Showing papers by "Climate Monitoring and Diagnostics Laboratory published in 2000"
TL;DR: Water vapor concentrations measured at two midlatltude locations in the northern hemisphere show water vapor amounts have increased at a rate of 1-1.5% yr'1 (0.05-0.07 ppmv yr"1) for the past 35 years as mentioned in this paper.
Abstract: Stratospheric water vapor concentrations measured at two midlatltude locations in the northern hemisphere show water vapor amounts have increased at a rate of 1-1.5% yr'1 (0.05-0.07 ppmv yr"1) for the past 35 years. At Washington, D.C., meas- urements were made from 1964-1976, and at Boulder, Colorado, observations began in 1980 and continue to the present. While these two data sets do not comprise a single time series, they individually show increases over their respective measurement periods. At Boulder the trends do not show strong seasonal differences; significant increases are found throughout the year in the altitude range 16-28 km. In winter these trends are significant down to about 13 km.
237 citations
TL;DR: In this article, clear sky heating rates were used to show that convective outflow in the tropics decreases rapidly with height between the 350 K and 360 K potential temperature surfaces (or between roughly 13 and 15 km).
Abstract: We use clear sky heating rates to show that convective outflow in the tropics decreases rapidly with height between the 350 K and 360 K potential temperature surfaces (or between roughly 13 and 15 km). There is also a rapid fall-off in the pseudoequivalent potential temperature probability distribution of near surface air parcels between 350 K and 360 K. This suggests that the vertical variation of convective outflow in the upper tropical troposphere is to a large degree determined by the distribution of sub cloud layer entropy.
63 citations
Cooperative Institute for Research in Environmental Sciences1, National Oceanic and Atmospheric Administration2, Climate Monitoring and Diagnostics Laboratory3, The Aerospace Corporation4, Goddard Space Flight Center5, Jet Propulsion Laboratory6, California Institute of Technology7, Harvard University8, Johns Hopkins University Applied Physics Laboratory9, University of Maryland, College Park10, University of Denver11, University of California, Berkeley12, Ames Research Center13
TL;DR: In situ measurements of radical and long-lived species were made in the lower Arctic stratosphere (18 to 20 km) between spring and early autumn in 1997 as discussed by the authors, and a photochemical box model constrained by these and other observations was used to compute the diurnally averaged destruction and production rates of O3 in this region.
Abstract: In situ measurements of radical and long-lived species were made in the lower Arctic stratosphere (18 to 20 km) between spring and early autumn in 1997. The measurements include O_3, ClO, OH, HO_2, NO, NO_2, N_(2)O, CO, and overhead O_3. A photochemical box model constrained by these and other observations is used to compute the diurnally averaged destruction and production rates of O3 in this region. The rates show a strong dependence on solar exposure and ambient O_3. Total destruction rates, which reach 19%/month in summer, reveal the predominant role of NO_x and HO_x catalytic cycles throughout the period. Production of O_3 is significant only in midsummer air parcels. A comparison of observed O_3 changes with destruction rates and transport effects indicates the predominant role of destruction in spring and an increased role of transport by early autumn.
19 citations