scholarly journals How unusual was 2015 in the 1984–2015 period of North Cascade Glacier Annual Mass Balance?

Author(s):  
Mauri S. Pelto

Abstract. In 1983 the North Cascade Glacier Climate Project (NCGCP) began annual monitoring 10 glaciers throughout the range, to identify their response to climate change. The annual observations include mass balance, terminus behaviour, and accumulation area ratio (AAR). Annual mass balance (Ba) measurements have been continued on 7 original glaciers that still exist. Two glaciers have disappeared: the Lewis Glacier and Spider Glacier. Foss Glacier was discontinued in 2014 as it has separated into several sections. In 1990, Easton Glacier and Sholes Glacier were added to the annual balance program. This comparatively long record from glaciers in one region conducted by the same research program using the same methods offers some useful comparative data to place the impact of regional climate warmth of 2015 in perspective. The mean annual balance of the North Cascade glaciers is reported in water equivalent thicknesses to the World Glacier Monitoring Service (WGMS). From 1984–2015 the mean Ba is –0.54 ma-1, ranging from –0.44 to –0.67  ma-1 for individual glacier's. This is equivalent to the WGMS global average for this period of –0.56 ma-1. The cumulative loss of 17.2 m w.e. and ~ 19 m of ice thickness represents more than 30 % of the volume of the glaciers. In 2015 the mean Ba of nine North Cascade glaciers was –3.10 m w.e., the most negative in the 32 year record, with 2005 the previous maximum loss at –2.84 m. The mean AAR of 3 % was likewise a minimum, previous minimum was 16 % in 2005. The correlation coefficient of Ba is above 0.80 between all glaciers including the USGS benchmark glacier, South Cascade Glacier. This indicates that the response is regional and not controlled by local factors. The similar mass balance losses in alpine glacier regions globally suggest global climate change is the principal driving force.

1988 ◽  
Vol 34 (117) ◽  
pp. 194-199 ◽  
Author(s):  
Mauri S. Pelto

AbstractThe annual balance has been measured for ten North Cascade glaciers in 1983–84, 1984–85, 1985–86, and 1986–87 (1984, 1985, 1986, and 1987). Based on these data, an annual balance prediction method was designed and tested. Comparison of measured versus predicted annual balances indicates an accuracy of ±0.22–0.30 m. The method is based on annual measurement of the accumulation area ratio (AAR), and determination of the perennially constant activity index and area-altitude distribution on each glacier. The accumulation area ratio is determined from aerial and ground photographs at the end of the ablation season. The activity index is identified from observation of the rise of the snow line with time, compared to measured snow depths above the snow line. The AAR-activity index method was used to calculate the annual balance of 47 North Cascade glaciers in 1984, 1985, 1986, and 1987. The mean balance during the 4 year period was —0.33 m.From the mass-balance records, it is apparent that North Cascade glaciers can be divided into six climatic sensitivity groups. Each glacier type responds differently to specific climatic conditions. The mass-balance variation for glaciers of the same type is small.Since 1977, warmer, drier climatic conditions have prevailed in the North Cascades, resulting in the retreat of 42 of the 47 glaciers examined.


2007 ◽  
Vol 7 (2) ◽  
pp. 11-27 ◽  
Author(s):  
Michele M. Betsill

Over the past decade the governance of global climate change has evolved into a complex, multi-level process involving actors and initiatives at multiple levels of social organization from the global to the local in both the public and private spheres. This article analyzes the North American Commission for Environmental Cooperation (CEC) as one component of this multilevel governance system. Specifically, it evaluates the CEC as a site of regional climate governance based on three potential advantages of governance through regional organizations: a small number of actors, opportunities for issue linkage, and linkage between national and global governance systems. On each count I find that the benefits of a CEC-based climate governance system are limited and argue for greater consideration of how such a system would interact with other forms of climate governance in North America.


