Physical and optical aerosol properties at the Dutch North Sea coast based on AERONET observations

Abstract

Abstract. Sun photometer measurements at the AERONET station at the North Sea coast in The Hague (The Netherlands) provide a climatology of optical and physical aerosol properties for the area. Results are presented from the period January 2002 to July 2003. For the analysis and interpretation these data are coupled to chemical aerosol data from a nearby station of the Dutch National Air Quality Network. This network provides PM 10 and black carbon concentrations. Meteorological conditions and air mass trajectories are also used. Due to the location close to the coast, the results are strongly dependent on wind direction, i.e. air mass trajectory. In general the aerosol optical properties are governed by industrial aerosol emitted form various industrial, agricultural and urban areas surrounding the site in almost all directions over land. For maritime air masses industrial aerosols are transported from over the North Sea, whereas very clean air is transported from the NW in clean polar air masses from the North Atlantic. In the winter the effect of the production of sea salt aerosol at high wind speeds is visible in the optical and physical aerosol data. In these cases fine and coarse mode radii are similar to those reported in the literature for marine aerosol. Relations are derived between theÅngström coefficients with both the fine/coarse mode fraction and the ratio of black carbon and PM 10 .

Exploring the relation between aerosol optical depth and PM<sub>2.5</sub> at Cabauw, the Netherlands

“…In the Netherlands the most frequent air mass origin is from the west. In contrast, valid AOD measurements are scarce for this wind direction, because it is mostly associated with cloudy skies (Kusmierczyk-Michulec et al, 2007). Moreover, the data do not indicate a positively defined relation between AOD and PM 2.5 .…”

Evaluation of simulated aerosol properties with the aerosol-climate model ECHAM5-HAM using observations from the IMPACT field campaign

“…3a, with wind coming from the southeast (2-4 May), from the east (4-12 May), from the northeast and north (13-21 May), and from the east again (22-26 May). Generally, winds coming from a direction between northeast and south advect continental polluted air to Cabauw, and winds coming from the northwest advect cleaner marine air (e.g., Khlystov et al, 1996;Kusmierczyk-Michulec et al, 2007). Between 26-31 May the weather at Cabauw is influenced by an occlusion, leading to rapid variations in wind direction.…”

Simulation of aerosol optical thickness during IMPACT (May 2008, The Netherlands) with ECHAM5-HAM

“…2a, with wind coming from the southeast (2-4 May), from the east (4-12 May), from the northeast and north (13-21 May), and from the east again (22-26 May). Generally, winds coming from a direction between northeast and south advect continental polluted air to Cabauw, and winds coming from the northwest advect cleaner marine air (e.g., Khlystov et al, 1996;Kusmierczyk-Michulec et al, 2007). Between 26-31…”