Povzetek
Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coefficients are required. HR was experimentally determined and apportioned (sources/species) in the EMEP/ACTRIS/COLOSSAL-2018 winter campaign in Milan (urban-background site). Two Aethalometers (AE31/AE33) were installed together with a MAAP, CPC, OPC, a low volume sampler (PM2.5) and radiation instruments. AE31/AE33 multiple-scattering correction factors (C) were determined using two reference systems for the absorption coefficient: 1) 5-wavelength PP_UniMI with low time resolution (12 h, applied to PM2.5 samples); 2) timely-resolved MAAP data at a single wavelength. Using wavelength- and time-independent C values for the AE31 and AE33 obtained with the same reference device, the total HR showed a consistency (i.e. reproducibility) with average values comparable at 95% probability. However, if different reference devices/approaches are used, i.e. MAAP is chosen as reference instead of a PP_UniMI, the HR can be overestimated by 23-30% factor (by both AE31/AE33). This became more evident focusing on HR apportionment: AE33 data (corrected by a wavelength- and time-independent C) showed higher HRFF (+24±1%) and higher HRBC (+10±1%) than that of AE31. Conversely, HRBB and HRBrC were -28±1% and -29±1% lower for AE33 compared to AE31. These inconsistencies were overcome by introducing a wavelength-dependent Cλ for both AE31 and AE33, or using multi-wavelength apportionment methods, highlighting the need for further studies on the influence of wavelength corrections for HR determination.
Finally, the temporally-resolved determination of C resulted in a diurnal cycle of the HR not statistically different whatever the source- speciation- apportionment used.
Ključne besede
climate change;heating rate;black carbon;light absorbing aerosols;
Podatki
Jezik: |
Angleški jezik |
Leto izida: |
2021 |
Tipologija: |
1.01 - Izvirni znanstveni članek |
Organizacija: |
UNG - Univerza v Novi Gorici |
UDK: |
53 |
COBISS: |
66309379
|
ISSN: |
0048-9697 |
Št. ogledov: |
1322 |
Št. prenosov: |
0 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
URN: |
URN:SI:UNG |
Strani: |
str. 1-19 |
Zvezek: |
ǂVol. ǂ791 |
Čas izdaje: |
2021 |
DOI: |
10.1016/j.scitotenv.2021.148277 |
ID: |
13002057 |