G1.13

G1.13 Uncoordinated lidar and microwave radiometer water vapor  measurements

Gap detailed description

Water vapour and carbon dioxide (CO₂) are the principle greenhouse gases (GHGs). CO₂ is the main driver of climate change. Water vapour changes largely happen as a response to the change. Sustained observations of water vapour in the troposphere and UT/LS in the next decades will benefit from the integration of existing networks and observatories and the implementation of a coordinated effort at the global scale. Several stations are routinely performing water vapour measurements with microwave radiometers and with Raman lidars (column and profiles) often at the same site exploiting synergies, but they are often not coordinated thus losing their powerful observing capability at a large scale. However, the construction of such an integrated system will strongly depend on the creation of long-term sustainability of the research based observational initiatives. Long-term commitment of national and international funding agencies to maintain research and development efforts and funding for atmospheric observations is of fundamental importance. In this sense, the joint effort spent by ACTRIS and NDACC to have a common strategy in future, still under implementation, is worthwhile and could strongly improve this gap over the next 5-10 years.

Activities within GAIA-CLIM related to this gap

No activities are expected within GAIA-CLIM related to this gap.

Gap remedy(s)

Remedy

Specific remedy proposed

A federated approach is the most comprehensive remedy in order to  minimize the number of redundant initiatives and to maximize the impact of the observational assets. The ESFRI funding might in the near future support this type of federated approach over long term (10 years at least). ACTRIS is a candidate to become an ESFRI research infrastructure starting from 2016. GAIA-CLIM will ideally contribute to this initiative by setting the metrology for both these techniques and thus facilitating their routine use at every site.

Measurable outcome of success

The common strategy recently agreed between ACTRIS and NDACC is already providing good results, but the most optimal  supporting measure would be  the implementation of a  global federated network for the measure of water vapour for  lidars and microwave radiometers.

Achievable outcomes

Technological / organizational viability: High, commercial lidars and microwave radiometer facilitate the resolution of this gap.

Indicative cost estimate: High (>5 million)/ medium (>1million), the total cost of this operation is not easy to quantify at the current stage and pending on project funding.

Relevance

Given the lack of funding tools to support such kind of infrastructure at the global scale, the establishment of a federated network is at present the only viable approach.

Timebound

The timeline for the proposed remedy is uncertain at the current stage, but some results maybe reported in 5 year from now when the ESFRI-ACTRIS strategy will be consolidated.

Gap risks to non-resolution