Changing Intrasynoptic Type Characteristics and Interannual Frequencies of Circulation Patterns Conducive to Lake-Effect Snowfall

2019 ◽  
Vol 58 (10) ◽  
pp. 2313-2328 ◽  
Author(s):  
Zachary J. Suriano
Keyword(s):  
Winter Season ◽  
Zonal Flow ◽  
Seasonal Temperature ◽  
Synoptic Scale ◽  
Synoptic Type ◽  
Synoptic Weather ◽  
Air Temperatures ◽  
Lake Effect ◽  
Circulation Patterns ◽  
Forcing Mechanisms

AbstractUsing a temporal synoptic index, synoptic-scale atmospheric patterns suitable for lake-effect snow downwind of Lakes Erie and Ontario are identified and analyzed from 1950 to 2009. In response to prior research noting a trend reversal of snowfall in this region, changes in the inherent meteorological characteristics and winter-season frequencies of lake-effect synoptic weather types are evaluated as possible forcing mechanisms. Four atmospheric patterns are identified during the December–February winter season as lake-effect synoptic types. Changes in inherent meteorological characteristics and winter frequencies of these types are attributed to between 88% and 95% of the observed snowfall changes during the study period. Decreasing air temperatures and surface pressures, increasing boundary layer instability, and changes toward stronger zonal flow are noted for multiple lake-effect synoptic types from 1950 to 1979 as likely forcing mechanisms of observed snowfall increases, on the order of nearly 1.0 cm yr−1 downwind of Lake Ontario per individual synoptic type. Similarly, the significant increases in the winter frequency of multiple lake-effect synoptic types also are attributed to some of the increases in snowfall. From 1980 to 2009, however, the lake-effect synoptic types remained relatively unchanged or decreased in frequency, as did snowfall totals. The results of this study indicate that changes in the synoptic-scale environment are a viable mechanism forcing snowfall trends, in addition to the more commonly considered seasonal temperature and lake-ice considerations, and should be incorporated into future discussions of lake-effect snowfall projections.

scholarly journals Synoptic atmospheric circulation patterns associated with deep persistent slab avalanches in the western United States

2021 ◽  
Vol 21 (2) ◽  
pp. 757-774
Author(s):  
Andrew R. Schauer ◽  
Jordy Hendrikx ◽  
Karl W. Birkeland ◽  
Cary J. Mock
Keyword(s):  
Atmospheric Circulation ◽  
Winter Season ◽  
Heavy Precipitation ◽  
Self Organizing Maps ◽  
Synoptic Type ◽  
Additional Tool ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Unique Distribution ◽  
In The Beginning

Abstract. Deep persistent slab avalanches are capable of destroying infrastructure and are usually unsurvivable for those who are caught. Formation of a snowpack conducive to deep persistent slab avalanches is typically driven by meteorological conditions occurring in the beginning weeks to months of the winter season, and yet the avalanche event may not occur for several weeks to months later. While predicting the exact timing of the release of deep persistent slab avalanches is difficult, onset of avalanche activity is commonly preceded by rapid warming, heavy precipitation, or high winds. This work investigates the synoptic drivers of deep persistent slab avalanches at three sites in the western USA with long records: Bridger Bowl, Montana; Jackson, Wyoming; and Mammoth Mountain, California. We use self-organizing maps to generate 20 synoptic types that summarize 5899 daily 500 mbar geopotential height maps for the winters (November–March) of 1979/80–2017/18. For each of the three locations, we identify major and minor deep persistent slab avalanche seasons and analyze the number of days represented by each synoptic type during the beginning (November–January) of the major and minor seasons. We also examine the number of days assigned to each synoptic type during the 72 h preceding deep persistent slab avalanche activity for both dry and wet slab events. Each of the three sites exhibits a unique distribution of the number of days assigned to each synoptic type during November–January of major and minor seasons and for the 72 h period preceding deep persistent slab avalanche activity. This work identifies the synoptic-scale atmospheric circulation patterns contributing to deep persistent slab instabilities and the patterns that commonly precede deep persistent slab avalanche activity. By identifying these patterns, we provide an improved understanding of deep persistent slab avalanches and an additional tool to anticipate the timing of these difficult-to-predict events.

scholarly journals Synoptic atmospheric circulation patterns associated with deep persistent slab avalanches in the western United States

