Abstract
Abstract. We present satellite based ozone profile estimates derived by combining radiances measured at thermal infrared (TIR) wavelengths from the Aura Tropospheric Emission Spectrometer (TES) and ultraviolet (UV) wavelengths measured by the Aura Ozone Monitoring Instrument (OMI). The advantage of using these combined wavelengths and instruments for sounding ozone over either instrument alone is improved sensitivity near the surface as well as the capability to consistently resolve the lower troposphere, upper troposphere, and lower stratosphere for scenes with varying geophysical states. For example, the vertical resolution of ozone estimates from either TES or OMI varies strongly by surface albedo and temperature. Typically, TES provides 1.6 degrees of freedom for signal (DOFS) and OMI provides less than 1 DOFS in the troposphere. The combination provides 2 DOFS in the troposphere with approximately 0.4 DOFS for near surface ozone (surface to 700 hPa). We evaluated these new ozone profile estimates with ozonesonde measurements and found that calculated errors for the joint TES and OMI ozone profile estimates are in reasonable agreement with actual errors as derived by the root-mean-square (RMS) difference between the ozonesondes and the joint TES/OMI ozone estimates. We also used a common a priori profile in the retrievals in order to evaluate the capability of different retrieval approaches on capturing near-surface ozone variability. We found that the vertical resolution of the joint TES/OMI ozone profile estimates shows significant improvements on quantifying variations in near-surface ozone with RMS differences of 49.9% and correlation coefficient of R = 0.58 for the TES/OMI near-surface estimates as compared to 67.2% RMS difference and R = 0.33 for TES and 115.8% RMS difference and R = 0.09 for OMI. This comparison removes the impacts of using the climatological a priori in the retrievals. However, it results in artificially large sonde/retrieval differences. The TES/OMI ozone profiles from the production code of joint retrievals will use climatological a priori and therefore will have more realistic ozone estimates than those from using a common a priori volume mixing ratio profile.
Highlights
GeoscientificThe vertical disMtriboutdioenlofDoezovnee plolapysmimeponrttant roles in theM than 1 degrees of freedom for signal (DOFS) in the troposphere
Acts as a greenhHouysde rgoasloingtyheaunppder troposphere, these new ozone profile estimates with ozonesonde measurements and found that calculated errors for the joint Tropospheric Emission Spectrometer (TES) and Ozone Monitoring Instrument (OMI) ozone profile estimates are in reasonable agreeregulates the oxidation affects the air quality cfaopEr ahacuitrmythaonfstShaeynldsowtveeergmaettmatioosnphneeraer, and the
We found that the vertical resolution of et al, 2006) and increase the risk of death from respiratory the joint TES/OMI ozone profile estimates shows signifi- causes (Weinhold, 2008; Jerrett et al, 2009)
Summary
In addition to our work, Cuesta et al (2013) developed a multiple spectral retrieval algorithm on tropospheric ozone soundings using IASI and GOME-2, which simultaneously measured radiances from the MetOp satellite in the sun-synchronous orbit (local time of ascending node: 09:31 a.m.). Both this work and Cuesta et al (2013) used identical spectral regions of the υ3 band in TIR and the Hartley and Huggins bands in the UV and showed similar vertical sensitivities and measurement uncertainties of ozone profile estimates. Both TES and OMI instruments are on the NASA Aura platform launched in 2004 in a near-polar, sun-synchronous, 705 km altitude orbit whose ascending node has a 13:38 equator crossing time
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.