This paper documents the diverse role of land-use/land-cover change on precipitation. Since land conversion continues at a rapid pace, this type human disturbance climate system will continue and become even more significant in coming decades.

Abstract We present a generalized version of SnowTran-3D (version 2.0), that simulates wind-related snow distributions over the range topographic and climatic environments found globally. This includes three primary enhancements to original Liston Sturm (1998) model: (1) an improved wind sub-model, (2) two-layer sub-model describing spatial temporal evolution friction velocity must be exceeded transport (the threshold velocity) (3) implementation three-dimensional, equilibrium-drift profile...

Abstract Arctic snow presence, absence, properties, and water amount are key components of Earth’s changing climate system that incur far-reaching physical biological ramifications. Recent dataset modeling developments permit relatively high-resolution (10-km horizontal grid; 3-h time step) pan-Arctic estimates for 1979–2009. Using MicroMet SnowModel in conjunction with land cover, topography, 30 years the NASA Modern-Era Retrospective Analysis Research Applications (MERRA) atmospheric...

Abstract We examined the effects of fire disturbance on permafrost degradation and thaw settlement across a series wildfires (from ~1930 to 2010) in forested areas collapse‐scar bog complexes Tanana Flats lowland interior Alaska. Field measurements were combined with numerical modeling soil thermal dynamics assess roles severity climate history postfire dynamics. Field‐based calculations potential following loss remaining ice‐rich averaged 0.6 m. This subsidence would cause surface...

Although the ecological dynamics of alpine treeline ecotone are influenced by climate, it is an imperfect indicator climate change. Mechanistic processes that shape ecotone—seed rain, seed germination, seedling establishment and subsequent tree growth form, or, conversely dieback—depend on microsite patterns. Growth forms affect wind snow, so develop positive negative feedback loops create these microsites. As a result, complex landscape patterns generated at multiple spatial scales....

Abstract Snow sublimation is an important component of the snow mass balance, but spatial and temporal variability this process not well understood in mountain environments. This study combines a process‐based model (SnowModel) with eddy covariance (EC) measurements to investigate (1) spatio‐temporal simulated respect station observations, (2) contribution ablation snowpack, (3) sensitivity response bark beetle‐induced forest mortality climate warming across north‐central Colorado Rocky...

Abstract NASA's 2017 SnowEx field campaign at Grand Mesa, CO, generated Airborne Laser Scans (ALS), Terrestrial (TLS), and snow‐probe transects, which allowed for a comparison between snow depth measurement techniques. At six locations, comparisons gridded ALS TLS observations, 1‐m resolution, had median difference of 5 cm, root‐mean‐square 16 mean‐absolute 10 3‐cm in standard deviation. generally greater but similar values to TLS, results were not sensitive the cell size 0.5 m. The greatest...

Abstract Seasonal snow is an important component of Earth's hydrologic cycle and climate system, yet it remains challenging to consistently accurately measure depth water equivalent (SWE) across the range diverse snowpack conditions that exist on Earth. The NASA SnowEx campaign focused addressing primary gaps in remote sensing order gain improved spatiotemporal understanding this resource further efforts toward a future satellite‐based mission. Ground‐penetrating radar (GPR) efficient mature...

High-elevation areas in the Rocky Mountain treeline ecotone exhibit heterogeneous snow distribution resulting from interactions among topography, vegetation, and wind. Our study area—Libby Flats—is a gently arched ridge at 3200 m a.s.l. Medicine Bow Mountains, Wyoming. The Libby Flats season (October-May) features sub-freezing temperatures, abundant snow, strong westerly winds (averaging 10 s–1). While relief is gentle on Flats, it, together with islands of krummholz flagged trees, produces...

Abstract A methodology for assimilating ground-based and remotely sensed snow data within a snow-evolution modeling system (SnowModel) is presented. The assimilation scheme (SnowAssim) consistent with optimal interpolation approaches in which the differences between observed modeled values are used to constrain outputs. calculated corrections applied retroactively create improved fields prior assimilated observations. Thus, one of this simulation snow-related distributions throughout entire...

ABSTRACT Snow cover presence, duration, properties, and water amount play a major role in Earth's climate system through its impact on the surface energy budget. conditions trends (1979–2014) were simulated for South America – entire Andes Cordillera. Recent data sets SnowModel developments allow relatively high‐resolutions of 3‐h time step 4‐km horizontal grid increment this domain. US Geological Survey's Global Multi‐resolution Terrain Elevation Data 2010 topography, Land Cover ( GlobCover...

Abstract. Permafrost underlies one-quarter of the Northern Hemisphere but is at increasing risk thaw from climate warming. Recent studies across Arctic have identified areas rapid permafrost degradation both top-down and lateral thaw. Of particular concern thawing syngenetic “yedoma” which ice-rich has a high carbon content. This type common in region around Fairbanks, Alaska, central Alaska expanding westward to Seward Peninsula. A major knowledge gap relating belowground measurements...