2020 ◽  
Author(s):  
Andrew R. Schauer ◽  
Jordy Hendrikx ◽  
Karl W. Birkeland ◽  
Cary J. Mock
Keyword(s):  
Atmospheric Circulation ◽  
Winter Season ◽  
Heavy Precipitation ◽  
Self Organizing Maps ◽  
Synoptic Type ◽  
Additional Tool ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Unique Distribution ◽  
In The Beginning

Abstract. Deep persistent slab avalanches are capable of destroying infrastructure and are usually unsurvivable to those who are caught. Formation of a snowpack conducive to deep persistent slab avalanches is typically driven by meteorological conditions occurring in the beginning weeks to months of the winter season, and yet the avalanche event may not occur for several weeks to months later. While predicting the exact timing of the release of deep persistent slab avalanches is difficult, onset of avalanche activity is commonly preceded by rapid warming, heavy precipitation, or high winds. This work investigates the synoptic drivers of deep persistent slab avalanches at three sites in the Western USA with long records: Bridger Bowl, Montana; Jackson, Wyoming; and Mammoth Mountain, California. We use self-organizing maps to generate twenty synoptic types that summarize 5,899 daily 500 mb geopotential height maps for the winters (November–March) of 1979/80–2017/18. For each of the three locations, we identify major and minor deep persistent slab avalanche seasons, and analyze the number of days represented by each synoptic type during the beginning (November–January) of the major and minor seasons. We also examine the number of days assigned to each synoptic type during the 72 hours preceding deep persistent slab avalanche activity for both dry and wet slab events. Each of the three sites exhibits a unique distribution of the number of days assigned to each synoptic type during November–January of major and minor seasons, and for the 72-hour period preceding deep persistent slab avalanche activity. This work identifies the synoptic scale atmospheric circulation patterns contributing to deep persistent slab instabilities, and the patterns that commonly precede deep persistent slab avalanche activity. By identifying these patterns, we provide an improved understanding of deep persistent slab avalanches, and an additional tool to anticipate the timing of these difficult-to-predict events.

scholarly journals Frequency of Major Avalanche Winters

1980 ◽  
Vol 26 (94) ◽  
pp. 43-52 ◽  
Author(s):  
B.B. Fitzharris ◽  
P. A. Schaerer
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Zonal Flow ◽  
Meridional Flow ◽  
Winter Snow ◽  
Circulation Patterns ◽  
Rail Line ◽  
Heavy Snow ◽  
Canadian Pacific Railway ◽  
Snow Fall

AbstractA 70-Year record has been compiled for avalanches affecting the Canadian Pacific Railway at Rogers Pass, British Columbia. Time series are presented for avalanche frequency, avalanche mass, and length of avalanche debris on the rail line for 26 avalanche paths as well as for winter snow-fall. Winters with the heaviest avalanche activity were 1971-72, 1934-35, 1919-20, 1932-33, and 1953-54. Time-series analysis indicates that the size of avalanches has decreased in recent decades. Spectral analysis shows avalanche activity to the similar to white noise but with a weak periodicity of about 18 years. An examination of the climatology of big avalanche winters reveals two distinct circulation patterns: a strong zonal flow with frequent Pacific storms and heavy snow-fall; or a pronounced meridional flow, Arctic air outbreaks, and catastrophic avalanching released by rapid advection of warm moist Pacific air. Major avalanche winters need not be big snow-fall winters.

scholarly journals Atmospheric circulation patterns, cloud-to-ground lightning, and locally intense convective rainfall associated with debris flow initiation in the Dolomite Alps of northeastern Italy

2016 ◽  
Vol 16 (2) ◽  
pp. 509-528 ◽  
Author(s):  
S. Jeffrey Underwood ◽  
Michael D. Schultz ◽  
Metteo Berti ◽  
Carlo Gregoretti ◽  
Alessandro Simoni ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Lightning Flash ◽  
Synoptic Scale ◽  
Convective Rainfall ◽  
Spatial And Temporal Scales ◽  
Circulation Patterns ◽  
Unconsolidated Material ◽  
Northeastern Italy ◽  
Debris Flow Initiation

