G2.35    Sites with high/low albedo and hot spot monitoring

Gap detailed description

So far, all TCCON sites are located in areas with good logistical support. Even sites like Ny-Aalesund or Ascension Island have a good infrastructure, although its time consuming and expensive to go there for maintenance. However, sites located in regions with high or low albedo are missing. Since retrievals could be biased by the albedo, observations at such sites would help investigating the existing biases in the satellite retrievals.

Furthermore, future satellite missions will concentrate on hot spot sites, like large mega cities. A validation by ground-based instruments like within TCCON would require sites around the cities to detect the emission. This can be done by the mobile COCCON instruments, but TCCON instruments would have the advantage of for example long term coverage or the detection of more trace gases. 

Activities within GAIA-CLIM related to this gap

This gap is not addressed within GAIA-CLIM.

Gap remedy(s)

Remedy #1

Specific remedy proposed

Identify suitable sites in geographical areas with high and low albedo. Establish contacts with scientists, or other appropriate partners.

Measurable outcome of success

New TCCON sites in target areas

Achievable outcomes

Atmospheric data from regions needed for satellite validation purposes

Technological / organizational viability: high.

Indicative cost estimate: medium (<1million).




The set-up of new TCCON sites depend on the financial support of the EU, ESA, NASA, or other sources. We currently expect no new site in such areas within the next five years.

Gap risks to non-resolution

Identified future risk / impact

Probability of occurrence if gap not remedied

Downstream impacts on ability to deliver high quality services to science / industry / society

Lack of column CO2 and CH4 measurements in areas required for satellite validation 


Low confidence in the true satellite quality in areas of high / low albedo and in areas of high emissions leading to reduced utility for emissions monitoring applications and lower confidence in changes in regional abundances.

Work package: