TY - JOUR

T1 - NDACC harmonized formaldehyde time series from 21 FTIR stations covering a wide range of column abundances

AU - Vigouroux, Corinne

AU - Augusto Bauer Aquino, Carlos

AU - Bauwens, Maite

AU - Becker, Cornelis

AU - Blumenstock, Thomas

AU - De Mazière, Martine

AU - García, Omaira

AU - Grutter, Michel

AU - Guarin, César

AU - Hannigan, James

AU - Hase, Frank

AU - Jones, Nicholas

AU - Kivi, Rigel

AU - Koshelev, Dmitry

AU - Langerock, Bavo

AU - Lutsch, Erik

AU - Makarova, Maria

AU - Metzger, Jean Marc

AU - Müller, Jean François

AU - Notholt, Justus

AU - Ortega, Ivan

AU - Palm, Mathias

AU - Paton-Walsh, Clare

AU - Poberovskii, Anatoly

AU - Rettinger, Markus

AU - Robinson, John

AU - Smale, Dan

AU - Stavrakou, Trissevgeni

AU - Stremme, Wolfgang

AU - Strong, Kim

AU - Sussmann, Ralf

AU - Té, Yao

AU - Toon, Geoffrey

PY - 2018/9/6

Y1 - 2018/9/6

N2 - Among the more than 20 ground-based FTIR (Fourier transform infrared) stations currently operating around the globe, only a few have provided formaldehyde (HCHO) total column time series until now. Although several independent studies have shown that the FTIR measurements can provide formaldehyde total columns with good precision, the spatial coverage has not been optimal for providing good diagnostics for satellite or model validation. Furthermore, these past studies used different retrieval settings, and biases as large as 50% can be observed in the HCHO total columns depending on these retrieval choices, which is also a weakness for validation studies combining data from different ground-based stations. For the present work, the HCHO retrieval settings have been optimized based on experience gained from past studies and have been applied consistently at the 21 participating stations. Most of them are either part of the Network for the Detection of Atmospheric Composition Change (NDACC) or under consideration for membership. We provide the harmonized settings and a characterization of the HCHO FTIR products. Depending on the station, the total systematic and random uncertainties of an individual HCHO total column measurement lie between 12% and 27% and between 1 and 11×1014moleccm-2, respectively. The median values among all stations are 13% and 2.9×1014moleccm-2 for the total systematic and random uncertainties. This unprecedented harmonized formaldehyde data set from 21 ground-based FTIR stations is presented and its comparison with a global chemistry transport model shows consistency in absolute values as well as in seasonal cycles. The network covers very different concentration levels of formaldehyde, from very clean levels at the limit of detection (few 1013moleccm-2) to highly polluted levels (7×1016moleccm-2). Because the measurements can be made at any time during daylight, the diurnal cycle can be observed and is found to be significant at many stations. These HCHO time series, some of them starting in the 1990s, are crucial for past and present satellite validation and will be extended in the coming years for the next generation of satellite missions.

AB - Among the more than 20 ground-based FTIR (Fourier transform infrared) stations currently operating around the globe, only a few have provided formaldehyde (HCHO) total column time series until now. Although several independent studies have shown that the FTIR measurements can provide formaldehyde total columns with good precision, the spatial coverage has not been optimal for providing good diagnostics for satellite or model validation. Furthermore, these past studies used different retrieval settings, and biases as large as 50% can be observed in the HCHO total columns depending on these retrieval choices, which is also a weakness for validation studies combining data from different ground-based stations. For the present work, the HCHO retrieval settings have been optimized based on experience gained from past studies and have been applied consistently at the 21 participating stations. Most of them are either part of the Network for the Detection of Atmospheric Composition Change (NDACC) or under consideration for membership. We provide the harmonized settings and a characterization of the HCHO FTIR products. Depending on the station, the total systematic and random uncertainties of an individual HCHO total column measurement lie between 12% and 27% and between 1 and 11×1014moleccm-2, respectively. The median values among all stations are 13% and 2.9×1014moleccm-2 for the total systematic and random uncertainties. This unprecedented harmonized formaldehyde data set from 21 ground-based FTIR stations is presented and its comparison with a global chemistry transport model shows consistency in absolute values as well as in seasonal cycles. The network covers very different concentration levels of formaldehyde, from very clean levels at the limit of detection (few 1013moleccm-2) to highly polluted levels (7×1016moleccm-2). Because the measurements can be made at any time during daylight, the diurnal cycle can be observed and is found to be significant at many stations. These HCHO time series, some of them starting in the 1990s, are crucial for past and present satellite validation and will be extended in the coming years for the next generation of satellite missions.

KW - GROUND-BASED FTIR

KW - MOLECULAR SPECTROSCOPIC DATABASE

KW - VOLATILE ORGANIC-COMPOUNDS

KW - MAX-DOAS OBSERVATIONS

KW - ISOPRENE EMISSIONS

KW - INFRARED MEASUREMENTS

KW - VERTICAL-DISTRIBUTION

KW - BIOGENIC EMISSIONS

KW - HIGH-RESOLUTION

KW - MODEL

UR - http://www.scopus.com/inward/record.url?scp=85053032489&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/ndacc-harmonized-formaldehyde-time-series-21-ftir-stations-covering-wide-range-column-abundances

U2 - 10.5194/amt-11-5049-2018

DO - 10.5194/amt-11-5049-2018

M3 - Article

AN - SCOPUS:85053032489

VL - 11

SP - 5049

EP - 5073

JO - Atmospheric Measurement Techniques

JF - Atmospheric Measurement Techniques

SN - 1867-1381

IS - 9

ER -