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In this study, we reported valuable information on the cryosphere of the Central Karakoram National Park (CKNP, the largest protected area of Pakistan and the highest park all over the world). In fact, in addition to the glacier inventory, we also estimated the glacier volume and we modeled the amount of meltwater derived from glacier ice ablation during a 18-day summer period (23 July���9 August 2011, time window where also field melt measurements were performed thus enabling a crosscheck of the obtained results). Moreover, glacial lakes were considered as well; for these latter glacier features we also analyzed their potentially dangerous conditions. All these information are given considering the CKNP as a whole and in detail by dividing it into five basins (i.e. Shigar, Hunza, Shyok, Upper Indus and Gilgit). As regards the CKNP as a whole, 608 glaciers are found with a total area of 3682.1 �� 61.0 km2, ~35% of the CKNP area. Analyzing in detail the five basins included in the CKNP area, they reflect the overall conditions regarding glacier distribution per size class, terminus elevation, length, and thickness. The widest basin (for number of ice bodies, glacier extent and ice volume) is the Shigar basin, where the largest glaciers are present (among which Baltoro Glacier), and the smallest one is the Gilgit basin. Finally, the highest number of debris-covered glaciers is located in the Shyok basin (62 glaciers). During 18 days in summer 2011, we quantified a total water magnitude of 1.54 km3 derived from ice melting. Even if we considered a relatively short period, this water volume equals ~11% of the reservoir capacity of the Tarbela Dam. In addition to glacier information, we provided glacial lake occurrence, as these ephemeral water bodies can develop into actual glacial risk conditions, which makes it important to list them and to survey them over time. The information reported in this study would provide base for future monitoring of glacial lakes and GLOFs and for planning and prioritizing disaster mitigation efforts in the park. In fact, even if the Potentially Dangerous Glacial Lakes (PDGLs) identified in the park territory are only 2, they are located in a high vulnerable and fragile area and the recent history suggests us to survey over time these water bodies to avoid losses of human lives and destructions of villages and communities. Moreover, many other supraglacial lakes identified in the park area could develop into conditions of PDGLs thus suggesting to prosecute the lake monitoring and to develop early strategies for risk mitigations and disaster management., JUNCO | Journal of UNiversities and international development COoperation, N. 1-2 (2018): Migrazioni, Pace e Sviluppo. Nuove sfide e nuovi attori nella cooperazione internazionale per lo sviluppo in Italia - Atti del V Congresso CUCS, Milano 14-15 settembre 2017

In this study we analyze the temperature and precipitation data collected by sixteen in-situ stations located in the high-elevated regions of northern Pakistan to provide a climatic characterization of the Karakoram mountains. We focus our attention on the analysis of the precipitation annual cycle at the various stations and on the investigation of the vertical variability of both precipitation and temperature, averaged over the Upper Indus Basin (UIB) area. The precipitation annual cycle at the individual stations generally shows higher precipitation amounts in winter (December to April) than in summer (June to September), confirming that northern Pakistan is not under the prevailing influence of the Indian monsoon. The spatially-averaged temperature and precipitation vertical gradients show that the temperature lapse rate is consistent with the moist adiabatic lapse rate of the atmosphere. The vertical precipitation gradient indicates an increase with elevation until about 3,000 m and then a decrease that can be attributed to the strong underestimate of solid precipitation by rain gauges at high-altitudes.

Surface energy fluxes estimated at the debris free surface of Changri Nup Glacier (5,700 m a.s.l.—Nepal Himalayas) since 2010 allow to determine glacier ablation rate and high resolution analysis of glacier albedo. Energy and meteorological data are measured from a supraglacial Automatic Weather Station (AWS). Moreover the impact of atmospheric absorbing aerosol (e.g. Black Carbon, BC) deposition on snow albedo variability has been analyzed. In fact the energy data (from the AWS) were coupled with BC concentration (in snow) values, estimated from the BC atmospheric concentration continuously measured at the Nepal Climate Observatory at Pyramid Station (5,079 m a.s.l.), thus making possible to investigate the relationship between BC deposition in snow and the percentage of albedo reduction at the glacier. Experimental results could improve glacier melt modelling also considering BC impacts on snow albedo variability and then on snow melt rates.

Glacier melt occurs whenever the surface temperature is null (273.15 K) and the net energy budget is positive. These conditions can be assessed by analysing meteorological and energy data acquired by a supraglacial Automatic Weather Station (AWS). In the case this latter is not present at the glacier surface the assessment of actual melting conditions and the evaluation of the melt amount is difficult and simple methods based on Temperature index (T-index) or degree days models are generally applied. These models require the choice of a correct temperature threshold. In fact, melt does not necessarily occur at air temperatures higher than 273.15 K, since it is determined by the surface energy budget which in turn is only indirectly affected by air temperature. This is particularly the case of the late spring period when ablation processes start at the glacier surface thus progressively reducing snow accumulation. In this paper, to detect the most indicative air temperature threshold witnessing snow or ice melting in the April–June period, we analysed air temperature data recorded from 2006 to 2012 by a supraglacial AWS set up on the ablation tongue of Forni Glacier (Italian Alps). Moreover we also evaluated the glacier energy budget and the Snow Water Equivalent (SWE) value during this time-frame. We also analysed air temperature data from a station located outside the studied glacier. Then the ablation amount is estimated both from the surface energy balance (from supraglacial AWS data) and from T-index method (from daily air temperature measured outside the glacier) and the results were compared.

