Lack Of Snow Cover Research Articles

Meteorologické a pôdne sucho na Slovensku v roku 2022

The year 2022 was exceptional for severe drought, not only in Europe, but also in Slovakia. The lack of snow cover in winter 2021/2022, higher average temperature, lack of precipitation in spring, and hot waves in summer caused extreme dry conditions on more than half of the area of Slovakia, while the duration of this drought was locally more than 200 days. The agriculturists and fruiterers in most regions of Slovakia reported the losses in crop yields. The drought hit significantly all nature ecosystems and key social-economic sectors, as the agriculture, energy industry and river transport. The drought in 2022 is evaluated in the article by two indices – SPEI and CMI, and also by the intensity of soil drought, relative saturation, and deficit of soil moisture. The analysis of meteorological and soil drought is supplemented by the information of drought impacts, representing the real effects of drought on the agricultural crops and fruit trees in various regions in Slovakia.

Soil frost affects stem diameter growth of Norway spruce with delay

Key messageA lack of snow cover and increased soil freezing may not only have short-term impacts on trees but longer-lasting lagged effects on radial growth.Soil temperature and soil frost intensity are affected by the depth of insulating snow cover and the timing of snowmelt which are predicted to change by climate warming. This may increase tree growth if there is less soil freezing or decrease growth if there is no insulating snow cover, but frost temperatures still exist. Previously, we showed that the changes in soil frost by snow manipulations in a ~ 50-year-old stand of Norway spruce [Picea abies (L.) Karst.] in eastern Finland in two winters (2005/2006 and 2006/2007) led to short-term changes in physiology, morphology, and the growth of the shoots and roots. The treatments were: (1) control with natural insulating snow accumulation and melting; (2) snow removal during winter; and (3) snow removal in winter and insulation at the top of the forest floor in late winter to delay soil thawing. In this study, we examined the lagged effects of those treatments by radial trunk increment cores during the nine-year recovery period after the termination of the treatments. Annual ring width index (AWI) was calculated for each year by normalization of the ring width in the respective year in proportion to the ring width in the last year (2005) before the treatments. No differences in AWI were found between the treatments before or during the snow manipulation period. However, differences started to appear 1 year after the treatments were finished, became significant 4 years later in 2011 and lasted for 3 years. The radial increment was lower in the treatment with snow removed than in the control and in the treatment with insulation to delay soil thawing, but there were no differences between the latter two treatments. The results indicate that a lack of snow cover may not only have short-term impacts but longer-lasting consequences on the radial growth of trees. The positive effects of prolonged growing season by the increasing summer temperatures on forest growth predicted for the boreal region may therefore not be fully realised due to the negative effects of decreased snow cover and increasing soil freezing.

Long-term forecast of changes in soil erosion losses during spring snowmelt caused by climate within the plain part of Ukraine

The paper deals with the forecast of changes in erosion soil losses during the spring snowmelt due to climate change in the regions of Ukraine in the middle of the 21st century (during 2031–2050) and at its end (during 2081–2100) compared with the values of the baseline period (1961–1990). The forecast is based on the use of the so-called “hydrometeorological factor of spring soil loss”. This factor is a part of the physical-statistical mathematical model of soil erosion lossduring spring snowmelt, developed at the Department of Physical Geography of Odesa I. I. Mechnikov State (since 2000 — National) University during the 1980s – 1990s. The long-term average value of the hydrometeorological factor is linearly related to the long-term average value of spring erosion soil loss. Therefore, the relative change in the hydrometeorological factor corresponds to the relative change in soil erosion losses. The developed methodology for assessing climate-induced changes in soil erosion losses in five regions of Ukraine (North, West, Center, East and South) takes into account the change in water equivalent of snow cover at the beginning of snow melting, the change in surface runoff and its turbidity, and changes in soil erodibility. The forecast of changes in erosion soil loss was carried out using projections of annual and monthly average air temperatures and precipitation for 2031–2050 and 2081–2100 in accordance with scenario A1B from AR4 of the IPCC. As a result of the research, it was found that both in the middle and at the end of the 21st century a decrease in the rate of soil erosion during the period of spring snowmelt is expected. During 2031–2050, the expected soil losses will be less than corresponding baseline period values within the West region by 79%, within the North and East regions by 81%, and within the Center region by 85%. In the South region, the spring soil losses will be zero due to the lack of snow cover. During 2081–2100 snow cover will be absent not only in the South region, but also in the Center and East regions. In the regions North and West snow cover will remain, but the spring soil erosion losses will decrease by dozens of times and will be so small that they can also be ignored.

