Right now, 99.7 percent of New Mexico is in a severe drought, 82.2 percent is in extreme drought and 53.4 percent is facing exceptional drought – all of which create considerable strain on local communities, agricultural efforts and wildlife. In the midst of these jaw-dropping numbers, unlocking future prospects could depend on analyzing snow and rain and how they are stored in New Mexico mountains.

A UNM faculty member will collaborate with international researchers on the Superior Council of Scientific Investigations (CSIC) funded project "Marginal Snowpacks: Characterizing and Developing Techniques for Monitoring and Modeling their Hydrological and Ecological Importance and Evolution under Climate Warming." Ryan Webb is a research assistant professor in the Department of Civil, Construction, and Environmental Engineering. His research focuses on how snow and rain produce streamflow, groundwater recharge and soil moisture storage in mountain environments.

Ryan Webb

“I use geophysical techniques, remote sensing, field observations and modeling to improve our understanding of what controls runoff processes and how these might change in the future,” explained Webb.

Projects he has been involved with include the flow of liquid water through snow, remote sensing of snow, the impacts of forest fires on hydrology and erosion, analysis of water movement through coal ash landfills, open channel hydraulics and water resources issues in developing communities.

On Feb. 10, the proposal for the snowmelt research consortium was funded and Webb will meet with researchers from around the globe to discuss the importance of marginal snowpacks to montane and downstream communities.

“The consortium is planned for later in 2021 with collaborative work in the following years. We are also trying to remain flexible given the uncertainty of the current pandemic and possible travel restrictions...We are hoping that we can hold the event in-person in Spain. If we need to have an initial meeting online, then we will and try to hold an in-person meeting at a later date,” explained Webb.

The event will last approximately one week, including trips to nearby field sites.

The main objective is to set the basis to improve the scientific capabilities to monitor and to model marginal snowpacks, creating appropriate tools and protocols useful to assess their environmental relevance, to map them under the current climate and identify the marginal snowpacks vulnerable to disappear, and the snow regions that will turn into marginal snowpacks under available scenarios of climate change.

“The main objective of the consortium will be to determine a path forward for the science of observing marginal snowpacks, snow that can be more shallow and possibly ‘patchy’ across the landscape,” said Webb.

The specific objectives are as follows:

1. Discuss and set an accurate definition of marginal snowpack to be accepted by the international community working on snow sciences.

2. Explore the use of LIDAR, unmanned aerial vehicles, and emerging high-resolution remote sensing products (i.e. Sentinel-2, PlanetScope images) not only to map and monitor the evolution of marginal snowpacks but also to downscale already existing products at the coarser resolution but covering longer periods (i.e. MODIS). This information will be used to set protocols to measure meteorological variables and snowpack in these environments.

3. Explore the optimal methodologies to reproduce atmospheric fields at very high resolution to be used as inputs of reliable snow energy and mass snow models.

4. Use previously defined methodologies to test the sensitivity of marginal snowpacks to changing climate, presence of impurities on the snow surface, thermal advection in patchy snowpacks, and complex interactions between vegetation and marginal snowpacks.

5. Begin study cases for detecting vulnerable areas of marginal snowpacks to disappear, and well-developed ones that may become marginal. This can be the base of regional or global studies.

Snow was recently listed as one of the essential climate variables to be monitored to support the work of the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change. Much of the traditional snow science has focused on cold, continental areas with well-developed and persistent snowpacks.

In the last few years, there has been growing recognition to understand and properly monitor marginal snow environments. Marginal snowpacks are found in areas lying close to the 0ºC winter isotherm, and often present a patchy distribution over the terrain and experience several cycles of melting an accumulation during a single snow season. Marginal snowpacks are found throughout the world at moderate altitudes and in mountain environments influenced by warmer more equatorial mid-latitude climate and more by maritime influences.

The importance of marginal snowpacks to montane and downstream communities is significant and makes them acutely vulnerable to climate change due to the warm temperatures and isothermal snowpack characteristics. The common location in the mid-latitudes and intertropical zone makes these areas prone to receive atmospheric aerosols (dust) reducing albedo and increasing energy inputs.

However, our current understanding of this and other hypotheses needs further research as most of our understanding comes from cold continental regions and melting rates of marginal snowpacks during the coldest months with low radiation that may be significantly different. Marginal snowpacks are of critical importance as under a warmer climate, large areas occupied now by well-developed cold snowpacks will become marginal snowpacks, and this research can underpin how we more completely understand the best way to use science to manage, plan, and adapt to the impacts of climate change.

Studying, monitoring, and modeling marginal snowpacks is definitively more complicated than well-developed snowpacks. First, it remains to provide a definitive and accurate definition to classify marginal snowpacks to be used in a consistent way globally. Second, their ephemeral and patchy nature force to work to be conducted at the very detailed resolution, in such a way that conventional remote sensing, manual measurement protocols, and modeling approaches fail to capture the spatial complexity of marginal snowpacks, or to reproduce specific physical processes affecting them (interactions with vegetation, advection of heat from surrounding bare ground). In addition, they need more accuracy than those applied to well-developed snowpacks since small errors are translated into large deviations in the estimation of the total resource.

However, in recent years, new remote sensing techniques have emerged (terrestrial LIDAR, UAV photogrammetry, high-resolution satellites, time-lapse photography, etc.) and new downscaling techniques for atmospheric models that can be linked to snow energy balance models may successfully address the mentioned challenges.

“I think that this consortium is an opportunity to get a little bit ahead of the problem. The marginal snowpacks that we intend to investigate are going to be some of the first to disappear with climate change. If we can improve our abilities to observe and understand these snowpacks, then we can better prepare for the changes in the future. This could be really important for a place like New Mexico, where a majority of our water resources come from snowmelt,” explained Webb.

The consortium team will consist of:

Lead Principal Investigator (PI):
Dr. Juan Ignacio López-Moreno (Spain, The Pyrenean Institute of Ecology)

Dr. Ryan Webb (USA, University of New Mexico)
Dr. Simon Gascoin (France, Center for Space Studies of the Biosphere)
Dr. Nik Callow (Australia, University of Western Australia)
Dr. Hamish McGowan (Australia, University of Queensland)

“I am really looking forward to working with this team. I have met most of them previously, and am familiar with everyone's work, but it will be really fun to work with such a great group of scientists and see what the results end up being,” said Webb.

To learn more about Ryan Webb and his upcoming and previous projects, visit his website.