Abstract. The Dolomite Alps of northeastern Italy experience debris flows with great frequency during the summer months. An ample supply of unconsolidated material on steep slopes and a summer season climate regime characterized by recurrent thunderstorms combine to produce an abundance of these destructive hydro-geologic events. In the past, debris flow events have been studied primarily in the context of their geologic and geomorphic characteristics. The atmospheric contribution to these mass-wasting events has been limited to recording rainfall and developing intensity thresholds for debris mobilization. This study aims to expand the examination of atmospheric processes that preceded both locally intense convective rainfall (LICR) and debris flows in the Dolomite region. 500 hPa pressure level plots of geopotential heights were constructed for a period of 3 days prior to debris flow events to gain insight into the synoptic-scale processes which provide an environment conducive to LICR in the Dolomites. Cloud-to-ground (CG) lightning flash data recorded at the meso-scale were incorporated to assess the convective environment proximal to debris flow source regions. Twelve events were analyzed and from this analysis three common synoptic-scale circulation patterns were identified. Evaluation of CG flashes at smaller spatial and temporal scales illustrated that convective processes vary in their production of CF flashes (total number) and the spatial distribution of flashes can also be quite different between events over longer periods. During the 60 min interval immediately preceding debris flow a majority of cases exhibited spatial and temporal colocation of LICR and CG flashes. Also a number of CG flash parameters were found to be significantly correlated to rainfall intensity prior to debris flow initiation.

scholarly journals Detection of annual and seasonal temperature variability and change using non-parametric test- A case study of Bundelkhand region of central India

2021 ◽  
Vol 23 (4) ◽  
pp. 402-408
Author(s):  
SUCHIT K. RAI ◽  
SUNIL KUMAR ◽  
MANOJ CHAUDHARY
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Monsoon Season ◽  
Economic Status ◽  
Winter Season ◽  
Central India ◽  
Warming Trend ◽  
Temperature Variability ◽  
Seasonal Temperature ◽  
Economic Activities

Consequences of global warming and climate change are major threat to humans and their socio-economic activities. Agriculture of Bundelkhand region is supposed to be more vulnerable due to emerging scenario of climate change and poor socio-economic status of farming community. Many studies carried out elsewhere have shown evidence of regional temperature variability along with global climate changes. This study focuses on the temporal variability and trend in annual and seasonal temperature (1901-2012) at six locations of Bundelkhand region. The results of the analysis reveal that the annual maximum (TMax) and minimum (TMin) temperature has significantly increasing trend in all the locations in the range of 0.5 to 2.0oC 100 year-1 and 0.5 to 1.1 oC 100 year-1, respectively. Seasonal analysis revealed warming trend in both TMax (0.6-2.6oC100 year-1) and TMin (0.9 to 2.3 oC 100 year-1) during post-monsoon and winter season in all the locations. Majority of the locations showed cooling trend (0.3-1.0 oC 100 year-1), in the mean maximum and minimum temperature during monsoon season except at two locations i.e Jhansi and Banda. However, a significant positive trends (2.9 oC) in the TMin was found for the period of hundred years at Banda district during monsoon season.

scholarly journals Cloud-resolving-model simulations of nocturnal precipitation over the Himalayan slopes and foothills

2021 ◽  
Author(s):  
Shiori Sugimoto ◽  
Kenichi Ueno ◽  
Hatsuki Fujinami ◽  
Tomoe Nasuno ◽  
Tomonori Sato ◽  
...  
Keyword(s):  
Moisture Transport ◽  
Wrf Model ◽  
Synoptic Scale ◽  
Reanalysis Dataset ◽  
Near Surface ◽  
Model Simulations ◽  
Lower Elevation ◽  
Circulation Patterns ◽  
Downslope Wind ◽  
Cloud Resolving Model

