Tuesday, August 20, 2013

What’s the Dirt on Snow…and Why You Shouldn’t Eat It

Growing up in NH I remember taking a scoopful of snow and dousing it with maple syrup; watching as the snow would magically become the world’s best, most simple dessert.  Those maple syrup snow desserts were a winter dietary staple through my late teens until I learned what could be in that allegedly white, pure snow.  As part of the NH EPSCoR ‘Ecosystems and Society’ Project my colleagues and I have been analyzing the non-snow components (chemical impurities) found within snowpacks throughout the state.  We also look at how these chemical impurities impact the structure of snow grains and albedo, or the amount of light an object reflects, of snow.  
Maple Syrup Snow Cone
blog.villagevoice.com Robert Sietsema February 2010
The chemical impurity that has garnered the majority of scientific and public attention is black carbon [EPA Information].  Black carbon is emitted into the atmosphere from the incomplete combustion of fossil fuels such as coal burning, diesel engines and forest fires.  Once black carbon is in the atmosphere it can be collected by snow as it falls to the earth or it can become the condensation nuclei [Definition]of snowflakes.  When black carbon is incorporated into the snow it ‘darkens’ the snow color; reducing its reflectivity or albedo.  Once albedo has decreased the snow pack will absorb more of the sun’s energy which causes additional warming and melting.   Both permanent and seasonal snow cover act as a white t-shirt for the earth, reflecting up to 90% of incoming solar energy and acting to cool the earth’s temperature.  However the reflectivity of the t-shirt decreases when chemical impurities, such as black carbon, become incorporated into the snow and thus can cause an increase the region’s overall temperature.  
Albedo data collection.  I am using an Analytical Spectral Device FieldSpec 4 (ASD) to measure the amount of sunlight reflecting off of the snow.  March 2013.  Thompson Farm Pasture, UNH. Photo credit: Luke Barbour.
Daily sampling throughout the 2012-2013 winter season revealed an overall decline in albedo when black carbon as well as other chemical impurity concentrations increased within snowpacks throughout the state.  During periods of rapid melt the albedo decreased by up to 30% over a period of three days while the black carbon increased 12 fold just within the top 5cm of the snowpack!  We have also observed astounding 27 fold increase in black carbon concentration following the blizzard on February 8th – 9th, 2013 (38 cm of new snow).  Understanding the mathematical relationship between an increase in black carbon and decrease in albedo is complex especially with the added factor of how fast snow can settle and increase in density.  For the upcoming 2013/2014 winter we will repeat the snow collection process to gather more data which will help us understand the relationship between albedo and chemical impurities within the snowpack.   

Collection of snow for chemical impurity analysis.  February 2013.  Burley Demeritt Organic Dairy Farm, UNH.
Photo credit: Luke Barbour.
Snow has always been an important climate regulator [Climate Regulator - NASA]because it reflects a great deal of the incoming solar energy back to space.  It is no secret that with shorter winters and more impurity laden snow the effectiveness of snow as a climate regulator could be declining.  The first step to creating cleaner, more reflective snow is to understand how chemical impurities, particularly black carbon, affect albedo within New Hampshire.   Once this relationship is fully understood more effective measures could be taken to preserve our snowpacks and create the white, pure snow so that I along with other NH and New England residents can enjoy the maple syrup snow cones that continuously brought so much joy to the winter season.  

Posted by: Jacqueline Amante, MS Earth Science: Geochemical Systems Student, Institute for the Study of Earth, Oceans and Space, University of New Hampshire

Tuesday, August 13, 2013

Splash into Science! with students investigating the quality of their local rivers and streams.

Splash into Science!
As Plymouth State University Graduate Student, Ashley Hyde looks on, two campers deploy electrical conductivity and stage pressure sensors in the Ashuelot River (Keene, NH)
“Splash into Science” was exactly what students did during their Kids On Campus program at  Keene State College two weeks ago. Steve Hale and I were fortunate enough to facilitate 11 middle school students during the week long session based on the LoVoTECS network data. Students learned how to define a watershed and several ways to assess water quality. Campers battled mosquitoes and lugged sledge hammers, waders, specific conductance meters, PVC housing, rebar and other equipment out to our site on the Ashuelot River to deploy a set of HOBO data loggers. Like the LoVoTECS network, sensors were set to collect temperature, electric conductivity (EC) and water pressure measurements at 3 minute increments. Macroinvertebrates were also collected in buckets and brought back to the classroom for classification. The faces of damselfly larva shocked students at first glance under the dissecting microscopes. The data from macroinvertebrate inventory was combined with the sensor data in order to draw a general conclusion of the Ashuelot’s quality of water. To the students’ surprise, EC levels were 100s of microsiemens lower than their predictions. In order to solidify the concept of how humans influence water quality within watersheds, students participated in a water pollution and land cover graphing activity with Skittles as well as Watershed Bingo. My favorite activity of the week was a concept analysis of the term “watershed.” On the first day of camp, prior to any ground-laying conversations, students were asked to draw a watershed. A majority of them drew an image of a shed with some sort of pipe system inside. On the last day of camp, students were asked to draw a watershed again. This time, their drawings included rivers, tributaries, and mountains along the perimeter, farms, factories, roads and bridges. It was clear that all students had a solid understanding of how to define the term. The students showed off their new vocabulary and summarized their findings by creating posters for a poster session for their parents and guardians. It was really neat to see the students articulate what they had learned during the week. We are working on packaging this week-long curriculum so it may be used in future camps or classroom settings.  

