A source of narrow bandwidth (,800 MHz) tunable laser radiation at 58.4 nm has been developed and is applied to record the 11S-21P transition in He and He. From the He transition frequency of 171 134.8936s58d cm21 a fivefold improved ground state Lamb shift of 1.3763s58d cm21 is deduced, in good agreement with the theoretical value of 1.3755s10d cm21. The measured 11S-21P transition isotope shi...

Weakly electric fish can perceive electric properties of objects by monitoring the responses of their epidermal electroreceptors (mormyromasts) to their own electric organ discharges (EOD), a process known as active electrolocation. Mormyrid fish can distinguish capacitative from resistive properties of objects. It is mainly animate objects that possess capacitative properties. Water conductivi...

Formation of bonded dicarbon C-C centers is deduced from the observation of Raman lines at 1742, 1708, and 1674 cm21 in GaAs codoped with C and C after annealing at 850 ±C with concomitant loss of vibrational scattering from CAs. The frequencies agree with results of ab initio theory for a C-C split interstitial (deep donor) formed by the trapping of a mobile interstitial C (displaced CAs) atom...

We report a narrow-linewidth ZnGeP2 (ZGP) optical parametric oscillator (OPO). It employs a Q-switched Nd:YAG-laser-pumped LiNbO3 OPO with an output at l 5 2.55 mm that is used as a pump for the ZGP OPO. With the singly resonant type II ZGP OPO cavity containing a diffraction grating and a Si etalon, we achieved mid-IR tunability from 3.7 to 8 mm with an output linewidth of ;0.1 cm21, correspon...

The authors examine the natural variability of the arctic climate system simulated by two very different models: the Geophysical Fluid Dynamics Laboratory (GFDL) global climate model, and an area-averaged model of the arctic atmosphere–sea ice–upper-ocean system called the polar cap climate model, the PCCM. A 1000-yr integration of the PCCM is performed in which the model is driven by a prescri...

A prototype, no-moving-parts, plane array infrared spectrograph (PA-IR) capable of routine spectral acquisition in the 3400 to 2000 cm21 region has been constructed. The instrument includes a continuous source, Czerney–Turner type monochromator system and an infrared camera that incorporates a 320 3 256 pixel InSb focal plane array detector cooled with liquid nitrogen. PA-IR spectra (;3400 to 2...

Nanocrystalline silicon layers have been deposited by electron cyclotron resonance chemical vapor deposition from silane as precursor. Although hydrogen was not deliberately introduced in the plasma it was incorporated in the grown layers as evidenced by the presence of a main infrared absorption band around 2100 cm21 with a shoulder at 2000 cm21. This suggests that most of the hydrogen is bond...

Ocean general circulation models (OGCMs) are important tools for climatological research. These models approximate the solution to the governing equations to predict horizontal velocity components, temperature, salinity, and other chosen parameters. The GFDL OGCM, or Modular Ocean Model (MOM), is an example of such a code. This code was originally developed at the Geophysical Fluids Dynamics La...

To date, little objective verification has been performed for rainfall predictions from numerical forecasts of landfalling tropical cyclones. Until 2001, digital output from the operational version of the Geophysical Fluid Dynamics Laboratory (GFDL) hurricane forecast model was available only on a 1° grid. The GFDL model was rerun or reanalyzed for 25 U.S. landfalling tropical cyclones from 199...

We describe the third version of Geophysical Fluid Dynamics Laboratory cloud microphysics scheme (GFDL MP v3) implemented in System for High-resolution prediction on Earth-to-Local Domains (SHiELD). Compared to GFDL v2, v3 is entirely reorganized, optimized, and modularized into functions. The particle size distribution (PSD) all hydrometeor categories redefined better mimic observations, dropl...