Figure 2 also shows available long-term mean ground-level observations, which are mostly for the latter part of this period.
The bottom right panel shows the 210 locations of global mean ground-level PM2.5 concentrations outside Canada, the United States, and Europe.
We estimated annual mean ground-level NO2 concentrations, averaged for 2005, by combining GEOS-Chem NO2 profiles with tropospheric NO2 columns obtained from the Ozone Monitoring Instrument on the satellite Aura (Atmospheric Composition Analysis Group 2010a; Lamsal et al. 2008).
Higher concentrations are visible in the eastern United States and in the San Joaquin Valley of California. Figure 1 also shows long-term mean ground-level PM2.5 measured during this period over Canada and the United States and comparison with the satellite-derived estimates.
In French, that means "a foot on the ground," so called because they were originally meant as basic ground level, second home apartments for the busy business executive to crash during the week or as a place to cache a mistress.
As this is likely to be due to floor level, an analysis based on the level of the child's bedroom, for example, showed that mean concentrations on the ground floor were 19.7 Bq m−3, and above the living room were 16.6 Bq m−3, whilst if the bedroom and living room were both above ground level the mean was 9.9 Bq m−3.
Of course, that does not mean that people agree at the ground level.
That could include rebuilding a house on or near the beach on giant pylons at least 2 feet above the projected flood level, which could mean 15 feet or more above ground level — a costly prospect.
The geo-referenced ALS point cloud data from Koli NP were collected on 13 July 2005 using an Optech ALTM 3100 scanner operating at a mean altitude of 900 m above ground level (a.g.l), which resulted in a nominal sampling density of ca. 4 measurements∙m–2.
Mean air temperature (20 cm above ground level) over each observation period was entered as a covariate to account for potential differences in microclimatic conditions between sites, which could promote differences in pollinator visitation rates, and might also influence how long it takes for achenes develop and flowering phenology.
