Who is validating instruments with the ozone process
Polar stratospheric clouds are composed of nitric acid hydrates, liquid solutions of sulfuric acid, water, and nitric acid, and (under very cold conditions) water ice (e.g., ref. Some of the key reactions are photochemical, so that the ozone hole does not form during midwinter when the polar cap is dark, but rather in late winter/spring as sunlight returns, provided that temperatures remain low.
Although the same basic chemical mechanisms operate in both hemispheres, the Arctic winter stratosphere is generally warmer than the Antarctic, and it warms up earlier in the spring.
The data provide direct evidence that heavily depleted air contains reduced nitric acid abundances, and better quantify the roles of polar stratospheric cloud chemistry and temperatures below −80 °C to −85 °C in ozone destruction.
Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions.
Although limited to a few sites in each hemisphere, these are the only data that extend from the 1960s onward, before the satellite era.
We next present microwave limb sounder (MLS) satellite observations (available from 2004 to present), to probe the consistency between the limited spatial sampling of the balloons from a few surface sites to the extensive coverage of the satellite and to examine how data from the MLS platform compare with the most extreme local depletions observed in situ.
METTLER TOLEDO offers a wide range of sensor simulation and validation kits.
At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica.
The data show that the lowest ozone values are associated with temperatures below −80 °C to −85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles.
METTLER TOLEDO sensor simulation kits are designed to help verify measurement loop setups.
These convenient simulators provide the same signals as actual analytical sensors.
Understanding how the ozone losses of the two polar regions compare is important not only to ensure a clear understanding of ozone depletion chemistry but also to accurately communicate the state of the science to the public. (12) presented ozonesonde and total ozone column data up to 2006 from stations in the Arctic and Antarctic.