Validation of nitric oxide and nitrogen dioxide measurements made by the Halogen Occultation Experiment for UARS platform

Abstract

The Halogen Occultation Experiment (HALOE) experiment on Upper Atmosphere Research Satellite (UARS) performs solar occultation (sunrise and sunset) measurements to infer the composition and structure of the stratosphere and mesosphere. Two of the HALOE channels, centered at 5.26 gm and 6.25 gm, are designed to infer concentrations of nitric oxide and nitrogen dioxide respectively. The NO measurements extend from the lower stratosphere up to 130 km, while the NO2 results typically range from the lower stratosphere to 50 km and higher near the winter terminator. Comparison with results from various instruments are presented, including satellite-, balloon-, and ground-based measurements. Both NO and NO2 can show large percentage errors in the presence of heavy aerosol concentrations, confined to below 25 km and before 1993. The NO2 measurements show mean differences with correlative measurements of about 10 to 15% over the middle stratosphere. The NO2 precision is about 7.5x10 '13 arm, degrading to 2x10 -12 arm in the lower stratosphere. The NO differences are similar in the middle stratosphere but sometimes show a low bias (as much as 35%) between 30 and 60 km with some correlative measurements. NO precision when expressed in units of density is nearly constant at lx10 '12 atmospheres, or approximately 0.1 ppbv at 10.0 mb or, 1.0 ppbv at 1.0 mb, and so forth when expressed in mixing ratio. Above 65 km, agreement in the mean with Atmospheric Trace Molecule Spectroscopy (ATMOS) NO results is very good, typically + 15%. Model comparisons are also presented, showing good agreement with both expected morphology and diurnal behavior for both NO2 and NO. hydrogen chloride (HCI), hydrogen fluoride (HF), methane (CH4), water vapor (H20), nitric oxide (NO), nitrogen dioxide (NOy), and aerosol extinction. Retrieved profiles cover an altitude range from the upper troposphere, in some cases, to the lower thermosphere for nitric oxide. Fifteen spacecraft sunrises and sunsets are observed daily and usually in opposite hemispheres, although at certain times these measurements occur on the same day and almost overlap in space. Details of the HALOE experiment, including geographic coverage, discussion of the experiment and instrument techniques, instrument ground test results, error mechanisms, in-orbit performance, initial pressure versus latitude cross sections, and orthographic projections are included in the HALOE overview by Russell et. al. [1993]. The purpose of 'this paper is to describe steps taken and 'the status of efforts to validate data from the NO gas correlation channel and the NO2 radiometer channel. All results were inferred using the most current archived HALOE data, version 17, released in November 1994. Version numbers were liberally changed during the continuous validation and evolution of the HALOE processing system. Attainment of research quality results coincided with version 16 in late summer of 1994, which was the first version released to the general science community. However, a second general processing ...

Operational total and tropospheric NO<sub>2</sub> column retrieval for GOME-2

“…This harmonic climatology has been derived from satellite measurements by UARS/HALOE (Gordley et al, 1996) and SPOT-4/POAM-III (Randall et al, 1998) and complementary information from ground-based measurements from the Network for the Detection of Atmospheric Composition Change (NDACC). The stratospheric NO 2 profiles are time dependent and given for 16 latitude bands.…”

Validation of ACE-FTS version 3.5 NO<sub><i>y</i></sub> species profiles using correlative satellite measurements

“…This study uses HALOE version 19 NO and NO 2 , which have very small differences relative to v17 (James M. Russell III, Hampton University, personal communication, December 2015). Gordley et al (1996) found that above 25 km HALOE v17 NO tended to agree with correlative satellite and balloon-based measurements within 15 %, but with a maximum low bias reaching 35 %. Also, above 25 km HALOE v17 NO 2 agreed with correlative satellite, balloon, and ground-based measurements to within 15 %.…”

“…The NO retrievals have a vertical resolution of 4 km at altitudes below ∼ 60 km (degrading to 7 km at higher altitudes), and the NO 2 retrievals have a vertical resolution of 2 km. The HALOE version 17 NO and NO 2 data were validated by Gordley et al (1996). This study uses HALOE version 19 NO and NO 2 , which have very small differences relative to v17 (James M. Russell III, Hampton University, personal communication, December 2015).…”

Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: validation of the technique through correlative comparisons

“…Therefore, this feature would be more likely due to a limitation of the HALOE and POAM III instruments for measuring NO 2 at these low altitude levels. The possible error sources on the HALOE and POAM III data are described in detail in Gordley et al (1996) and Randall et al (2002). A source of systematic error is the strong variations of NO 2 along a solar occultation measurement line of sight.…”

“…HALOE was launched on board the Upper Atmosphere Research Satellite (UARS) in September 1991 (Gordley et al, 1996). As for POAM III, the satellite instrument probes the atmosphere in solar occultation.…”