"Mountain lakes of high altitude (Himalaya)" in Long Term Ecological Research Network-Italy Location: Lat 27 ° 57'45 "N Long 86 ° 48'56" E; Lake Area (m2): 16.7 103: Average Depth (m): unknown; Maximum depth (m): 8.2; Altitude of the lake (m asl): 5067; Region: Himalayas, Khumbu Valley, Mount Everest.,

In the Khumbu Valley, located in the central part of the Himalayan range and including the area of Sagarmatha National Park, a network of 7 Automatic Weather Stations (AWSs) has been installed since 1994. These weather stations are located at different altitudes: Lukla (2,660 m a.s.l), Namche (3,570 m a.s.l), Periche (4,260 m a.s.l), Lobuche (5,050 m a.s.l) near the Pyramid - Laboratory Observatory, Kala Patthar (5,600 m a.s.l), Changri Nup Glacier (5,700 m a.s.l) and Mt. Everest - South Col (8.000 m a.s.l). The network mainly takes measurements of 7 standards parameters: air temperature, relative humidity, atmospheric pressure, wind speed and direction, global radiation and total precipitation. Meteo-climatic observations in this area are very important to better understand the environmental changes that are affecting the ecosystem, helping the scientific community to improve the prediction of this environmental phenomena’s evolution and modification. The Kala Patthar AWS was installed on May 2008, at 5600 m asl. Geographical coordinated: - Latitude: 27° 59' 24" N - Longitude: 86° 49' 48" E

At the AWS Kala Patthar station the DQA030 rain gauge is manufactured by LSI-Lastem equipped with a siphon placed on the cone's nozzle; it has two functions: during light rain the drizzle falls on the bascule without moving it and therefore evaporates without being measured; during heavy rain, it regulates the flow into the bascule permitting all the water to fall inside. LSI-LASTEM rain gauges have stainless steel housing whereas the cone has been designed to avoid the drops splash phenomena and to allow water droplets to dribble down inside even in case of very light rain. The rain gauge can be placed either directly on the ground by means of the DYA042 base plate or mounted on the top or the side of 50 mm diameter. For sites with sub-zero temperatures, the thermostatic heated models ensure the complete melting of snow, even at extreme temperature, whereas minimizing losse of evaporation; these models are insulated to reduce heat dispersion. Technical characteristic: Collettor surface area: 324 cmq Collector area diameter: 203 mm Measurement range: Max 10 mm/min Resolution: 0.2 mm/imp. (opt. 0.1, 0.5 mm/imp) Accuracy: 0-1 mm/min: +- 1 basculata/tip 1-10 mm/min:1% Contact: 1 reed (opt. N.2 REED) 0.5 a/24v non inductive Pulse duration: 100 msec+-50 Collector cone material: Aluminium External housing material: Aluminium Tipping bucket material: Aluminium

In 2013 the Wind Set WA15 by Vaisala has been installed in Lukla. Overview • High-performance wind measurement set • Long and successful track record in meteorological applications • Low measurement starting threshold • Conical anemometer cups provide excellent linearity • Heated shaft prevents bearings from freezing Technical Specifications Wind speed Sensor / transducer type: cup anemometer / opto-chopper Measurement range: 0.4...75 m/s Starting threshold: <0.5 m/s * Distance constant: 2.0 m Accuracy (range 0.4...60 m/s) with characteristic transfer function: ±0.17 m/s ** with transfer function U=0.1xR: ±0.5 m/s Wind direction Sensor / transducer type: vane / optical code disc Measurement range: 0...360° Starting threshold: <0.4 m/s Delay distance: 0.4 m Resolution: ±2.8° Accuracy: better than ±3°

