Monitoring atmospheric composition & climate
Verification of Global Services

Validation Reports

The global system is being validated on a 3-monthly basis. A general description of the validation protocol and the validation reports themselves are available here:

Quick-look verification pages


MACC uses a multitude of independent data sets to verify its global services. Both the near-real-time forecasts and the reanalysis are carefully monitored to provide clear indications of the quality of these products. This page provides an overview of the current means of verification.

Near-real-time Ozone and Carbon Monoxide forecasts

Surface ozone and carbon monoxide from the near-real-time analysis/forecast system are routinely verified against data from some of the WMO GAW stations.

Near-real-time evaluation using IAGOS data

O3 and CO from the MACC NRT models as well as the MACC reanalysis are validated with profiles from IAGOS/MOZAIC aircrafts. Time-series of the difference between model and observations are presented for each available year, along with profiles at individual airports, and the observed climatologies.

Tropospheric CO and O3 evaluation

This service provides evaluation of MACC simulations against MOPITT CO data and surface CO and O3 observations from EMEP and NOAA-GMD.

Tropospheric ozone evaluation

This evaluation service contains the following elements:

  1. Surface O3 from the MACC-II near-real time models are compared to ozone data from NOAA Earth System Research Laboratory (ESRL) stations.
  2. Surface O3 from the MACC reanalysis (2003-2012) are verified against observations from the EuropeanEMEP network.



Near-real-time evaluation with SCIAMACHY measurements

Tropospheric NO2 and HCHO columns as well as stratospheric NO2 from the near-real-time forecasting/analysis systems and the MACC reanalysis are being verified operationally against independent SCIAMACHY and GOME-2 satellite retrievals. The verification plots include comparison of monthly averages as maps and comparison of time series over selected regions. This allows constant monitoring of the MACC forecasting/analysis system.

Stratospheric Ozone analyses

The integrated stratospheric ozone web service provides qualitative and quantitative verification of the NRT and historic MACC global atmospheric composition. The MACC analysis is currently verified in near-real time against BASCOE, SACADA and TM3DAM models. Additionally, the website provides information on the development of the latest A(nta)rctic ozone hole.

NDACC evaluation in stratosphere and troposphere

This service presents quality assessment of the MACC products using ground-based remote-sensing data from the global Network for the Detection of Atmospheric Composition Change (NDACC). This includes verification plots using NDACC remote-sensing data from ground-based LIDAR, microwave radiometers, Fourier-transform infrared and UV-Visible (MAX-DOAS) spectrometers, for the following MACC-II products: CO, CH4, O3, NO2, HCHO and aerosol extinction (total column abundances and/or vertical profiles). This service is delivered by the EU FP7 project NORS.

Near-real-time Aerosol Forecasts using AERONET

The aerosol analysis/forecasting system is being verified operationally against AERONET observations. The aerosol verification plots show comparisons of aerosol optical depth (AOD) values from the MACC analysis compared to the various AERONET station observations. The verification plots also show the individual aerosol types as modelled by the MACC system. This allows constant monitoring of the quality of the MACC aerosol analysis/forecasting system.

Aerocom Evaluation

The performance of the aerosol model in IFS is illustrated by evaluation plots which are made available through the AeroCom web interface. Examples include: Score tables, maps, scatter plots, zonal bias, bias maps, histograms, time series, performance comparison in between years and a WEB LINK to AeroCom interface comparison of total aerosol, dust, and sulfate AOD and Angstroem exponent for a given month.


WMO Sand and Dust Storm Warning Advisory and Assessment System

The MACC aerosol forecasts contribute in the WMO Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). The forecasts are verified with near-real time AERONET data. Evaluation metrics are available on a monthly and seasonal basis. A near-real time model comparison of contributing dust models is available.

CO2 forecast evaluation with ICOS observations

The MACC-II near-real-time CO2 forecasts are routinely monitored with observations from the European Integrated Carbon Observation System (ICOS). This provides helpful information about the forecasts as well as useful feedback to the groups making the observations. 


Monitoring of satellite data usage in the Reanalysis and Near-Real-Time production

The usage of satellite data in the reanalysis is carefully monitored to detect any problems. Departure monitoring plots provide a statistical measure of the differences between the observations and the model before and after assimilation.
Increment monitoring plots show the changes for each variable for every 12-hour assimilation due to the assimilation of observations.

A full explanation of the plots is given here.