Resources of the Manchurian pheasant (Phasianus colchicus pallasi) in the Amur region

This article is based on the materials of long-term (2000-2019) data of winter route census (WMA) of the Manchurian pheasant population inhabiting the Amur Region. The main limiting factors causing fluctuations in the number of these bird species have been identified. The spatial distribution of birds by habitat within the range in the study area is considered. In winter, the main ecological factors that determine the features of the spatial distribution and the success of wintering of grouse birds in a sharply continental climate with monsoon features are the presence and abundance of available food and the state of the snow cover. In some cases, it is deep snow that determines the success of bird wintering. At night, at extremely low temperatures and strong winds, birds die from a lack of snow cover: either the snow cover is not deep enough, or a crust is formed (when thawing / due to wind). In the spring-summer period, the main limiting factors for birds that survived the winter are weather and climatic conditions that affect the survival of clutch and young stock; natural emergencies (fires, floods, floods, etc.), diseases, anthropogenic factors, etc.

Identifying persistent temperature inversion events in a subalpine basin using radon-222

Abstract. One year of meteorological and atmospheric radon observations in a topographically complex subalpine basin are used to identify persistent temperature inversion (PTI) events. PTI events play a key role in public health due to the accumulation of urban pollutants that they cause. Two techniques are compared: a new radon-based method (RBM), based on single-height 222Rn measurements from a single centrally located station, and an existing pseudo-vertical temperature gradient method (TGM) based on observations from eight weather stations around the subalpine basin. The RBM identified six PTI events (four in winter, two in autumn), a subset of the 17 events identified by the TGM. The RBM was more consistent in its identification of PTI events for all seasons and more selective of persistent strongly stable conditions. The comparatively poor performance of the TGM was attributed to seasonal inconsistencies in the validity of the method's key assumptions (influenced by mesoscale processes, such as local drainage flows, nocturnal jets, and intermittent turbulence influence) and a lack of snow cover in the basin for the 2016–2017 winter period. Corresponding meteorological quantities for RBM PTI events (constituting 27 % of the autumn–winter cold season) were well characterized. PTI wind speeds in the basin were consistently low over the whole diurnal cycle (typically 0.2–0.6 m s−1). Suitability of the two techniques for air quality assessment was compared using hourly PM10 observations. Peak PM10 concentrations for winter (autumn) PTI events were underestimated by 13 µg m−3 (11 µg m−3) by the TGM compared with the RBM. Only the RBM indicated that nocturnal hourly mean PM10 values in winter PTI events can exceed 100 µg m−3, the upper threshold of low-level short-term PM10 exposure according to World Health Organization guidelines. The efficacy, simplicity, and cost effectiveness of the RBM for identifying PTI events has the potential to make it a powerful tool for urban air quality management in complex terrain regions, for which it adds an additional dimension to contemporary atmospheric stability classification tools. Furthermore, the long-term consistency of the radon source function will enable the RBM to be used in the same way in future studies, enabling the relative magnitude of PTI events to be gauged, which is expected to assist with the assessment of public health risks.

Bacterial and fungal communities in boreal forest soil are insensitive to changes in snow cover conditions.

The northern regions are experiencing considerable changes in winter climate leading to more frequent warm periods, rain-on-snow events and reduced snow pack diminishing the insulation properties of snow cover and increasing soil frost and freeze-thaw cycles. In this study, we investigated how the lack of snow cover, formation of ice encasement and snow compaction affect the size, structure and activities of soil bacterial and fungal communities. Contrary to our hypotheses, snow manipulation treatments over one winter had limited influence on microbial community structure, bacterial or fungal copy numbers or enzyme activities. However, microbial community structure and activities shifted seasonally among soils sampled before snow melt, in early and late growing season and seemed driven by substrate availability. Bacterial and fungal communities were dominated by stress-resistant taxa such as the orders Acidobacteriales, Chaetothyriales and Helotiales that are likely adapted to adverse winter conditions. This study indicated that microbial communities in acidic northern boreal forest soil may be insensitive to direct effects of changing snow cover. However, in long term, the detrimental effects of increased ice and frost to plant roots may alter plant derived carbon and nutrient pools to the soil likely leading to stronger microbial responses.