2010 ◽  
Vol 4 (1) ◽  
pp. 67-75 ◽  
Author(s):  
M. S. Pelto

Abstract. Temperate alpine glacier survival is dependent on the consistent presence of an accumulation zone. Frequent low accumulation area ratio values, below 30%, indicate the lack of a consistent accumulation zone, which leads to substantial thinning of the glacier in the accumulation zone. This thinning is often evident from substantial marginal recession, emergence of new rock outcrops and surface elevation decline in the accumulation zone. In the North Cascades 9 of the 12 examined glaciers exhibit characteristics of substantial accumulation zone thinning; marginal recession or emergent bedrock areas in the accumulation zone. The longitudinal profile thinning factor, f, which is a measure of the ratio of thinning in the accumulation zone to that at the terminus, is above 0.6 for all glaciers exhibiting accumulation zone thinning characteristics. The ratio of accumulation zone thinning to cumulative mass balance is above 0.5 for glacier experiencing substantial accumulation zone thinning. Without a consistent accumulation zone these glaciers are forecast not to survive the current climate or future additional warming. The results vary considerably with adjacent glaciers having a different survival forecast. This emphasizes the danger of extrapolating survival from one glacier to the next.


Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 96
Author(s):  
Shengqi Jian ◽  
Tiansheng Zhu ◽  
Jiayi Wang ◽  
Denghua Yan

Catalpa bungei C. A. Mey. (C. bungei) is one of the recommended native species for ecological management in China. It is a fast-growing tree of high economic and ecological importance, but its rare resources, caused by anthropogenic destruction and local climatic degradation, have not satisfied the requirements. It has been widely recommended for large-scale afforestation of ecological management and gradually increasing in recent years, but the impact mechanism of climate change on its growth has not been studied yet. Studying the response of species to climate change is an important part of national afforestation planning. Based on combinations of climate, topography, soil variables, and the multiple model ensemble (MME) of CMIP6, this study explored the relationship between C. bungei and climate change, then constructed Maxent to predict its potential distribution under SSP126 and SSP585 and analyzed its dominant environmental factors. The results showed that C. bungei is widely distributed in Henan, Hebei, Hubei, Anhui, Jiangsu, and Shaanxi provinces and others where it covers an area of 2.96 × 106 km2. Under SSP126 and SSP585, its overall habitat area will increase by more than 14.2% in 2080–2100, which mainly indicates the transformation of unsuitable areas into low suitable areas. The center of its distribution will migrate to the north with a longer distance under SSP585 than that under SSP126, and it will transfer from the junction of Shaanxi and Hubei province to the north of Shaanxi province under SSP585 by 2100. In that case, C. bungei shows a large-area degradation trend in the south of the Yangtze River Basin but better suitability in the north of the Yellow River Basin, such as the Northeast Plain, the Tianshan Mountains, the Loess Plateau, and others. Temperature factors have the greatest impact on the distribution of C. bungei. It is mainly affected by the mean temperature of the coldest quarter, followed by precipitation of the wettest month, mean diurnal range, and precipitation of the coldest quarter. Our results hence demonstrate that the increase of the mean temperature of the coldest quarter becomes the main reason for its degradation, which simultaneously means a larger habitat boundary in Northeast China. The findings provide scientific evidence for the ecological restoration and sustainable development of C. bungei in China.


2013 ◽  
Vol 17 (2) ◽  
pp. 565-578 ◽  
Author(s):  
J. A. Velázquez ◽  
J. Schmid ◽  
S. Ricard ◽  
M. J. Muerth ◽  
B. Gauvin St-Denis ◽  
...  

