The GLAM Airborne Campaign across the Mediterranean Basin

Abstract

The Gradient in Longitude of Atmospheric Constituents above the Mediterranean Basin (GLAM) airborne campaign was set up to investigate the summertime variability of gaseous pollutants, greenhouse gases, and aerosols between the western (∼3°E) and eastern (∼35°E) sections of the Mediterranean basin as well as how this connects with the impact of the Asian monsoon anticyclone on the eastern Mediterranean in the mid- to upper troposphere (∼5–10 km). GLAM falls within the framework of the Chemistry–Aerosol Mediterranean Experiment (ChArMEx) program. GLAM used the French Falcon-20 research aircraft to measure aerosols, humidity, and chemical compounds: ozone, carbon monoxide, methane, and carbon dioxide. GLAM took place between 6 and 10 August 2014, following a route from Toulouse (France) to Larnaca (Cyprus) and back again via Minorca (Spain), Lampedusa (Italy), and Heraklion (Crete, Greece). The aircraft flew at an altitude of 5 km on its outbound journey and 10 km on the return leg. GLAM also collected vertical profiles around the landing sites listed above. A combination of model outputs, chemical mapping analyses, and spaceborne and surface station measurements gathered prior to and during the campaign were used to interpret the in situ airborne measurements. The main outcome of this study is the impact of intercontinental transport on the longitudinal variability of pollutants, greenhouse gases, and aerosols at an altitude of 10 km. The eastern Mediterranean is affected by air masses from the Arabian Sea surface, and the western Mediterranean is impacted by air masses from North America (biomass burning) and West Africa (desert dust).

The SPIRIT airborne instrument: a three-channel infrared absorption spectrometer with quantum cascade lasers for in situ atmospheric trace-gas measurements

“…SPIRIT has already been applied with success in several large field campaigns, such as those linked to FP7 European projects SHIVA [26,27] and DAC-CIWA-EUFAR-APSOWA [28,29] and to national projects such as MISTRAL-CHARMEX [30]. Enhanced volume mixing ratios of CO, NO 2, and/or CH 4 of a few ppbv to tens of ppbv were observed during flights when crossing, in the upper troposphere convective clouds rapidly transporting near-surface polluted air, in the boundary layer pollutant emission plumes from offshore oil extraction platforms, and in the middle troposphere air masses containing biomass burning products transported over a long distance.…”

Intercontinental transport of biomass burning pollutants over the Mediterranean Basin during the summer 2014 ChArMEx-GLAM airborne campaign

“…Long-range transport is now recognized as one of the most important processes affecting the spatial variability of pollutants (Roiger et al, 2012). As a result, air pollution from one continent can alter the chemical composition of the atmosphere above another continent.…”

Evidence of free tropospheric and long-range transport of microplastic at Pic du Midi Observatory

“…The atmospheric monitoring platform forms part of the long-term monitoring ongoing at this station 17 , 35 , 36 . This station provides extensive aerosol datasets for humidity and chemical compounds including ozone, mercury, carbon monoxide, methane and carbon dioxide 17 , 37 . The site is defined as remote due to elevation and location.…”