Global Disappearance of Tropical Mountain Glaciers: Observations, Causes, and Challenges

For a pilot study of change detection of small tropical mountain glaciers from SPOT satellite, Mount Kenya was chosen because a map at scale 1 : 5000 in a local coordinate system, based on aerial photography in September 1987, provided a control for mapping of horizontal ice extent, and because the precipitous relief offered a particular challenge for technique development. A terrain model in compatible map projection was constructed from the topography of the 1987 map. A SPOT subscene of February 1988 was geocoded and terrain corrected to conform with the terrain model and identifiable terrain features. Another 26 control points established on the ground were entered in the digital array. The pixels were re-sampled to a nominal resolution of 10 m. This digital map was output at scale 1 : 5000. The glacier boundaries and the location of the terrain control points agreed with the September 1987 map within the mapping accuracy commensurate with the 1 : 5000 scale. This satellite-based mapping provides an internally consistent reference for determining the changes of Mount Kenya’s glaciers from February 1988 to a SPOT sampling intended for the mid-1990s. This pilot study further indicates the feasibility of glacier change detection on various other high mountains of the tropics.

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Accelerating shrinkage of Patagonian glaciers from the Little Ice Age (~AD 1870) to 2011

Journal of Glaciology ◽

10.3189/2012jog12j026 ◽

2012 ◽

Vol 58 (212) ◽

pp. 1063-1084 ◽

Cited By ~ 92

Author(s):

B.J. Davies ◽

N.F. Glasser

Keyword(s):

Little Ice Age ◽

Ice Age ◽

South American ◽

Ice Caps ◽

Mountain Glaciers ◽

Northern Patagonia ◽

Area Loss ◽

Southern Patagonia

AbstractWe used Little Ice Age (LIA) trimlines and moraines to assess changes in South American glaciers over the last ~140 years. We determined the extent and length of 640 glaciers during the LIA (~AD1870) and 626 glaciers (the remainder having entirely disappeared) in 1986, 2001 and 2011. The calculated reduction in glacierized area between the LIA and 2011 is 4131 km2 (15.4%), with 660 km2 (14.2%) being lost from the Northern Patagonia Icefield (NPI), 1643km2 (11.4%) from the Southern Patagonia Icefield (SPI) and 306 km2 (14.4%) from Cordillera Darwin. Latitude, size and terminal environment (calving or land-terminating) exert the greatest control on rates of shrinkage. Small, northerly, land-terminating glaciers shrank fastest. Annual rates of area loss increased dramatically after 2001 for mountain glaciers north of 52° S and the large icefields, with the NPI and SPI now shrinking at 9.4km2a-1 (0.23% a-1) and 20.5 km2a-1 (0.15% a-1) respectively. The shrinkage of glaciers between 52° S and 54° S accelerated after 1986, and rates of shrinkage from 1986 to 2011 remained steady. Icefield outlet glaciers, isolated glaciers and ice caps south of 54° S shrank faster from 1986 to 2001 than they did from 2001 to 2011.

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Toward the satellite monitoring of glacier changes on Mount Kenya

Annals of Glaciology ◽

10.3189/s026030550001291x ◽

1993 ◽

Vol 17 ◽

pp. 245-249

Author(s):

Stefan Hastenrath

Keyword(s):

Pilot Study ◽

Change Detection ◽

Local Coordinate System ◽

Satellite Monitoring ◽

Control Points ◽

Mountain Glaciers ◽

Terrain Model ◽

Tropical Mountain ◽

Glacier Changes ◽

The Tropics

For a pilot study of change detection of small tropical mountain glaciers from SPOT satellite, Mount Kenya was chosen because a map at scale 1 : 5000 in a local coordinate system, based on aerial photography in September 1987, provided a control for mapping of horizontal ice extent, and because the precipitous relief offered a particular challenge for technique development. A terrain model in compatible map projection was constructed from the topography of the 1987 map. A SPOT subscene of February 1988 was geocoded and terrain corrected to conform with the terrain model and identifiable terrain features. Another 26 control points established on the ground were entered in the digital array. The pixels were re-sampled to a nominal resolution of 10 m. This digital map was output at scale 1 : 5000. The glacier boundaries and the location of the terrain control points agreed with the September 1987 map within the mapping accuracy commensurate with the 1 : 5000 scale. This satellite-based mapping provides an internally consistent reference for determining the changes of Mount Kenya’s glaciers from February 1988 to a SPOT sampling intended for the mid-1990s. This pilot study further indicates the feasibility of glacier change detection on various other high mountains of the tropics.

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Keeping Dairy Cows for Longer: A Critical Literature Review on Dairy Cow Longevity in High Milk-Producing Countries

Animals ◽

10.3390/ani11030808 ◽

2021 ◽

Vol 11 (3) ◽

pp. 808

Author(s):

Gabriel M. Dallago ◽

Kevin M. Wade ◽

Roger I. Cue ◽

J T. McClure ◽

René Lacroix ◽

...

