Aerosol number concentration

PM is measured using the optical particle counter (OPC GRIMM 190), which measures the size distributions for particle with diameters greater than 0.25 up to 32µm by means of 90° laser light scattering.

The Aerosol number concentration measurement is a subset of core variables that are recommended by the GAW Scientific Advisory Group on Aerosols for long-term measurements in the global network.

Citation proposal
(2011) . Aerosol number concentration. https://geoportal.mountaingenius.org/geonetwork/srv/api/records/27f389b8-6cad-41dd-8ce0-db21cbe3be87

Simple

Date ( Publication ): 2011-04-12T19:08:00

Edition

Purpose

Aerosol particles are ubiquitous in the atmosphere.

They exert significant effects on the Earth’s climate. First, they absorb and scatter incoming solar radiation (direct radiative forcing).

Second, they act as cloud condensation nuclei (CCN), influencing the cloud microphysical and optical properties as well as their life-time and precipitation (indirect effect).

Due to the high variability of the natural as well as the anthropogenic aerosol in the troposphere, the corresponding radiative effects vary highly in time and space. The latest report from IPCC has shown that atmospheric aerosols represent the largest uncertainty in understanding and giving future predictions of the Earth’s climate. Aerosol number concentration varies greatly in both, time and space.

Meanwhile, the existing in-situ aerosol observation system is patchy with respect to global coverage, very little information are available especially remote environment and in free troposphere.

Status: Completed

Point of contact

Ev-K2-CNR - ( )

Via San Bernardino 145 Bergamo BG 24126 Italy

+39 035 3230511

+39 035 3230551

Website: http://www.evk2cnr.org/

Point of contact

Institute of Atmospheric Sciences and Climate (ISAC) - CNR - Paolo Bonasoni ( )

Via Gobetti 101 Bologna BO 40129 Italy

+39 051 639 9590

+39 051 639 9652

Principal investigator

Institute of Atmospheric Sciences and Climate (ISAC) - CNR - Angela Marinoni ( )

Via Gobetti 101 Bologna 40129 Italy

+39 051 6399597

+39 051 6399652

Maintenance and update frequency: As needed

Keywords ( Theme )

SHARE , network , CEOP , GAWSIS

Keywords ( Place )

Nepal

GEMET themes ( Theme )

air , climate , natural areas, landscape, ecosystems , pollution , research

Keywords ( Theme )

high elevation , aerosol , optical particle concentration

Use limitation: No conditions apply

Access constraints: Intellectual property rights

Other constraints

Spatial representation type: Vector

Metadata language: eng

Character set: UTF8

Topic category

Climatology, meteorology, atmosphere
Geoscientific information
Environment

Description

Supplemental Information

Reference system identifier: EPSG / WGS 84 (EPSG:4326) / 7.4

Topology level: Geometry only

Geometric object type: Point

Geometric object count: 1

OnLine resource: SHARE Geonetwork
SHARE Geonetwork

OnLine resource: WMO/GAW AEROSOL MEASUREMENT PROCEDURES GUIDELINES AND RECOMMENDATIONS
WMO/GAW AEROSOL MEASUREMENT PROCEDURES GUIDELINES AND RECOMMENDATIONS

OnLine resource: https://geoportal.mountaingenius.org/geoserver/wms

OnLine resource: Global Atmosphere Watch Station Information System
GAWSIS (Global Atmosphere Watch Station Information System) report about Nepal Climate Observatory - Pyramid

OnLine resource

CEOP - HE (Coordinated Energy and water cycle Observation Project

Official website of CEOP- HE

(Coordinated Energy and water cycle Observation Project - High Elevation)

Hierarchy level: Series

Other: data: aerosol number concentration

Accuracy of time measurement

Name of measure: time resolution

Measure description: TIME INTERVAL: continuos

Conformance result

Date ( Creation )

Explanation

The final data reporting protocols for the GAW aerosol data must be prepared in coordination with groups responsible for the other parameters measured at GAW sites.

For continuously measured aerosol parameters, one-hour time resolution is appropriate with a measure of the central value (arithmetic mean) and variability (standard deviation) reported for each parameter for each hour.

Pass: true

Statement

Measurement data from March 2006 are recorded at the station Nepal Climate Observatory at Pyramid in the Himalaya (Nepal, 5059 m asl) are part of ABC-DISC database, maintained by UNEP (United Nations Environmental Programme).

Optical Particle Counter (OPC, GRIMM 190) determining the aerosol size distribution for particle diameters from 0.25 up to 32 µm in 31 channels, with an accuracy of 2%, on concentrations. Coarse particles, with diameters larger than 1 µm are considered as a proxy of dust aerosol.

From the OPC measurements the mass concentrations of PM1 were derived.

Due to instrument failure, the measurements were interrupted on 4 December 2007 and resumed on 5 February 2008.