Evaluating snow cover changing trends of the Western Indian Himalaya

The extent of snow cover in the Western Indian Himalaya determines the fluctuations in river discharge during the summer months and affects the water supply for hydroelectric generation, agriculture and related socio-economic systems which further affect the livelihood of the population in the area and downstream. Despite this importance, there is a lack of information about this region primarily due to the complexities of the processes involved in snow hydrology and the lack of snow cover and depth data in the high elevation areas. Periodical monitoring of the snow cover area (SCA) is an indispensable demand for short-term forecasts of the daily river flows and seasonal forecasts of run-off volume. Therefore, this study is an attempt to assess the annual, seasonal and monthly variations in the extent of snow cover of the Western Indian Himalaya. SCA was estimated using the MODIS/Terra Snow Cover 8-Day L3 Global 500 m (MOD10A2) data for the period 2000–2015. Monthly composite maps of SCA were prepared from 8 days composite snow cover area maps for the Kashmir, Himachal and Kumaon Himalaya. The study found a reduction in snow cover in the Indian Western Himalaya. The inter-seasonal variation in SCA was also observed in the study area. The study found an inter-regional variations in the extent of snow cover in the Western Indian Himalaya during the period of analysis. Emerging changes in the extent of snow cover would influence the availability of water in the near future.

Reduced snow cover affects productivity of upland temperate grasslands

The 2013/2014 winter season showed exceptionally sparse snow cover conditions north of the Alps, which allowed an in situ investigation of the response of vegetation to changed environmental conditions. Examination of carbon dioxide fluxes at three grassland sites along an elevation gradient from 595 to 864ma.m.s.l. revealed that elevation, snow cover extent, soil temperature (Tsoil) and management were determinative factors for productivity. In the absence of snow cover at the highest elevation site (864m), substantial growth started only when the mean daily Tsoil exceeded 5°C. The lack of snow cover at the lowest elevation site (595m) allowed the vegetation to remain photosynthetically active throughout the winter, with a canopy that developed after the last harvest of the previous season. The reduced snow cover at the lower elevation sites (595 and 769m) resulted in an earlier spring, a significant increase in gross ecosystem production and ecosystem respiration, as well as enhanced seasonal carbon dioxide uptake. The reduced snow cover in the 2013/2014 winter season is attributed to low precipitation and high energy influx, which in turn were best explained by exceptionally frequent foehn, i.e., southern advection of dry, warm air across the Alps.

Long term (1921–2011) hydrological regime of Alpine catchments in Northern Italy

Long term (1921–2011) yearly and seasonal hydrological regime of 23 Alpine rivers in Northern Italy (ca. 102–104km2) was investigated here. First, for regulated catchment, the potential effect of flow storage was investigated using an index of potential flow regulation, and pre and post reservoirs’ installation flow analysis. For catchments displaying little regulation effect, non stationarity was studied using linear regression, including variable (segmented) slope analysis, and Mann Kendall test, traditional and progressive. The link of the observed trends against descriptive physiographic variables was then investigated, to highlight geographic and topographic patterns of changes of the hydrological cycle. Dependence upon global thermal and North Atlantic Oscillation NAO anomalies were analysed to highlight potential impact of large scale climate drivers against regional hydrological regimes. Also, the correlation between stream flows and climatic drivers of precipitation and temperatures in nearby stations was investigated, to highlight climate trends potentially driving hydrological changes, and potential changes in the nexus between climate and hydrology given by reservoirs’ operation.The results display for several Alpine rivers here likelihood of significant changes of hydrological fluxes, notably during Winter, Spring and Summer. Winter discharges is decreasing on average, but decrease is seen below 1800m a.s.l. or so, while increase is found above, and the more Northern the larger the increase. Discharges during Spring mostly decrease in time, and more so for increasing outlet altitude, while Summer specific discharges always decrease, and more notably with increasing altitude of the contributing catchment. NAO and global thermal anomalies are correlated against the rate of variation of hydrological fluxes, with the intensity of correlation linked to altitude, longitude, and basin’s size. Specifically targeted studies are necessary to investigate the underlying mechanisms of modified hydrological cycle within different catchments. Besides the presence of expectedly little changes as given by flow operation in regulated streams, the observed trends may be explained by modified hydrological cycle within the Alps of Italy, as given by (i) trading of rainfall for snowfall during Winter, resulting into larger flows, and affecting more highest catchments and Northern areas, (ii) lack of snow cover at thaw, and shrinking of ice covered areas, decreasing melt water deliver during Spring, and Summer, more evident at the highest altitudes, and (iii) increase of evapotranspiration driven by temperature, leading to increased soil moisture uptake and decreased stream fluxes at the intermediate altitudes. The proposed study seems of interest as a benchmark for the assessment of water resources in the Alps, and for conjecture upon future water availability.