Abstract. Understanding the impact of tree structure on snow depth and extent is important in order to make predictions amounts how changes forest cover may affect future water resources. In this work, we investigate under canopies open areas quantify role controlling depth, as well controls from wind topography. We use fine-scale terrestrial laser scanning (TLS) data collected across Grand Mesa, Colorado, USA (winter 2016–2017), measure extract horizontal vertical descriptors (metrics) at...

Abstract Fluctuations in the Greenland ice sheet (GrIS) surface mass balance (SMB) and freshwater influx to surrounding oceans closely follow climate fluctuations are of considerable importance global eustatic sea level rise. A state-of-the-art snow-evolution modeling system (SnowModel) was used simulate variations GrIS melt extent, water components, changes SMB, ocean. The simulations based on Intergovernmental Panel Climate Change scenario A1B modeled by HIRHAM4 regional model (RCM) using...

Accurate identification of the relationships between permafrost extent and landscape patterns can help to develop airborne geophysical or remote sensing tools map in locations across large areas. These will be particularly applicable discontinuous where climate warming disturbances such as human development fire lead rapid degradation. We have linked field-based geophysical, point-scale, imagery surveying measurements at five scars (1930, 1975, 1988, 2001, 2010) on Tanana Flats central...

ABSTRACT Glacier surface mass balance ( SMB ) observations for the Andes Cordillera are limited and therefore estimates of contribution to sea‐level rise highly uncertain. Here (in Part 3), we simulate glacier meteorological hydrological conditions trends (1979/80–2013/14; 35 years), covering tropical latitudes in north down sub‐polar far south, including Northern Patagonia Icefield NPI Southern SPI ). Surface heat‐ mass‐transfer processes were simulated all glaciers having an area equal or...

Abstract The freshwater flux from the Greenland Ice Sheet (GrIS) to ocean is of considerable importance global eustatic sea level rise. A physical modelling approach using SnowModel, a state‐of‐the‐art snow‐evolution system that includes four submodels (MicroMet, EnBal, SnowPack, and SnowTran‐3D), was used quantify 1995–2007 GrIS surface mass‐balance (SMB), including flux. Meteorological observations 26 meteorological stations located on (Greenland Climate Network; GC‐Net stations) in...

High-elevation areas in the Rocky Mountain treeline ecotone exhibit heterogeneous snow distribution resulting from interactions among topography, vegetation, and wind. Our study area—Libby Flats—is a gently arched ridge at 3200 m a.s.l. Medicine Bow Mountains, Wyoming. The Libby Flats season (October-May) features sub-freezing temperatures, abundant snow, strong westerly winds (averaging 10 s–1). While relief is gentle on Flats, it, together with islands of krummholz flagged trees, produces...

Atmospheric mercury (Hg) is deposited to Polar Regions during springtime atmospheric depletion events (AMDEs) that require halogens and snow or ice surfaces. The fate of this Hg following snowmelt largely unknown. We measured Hg, major ions, stable water isotopes from the snowpack through entire spring melt runoff period for two years. Our small (2.5 ha) watershed near Barrow (now Utqiaġvik), Alaska. discharge, made 10 000 depths, collected over 100 samples meltwater chemical analysis in...

Abstract A regional atmospheric model, the HIRHAM4 climate model (RCM) using boundary conditions from ECHAM5 atmosphere–ocean general circulation (AOGCM), was downscaled to a 500-m gridcell increment SnowModel simulate 131 yr (1950–2080) of hydrologic cycle evolution in west Greenland’s Kangerlussuaq drainage. Projected changes Greenland Ice Sheet (GrIS) surface mass balance (SMB) and runoff are relevant for potential hydropower production prediction ecosystem sensitive Fjord systems. Mean...

Abstract In this paper four simple computationally inexpensive, direct insertion data assimilation schemes are presented, and evaluated, to assimilate Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover, which is a binary observation, Advanced Microwave Scanning Radiometer for Earth Observing System (EOS) (AMSR-E) water equivalent (SWE) observations, at coarser resolution than MODIS, into numerical evolution model. The 1) MODIS cover on its own with an arbitrary 0.01 m added the...

Abstract Mass changes and mass contribution to sea level rise from glaciers ice caps (GIC) are key components of the earth’s changing level. GIC surface balance (SMB) magnitudes individual regional mean conditions trends (1979–2009) were simulated for all having areas greater or equal 0.5 km2 in Northern Hemisphere north 25°N latitude (excluding Greenland Ice Sheet). Recent datasets, including Randolph Glacier Inventory (RGI; v. 2.0), NOAA Global Land One-km Base Elevation Project (GLOBE),...

Abstract. Permafrost underlies one quarter of the northern hemisphere but is at increasing risk thaw from climate warming. Recent studies across Arctic have identified areas rapid permafrost degradation both top-down and lateral thaw. Of particular concern thawing ice rich high carbon content syngenetic yedoma like much in region around Fairbanks, Alaska. With a mean annual temperature −2 °C subtle differences ecotype soil control near-surface thermal regime. Long-term measurements...