Abstract. Over the recent years, several research efforts investigated the impact of climate change on water resources for different regions of the world. The projection of future river flows is affected by different sources of uncertainty in the hydro-climatic modelling chain. One of the aims of the QBic3 project (Québec-Bavarian International Collaboration on Climate Change) is to assess the contribution to uncertainty of hydrological models by using an ensemble of hydrological models presenting a diversity of structural complexity (i.e., lumped, semi distributed and distributed models). The study investigates two humid, mid-latitude catchments with natural flow conditions; one located in Southern Québec (Canada) and one in Southern Bavaria (Germany). Daily flow is simulated with four different hydrological models, forced by outputs from regional climate models driven by global climate models over a reference (1971–2000) and a future (2041–2070) period. The results show that, for our hydrological model ensemble, the choice of model strongly affects the climate change response of selected hydrological indicators, especially those related to low flows. Indicators related to high flows seem less sensitive on the choice of the hydrological model.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yanfei Li ◽  
Zhaohua Li ◽  
Zhihui Li ◽  
Xiaoli Geng ◽  
Xiangzheng Deng

The climatic effects of LUCC have been a focus of current researches on global climate change. The objective of this study is to investigate climatic effects of grassland degradation in Northwest China. Based on the stimulation of the conversion from grassland to other land use types during the next 30 years, the potential effects of grassland degradation on regional climate in the overgrazing area of Northwest China from 2010 to 2040 have been explored with Weather Research and Forecasting model (WRF). The analysis results show that grassland will mainly convert into barren land, croplands, and urban land, which accounts for 42%, 48%, and 10% of the total converted grassland area, respectively. The simulation results indicate that the WRF model is appropriate for the simulation of the impact of grassland degradation on climate change. The grassland degradation during the next 30 years will result in the decrease of latent heat flux, which will further lead to the increase of temperature in summer, with an increment of 0.4–1.2°C, and the decrease of temperature in winter, with a decrement of 0.2°C. In addition, grassland degradation will cause the decrease of precipitation in both summer and winter, with a decrement of 4–20 mm.


2020 ◽  
Vol 12 (20) ◽  
pp. 3280 ◽  
Author(s):  
Yanjun Che ◽  
Shijin Wang ◽  
Shuhua Yi ◽  
Yanqiang Wei ◽  
Yancong Cai

Glacier retreat is a common phenomenon in the Qinghai-Tibetan Plateau (QTP) with global warming during the past several decades, except for several mountains, such as the glaciers in the Karakoram and the western Kunlun Mountains. The dynamic nature of glaciers significantly influences the hydrologic, geologic, and ecological systems in the mountain regions. The sensitivity and dynamic response to climate change make glaciers excellent indicators of regional and global climate change, such as glacier melting and retreat with the rise of local air temperature. Long-term monitoring of glacier change is important to understand and assess past, current, and possible future climate environments. Some glacier surfaces are safe and accessible by foot, and are monitored using mass balance stakes and snow pits. Meanwhile, some glaciers with inaccessible termini may be surveyed using satellite remote images and Unmanned Aerial Vehicles (UAVs). Those inaccessible glaciers are generally covered by debris in the southeast QTP, which is hardly accessible due to the wide distribution of crevasses and cliffs. In this paper, we used the UAV to monitor the dynamic features of mass balance and velocity of the debris-covered region of Baishui River Glacier No. 1 (BRG1) on the Yulong Snow Mountain (YSM), Southeast QTP. We obtained the Orthomosaic and DEM with a high resolution of 0.10 m on 20 May and 22 September 2018, respectively. The comparison showed that the elevation of the debris-covered region of the BRG1 decreased by 6.58 m ± 3.70 m on average, and the mean mass balance was −5.92 m w.e. ± 3.33 m w.e. during the summer, correspondingly. The mean displacement of debris-covered glacier surface was 18.30 m ± 6.27 m, that is, the mean daily velocity was 0.14 m/d ± 0.05 m/d during the summer. In addition, the UAV images not only revealed the different patterns of glacier melting and displacement but also captured the phenomena of mass loss due to ice avalanches at the glacier front and the development of large crevasses. This study provides a feasible method for understanding the dynamic features of global debris-covered glaciers which are inaccessible and unobservable by other means.


