A Case Study of Four Atmospheric River Events Over the Pacific West Coast of the United States

Atmospheric Rivers (AR) are moisture phenomena related to cyclones which bring moisture and large amounts of precipitation to areas of enhanced elevation along coastal areas. These events bring much of the rain received by the state of California, and the past winter was no exception, as many AR events brought much-needed rain to the region. Four different events from the 2016 fall through 2017 spring seasons are examined to better identify the relative roles of long-range moisture transport versus local moisture fluxes in AR events. Cross-sections of areas and times of interest during each event are generated, along with trajectory analyses which will aid in determining the origin of the moisture being moved. Both the cross-sections and trajectory analyses are taken from the CFSR (Climate Forecast System Reanalysis) model. It is expected that the results of these processes will support the findings of Dacre et al. (2015), which show that the moisture anomaly present during AR events is not actually due to moisture transport directly along the AR. Rather, the AR is the result of moisture convergence from a combination of the warm conveyor belt forcing the ascent of moisture over the warm front and the trailing cold front forcing ascent as it moves eastward. The importance of this research is evident on the US West Coast, as water conservation in this naturally dry region is extremely important to the ever-expanding cities and communities present there and requires long-term planning, which is aided by our increased understanding of AR events

Molecular contamination study by interaction of a molecular beam with a platinum surface

The capability of molecular beam scattering from a solid surface is analyzed for identification of molecular contamination of the surface. The design and setup of the molecular beam source and the measuring setup for the application of a phase sensitive measuring technique for the determination of the scattered beam intensity are described. The scattering distributions of helium and nitrogen molecular beams interacting with a platinum surface were measured for different amounts of contamination from diffusion pump oil for surface temperatures ranging from 30 to 400 C. The results indicate the scattering of molecular beams from a platinum surface is a very sensitive method for detecting surface contamination

Solar panel thermal cycling testing by solar simulation and infrared radiation methods

For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method

Stable operation of a synchronously pumped colliding-pulse mode-locked ring dye laser

Pulses of 100-fsec duration are obtained by synchronous pumping of a colliding-pulse ring dye laser with a mode-locked Ar+-ion laser. Stable operation of the synchronously pumped colliding-pulse mode-locked laser over hours was obtained by a suitable choice of the distance between the gain and the absorber in combination with an appro-priate pump-pulse sequence. Passive mode locking of a ring dye laser by the inter-action of two counterpropagating pulses in a thin sat-urable absorber (colliding-pulse mode locking) yields femtosecond laser pulses. ' In these lasers the gain medium (Rhodamine 6G) is pumped by a cw Ar+-ion laser. The saturable absorber (DODCI, 3,3-diethyl-oxadicarbocyanine iodide) synchronizes two counter-propagating pulses meeting in the absorber jet stream. The colliding pulses form a transient grating, which synchronizes and stabilizes the pulses.2 In order to ensure equal amplification for both counterpropagatin