The Nepal Climate Observatory - Pyramid (NCO-P, 27.95 N, 86.82 E; 5079 m a.s.l.) is located in the southern Himalayan region at the confluence of the secondary valley of Lobuche (oriented NNW-SSE) and the main Khumbu Valley. The station was placed not far from the Pyramid International Laboratory/Observatory and in proximity of the Mt. Everest base camp. All the instrumentation is housed in a wood and aluminium shelter consisting of two rooms, one for the instruments and a smaller one where batteries for the power supply are stored. The power needed to carry out the experimental activity (~ 3 kW) is provided by 96 photovoltaic panels with 120 electric storage cells. Through the aluminium roof, four sampling lines allow the sampling of gases and aerosol particles.
In July 2010 the NCO-P was upgraded to GAW Global Station.
In the framework of the UNEP ABC and Ev-K2.CNR SHARE projects since March 2006 high quality continuous measurements of trace gases, aerosol and meteorological parameters have been conducted. The station has been installed with the aim to promote continuous scientific observations in key high-mountain regions able to contribute to knowledge on regional and global climate change.
Specific aims of the measurements conducted at this station are:
- to obtain a chemical climatology of aerosol properties (optical, chemical and physical) at an high elevation site in Himalayas;
- to evaluate temporal trends of aerosol composition as a function of sources/transport;
- to evaluate the variations of radiative forcing produced by aerosols;
- to study the background ozone behavior and evaluate the contributions of stratospheric ozone intrusions as well as long range and regional transport of polluted air masses;
- to monitor the concentration trends of major Halocarbons and greenhouse gases.
The Nepal Climate Observatory - Pyramid (Nepal, 27.95N, 86.82E, 5079 m a.s.l.) has been installed in February 2006 in the high Khumbu Valley, above the timber line in a rocky and mossy environment not far from the base camp area of Mt. Everest.
The Observatory is running in the framework of the Atmospheric Brown Clouds Project (ABC) of UNEP, and is part of AERONET network and WMO-GAW program.
Since 2010 NCO-P is a global GAW station. The instrument set-up was defined in accordance with “ABC” Project standards (Ramanathan et al., 2006) and includes: (a) a surface ozone analyser, (b) a Multi-Angle Absorption Photometer which measures aerosol light absorption also allowing the determination of the BC concentration in atmosphere, (c) a Differential/Scanning Mobility Particle Sizer to determine the aerosol size distribution from 10 to 500 nm, (d) an optical particle counter to complete the aerosol size distribution till 32 µm also allowing to reconstruction of aerosol mass, (e) a three wavelength integrating nephelometer to determine aerosol total and back scattering coefficients, (f) a sun photometer for measuring the aerosol optical depth, (g) a high volume aerosol sampler for chemical analyses, (h) a “clean” sampling device to collect grab air samples for halocarbons analyses, (i) a pyranometer for measuring the global solar irradiance, (j) a pirgeometer for measuring the downwelling infra-red irradiance, (k) a meteorological unit measuring temperature, pressure, relative humidity, rain, wind intensity and direction.
The power needed to carry out the experimental activity (~ 3 kW) is provided by 96 photovoltaic panels with 120 electric storage cells.
A satellite connection makes remote control of the devices and instrumentation possible so that operating instruments can be directly accessed from ISAC-CNR (Bologna, Italy) headquarter.
Quality control for instrumentation and data are continuously performed according to GAW-WMO, AERONET, EUSAAR, AGAGE and CEOP procedures.