2021 ◽  
Vol 164 (1-2) ◽  
Author(s):  
Bano Mehdi ◽  
Julie Dekens ◽  
Mathew Herrnegger

AbstractThe Ruhezamyenda catchment in Uganda includes a unique lake, Lake Bunyonyi, and is threatened by increasing social and environmental pressures. The COSERO hydrological model was used to assess the impact of climate change on future surface runoff and evapotranspiration in the Lake Bunyonyi catchment (381 km2). The model was forced with an ensemble of CMIP5 global climate model (GCM) simulations for the mid-term future (2041–2070) and for the far future (2071–2100), each with RCP4.5 and RCP8.5. In the Ruhezamyenda catchment, compared to 1971–2000, the median of all GCMs (for both RCPs) showed the mean monthly air temperature to increase by approximately 1.5 to 3.0 °C in the mid-term future and by roughly 2.0 to 4.5 °C in the far future. The mean annual precipitation is generally projected to increase, with future changes between − 25 and + 75% (RCP8.5). AET in the Lake Bunyonyi catchment was simulated to increase for the future by approximately + 8 mm/month in the median of all GCMs for RCP8.5 for the far future. The runoff for future periods showed much uncertainty, but with an overall increasing trend. A combination of no-regrets adaptation options in the five categories of: governance; communication and capacity development; water, soil, land management and livelihoods improvement; data management; and research, was identified and validated with stakeholders, who also identified additional adaptation actions based on the model results. This study contributes to improving scientific knowledge on the impacts of climate change on water resources in Uganda with the purpose to support adaptation.


2011 ◽  
Vol 5 (1) ◽  
pp. 95-129 ◽  
Author(s):  
F. Pithan

Abstract. The impact of climate change on Himalaya mountain glaciers is increasingly subject of public and scientific debate. However, observational data are sparse and important knowledge gaps remain in the understanding of what drives changes in these glaciers' mass balances. The present study investigates the glacier regime on Chhota Shigri, a benchmark glacier for the observation of climate change in the monsoon-arid transition zone of Western Himalaya. Results of an energy-balance model driven by reanalysis data and the observed mass balances from three years on 50 m altitude intervals across the glacier display a correlation coefficient of 0.974. Contrary to prior assumptions, monsoon precipitation accounts for a quarter to a third of total accumulation. It has an additional importance because it lowers the surface albedo during the ablation season. Results confirm radiation as the main energy source for melt on Himalaya glaciers. Latent heat flux acts as an important energy sink in the pre-monsoon season. Mass balance is most sensitive to changes in atmospheric humidity, changing by 900 mm w.e. per 10% change in humidity. Temperature sensitivity is 220 mm w.e.K−1. Model results using 21st century anomalies from a regional climate model based on the SRES A2 scenario suggest that a monsoon increase might offset the effect of warming.


2021 ◽  
Author(s):  
Csenge Dian ◽  
Rita Pongrácz ◽  
Judit Bartholy ◽  
Attila Talamon

<p>Similarly to many other regions, warming and extreme weather conditions (e.g. related to temperature and precipitation) are expected to increase due to the effects of climate change in the Carpathian Basin during the 21st century. Consequently, as a result of the clearly detectable warming, the number of frost days in winter decreases and the summer heat waves become more frequent. The transition between winter and summer tends to become shorter and the inter-annual variability is likely to increase. The precise definition of the transition periods between the two extremes of the annual temperature course is very important for several disciplines, e.g. building energy design, where outdoor temperature is a key input to determine the beginning and end of heating and cooling periods. The aim of this research is to examine the possible transformation of the four seasons characteristics of the Carpathian Basin in details using various specific climate indexes (e.g. monthly percentiles, daily temperature fluctuation time series) based on the data of regional climate model simulations taking into account different future scenarios. For this purpose, RCP4.5 and RCP8.5 scenarios are compared to historical runs, and simulated temperature data series are analyzed for the middle and end of the century.</p>


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