HOME

TheInfoList




In
hydrology Hydrology (from Ancient Greek, Greek wikt:ὕδωρ, ὕδωρ, ''hýdōr'' meaning "water" and wikt:λόγος, λόγος, ''lógos'' meaning "study") is the scientific study of the movement, distribution, and management of water on Earth and ...
, snowmelt is
surface runoff Surface runoff (also known as overland flow) is the flow of water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it ac ...
produced from melting
snow Snow comprises individual ice Ice is water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). ...

snow
. It can also be used to describe the period or season during which such runoff is produced. Water produced by snowmelt is an important part of the annual
water cycle The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle In ecology Ecology (from el, οἶκος, "house" and el, -λογία, label=none, "study of") is the study of the relationships ...

water cycle
in many parts of the world, in some cases contributing high fractions of the annual runoff in a watershed. Predicting snowmelt runoff from a
drainage basin A drainage basin is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. The drainage basin includes all the surface water from surface runoff, rain runoff, snowm ...

drainage basin
may be a part of designing water control projects. Rapid snowmelt can cause
flooding A flood is an overflow of water that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide Tides are the rise and fall of s caused by the combined effects of the fo ...

flooding
. If the snowmelt is then frozen, very dangerous conditions and accidents can occur, introducing the need for
salt Salt is a mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure fo ...

salt
to melt the
ice Ice is water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). It is vital for all known forms of , eve ...

ice
.


Energy fluxes related to snowmelt

There are several energy fluxes involved in the melting of snow. These fluxes can act in opposing directions, that is either delivering heat to or removing heat from the
snowpack Snowpack forms from layers of snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of f ...
. Ground heat flux is the energy delivered to the snowpack from the soil below by conduction. Radiation inputs to the snowpack include net
shortwave Shortwave radio is radio Radio is the technology of signaling and communicating Communication (from Latin ''communicare'', meaning "to share") is the act of developing Semantics, meaning among Subject (philosophy), entities or Organiza ...

shortwave
(solar radiation including visible and ultraviolet light) and longwave (
infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior ...

infrared
) radiation. Net shortwave radiation is the difference in energy received from the sun and that reflected by the snowpack because of the snowpack
albedo Albedo (prounounced ; la, albedo, meaning 'whiteness') is the measure of the diffuse reflection Diffuse reflection is the reflectionReflection or reflexion may refer to: Philosophy * Self-reflection Science * Reflection (physics), a comm ...

albedo
. Longwave radiation is received by the snowpack from many sources, including ozone, carbon dioxide, and water vapor present in all levels of the atmosphere. Longwave radiation is also emitted by the snowpack in the form near-
Black-body radiation Black-body radiation is the within or surrounding a body in with its environment, emitted by a (an idealized opaque, non-reflective body). It has a specific spectrum of wavelengths, inversely related to intensity that depend only on the bod ...
, where snow has an emissivity between 0.97 and 1.0. Generally the net longwave radiation term is negative, meaning a net loss of energy from the snowpack. Latent temperature flux is the energy removed from or delivered to the snowpack which accompanies the mass transfers of
evaporation Evaporation is a type of vaporization Vaporization (or vaporisation) of an element or compound is a phase transition from the liquid phase to vapor. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phe ...

evaporation
, sublimation, or
condensation Condensation is the change of the state of matter In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space ...

condensation
. Sensible heat flux is the heat flux due to
convection Convection is single or multiphase fluid flow that occurs Spontaneous process, spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When t ...

convection
between the air and snowpack.


Thaw circles around tree trunks

Tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only wood plants with se ...

Tree
trunks absorbing
sunlight Sunlight is a portion of the given off by the , in particular , , and light. On , sunlight is and through , and is obvious as when the Sun is above the . When direct is not blocked by s, it is experienced as sunshine, a combination of b ...

sunlight
become warmer than the
air The atmosphere of Earth is the layer of gas Gas is one of the four fundamental states of matter In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (ph ...
and cause earlier melting of snow around them. The snow does not melt slower gradually with distance from the trunk, but creates a wall surrounding snow-free ground around it rather. According to some of sources,
North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continen ...

North America
n spring ephermal plants like
spring beauty
spring beauty
(''Claytonia caroliniana''), trout lily (''Erythronium americanum'') and red trillium (Trillium erectum L.) benefit from such thaw circle. They can emerge earlier inside these circles, what gives them more time before development of tree
canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapevine Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...
foliage A leaf (plural leaves) is the principal lateral appendage of the vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia art ...

foliage
cutting off significant portion of the light. They perform nearly all of their yearly
photosynthesis Photosynthesis is a process used by plants and other organisms to convert Conversion or convert may refer to: Arts, entertainment, and media * Conversion (Doctor Who audio), "Conversion" (''Doctor Who'' audio), an episode of the audio drama ' ...

photosynthesis
during this period.
Evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Anc ...

Evergreen
trees tend to produce larger thaw circles than
deciduous In the fields of horticulture Horticulture is the art of cultivating plants in gardens to produce food and medicinal ingredients, or for comfort and ornamental purposes. Horticulturists are agriculturists who grow flowers, fruits and nuts, ...
trees. This involves largely a different mechanism and spring ephemeral plants don't occur there. The snow melts earlier in forest also for example on microtopographic mounds (small elevations) or in wet places like edges of
creek A creek is a stream that is usually smaller than a river Creek may refer to: People * Muscogee, also known as Creek, Native Americans * Murder of Amber Creek, Amber Creek (1982–1997), American murder victim * Mitch Creek (born 1992), Austral ...

creek
s or in seeps. These microsites affect distribution of many
herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is app ...

herb
s too.


