Abstract

This work presents airborne observations of sub-3 nm particles in the lower troposphere and investigates new particle formation (NPF) within an evolving boundary layer (BL). We studied particle concentrations together with supporting gas and meteorological data inside the planetary BL over a boreal forest site in Hyytiala, southern Finland. The analysed data were collected during three flight measurement campaigns: May-June 2015, August 2015 and April-May 2017, including 27 morning and 26 afternoon vertical profiles. As a platform for the instrumentation, we used a Cessna 172 aircraft. The analysed flight data were collected horizontally within a 30 km distance from SMEAR II in Hyytiala and vertically from 100 m above ground level up to 2700 m. The number concentration of 1.5-3 nm particles was observed to be, on average, the highest near the forest canopy top and to decrease with increasing altitude during the mornings of NPF event days. This indicates that the precursor vapours emitted by the forest play a key role in NPF in Hyytiala. During daytime, newly formed particles were observed to grow in size and the particle population became more homogenous within the well-mixed BL in the afternoon. During undefined days with respect to NPF, we also detected an increase in concentration of 1.5-3 nm particles in the morning but not their growth in size, which indicates an interrupted NPF process during these undefined days. Vertical mixing was typically stronger during the NPF event days than during the undefined or non-event days. The results shed light on the connection between boundary layer dynamics and NPF.
Original languageEnglish
JournalAtmospheric Chemistry and Physics
Volume19
Issue number6
Pages (from-to)4127-4138
Number of pages12
ISSN1680-7316
DOIs
Publication statusPublished - 2 Apr 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • ATMOSPHERIC BOUNDARY-LAYER
  • NUCLEATION MODE PARTICLES
  • SIZE DISTRIBUTION DATA
  • FORMATION EVENTS
  • AIRBORNE MEASUREMENTS
  • AEROSOL FORMATION
  • GROWTH-RATES
  • SMEAR-II
  • HYYTIALA
  • PRESSURES
  • 114 Physical sciences

Cite this

@article{aceaeee090024d44b8e35a4a69e7d1b3,
title = "Vertical profiles of sub-3nm particles over the boreal forest",
abstract = "This work presents airborne observations of sub-3 nm particles in the lower troposphere and investigates new particle formation (NPF) within an evolving boundary layer (BL). We studied particle concentrations together with supporting gas and meteorological data inside the planetary BL over a boreal forest site in Hyytiala, southern Finland. The analysed data were collected during three flight measurement campaigns: May-June 2015, August 2015 and April-May 2017, including 27 morning and 26 afternoon vertical profiles. As a platform for the instrumentation, we used a Cessna 172 aircraft. The analysed flight data were collected horizontally within a 30 km distance from SMEAR II in Hyytiala and vertically from 100 m above ground level up to 2700 m. The number concentration of 1.5-3 nm particles was observed to be, on average, the highest near the forest canopy top and to decrease with increasing altitude during the mornings of NPF event days. This indicates that the precursor vapours emitted by the forest play a key role in NPF in Hyytiala. During daytime, newly formed particles were observed to grow in size and the particle population became more homogenous within the well-mixed BL in the afternoon. During undefined days with respect to NPF, we also detected an increase in concentration of 1.5-3 nm particles in the morning but not their growth in size, which indicates an interrupted NPF process during these undefined days. Vertical mixing was typically stronger during the NPF event days than during the undefined or non-event days. The results shed light on the connection between boundary layer dynamics and NPF.",
keywords = "ATMOSPHERIC BOUNDARY-LAYER, NUCLEATION MODE PARTICLES, SIZE DISTRIBUTION DATA, FORMATION EVENTS, AIRBORNE MEASUREMENTS, AEROSOL FORMATION, GROWTH-RATES, SMEAR-II, HYYTIALA, PRESSURES, 114 Physical sciences",
author = "Katri Leino and Janne Lampilahti and Pyry Poutanen and Riikka V{\"a}{\"a}n{\"a}nen and Antti Manninen and Mazon, {Stephany Buenrostro} and Lubna Dada and Anna Franck and Daniela Wimmer and Aalto, {Pasi P.} and Ahonen, {Lauri R.} and Joonas Enroth and Juha Kangasluoma and Petri Keronen and Frans Korhonen and Heikki Laakso and Teemu Matilainen and Erkki Siivola and Manninen, {Hanna E.} and Katrianne Lehtipalo and Veli-Matti Kerminen and Tuukka Pet{\"a}j{\"a} and Markku Kulmala",
year = "2019",
month = "4",
day = "2",
doi = "10.5194/acp-19-412-2019",
language = "English",
volume = "19",
pages = "4127--4138",
journal = "Atmospheric Chemistry and Physics",
issn = "1680-7316",
publisher = "COPERNICUS GESELLSCHAFT MBH",
number = "6",

}

TY - JOUR

T1 - Vertical profiles of sub-3nm particles over the boreal forest

AU - Leino, Katri

AU - Lampilahti, Janne

AU - Poutanen, Pyry

AU - Väänänen, Riikka

AU - Manninen, Antti

AU - Mazon, Stephany Buenrostro

AU - Dada, Lubna

AU - Franck, Anna

AU - Wimmer, Daniela

AU - Aalto, Pasi P.

