The TAPIOWCA project aims to tackle several technical challenges and, then, to reassess the present-day mean distribution, climate variability and long-term trend in water vapour and ozone across the troposphere and stratosphere.
In particular, we propose
- to improve the agreement between tropospheric ozone Climate Data Records (CDRs):
- by homogenising IASI measurements, and,
- by applying a harmonisation scheme that corrects for differences in the vertical perception of all major CDRs;
- to characterise remaining differences between tropospheric ozone CDRs;
- to investigate, using multiple linear regression (MLR) techniques, whether changes in ozone precursor concentrations or in exchanges between stratosphere and troposphere can explain tropospheric ozone trends;
- to better capture interannual variability through an optimisation of the time lag of the response of ozone to natural processes;
- to assess the present-day mean state, the interannual variations and the long-term trend of ozone in the troposphere & stratosphere, and, of water vapour in the upper troposphere and stratosphere;
- to adopt a systematic and comprehensive approach across the project, in order to reduce uncertainty and to maximise robustness of the project’s assessments.
Ultimately, TAPIOWCA strives to find (partial) answers to several open science questions and to contribute substantially to environmental assessments of climate change, the ozone layer, and air quality. We therefore align the project’s methodology, output and timeline to the needs of ongoing and planned initiatives by the climate monitoring and trend assessment communities, in particular, TOAR-II, CEOS AC-VC/WGCV, APARC LOTUS, WMO/UNEP, and IPCC.
