Department of Hydrology and Atmospheric Sciences, The University of Arizona, Tucson, Arizona
The glaciers residing in the mountain ranges of the eastern Hindukush, western Karakoram and northwester Himalaya centered in Northern Pakistan are not responding to the global warming as their counterparts elsewhere. Their retreating trend is less than the global average, and in some cases, they are either stable or growing. This anomalous behavior is termed as ‘The Karakoram Anomaly’. The role of climatic factors in the establishment of the Karakoram Anomaly is in question. Here we analyze climatic and novel synoptic observations for the last five decades reported from the meteorological observatory network of Pakistan. These data have not been available before. We find that over this period an increase in humidity, cloud cover, and precipitation and decrease in net-radiation, near-surface wind speed, potential evapotranspiration and river flow, especially in the summer season, are facilitating the anomalous behavior of the glaciers at regional scale. Our findings confirm the existence of the Karakoram Anomaly and show that it is a regional response to the changes in energy, mass and momentum due to the global warming. Moreover, gridded observed and reanalysis datasets that have been used to understand the hydroclimatology of the Karakoram glaciers do not reflect long-term observational trends.