At the Kala Patthar station the the CM6B pyranometer, manufactured by Kipp & Zonen is installed. This sensor is a first class pyranometer as defined by the World Meteorological Organization. It is suitable for the measurement of solar irradiance on a plane surface (W/m2). It incorporates a 64-thermocouple sensor, which is rotationally symmetrical, housed under K5 domes. A white screen prevents the body of the pyranometer from heating up. The pyranometer is supplied with a spirit level and screws for accurate levelling. CM6B technical characteristics: - Spectral range 305 to 2800 nm (50%points) - Sensitivity 9 to 15 ?V/Wm-2 - Impedance 70 to 100 Ohm - Response time 1/e 5 s, 99 % 55 s - Non-linearity <1.5 % (<1000 W/m 2 ) - Tilt error <1.5 % at 1000 W/m 2 - Operating temperature -40 to +90 °C - Temperature dependence of sensitivity _2 % (-10 to +40 °C) - Maximum irradiance 2000 W/m2 - Directional error < _20 W/m2 at 1000 W/m2 - Weight 0.85 kg - Cable length 10 m

In Lukla the CX115P Lsi-Lastem barometer is connected with a measurement system (recorder, data logger) that accepts analog signals. The barometer works according to the piezometric principle: a resistive film is deposited on a slice of silica with a bridge form; as the pressure changes, the slice will deform and consequently changes the system's resistance. The CX115P model mounts a special thermal compensation system that significantly reduces drift. General characteristics: Range: 800 ž 1100 hPa (1 hPa=1 mBar) Sea level correction range: -300...+2000 mt. Thermal drift: 0,01 hPa/°C (-10..+60°C) Linearity&Hysteresis: < 0,3% of the range Overload: max. 2 Pa Load resi stance: Current output types: <500W. Power consumption: 3 W Response time (T90): 1 ms Environmental limits: -25 .. +60°C Output connections: terminals Weight: 650 gr. Housing case material: Plastic Protection: IP40 Downward cable outlet

At the AWS Namche station the DQA035 Lsi-Lastem rain gauge is mounted on a 1,5 m mast. This model of Rain gauge has a 1.000 cmq collector area. The measurement device is composed of a collector cone and a double chamber bascule connected to a magnete that operates one (optional two) reed switch, which generates impulses that can be counted by external meters: each impulse is equal to 0.2 mm of rain (optional from 0.1 to 0.5 mm). The mechanical and electrical specifications are: - Collector surface area: 1000 cmq - Collector area diameter: 420 mm - Measurements range: 180 mm/hr - Resolution: o,2 mm/imp. (opt. 0,1; 0,3; 0,4; 0,5; mm/imp.) - Accuracy: 0-1 mm/min: 1% 1-3 mm/min: 2% 3-5 mm/min: 4% 5-10 mm/min: 8% - Contact: 1 reed (opt. N.2 reed) 0,5 A/24V non inductive - Pulse duration: 100 msec.± 5 - Collector cone material: Brass - External housing material: Inox AISI30 - Tipping bucket material: Alluminium - Cable: 10 m - Weight: 6,3 kg - Power supply: /thermocover 100 W, 24 Vca/Va

At the Lukla station the the CM6B pyranometer, manufactured by Kipp & Zonen is installed. This sensor is a first class pyranometer as defined by the World Meteorological Organization. It is suitable for the measurement of solar irradiance on a plane surface (W/m2). It incorporates a 64-thermocouple sensor, which is rotationally symmetrical, housed under K5 domes. A white screen prevents the body of the pyranometer from heating up. The pyranometer is supplied with a spirit level and screws for accurate levelling. CM6B technical data - Spectral range 305 to 2800 nm (50%points) - Sensitivity 9 to 15 ?V/Wm-2 - Impedance 70 to 100 Ohm - Response time 1/e 5 s, 99 % 55 s - Non-linearity <1.5 % (<1000 W/m 2 ) - Tilt error <1.5 % at 1000 W/m 2 - Operating temperature -40 to +90 °C - Temperature dependence of sensitivity _2 % (-10 to +40 °C) - Maximum irradiance 2000 W/m2 - Directional error < _20 W/m2 at 1000 W/m2 - Weight 0.85 kg - Cable length 10 m