In this PhD Thesis are reported the main results from an interdisciplinary research focused on evaluating impacts and effects of black carbon (BC) on glacier snow and ice melting. With this purpose we selected two glaciers: the Changri Nup glacier (Nepal, Himalaya) and the Forni glacier (Italian Alps). The glaciers have been chosen due to their representativity (geographical setting, size, morphology) and the availability of meteorological and energy data collected at the glacier surface through Automatic Weather Stations (AWSs). In fact on both the glaciers AWSs have been installed in the recent years and they have been running without meaningful interruptions thus permitting to analyze glacier micrometeorology and to evaluate glacier surface energy balance and its variability (data are sampled with a hourly frequency all over the year). Moreover we planned and performed field campaigns to collect snow samples for describing chemical and physical features of soot and dust present in the glacier snow. More precisely, since the Autumn 2005 and AWS has been running at the melting surface of the Forni Glacier (Italian Alps). The AWS is property of UNIMI and it attends the international network SHARE (Stations at High Altitude for Research on the Environment) promoted and managed by EVK2CNR Committee. Within the Ev-K2-CNR Project SHARE on February 2010 an AWS has been installed on the debris-free surface of the Changri Nup Glacier (Nepal, Himalayas, Sagarmatha Nationa Park) at 5,700 m asl to acquire meteorological data and energy fluxes (incoming and outgoing) at the glacier surface. The AWS is property of EvK2CNR Committee. The acquired data permit the calculation of glacier energy balance and high resolution analysis of glacier albedo. In the present study more than 85.000 meteorological parameters, related to the time window 2010-2012 and collected by The Changri Nup AWS, have been analyzed, processed and validated. Average daily parameters estimated at glacier surface have been: temperature: -4.61 �C, relative humidity: 78.47%, atmospheric pressure: 505.6 hPa, SWin: 220 W m-2, SWout:136 W m-2, LWin: 240 W m-2, LWout: 280 W m-2, wind speed: 1.48 m s-1, prevalent wind direction: 183�. Yearly albedo, deriving from SWout/SWin was 0.7, with an average of 0.75 for snow and 0.26 for glacier ice. Instead data from Forni AWS were already available thanks to another PhD research presently on line at the University of Milan. Ablation season at the Changri Nup glacier occurred in summer period, in the monsoon season, when the temperature conditions (T>0�C) and radiation and rain precipitation increase the melting process. Results have been compared with the Alpine site of Forni glacier, the largest Italian valley glacier, located in the Stelvio National Park and characterized by a ?strategic? location on the Central-Eastern Alpine sector, able to be reached by southern fluxes and close to the northern Alpine Italian boundary. This part of the research was performed within the SHARE STELVIO project aiming at detecting and quantifying climate change evidences and effects on a sensible area located in the Stelvio National Park ? Lombardy sector (600 km2 of area). This project will permit to evaluate composition, quality and variability of high elevation atmosphere and effects on the alpine water resource (i.e. snow, glaciers and meltwater rivers). In both sites the main component deterring melting are positive temperature and shortwave radiation, this latter higher in the Himalaya due to the difference of latitude, altitude and incident direction. Melting season in the Alps is longer than in the Himalaya and in both sites the effect of latent and sensible heat fluxes have a minor effect in driving melting processes. Both sites are characterized by a typical katabatic wind regime. At the Changri Nup glacier surface some ablation stakes have been positioned in the debris free part of the glacier and two of these stakes were located nearby the AWS. Glacier ablation was evaluated through field campaigns twice: February-May 2010 and May-November 2012. The field data allowed to compare measured glacier ablation with melting amount derived from energy balance measurements and to evaluate the reliability of our computations. It was found by previous authors that absorbing aerosols and dust play a key role in varying snow and ice albedo and in driving glacier ablation on several high elevation glaciers. In this study, by coupling energy data (from the AWS) with the atmospheric measurement of BC concentration allow the investigation of the relations among atmosphere and cryosphere and to quantify impacts of atmospheric black carbon deposition on glacial ablation rates. In Himalaya atmospheric observations are carried out at the Nepal Climate Observatory-Pyramid (NCO-P) located at 5,079 m asl near the Pyramid Laboratory Observatory, while at Forni glacier a summer campaign has been held in 2012 at Guasti Hut (c. 3200 m asl). Results at Changri Nup glacier were consistent with the typical estimation available in literature of BC deposition and % of albedo reduction in premonsoon season, where the atmospheric concentration are high. Experimental results reports that at Changri Nup the % of albedo reduction has been 4.26% for an estimated BC deposition in snow of 49 �g kg-1 consistent with the concentration range of BCC in snow of 26.0?68.2 ?g kg?1 due to snow density variations between 195?512 kg m?3 as reported in literature. The same estimation has been done at Forni Glacier too, but results were different because the summer BC monitoring campaign detected BC concentrations in the atmosphere typical of free troposphere background conditions, thus in the analyzed period, their deposition didn?t have a predominant effect in driving melting process. To compare the estimated BC deposition in snow deriving from atmospheric measurements, snow samples has been done at the Changri Nup glaciers and the chemical analysis allow to determine a typical premonsoon concentration consistent with literature data and with the experimental estimation done at Changri Nup glaciers. Future step will foresee a further analysis of these results, thanks also to the availability of long term dataset, moreover, in order to improve the knowledge of the effect of dust and aerosol deposition on glacier, more samples will be collected and analyzed.

