Page History

...

...

1. Convert mass mixing ratio (MMR) to mass concentration or to volume mixing ratio (VMR)

2. Representations of SO2 and SO4 in CAMS reanalysis

3. CAMS global sea salt aerosol mixing ratios
4. For details on how convert from mixing ratio (kg per kg dry air) to concentration (kg/m3): CAMS Surface concentration of a given species

5. Anchor
   uv_index uv_index

   Expand
   title UV Index definition and computation
   CAMS provides a global solar UV index forecast (from the ADS), conforming to the WHO definition. UV Index data is available as: UV biologically effective dose rate, uvbed, 214002, in W/m2 UV biologically effective dose rate clear-sky, uvbedcs, 214003, in W/m2 To generate this data, we compute the surface down-welling spectral solar irradiance in the range 280-340nm at 5nm resolution taking into account local surface albedo, aerosol, clouds and ozone in the model profile. This is then convoluted with the erythema spectrum, resulting in the biologically active UV radiation. For more details please have a look here. UV Index plots are available showing: total UV index clear sky UV index corresponding to the two UV index parameters described above. To create the plots we divide the UV biologically effective dose rate by 0.025 W/m2 (i.e. multiplied by 40), resulting in the dimensionless UV index where one unit of measurement (ie the difference between UV Index X and X+1) represents 25mW/m2 of UVA and UVB radiation absorbed by the human skin. UV Index values are instantaneous, not cumulated.

   
   

6. 
   

   Expand
   title Web charts of biomass-burning AOD
   The actual aerosol species represented in the model are defined more according to their chemical composition (e.g. sulphate, black carbon, organic matter) rather than their source type (e.g. biomass burning or fossil fuels). What is presented on the web charts as "biomass-burning AOD" is the sum of organic matter AOD (omaod550) and black carbon AOD (bcaod550). Organic matter is almost always the dominant component out of these. Historically, biomass-burning was the main source of such aerosols in the model, apart from a much lower background of primary OM+BC from fossil fuels and of OM from biogenic secondary organic aerosol (SOA). However, since a representation of anthropogenic SOA as a source of OM was added (in cycle 43r1, implemented in January 2017), the model also captures the relatively high levels of this OM around polluted cities. To sum up, if you want the data used for those web charts, take omaod550+bcaod550 (which will usually be fairly close to omaod550 alone). However, note that this will also show significant aerosol plumes from anthropogenic pollution as well as biomass burning.

   
   

...