Retrieval of NO₂ vertical profiles from ground‐based UV‐visible measurements: Method and validation

Abstract

Abstract. Vertical profiles of NO 2 are retrieved from ground-based UV-visible slant columns by sequential estimation, using a forward model that consists of a stacked box photochemical model and a radiative transfer model. The retrieval method is characterized, and a rigorous error analysis is presented. The vertical resolution of the retrieved profiles is shown to vary from 5 to 10 km, depending on the retrieval altitude. The retrieved profiles are found to be moderately sensitive to the assumed vertical profiles of ozone and aerosol, to the range of solar zenith angles of the observations, and to the error in the slant column. However, in the altitude range 10 to 35 km they are relatively insensitive to a priori information and agreed well with profiles from simultaneous balloon-borne measurements.

The use of NO<sub>2</sub> absorption cross section temperature sensitivity to derive NO<sub>2</sub> profile temperature and stratospheric–tropospheric column partitioning from visible direct-sun DOAS measurements

“…Vertical stratospheric NO 2 profiles during sunset/sunrise were derived from zenith sky (e.g., McKenzie et al, 1991;Preston et al, 1997;Hendrick et al, 2004) and balloon DOAS measurements (e.g., Pommereau and Piquard, 1994;Butz et al, 2006;Kritten et al, 2010). Sunset and sunrise stratospheric NO 2 columns have been measured since 1991 at multiple locations throughout the world as part of the international Network for the Detection of Atmospheric Composition Change (NDACC) .…”

Ground‐based measurements of ozone and NO2during MANTRA 1998 using a Zenith‐sky spectrometer

“…An optimal estimation approach based on that described by Preston et al (1997Preston et al ( , 1998 has been applied to the data, and will be compared to the co-located and simultaneous NO 2…”

“…The NO 2 vertical column increases throughout the day as N 2 O 5 (a night-time reservoir species of NO 2 ) is photolyzed to produce NO 2 . As part of our ongoing work to retrieve vertical profiles of NO 2 using the method described by Preston et al (1997Preston et al ( , 1998, it is necessary to employ a model that simulates NO x partitioning (see Section 5 for further details). Such a model could also be used to create chemically modified Langley plots for NO 2 (Lee et al, 1994).…”

“…In addition to ozone and NO 2 , differential optical absorption spectroscopy (DOAS) has been used successfully to measure vertical columns of OClO (Solomon et al, 1987a), BrO (Solomon et al, 1989), and NO 3 at night using direct viewing of the moon (Noxon et al, 1978). Efforts have also been made to obtain vertical profiles of NO 2 from the change in retrieved DOAS slant column with solar zenith angle during twilight (McKenzie et al, 1991;Preston et al, 1997Preston et al, , 1998.…”

MANTRA ‐ A Balloon Mission to Study the Odd‐Nitrogen Budget of the Stratosphere

“…The zenith-sky spectrometer and data analysis are described by Bassford et al (this issue). Vertical profiles of NO 2 can also be retrieved, following the approach of Preston (1995) and Preston et al (1997Preston et al ( , 1998, as described by Melo et al (2004) and Melo et al (this issue). The MANTRA 1998 campaign provided an opportunity to deploy this new instrument and to evaluate its performance against simultaneous measurements of ozone and NO 2 made by a number of other instruments.…”