This paper presents a detailed review of atmospheric pollution observed in the Hindu Kush-Himalaya (HKH) region and its implications for regional climate. Data from in situ measurements made at high-altitude stations in the HKH region, observations from satellite-based instruments, and global climate modeling study results are discussed. Experimental observations discussed include both atmospheric measurements and data from snow and ice core sampling from different glaciers in the HKH region. The paper focuses on the atmospheric brown cloud loadings over the Himalayas, particularly black carbon (BC) and ozone, which have links to regional climate and air-pollution-related impacts. Studies show elevated levels of anthropogenic ozone and BC over the Himalayas during the pre-monsoon season with concentrations sometimes similar to those observed over an average urban environment. The elevated concentration observed over the Himalayas is thought to come from the lowlands, especially the highly populated areas of the Indo-Gangetic Plains. The implications of high BC loading in the Himalayan atmosphere as well as elevated BC deposition on snow and ice surfaces for regional climate, hydrological cycle, and glacial melt are discussed.

Technical description of the NCO-P station in Himalayas

Atmospheric Chemistry and Physics, 10 (14), ISSN:1680-7375, ISSN:1680-7367

This paper provides a detailed description of the atmospheric conditions characterizing the high Himalayas, thanks to continuous observations begun in March 2006 at the Nepal Climate Observatory-Pyramid (NCO-P) located at 5079 m a.s.l. on the southern foothills of Mt. Everest, in the framework of ABC-UNEP and SHARE-Ev-K2-CNR projects. The work presents a characterization of meteorological conditions and air-mass circulation at NCO-P during the first two years of activity. The mean values of atmospheric pressure, temperature and wind speed recorded at the site were: 551 hPa, −3.0 °C, 4.7 m s−1, respectively. The highest seasonal values of temperature (1.7 °C) and relative humidity (94%) were registered during the monsoon season, which was also characterized by thick clouds, present in about 80% of the afternoon hours, and by a frequency of cloud-free sky of less than 10%. The lowest temperature and relative humidity seasonal values were registered during winter, −6.3 °C and 22%, respectively, the season being characterised by mainly cloud-free sky conditions and rare thick clouds. The summer monsoon influenced rain precipitation (seasonal mean: 237 mm), while wind was dominated by flows from the bottom of the valley (S–SW) and upper mountain (N–NE). The atmospheric composition at NCO-P has been studied thanks to measurements of black carbon (BC), aerosol scattering coefficient, PM1, coarse particles and ozone. The annual behaviour of the measured parameters shows the highest seasonal values during the pre-monsoon (BC: 316.9 ng m−3, PM1: 3.9 μg m−3, scattering coefficient: 11.9 Mm−1, coarse particles: 0.37 cm−3 and O3: 60.9 ppbv), while the lowest concentrations occurred during the monsoon (BC: 49.6 ng m−3, PM1: 0.6 μg m−3, scattering coefficient: 2.2 Mm−1, and O3: 38.9 ppbv) and, for coarse particles, during the post-monsoon (0.07 cm−3. At NCO-P, the synoptic-scale circulation regimes present three principal contributions: Westerly, South-Westerly and Regional, as shown by the analysis of in-situ meteorological parameters and 5-day LAGRANTO back-trajectories. The influence of the brown cloud (AOD>0.4) extending over Indo–Gangetic Plains up to the Himalayan foothills has been evaluated by analysing the in-situ concentrations of the ABC constituents. This analysis revealed that brown cloud hot spots mainly influence the South Himalayas during the pre-monsoon, in the presence of very high levels of atmospheric compounds (BC: 1974.1 ng m−3, PM1: 23.5 μg m−3, scattering coefficient: 57.7 Mm−1, coarse particles: 0.64 cm−3, O3: 69.2 ppbv, respectively). During this season 20% of the days were characterised by a strong brown cloud influence during the afternoon, leading to a 5-fold increased in the BC and PM1 values, in comparison with seasonal means. Our investigations provide clear evidence that, especially during the pre-monsoon, the southern side of the high Himalayan valleys represent a "direct channel" able to transport brown cloud pollutants up to 5000 m a.s.l., where the pristine atmospheric composition can be strongly influenced., Atmospheric Chemistry and Physics, 10 (15), ISSN:1680-7375, ISSN:1680-7367