Posted by Ashley Hyde, Graduate Student Plymouth State University and Stephen Hale, Research Associate, University of New Hampshire Joan and James Leitzel Center

Forests and Climate Mitigation in New Hampshire

Forests and Climate Mitigation in New Hampshire:

Valuing the Climate Benefits of Forest Ecosystems in the Granite State

Delegates at the Doha UNFCC meeting in 2012
The world's governments are currently assessing how to respond to and prevent changes to the Earth's climate from the extensive release of greenhouse gasses (GHGs). For several decades, countries throughout the world have set together a series of agreements to limit their overall emissions of GHGs. A good example of a longstanding agreement amongst several countries to do this can be found in the United Nations Framework on Climatic Change and the Kyoto Protocol. This treaty essentially binds certain countries to reduce their emissions by a set time period. There are several market mechanisms within the Kyoto Protocol by which countries can exchange and offset some of their emissions, from emissions trading to the development of projects that sequester or reduce GHG emissions which then generate emissions credits. Policies set to reduce GHG emissions exist on other levels, too, from cities to groups of states to over-the-counter exchanges.

Since trees are large carbon storage vessels, incorporating forests into GHG emission reduction platforms has been promoted as a method that serves additional conservation and preservation benefits.  In general, when forests are valued for their ability to sequester and store carbon, they often are more valuable left standing than harvested and processed, particularly in tropical areas where carbon storage can be great. As a result, forest land-owners have been particularly involved in trying to obtain funding for the carbon sequestration capabilities and climatic benefits of their trees. While such payments-for-ecosystem-service mechanisms involving forests do not exist in the Kyoto Protocol currently, similar transactions have been incorporated into other emissions reductions agreements (i.e. the California Environmental Protection Agency's Air Resources Board Compliance Offset Program).

Ecosystems such as forests also provide additional climatic benefits than through carbon sequestration and storage, however. Albedo is described as a unit-less index ranging from zero to one which describes how well a surface can reflect incoming radiation. Ground that is covered by snow is highly reflective and has an albedo that approaches a value of 1.0. A dark surface, such as a Spruce forest, often has a lower value of albedo, approaching 0.10. When incoming solar energy in the form of ultraviolet light hits the Earth's surface, it is either reflected back into space, or is absorbed and re-emitted as heat which is trapped by the greenhouse layer. Thus, brighter and more reflective surfaces, such as snowy ground and sea ice cover, help provide climate-mitigation services.

The White Mountain National Forest, New Hampshire
Forests in northern latitudes which receive snow regularly throughout the winter therefore provide two different climate-regulating ecosystem services: carbon storage and albedo reflectance. Our recent research for the New Hampshire EPSCoR project examines forests in the White Mountain National Forest and these benefits in the context of different management strategies and economic values. Primarily, we were interested to see what happens when the benefits of albedo were valued, since in all climate mitigation platforms forests are solely valued for their carbon storage. Forest albedo benefits are realized when forests are cut and snow is allowed to accumulate on bare ground, whereas carbon benefits are realized through the growth of forest trees. Therefore, when both of these services are valued, there are tradeoffs that may occur by harvesting trees at different times. This information is very important for future planning of forests in New Hampshire in the new era of climate mitigation.

Snowfall as viewed by the MODIS sensor
Figuring out how these properties of services and the economics balanced out required the extensive use of computer models. Using a model of the world's economy called DICE, which is classified as an integrated assessment model of the climate and the economy, we calculated the potential climatic damages on the economy due to climate change. We were able to construct shadow prices for both carbon storage as well as the energy that is reflected through albedo. We then used these prices to determine the total revenue streams by simulating the growth of forests in a computer model. We simulated albedo over time by looking at historical measurements of albedo taken by NASA's MODIS instrument which flies on board two satellites and takes images of the Earth continuously.

High altitude spruce-fir forests in the White Mountains
The results of this research indicate that the climatic benefits of albedo are quite important. When only carbon and the revenue provided by timber harvest are considered, most forests in the White Mountains should be maintained standing, with infrequent harvest. However, when there is an economic value for albedo, the benefits of harvest become more significant. In some high-altitude spruce-fir forests the albedo effect is so valuable that it is most economical to harvest trees frequently so as to maximize the climatic benefits of albedo. Although our project has only looked at a small area within the White Mountains, we intend to expand this analysis throughout the state. This will provide us with a guide as to the management strategies that may provide the biggest economic and climatic benefits of our forests.    Future work on this research will also incorporate the influence of climate change on the quantity and timing of snowfall, and how that may influence management in the context of albedo.

Posted by David Lutz, Research Associate,  Environmental Studies Program, Dartmouth College