposite direction, with increased snow/ice cover as a result. Scientist James Croll was the first to link this to the global climate cycle of ice ages and warmer periods.
Currently, the ice-albedo feedback concept is mainly regarded in research of arctic sea mechanisms, for example in the work of Perovich et al. Their research addresses the variability of absorbed solar energy in the Arctic Sea Basin over the past few decades. Their results present a positive trend in absorbed energy in 89% of the upper ocean surface, which they link to the ice-albedo feedback cycle. (Perovich et al.) Besides considering this mechanism only in larger spacial and temporal frameworks, it is also included in  the analysis of seasonal cycles in one location, such as the sea ice retreat in the Sea of Otshok. They examine the effect of the ice-albedo feedback mechanism, among other factors such as upper ocean mixing due to wind, on the inter-annual variability of ice cover in this arctic sea. Their findings display a positive correllation between the feedback mechanism and ice retreat in the active melting season - mainly the month of April.  (Nihashi et al. 2011) Both articles have concisely explained methodologies and are well worth reading for more in-depth knowledge on the application of this major feedback cycle.

For now, this is it for the first 'melting snowman' post. More to come soon!