Historical cases

In northern Alaska, the melt-date has advanced by 8 days since the mid-1960s. Decreased snowfall in winter followed by warmer spring conditions seems to be the cause for the advance. In Europe, the 2012 heat wave has especially been anomalous at higher altitudes. For the first time on record, some of the highest Alpine peaks in Europe were snow-free. Although it would seem that the two were related, the question of how much of this is due to climate change firmly remains a center of debate. Increased water runoff due to snowmelt was a cause of many famous floods. One well-known example is the Red River Flood of 1997, when the
Red River of the North The Red River (french: rivière Rouge or , American English: Red River of the North) is a river in the north-central United States and central Canada. Originating at the confluence of the Bois de Sioux River, Bois de Sioux and Otter Tail River, ...

Red River of the North
in the
Red River Valley The Red River Valley is a region in central North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to ...
of the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

United States
and
Canada Canada is a country in the northern part of North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, ...

Canada
flooded. Flooding in the Red River Valley is augmented by the fact that the river flows north through
Winnipeg, Manitoba Winnipeg () is the capital and largest city of the province of Manitoba in Canada. It is centred on the confluence of the Red River of the North, Red and Assiniboine River, Assiniboine rivers, near the Longitude, longitudinal centre of North ...
and into
Lake Winnipeg Lake Winnipeg (french: Lac Winnipeg, oj, ᐑᓂᐸᑲᒥᐠᓴᑯ˙ᑯᐣ, italics=no, Weenipagamiksaguygun) is a very large, relatively shallow lake A lake is an area filled with water, localized in a basin, surrounded by land ...
. As snow in
Minnesota Minnesota () is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The State'' (newspaper), a daily newspaper ...

Minnesota
,
North Dakota North Dakota () is a U.S. state In the , a state is a , of which there are currently 50. Bound together in a , each state holds al jurisdiction over a separate and defined geographic territory where it shares its with the . Due to th ...
, and
South Dakota South Dakota () (Sioux The Sioux or Oceti Sakowin (; Dakota Dakota may refer to: * Dakota people, a sub-tribe of the Sioux ** Dakota language, their language From this origin, Dakota may also refer to: Places United States * Dako ...

South Dakota
begins to melt and flow into the Red River, the presence of downstream ice can act as a dam and force upstream water to rise. Colder temperatures downstream can also potentially lead to freezing of water as it flows north, thus augmenting the ice dam problem. Some areas in
British Columbia ( en, Splendour without diminishment) , image_map = British Columbia in Canada 2.svg , Label_map = yes , coordinates = , official_lang = None , Slogan = Beautiful British C ...

British Columbia
are also prone to snowmelt flooding as well.


Scholarly conversation

The date of annual melt is of great interest as a potential indicator of climate change. In order to determine whether the earlier disappearance of spring snow cover in northern Alaska is related to global warming versus an appearance of a more natural, continual cycle of the climate, further study and monitoring is necessary. Large year-to-year variability complicates the picture and furthers the debate. Inter-annual variability of springtime snow pack comes largely from variability of winter month precipitation which is in turn related to the variability of key patterns of atmospheric circulation. A study of the mountains in the western United States show a region wide decline in spring snow-pack since the mid-1900s, dominated by loss at low elevations where winter temperatures are near freezing. These losses are an indication of increased temperatures which lead to snow loss via some combination of increased regularity of rain versus snow and increased melting during winter months. These natural variations make it challenging to quantify trends with confidence, to deduce observed changes to predict future climate, or to clearly detect changes in snow-pack due to human impact on warming trends.


See also

*
Albedo Albedo (prounounced ; la, albedo, meaning 'whiteness') is the measure of the diffuse reflection Diffuse reflection is the reflectionReflection or reflexion may refer to: Philosophy * Self-reflection Science * Reflection (physics), a comm ...

Albedo
*
Ice melt , 1933 Snow removal or snow clearing is the job of removing snow after a snowfall to make travel easier and safer. This is done by both individual households and by governments and institutions. De-icing and anti-icing De-icing is defined as rem ...
*
Snowmelt system A snowmelt system prevents the build-up of snow and ice on cycleways, walkways, patios and roadways, or more economically, only a portion of the area such as a pair of -wide tire tracks on a driveway or a center portion of a sidewalk, etc. It ...
*
Snowpack Snowpack forms from layers of snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of f ...


Gallery

Dust Dust is made of s of solid . On Earth, it generally consists of particles in the that come from various sources such as lifted by wind (an ), , and . Dust in homes is composed of about 20–50% dead . The rest, and in offices, and other ...
accelerates snow melt in the
San Juan Mountains The San Juan Mountains is a high and rugged mountain range in the Rocky Mountains in southwestern Colorado Colorado (, other variants) is a U.S. state, state in the Mountain states, Mountain West region of the United States. It encompasses ...

San Juan Mountains
" perrow="4"> Dust Reduces Snow Cover in the San Juans - 2005.jpg, 2005 (Less dust) Dust Reduces Snow Cover in the San Juans - 2006.jpg, 2006 (More dust) Dust Accelerates Snow Melt in San Juan Mountains - May 31, 2008.jpg, 2008 (Less dust) Dust Accelerates Snow Melt in San Juan Mountains - May 18, 2009.jpg, 2009 (More dust)


References

{{Authority control Hydrology Snow