Keyword(s):

Literature Review ◽

Dairy Cow ◽

Animal Health ◽

Current Status ◽

Dairy Farmers ◽

Age At First Calving ◽

Productive Life ◽

Use Of Resources ◽

Animal Remains ◽

Critical Literature

The ability of dairy farmers to keep their cows for longer could positively enhance the economic performance of the farms, reduce the environmental footprint of the milk industry, and overall help in justifying a sustainable use of animals for food production. However, there is little published on the current status of cow longevity and we hypothesized that a reason may be a lack of standardization and an over narrow focus of the longevity measure itself. The objectives of this critical literature review were: (1) to review metrics used to measure dairy cow longevity; (2) to describe the status of longevity in high milk-producing countries. Current metrics are limited to either the length of time the animal remains in the herd or if it is alive at a given time. To overcome such a limitation, dairy cow longevity should be defined as an animal having an early age at first calving and a long productive life spent in profitable milk production. Combining age at first calving, length of productive life, and margin over all costs would provide a more comprehensive evaluation of longevity by covering both early life conditions and the length of time the animal remains in the herd once it starts to contribute to the farm revenues, as well as the overall animal health and quality of life. This review confirms that dairy cow longevity has decreased in most high milk-producing countries over time and its relationship with milk yield is not straight forward. Increasing cow longevity by reducing involuntary culling would cut health costs, increase cow lifetime profitability, improve animal welfare, and could contribute towards a more sustainable dairy industry while optimizing dairy farmers’ efficiency in the overall use of resources available.

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Current status of conventional insecticides in the management of stored product insect pests in the tropics

International Journal of Tropical Insect Science ◽

10.1017/s1742758400022797 ◽

1987 ◽

Vol 8 (4-5-6) ◽

pp. 695-701 ◽

Cited By ~ 1

Author(s):

R. I. Egwuatu

Keyword(s):

Insect Pests ◽

Current Status ◽

The Tropics

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Human Impacts on Fish Fauna in the Danube River in Serbia: Current Status and Ecological Implications

Geobotany Studies - Human Impact on Danube Watershed Biodiversity in the XXI Century ◽

10.1007/978-3-030-37242-2_13 ◽

2020 ◽

pp. 257-279

Author(s):

Mirjana Lenhardt ◽

Marija Smederevac-Lalić ◽

Aleksandar Hegediš ◽

Stefan Skorić ◽

Gorčin Cvijanović ◽

...

Keyword(s):

Human Impacts ◽

Fish Fauna ◽

Danube River ◽

Current Status ◽

The Danube River ◽

Ecological Implications

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Deforestation Impacts on Amazon-Andes Hydroclimatic Connectivity

10.21203/rs.3.rs-600041/v1 ◽

2021 ◽

Author(s):

Juan P. Sierra ◽

C. Junquas ◽

J. C. Espinoza ◽

H. Segura ◽

T. Condom ◽

...

Keyword(s):

Transition Region ◽

Amazon Basin ◽

Atmospheric Stability ◽

Austral Summer ◽

Hadley Cell ◽

South American ◽

Tropical Andes ◽

Tropical Glaciers ◽

Precipitation Recycling ◽

The Rich

Abstract Amazonian deforestation has accelerated during the last decade, threatening an ecosystem where almost one third of the regional rainfall is transpired by the local rainforest. Due to the precipitation recycling, the southwestern Amazon, including the Amazon-Andes transition region, is particularly sensitive to forest loss. This study evaluates the impacts of Amazonian deforestation in the hydro-climatic connectivity between the Amazon and the eastern tropical Andes during the austral summer (December-January-February) in terms of hydrological and energetic balances. Using 10-year high-resolution simulations (2001–2011) with the Weather Research and Forecasting Model, we analyze control and deforestation scenario simulations. Regionally, deforestation leads to a reduction in the surface net radiation, evaporation, moisture convergence and precipitation (~ 20%) over the entire Amazon basin. In addition, during this season, deforestation increases the atmospheric subsidence over the southern Amazon and weakens the regional Hadley cell. Atmospheric stability increases over the western Amazon and the tropical Andes inhibiting convection in these areas. Consequently, major deforestation impacts are observed over the hydro-climate of the Amazon-Andes transition region. At local scale, nighttime precipitation decreases in Bolivian valleys (~ 20–30%) due to a strong reduction in the humidity transport from the Amazon plains toward Andes linked to the South American low-level jet. Over these valleys, a weakening of the daytime upslope winds is caused by local deforestation, which reduces the turbulent fluxes at lowlands. These alterations in rainfall and atmospheric circulation could impact the rich Andean ecosystems and its tropical glaciers.

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