This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 640276.
G2.10 Tropospheric ozone profile data from non - satellite measurement sources is limited and improved capability is needed to characterise new satellite missions
Submitted by Anna Mikalsen on 9 June, 2017 - 16:14
Gap abstract:
Tropospheric ozone has an impact on air quality and acts as a greenhouse gas and therefore plays a role in public and environmental health, as well as climate change, linking the two subjects. Establishing processes and trends in tropospheric ozone, in particular in the free troposphere, above the mixed layer and below the stratosphere, is difficult due to a lack of data. Also, ozone soundings using balloon borne samplers are too scarce to capture the relatively high spatial and temporal variability in the troposphere. Contrary to stratospheric ozone, passive satellite observations have limited access to information about tropospheric ozone. However, new sensors on the next generation of satellite measurements shall have better tropospheric sensing capabilities, and shall require validation.
Part I Gap description
Primary gap type:
- Spatiotemporal coverage
Secondary gap type:
- Vertical domain and/or vertical resolution
ECVs impacted:
- Ozone
User category/Application area impacted:
- Operational services and service development (meteorological services, environmental services, Copernicus Climate Change Service (C3S) and Atmospheric Monitoring Service (CAMS), operational data assimilation development, etc.)
- Climate research (research groups working on development, validation and improvement of ECV Climate Data Records)
Non-satellite instrument techniques involved:
- Ozonesonde
- Lidar
- Pandora
Detailed description:
Tropospheric ozone has an impact on air quality and acts as a greenhouse gas and therefore plays a role in public and environmental health, as well as climate change, linking the two subjects. Establishing processes and trends in tropospheric ozone, in particular in the free troposphere, above the mixed layer and below the stratosphere, is difficult due to a lack of direct observational data. Tropospheric ozone is much more variable in space and time than stratospheric ozone due to transport and chemistry. The frequency and accuracy of the observations should ideally be adjusted to account for this elevated variability. In addition, the balloon borne ozone samplers are optimised for stratospheric observations, which implies sub optimal performance in the troposphere. Therefore, other observational techniques are required to fill the need for observations of tropospheric ozone from non-satellite sources that are more routinely operational. Contrary to stratospheric ozone, passive satellite observations have limited access to information about tropospheric ozone as the TOA down view is largely dominated by the much higher stratospheric loadings across the sensitive regions of the E-M spectrum. However, currently planned missions are envisaged to have better tropospheric ozone sensing capabilities. Also, ozone soundings using balloon borne samplers are too scarce to capture the relatively high spatial and temporal variability in the troposphere.
Operational space missions or space instruments impacted:
- Copernicus Sentinel 4/5
- MetOp
- MetOp-SG
- Polar orbiters
- Geostationary satellites
- UV/VIS nadir
- Passive sensors
OMPS
Validation aspects addressed:
- Geophysical product (Level 2 product)
- Gridded product (Level 3)
- Assimilated product (Level 4)
- Time series and trends
- Representativity (spatial, temporal)
- Calibration (relative, absolute)
Gap status after GAIA-CLIM:
- After GAIA-CLIM this gap remains unaddressed
Part II Benefits to resolution and risks to non-resolution
| Identified benefit | User category/Application area benefitted | Probability of benefit being realised | Impacts |
|---|---|---|---|
Upcoming satellite missions will have improved capabilities for tropospheric ozone. Sub-orbital observation capacity will be used to assess the satellite data quality. |
|
| Improved knowledge of tropospheric ozone will reduce uncertainty in radiative transfer (climate) and improve results for chemistry. |
| Identified risk | User category/Application area at risk | Probability of risk being realised | Impacts |
|---|---|---|---|
Tropospheric ozone profile data is relatively scarce and limits applicability to range of activities including tropospheric ozone validation from satellites. |
|
| Remaining gap in appropriate data sources to optimally use new satellite data and to understand processes in the troposphere related to the linkage between air pollution and climate change. |
Part III Gap remedies
Gap remedies:
Remedy 1: Expand coverage of differential absorption lidars to improve ability to characterise tropospheric ozone
Primary gap remedy type:
Deployment
Secondary gap remedy type:
Technical
Proposed remedy description:
An increase in data on tropospheric ozone is expected from various space-borne platforms with increased capabilities, such as OMPS, TES and TROPOMI and the instruments proposed for Sentinel 4 and 5. However, a reinforcement of the ground based observational capacity is also required to validate these space-borne observations and establish high-quality time series. An increase in the number of ozone balloon borne soundings is not likely due to the high costs involved (material and personnel). There is a potential for tropospheric ozone lidars (using the differential absorption lidar technique) to fill this gap. In the US, a network of tropospheric ozone lidars has been established (TOLNET). Similar initiatives could be pursued in Europe, where a latent tropospheric ozone lidar network could be revived. In Europe, such a network might become part of ACTRIS, the European Research Infrastructure which deals with short-lived greenhouse agents. Similar efforts are required in other areas of the globe to enable full characterisation of tropospheric ozone capabilities by future satellite missions.
Relevance:
An increase in data on tropospheric ozone is expected from various space-borne platforms with increased capabilities, such as OMPS, TES and TROPOMI and the instruments proposed for Sentinel 4 and 5. However, a reinforcement of the ground based observational capacity is also required to validate these space borne observations and establish high-quality time series. The issue is relevant to understand the links between air pollution and climate change. Satellite data alone will likely not suffice to fill the gap.
Measurable outcome of success:
A measure of success is the increase in the number of available tropospheric ozone profiles.
Expected viability for the outcome of success:
- Medium
Scale of work:
- Programmatic multi-year, multi-institution activity
Time bound to remedy:
- Less than 3 years
Indicative cost estimate (investment):
- High cost (> 5 million)
Indicative cost estimate (exploitation):
- Yes
Potential actors:
- EU H2020 funding
- Copernicus funding
- National funding agencies
- National Meteorological Services
- WMO
- ESA, EUMETSAT or other space agency