SMILES zonal and diurnal variation climatology of stratospheric and mesospheric trace gasses: O₃, HCl, HNO₃, ClO, BrO, HOCl, HO₂, and temperature

Abstract

[1] We present a climatology of the diurnal variation of short-lived atmospheric compounds, such as ClO, BrO, HO 2 , and HOCl, as well as longer-lived species: O 3 , the hydrogen chloride isotopes H 35 Cl and H 37 Cl, and HNO 3 . Measurements were taken by the Superconducting Submillimeter-wave Limb-Emission Sounder (SMILES). This spectrally resolving radiometer, with very low observation noise and altitude range from the lower stratosphere to the lower thermosphere (20-100 km), was measuring vertical profiles of absorption spectra along a non-sun-synchronous orbit, thus observing at all local times. We used the retrieved volume mixing ratio profiles to compile climatologies that are a function of pressure, a horizontal coordinate (latitude or equivalent latitude), and a temporal coordinate (solar zenith angle or local solar time). The main product presented are climatologies with a high resolution of the temporal coordinate (diurnal variation climatologies). In addition, we provide climatologies with a high resolution of the horizontal coordinate (zonal climatologies).The diurnal variation climatologies are based on data periods of 2 months and the zonal climatologies on monthly data periods. Consideration of the SMILES time-space sampling patterns with respect to the averaging coordinates is a key issue for climatology creation, especially in case of diurnal variation climatologies. Biases induced by inhomogeneous sampling are minimized by carefully choosing the size of averaging bins. The sampling biases of the diurnal variation climatology of ClO and BrO are investigated in a comparison of homogeneously sampled model data versus SMILES-sampled model data from the stratospheric Lagrangian chemistry and transport model Alfred Wegener Institute Lagrangian Chemisrty/Transport System. In most cases, the relative sampling error is in the range of 0-20%. The strongest impact of sampling biases is found where the species' temporal gradients are strongest (mostly at sunrise and sunset), with a relative error of 60-100%. The SMILES climatology data sets are available via the SMILES data distribution home page.Citation: Kreyling, D., H. Sagawa, I. Wohltmann, R. Lehmann, and Y. Kasai (2013), SMILES zonal and diurnal variation climatology of stratospheric and mesospheric trace gasses: O 3 , HCl, HNO 3 , ClO, BrO, HOCl, HO 2 , and temperature, J. Geophys.

Overview and sample applications of SMILES and Odin-SMR retrievals of upper tropospheric humidity and cloud ice mass

“…This feature is valid for all the quantities measured by SMILES (e.g. Kreyling et al, 2013). For a particular region, there is not an instantaneous complete coverage in local time and only seasonal mean variations can be derived.…”

Past changes in the vertical distribution of ozone – Part 1: Measurement techniques, uncertainties and availability

“…This instrument measured about 1600 profiles per day (both daytime and nighttime) within the latitude range of 38 • S-65 • N. Owing to the non-sun-synchronous orbit of the ISS, measurements of the atmosphere are taken at different local times. This data set provides unprecedented opportunities to study diurnal ozone variations throughout the stratosphere Sakazaki et al, 2013;Kasai et al, 2013;Kreyling et al, 2013).…”

HO Generation Above Sprite‐Producing Thunderstorms Derived from Low‐Noise SMILES Observation Spectra

“…Although solar proton and energetic electron precipitation events are known to enhance the nighttime abundance of HO (H, OH, and HO ) in the high‐latitude region owing to the reaction between electrons and hydrated cluster ions (Jackman et al, , ; Solomon et al, ), their activity was quite low at the low‐latitude region and during the SMILES observations that took place from 12 October 2009 to 21 April 2010 (Andersson et al, ). The diurnal variation in mesospheric HO is mostly controlled by the photolysis of H O by sunlight (Kreyling et al, ), which only depends on the local time and lifetime of HO species, making it incapable of producing the local enhancement. Horizontal transportation by zonal winds may impact the estimated HO productions as demonstrated in Arnone et al () for nitrogen oxides.…”

“…The atmospheric profiles include the volume mixing ratio of HO , temperature, and pressure. Vertical atmospheric profiles are obtained from the averaged values of the SMILES Level‐2 research (L2r) product data Version 3.0.0, an updated version of Version 2.1.5 (Baron et al, ; Kasai et al, ; Kreyling et al, ), at adjacent observation scans. The calculated spectra are convoluted with frequency response functions of acousto‐optic spectrometers (Mizobuchi et al, ).…”