Comparison of visual‐based helicopter and fixed‐wing forward‐looking infrared surveys for counting white‐tailed deer Odocoileus virginianus

AbstractAerial surveys using direct counts of animals are commonly used to estimate deer abundance. Forward‐looking infrared (FLIR) technology is increasingly replacing traditional methods such as visual observation from helicopters. Our goals were to compare fixed‐wing FLIR and visual, helicopter‐based counts in terms of relative bias, influence of snow cover and cost. We surveyed five plots: four 41.4 km2 plots with free‐ranging white‐tailed deer Odocoileus virginianus populations in Wisconsin and a 5.3 km2 plot with a white‐tailed deer population contained by a high fence in Michigan. We surveyed plots using both fixed‐wing FLIR and helicopters, both with snow cover and without snow. None of the methods counted more deer than the other when snow was present. Helicopter counts were lower in the absence of snow, but lack of snow cover did not apparently affect FLIR. Group sizes of observed deer were similar regardless of survey method or season. We found that FLIR counts were generally precise (CV = 0.089) when two or three replicate surveys were conducted within a few hours. However, at the plot level, FLIR counts differed greatly between seasons, suggesting that detection rates vary over larger time scales. Fixed‐wing FLIR was more costly than visual observers in helicopters and was more restrictive in terms of acceptable survey conditions. Further research is needed to understand what factors influence the detection of deer during FLIR surveys.

An exceptional Calluna vulgaris winter die-back event, Abernethy Forest, Scottish Highlands

Background: Calluna vulgaris is a woody shrub forming plant communities of economic and international conservation importance. Following winter 2002–2003, there was exceptional Calluna die-back in the central Scottish Highlands. Aim: To understand the effects and causes of this die-back event at Abernethy Forest Nature Reserve, Cairngorms National Park. Methods: Patterns of weather, foliage moisture and microclimate were interpreted in relation to patterns of Calluna vulgaris die-back. Vegetation development was investigated over 4 years, based on pre-existing monitoring plots. Results: February 2003 included a period of exceptionally low air humidity, during which unusually low Calluna shoot moisture readings were made, particularly in areas that subsequently had severe die-back. In monitored areas, Calluna cover declined by a third, with minimal recovery after three growing seasons. Die-back was more severe where Calluna was longer-stemmed and less abundant, and where topography was flatter or more north-facing. These topographical features, and die-back, were correlated with colder winter microclimates. A doubling in Vaccinium myrtillus cover in forest plots was strongly correlated with the pattern of Calluna die-back. Meteorological data showed an eight-fold increase in the variability of winter humidity minima since 1983–1984. Conclusions: Die-back probably followed severe ‘winter desiccation’, caused by extreme low humidity conditions, combined with low temperatures, lack of snow cover, and Calluna vulnerability due to age. It led to a major vegetation change in the direction of management aims at this site, but contrary to aims at many other Calluna-dominated sites. The importance of climatic variability as a potential driver of major vegetation change is emphasised.

Climate Change and Winter Survival of Perennial Forage Crops in Eastern Canada

Severe winter climatic conditions cause recurrent damage to perennial forage crops in eastern Canada. Predicted increases of 2 to 6°C in minimum temperature during winter months due to global warming will likely affect survival of forage crops. Potential impacts of climate change on overwintering of perennial forage crops in eastern Canada were assessed using climatic indices reflecting risks of winter injuries related to cold intensity and duration, lack of snow cover, inadequate cold hardiness, soil heaving, and ice encasement. Climatic indices were calculated for 22 agricultural regions in eastern Canada for the current climate (1961–1990) and future climate scenarios (2010–2039 and 2040–2069). Climate scenario data were extracted from the first‐generation Canadian Global Coupled General Circulation Model. Compared with current conditions, the hardening period in 2040 to 2069 would be shorter by 4.0 d, with a lower accumulation of hardiness‐inducing cool temperatures. The period during which a temperature ≤−15°C can occur (cold period) would be reduced by 23.8 d, and the number of days with snow cover of at least 0.1 m would be reduced by 39.4 d. Consequently, the number of days with a protective snow cover during the cold period would be reduced by 15.6 d. Under predicted future climate, risks of winter injury to perennial forage crops in eastern Canada will likely increase because of less cold hardening during fall and reduced protective snow cover during the cold period, which will increase exposure of plants to killing frosts, soil heaving, and ice encasement.