AU - Ahonen, Lauri R.

AU - Enroth, Joonas

AU - Kangasluoma, Juha

AU - Keronen, Petri

AU - Korhonen, Frans

AU - Laakso, Heikki

AU - Matilainen, Teemu

AU - Siivola, Erkki

AU - Manninen, Hanna E.

AU - Lehtipalo, Katrianne

AU - Kerminen, Veli-Matti

AU - Petäjä, Tuukka

AU - Kulmala, Markku

PY - 2019/4/2

Y1 - 2019/4/2

N2 - This work presents airborne observations of sub-3 nm particles in the lower troposphere and investigates new particle formation (NPF) within an evolving boundary layer (BL). We studied particle concentrations together with supporting gas and meteorological data inside the planetary BL over a boreal forest site in Hyytiala, southern Finland. The analysed data were collected during three flight measurement campaigns: May-June 2015, August 2015 and April-May 2017, including 27 morning and 26 afternoon vertical profiles. As a platform for the instrumentation, we used a Cessna 172 aircraft. The analysed flight data were collected horizontally within a 30 km distance from SMEAR II in Hyytiala and vertically from 100 m above ground level up to 2700 m. The number concentration of 1.5-3 nm particles was observed to be, on average, the highest near the forest canopy top and to decrease with increasing altitude during the mornings of NPF event days. This indicates that the precursor vapours emitted by the forest play a key role in NPF in Hyytiala. During daytime, newly formed particles were observed to grow in size and the particle population became more homogenous within the well-mixed BL in the afternoon. During undefined days with respect to NPF, we also detected an increase in concentration of 1.5-3 nm particles in the morning but not their growth in size, which indicates an interrupted NPF process during these undefined days. Vertical mixing was typically stronger during the NPF event days than during the undefined or non-event days. The results shed light on the connection between boundary layer dynamics and NPF.

AB - This work presents airborne observations of sub-3 nm particles in the lower troposphere and investigates new particle formation (NPF) within an evolving boundary layer (BL). We studied particle concentrations together with supporting gas and meteorological data inside the planetary BL over a boreal forest site in Hyytiala, southern Finland. The analysed data were collected during three flight measurement campaigns: May-June 2015, August 2015 and April-May 2017, including 27 morning and 26 afternoon vertical profiles. As a platform for the instrumentation, we used a Cessna 172 aircraft. The analysed flight data were collected horizontally within a 30 km distance from SMEAR II in Hyytiala and vertically from 100 m above ground level up to 2700 m. The number concentration of 1.5-3 nm particles was observed to be, on average, the highest near the forest canopy top and to decrease with increasing altitude during the mornings of NPF event days. This indicates that the precursor vapours emitted by the forest play a key role in NPF in Hyytiala. During daytime, newly formed particles were observed to grow in size and the particle population became more homogenous within the well-mixed BL in the afternoon. During undefined days with respect to NPF, we also detected an increase in concentration of 1.5-3 nm particles in the morning but not their growth in size, which indicates an interrupted NPF process during these undefined days. Vertical mixing was typically stronger during the NPF event days than during the undefined or non-event days. The results shed light on the connection between boundary layer dynamics and NPF.

KW - ATMOSPHERIC BOUNDARY-LAYER

KW - NUCLEATION MODE PARTICLES

KW - SIZE DISTRIBUTION DATA

KW - FORMATION EVENTS

KW - AIRBORNE MEASUREMENTS

KW - AEROSOL FORMATION

KW - GROWTH-RATES

KW - SMEAR-II

KW - HYYTIALA

KW - PRESSURES

KW - 114 Physical sciences

U2 - 10.5194/acp-19-412-2019

DO - 10.5194/acp-19-412-2019

M3 - Article

VL - 19

SP - 4127

EP - 4138

JO - Atmospheric Chemistry and Physics

JF - Atmospheric Chemistry and Physics

SN - 1680-7316

IS - 6

ER -