569 research outputs found
What causes the irregular cycle of the atmospheric tape recorder signal in HCN?
Variations in the mixing ratio of long-lived trace gases entering the stratosphere in the tropics are carried upward with the rising air with the signal being observable throughout the tropical lower stratosphere. This phenomenon, referred to as "atmospheric tape recorder" has previously been observed for water vapor, CO2, and CO which exhibit an annual cycle. Recently, based on Microwave Limb Sounder (MLS) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) satellite measurements, the tape recorder signal has been observed for hydrogen cyanide (HCN) but with an approximately two-year period. Here we report on a model simulation of the HCN tape recorder for the time period 2002-2008 using the Chemical Lagrangian Model of the Stratosphere (CLaMS). The model can reproduce the observed pattern of the HCN tape recorder signal if time-resolved emissions from fires in Indonesia are used as lower boundary condition. This finding indicates that inter-annual variations in biomass burning in Indonesia, which are strongly influenced by El Nino events, control the HCN tape recorder signal. A longer time series of tropical HCN data will probably exhibit an irregular cycle rather than a regular biannual cycle. Citation: Pommrich, R., R. Muller, J.-U. Grooss, G. Gunther, P. Konopka, M. Riese, A. Heil, M. Schultz, H.-C. Pumphrey, and K. A. Walker (2010), What causes the irregular cycle of the atmospheric tape recorder signal in HCN?, Geophys. Res. Lett., 37, L16805, doi:10.1029/2010GL044056
The Underwater Noise of Rain
Numerous data on the spectra of underwater noise due to natural as well as artificial rain show a prominent and characteristic peak at a frequency around 14 kHz. It is argued that this acoustic emission is due to bubbles entrained in the liquid by the impact of raindrops. The mechanics of the entrainment is such that only drops in a narrowly defined size range have a high probability of entraining bubbles. The narrowness of this size range may explain why the 14?kHz peak is so ubiquitous and well defined
EOS MLS observations of dehydration in the 2004-2005 polar winters
We prove various estimates for the first eigenvalue of the magnetic Dirichlet
Laplacian on a bounded domain in two dimensions. When the magnetic field is
constant, we give lower and upper bounds in terms of geometric quantities of
the domain. We furthermore prove a lower bound for the first magnetic Neumann
eigenvalue in the case of constant field.Comment: 19 page
Water vapor in the tropical lower stratosphere during the driest phase of the atmospheric "tape recorder"
The photochemistry of carbon monoxide in the stratosphere and mesosphere evaluated from observations by the Microwave Limb Sounder on the Aura satellite
Building a Simple General Model of Municipal Water Conservation Policy for Communities Overlying the Ogallala Aquifer
Cirrus and water vapor in the tropical tropopause layer observed by Upper Atmosphere Research Satellite (UARS)
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Polymetrics
Polymetrics is a one-movement work for symphonic wind ensemble, of approximately 8 minutes' duration. The instrumentation includes thirty woodwinds, thirteen brasses, and ten percussionists. The pitch organization is based on two hexachords that encompass all twelve pitch classes
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