.. _datafields_o3: Ozone Data Fields ***************** Ozone Concentration ^^^^^^^^^^^^^^^^^^^ The ozone concentration field and associated error are given in units of mol/m\ :sup:`3`. Multiply by :math:`6.02214076 \times 10^{17}` to convert these fields to units of molecules/cm\ :sup:`3`. :ozone_concentration: Mole concentration of ozone in units of mol/m\ :sup:`3`. Only converged values in the retrieval range and above any cloud layer are reported. The associated error in the retrieved ozone is given by: :ozone_concentration_standard_error: Standard uncertainty of the retrieved ozone concentration in units of mol/m\ :sup:`3`. The vertical resolution is computed for every retrieved profile from the FWHM of the averaging kernel and is given by: :vertical_resolution: FWHM of the averaging kernel, with units of km. Although not recommended for general use, the field ``_rtm_internal_ozone_concentration`` may be useful in investigating possible biases due to retrieval saturation or other similar effects. This field includes altitudes affected by clouds and those that have not fully converged. :_rtm_internal_ozone_concentration: The full ozone concentration profile as used in the SASKTRAN radiative transfer model in units of mol/m\ :sup:`3`. Clouds ^^^^^^ The cloud altitudes retrieved during the aerosol extinction retrieval. Clouds are separated into two categories: :cloud_top_altitude: The altitude, in km, of the top of a cloud detected in this profile, NaN otherwise :psc_altitude: The altitude, in km, of a polar stratospheric cloud detected in this profile, NaN otherwise .. Note:: While the ozone concentration is reported in ``_rtm_internal_ozone_concentration`` when clouds are flagged, it is unlikely to be a reliable quantitative measure, as assumptions made in the retrieval are not consistent with cloud microphysics. Meteorology ^^^^^^^^^^^ A few meteorological fields are included in the data to aid in analysis. :temperature: Temperature taken from MERRA 2 and interpolated to the current geometrical altitude grid. :pressure: Pressure in hPa taken from MERRA 2 and interpolated to the current geometrical altitude grid. :tropopause_altitude: Tropopause in km based on WMO lapse-rate tropopause definition; the first parameter for the lowest tropopause.Calculated from MERRA 2 temperature profiles. Geometry ^^^^^^^^ For ease of use, each OSIRIS scan is assigned to a specific geographic location and time. This is not strictly true, as a scan takes approximately 90 seconds to complete and spans a few degrees latitude over this time. The geometric data fields are defined at the 30 km point of each scan. :latitude: latitude in degrees north :longitude: longitude in degrees east :time: days since 1900-01-01 00:00:00 :local_solar_time: Local solar time in hours In addition to the geographic location, three solar angles are provided that define the measurement geometry of the line of sight with respect to sun. :ssa: Solar scattering angle. The angle between the line of sight and the solar beam. :sza: Solar zenith angle. The angle between solar beam and the vertical direction at the tangent point. :saa: Solar azimuth angle. The angle between the horizontal projection of the solar beam and the line of sight. Additional Fields ^^^^^^^^^^^^^^^^^ :albedo: The retrieved albedo of the surface. Retrieval ^^^^^^^^^ These fields provide information about the retrieved ozone concentration profiles. It should be noted that values below ``retrieval_lowerbound`` are truncated from ``ozone_concentration``. Profiles with poor convergence are also filtered from this product. :retrieval_lowerbound: Lowest altitude in km that is valid for the ozone retrieval. :convergence_ratio: Convergence ratio of the ozone retrieval. :chi_sq: The :math:`{\chi}`:sup:`2` value of the ozone retrieval.