During the recent Italian expedition ‘K2 2004 – 50 years later’ (June–July 2004) on Baltoro glacier, Karakoram, Pakistan, glaciological field experiments were carried out on the debris-covered area of this high-elevation glacier. The aim was to investigate the ice ablation and its relations with debris thermal properties and meteorological conditions. Ablation measurements along the glacier up to about 5000m and within a dedicated test field were combined with meteorological data from two automatic weather stations located at Urdukas (4022ma.s.l.) and at K2 Base Camp (5033ma.s.l.). In addition, temperature measurements of the debris cover at different depth levels along the glacier allowed the calculation of debris surface temperature and of the debris thermal resistance (R). Using the air temperature, the local mean lapse rate (0.00758 K/m) and the measured ablation, the degree-day factors (K) at different locations on the glacier were calculated. The ice ablation rates were related to debris thickness and elevation. They are typically on the order of 4cm/ day during the observation period. However, it was found that the surface topography (slope, aspect) has an influence on the total ablation similar to that of the debris thickness. Thermal resistance of the debris cover and its distribution over the glacier were estimated. Finally, a best-guess estimate of the total meltwater production was calculated from available climate data.

A distributed surface energy-balance study was performed to determine sub debris ablation across a large part of Baltoro glacier, a wide debris-covered glacier in the Karakoram range, Pakistan. The study area is ca 124km2. The study aimed primarily at analyzing the influence of debris thickness on the melt distribution. The spatial distribution of the physical and thermal characteristics of the debris was calculated from remote-sensing (ASTER image) and field data. Meteorological data from an automatic weather station at Urdukas (4022ma.s.l.), located adjacent to Baltoro glacier on a lateral moraine, were used to calculate the spatial distribution of energy available for melting during the period 1–15 July 2004. The model performance was evaluated by comparisons with field measurements for the same period. The model is reliable in predicting ablation over wide debris covered areas. It underestimates melt rates over highly crevassed areas and water ponds with a high variability of the debris thickness distribution in the vicinity, and over areas with very low debris thickness (<0.03 m). We also examined the spatial distribution of the energy-balance components (global radiation and surface temperature) over the study area. The results allow us to quantify, for the study period, a meltwater production of 0.058km3.

Monte Curcio (MCU) instruments: Thermo Scientific Multiangle Absorption Photometer (MAAP). The MAAP 5012 measures black carbon content of aerosols determined by simultaneous measurement of optical absorption and scattering of light by the particles collected on the glass fiber tape. The minimum detection limit are: 2 min. average less than 100ng/m3; 10 min. average less than 50ng/m3; 30 min. average less than 100ng/m3.

Monte Curcio (MCU) instruments: Fai SWAM Dual Particulate Matter Sampler. The SWAM is a dual channel sampler for particulate matter, and a mass measurement technique. The system combines field-proven beta attenuation analysis with dual-channel sequential sampling yielding simultaneously PM10, PM2.5 and total mass concentration.

Monte Curcio (MCU) instruments: API Teledyne 700 mass flow calibrator. The Model M700 can generate diluted calibration gas including ozone, gas phase titration (NO2) from gas cylinders, or from a permeation tube source gas. Each concentration is generated precisely by mixing the gas with diluent zero air in which the mixing ratio is controlled by the mass flow controller. The diluent air mass flow controller has a range of 10 SLPM (20 SLPM option), and the gas mass flow controller has a range of 100 cc/min. (0-50 cc/min., 0-200cc/min. options). The mass flow controllers assure a precise mixing ratio for accurate and precise calibration gas generation using the state-of- the-art electronic closed-loop control.

Monte Curcio (MCU) instruments: TSI Scanning Mobility Particle Sizer (SMPS). The Model SMPS is designed for long-term measurement of aerosol particles and over there in highly burden regions. It is a mobility particle size spectrometer, which can measure continuously the particle number size distribution in a size range from 10 to 800 Nanometres. The temporal resolution to measure a complete particle number size distribution is approximately 5 minutes. Equipment is based on TSI CPC 3775.

Monte Curcio (MCU) instruments: API Teledyne 200AU nitrogen oxide analyser. The Model 200AU uses chemiluminescence detection, coupled with microprocessor technology to provide ambient nitric oxide (NO), nitrogen dioxide (NO2) and the total nitrogen oxides (NOx). It calculates the amount of NO by measuring the amount of chemiluminescence given off when the sample gas is exposed to ozone (O3). A catalytic-reactive converter converts any NO2 in the sample gas to NO, which is then measured as above (including the original NO in the sample gas) and reported as NOx. NO2 is calculated as the difference between NOX and NO.