The 210 Pb-7 Be-O 3 relationships observed in three aircraft missions over the western Pacific (PEM-West A and B, TRACE-P) are simulated with a global 3-D chemical tracer model (GEOS-CHEM) driven by assimilated meteorological observations. Results are interpreted in terms of the constraints that they offer on sources of tropospheric ozone (O 3). Aircraft observa

The Taquari River basin (TRB) drains an area of 28,000 km in the plateau adjacent to the so-called Pantanal, a large floodplain area in midwest Brazil. It is characterized by sedimentary soils, primarily sandy soils, with areas of accentuated declivities and high erosive potential. These characteristics of TRB, associated with its intensive use and the mishandling of the soil by agricultural ac...

Cave deposits have been widely used as proxy recorders in deciphering palaeoclimate during the last glacial/interglacial maxima (~ 120 ka) [Harmon et al., 1975; Atkinson et al., 1978; Goede and Harmon, 1983; Ayliffe and Veeh, 1989]. Palaeoclimatic studies of cave deposits for the past 1-1000 yr time scale require a precise dating technique, that until now has been lacking. Due to the multiple s...

Persistence of tidal wetlands under conditions sea level rise depends on vertical accretion organic and inorganic matter, which vary in their relative abundance across estuarine gradients. We examined the contribution matter to soil using lead-210 (210Pb) dating cores collected spanning a freshwater brackish gradient Chesapeake Bay subestuary. Only 8 out 15 subsites had rates higher than for ar...