AbstractA numerical experiment with a 2-km resolution was conducted using the Weather Research and Forecasting (WRF) model to investigate physical processes driving nocturnal precipitation over the Himalayas during the mature monsoon seasons between 2003 and 2010. The WRF model simulations of increases in precipitation twice a day, one in the afternoon and another around midnight, over the Himalayan slopes, and of the single nocturnal peak over the Himalayan foothills were reasonably accurate. To understand the synoptic-scale moisture transport and its local-scale convergence generating the nocturnal precipitation, composite analyses were conducted using the reanalysis dataset and model outputs. In the synoptic scale, moisture transport associated with the westward propagation of low pressure systems was found when nocturnal precipitation dominated over the Himalayan slopes. In contrast, moisture was directly provided from the synoptic-scale monsoon westerlies for nocturnal precipitation over the foothills. The model outputs suggested that precipitation occurred on the mountain ridges in the Himalayas during the afternoon, and expanded horizontally towards lower-elevation areas through the night. During the nighttime, the downslope wind was caused by radiative cooling at the surface and was intensified by evaporative cooling by hydrometeors in the near-surface layer. As a result, convergence between the downslope wind and the synoptic-scale flow promoted nocturnal precipitation over the Himalayas and to the south, as well as the moisture convergence by orography and/or synoptic-scale circulation patterns. The nocturnal precipitation over the Himalayas was not simulated well when we used the coarse topographic resolution and the smaller number of vertical layers.

scholarly journals ANALYSIS OF ALTERNATIVE ENERGY SOURCES AND THEIR USE IN THE PIG BREEDING FARM DURING THE WINTER PERIOD

2018 ◽  
Author(s):  
Aleksandra MINAJEVA
Keyword(s):  
Weight Gain ◽  
Alternative Energy ◽  
Cooling System ◽  
Winter Season ◽  
Exhaust System ◽  
Winter Period ◽  
Alternative Energy Sources ◽  
Air Temperatures ◽  
Reduce Emissions ◽  
Manure Slurry

Investigations were carried out at the pig breeding farm located in Šalčininkai district. There are 9 hulls in the pig farm, two of which are dedicated to pig breeding. One barn was reconstructed: installed heated-cooled floor with the heat pump and a manure-slurry cooling system. The second barn was installed more than 50 years ago and has not been modernized yet. This hull doesn’t have mechanical cooling system, is heated by a gas heater, infrared rays are installed in the pig holders. Both barns have a mechanical air exhaust system. The research data were collected during the winter season. Also was collected statistical data on the birth rate, weight gain, morbidity and piglets’ death. The parameters of the old barn microclimate depended directly on outdoor air parameters. The average temperature in the old housing was 21 ° C, in the modernized 27 °C; humidity was 79% and 54% respectively. In the winter period, in the old barn, due to low air temperatures and high humidity, the piglets’ death was 7.8% upper and the weight gain of 35% lower than in the reconstructed barn. It has been determined that the microclimate parameters influence the growth of the weight of piglets, their fall, and morbidity. The installed heated-cooled floor and manure-slurry cooling systems allow the farm to not use other types of fuel, facilitate the maintenance of the microclimate parameters of the barn (maintenance of the design temperature all the year), reduce emissions of CO2 and NH3 into the environment, and receive higher revenues from growing and selling products.

scholarly journals Assessment of Future Climate Change Projections Using Multiple Global Climate Models

2019 ◽  
Vol 5 (10) ◽  
pp. 2152-2166 ◽  
Author(s):  
Han Thi Oo ◽  
Win Win Zin ◽  
Cho Cho Thin Kyi
Keyword(s):  
Climate Change ◽  
Temperature Rise ◽  
Climate Models ◽  
Hydrological Cycle ◽  
Winter Season ◽  
Future Climate ◽  
Maximum Temperature ◽  
Future Climate Change ◽  
Seasonal Temperature ◽  
Suitable Climate

Nowadays, the hydrological cycle which alters river discharge and water availability is affected by climate change. Therefore, the understanding of climate change is curial for the security of hydrologic conditions of river basins. The main purpose of this study is to assess the projections of future climate across the Upper Ayeyarwady river basin for its sustainable development and management of water sector for this area. Global Ten climate Models available from CMIP5 represented by the IPCC for its fifth Assessment Report were bias corrected using linear scaling method to generate the model error. Among the GCMs, a suitable climate model for each station is selected based on the results of performance indicators (R2 and RMSE). Future climate data are projected based on the selected suitable climate models by using future climate scenarios: RCP2.6, RCP4.5, and RCP8.5. According to this study, future projection indicates to increase in precipitation amounts in the rainy and winter season and diminishes in summer season under all future scenarios. Based on the seasonal temperature changes analysis for all stations,  the future temperature are  predicted to steadily increase with higher rates during summer than the other two seasons and it can also be concluded that the monthly minimum temperature rise is a bit larger than the maximum temperature rise in all seasons.

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