Effects of soil freezing and drought stress on abscisic acid content of sugar maple sap and leaves.

In 1991 and 1992, mature maple trees (Acer saccharum Marsh.) were freeze-stressed or drought-stressed by preventing precipitation (snow or rain) from reaching the forest floor under selected trees. Lack of snow cover caused a decrease in soil temperature to well below 0 degrees C from December to April and a lowering of the soil water content to 10%. The abscisic acid (ABA) concentration in the spring sap of deep-soil frost-stressed trees was significantly higher than in control or drought-stressed trees. The increase in ABA concentration in the xylem sap in the spring of 1991 and 1992 preceded symptoms of canopy decline and a decrease in leaf area that were observed during the summers of 1991 and 1992. These results suggest a role for ABA in root-to-shoot communication in response to environmental stress. The largest differences in ABA concentration induced by the treatments was found in sap collected at the end of sap flow. The increase in ABA concentration in spring sap at the end of the sap flow could be used as an early indicator of stress suffered by trees during the winter. Not only did the increase in ABA concentration occur before any visible symptoms of tree decline appeared, but the trees that showed the most evident decline had the highest ABA concentrations in the spring sap. Leaf ABA concentration was not a good indicator of induced stress.

Some Empirical Evidence for the Influence of Snow Cover on Temperature and Precipitation

Abstract A case study is made of the effect of snow cover or lack of snow cover on the surface temperature and precipitation in the coterminous United States during winter 1983/1984. Extensive snow occurred in the eastern half of the country early in December 1983; this snow cover appears to have produced substantial reduction in the observed surface temperature, especially during January 1984. This diminution was especially pronounced in the daytime maximum temperatures, presumably due to increase surface albedo. The effect involving anomalous snow cover also shows up in the Great Basin area during February 1984. A quantitative evaluation of the net effect of snow cover is made using errors of temperature specifications from 700 mb patterns formed from stepwise multiple regression equations. Temperature differences as great as 5°C were found over the temperature expected from the large-scale circulation alone. The concomitant effect of increased static stability near the surface may have played a role in...

Factors Controlling Stability of Mountain Ecosystems in Northern Mongolia

Factors Controlling Stability of Mountain Ecosystems in Northern Mongolia

INTERPRETATION DES RELATIONS ENTRE LE CLIMAT ET LA SURVIE À L’HIVER DE LA LUZERNE PAR L’ANALYSE DES CORRELATIONS

The relationships between climatic data for the whole year (May to April) and the winter survival of alfalfa were examined with the use of simple correlation analysis for 48 station-years in Eastern Canada. It was found that the winter period is most critical. The most important meteorological factors are low soil temperatures, high air temperatures, lack of snow cover and rain during periods without snow cover. The vegetative growth and the hardening periods were found to be of equal importance. The most limiting factors during the growth period are: low soil temperatures from April to June and high temperatures during July and August, low insolation and excess rain. During the hardening period high soil temperatures and abnormal precipitation are most important. This analysis over a whole year should help in the development of a model for predicting annual damages and in planning research on alfalfa survival.

EFFETS DE CERTAINS FACTEURS CLIMATIQUES ET EDAPHIQUES SUR LA SURVIE A L’HIVER DE LA LUZERNE AU QUEBEC

A comparative study conducted for the winters of 1973–74 and 1974–75 in three zones of the Province of Quebec permitted us to point out the principal climatic and edaphic factors in the winterkilling of alfalfa fields. Alfalfa plants were sampled on 21 different location–years in order to measure their potential yield index (IRP) and the heaving index (ID) of the tap root. Climatic conditions were suitable for the survival during the winter of 1974–75. Yet, during the winter of 1973–74, alternate freezing and thawing, rainfall and the lack of snow cover gave significant differences between the three zones. The IRP increased from the South (zone I) to the North (zone III) of the province. Partial correlations analysis emphasized the importance of rainfall on soil water (r = 0.58) and on snow depth (r = 0.79). Stepwise regression analysis showed that the change in soil water content during the winter was the variable which had the greatest impact on the IRP and the ID. These field experiments suggest the development, on a national basis, of an agrometeorological and statistical survey system to assess alfalfa crop injury and to recognize regional differences.