Search Results

You are looking at 101 - 110 of 807 items for :

  • Journal of Atmospheric and Oceanic Technology x
  • Refine by Access: All Content x
Clear All
Viatcheslav V. Tatarskii, Maia S. Tatarskaia, and Ed R. Westwater

estimatorof p(h) and its integral does not equal V. In the following, we introduce our method that yields an estimate that is positive and integrates to V but is not anunbiased statistical estimator. Many problems in climatology and weather forecasting require information about humidity fields ofthe atmosphere. There is now an increased availabilityof instruments to measure integrated moisture contentof the atmosphere from the ground--for example, microwave radiometers (Westwater 1993), Global

Full access
Brett T. Hoover and Chris S. Velden

brightness temperature observations from observed radiance (top). The largest absolute impact for Joaquin comes from in situ aircraft observations from the U.S. Meteorological Data Collection and Reporting System (MDCRS), a U.S. branch of the World Meteorological Organization’s Aircraft Meteorological Data Relay (AMDAR) program. These observations include winds, temperatures, and moisture observations collected both at flight level and in profiles when aircraft are ascending and descending at airports

Restricted access
C. A. Friehe, R. L. Grossman, and Y. Pann

instrument to changes in ambient moisture is difficult to determine or measure. Frequently, vari ation of the many adjustments results in an over damped or under-damped, oscillating, condition. With proper adjustment, response time is of the order of a few Seconds. Cooling rates can be 3.0-C s-~. Accuracy is +_0.5-C above freezing and ___ 1.0-C below freezing. The Lyman-alpha hygrometer operates on the principle of Beers' Law absorption of light by the densityof water vapor in the atmospheric path

Full access
Shixuan Pang, Hartmut Graßl, and Horst Jäger

vapor from the air. Therefore,the capacitance of the porous material varies with humidity, usually relative humidity (RH). For example,a capacitive sensor's capacitance changes from 107 to122 pF when relative humidity varies from 0% to 100%(Ward 1983). Most of these sensors are relatively cheap, small, andeasy to use, particularly polymer sensors. However,they suffer from hysteresis due to unequal moisture adsorption and desorption (Coantic and Friehe 1980),which significantly limits their

Full access
Martha Shulski, Stonie Cooper, Glen Roebke, and Al Dutcher

management decisions, and provide soil moisture and precipitation for municipal flood control decisions. Financial support through client relationships for measuring environmental parameters is critical to the operations of the mesonet and provides a significant source of funding. The current rate on a per station basis is \$2,600 per year. This charge covers all necessary requirements to maintain a station, including transportation to and from the location, communications, calibration services, sensor

Full access
Renee A. McPherson, Christopher A. Fiebrich, Kenneth C. Crawford, James R. Kilby, David L. Grimsley, Janet E. Martinez, Jeffrey B. Basara, Bradley G. Illston, Dale A. Morris, Kevin A. Kloesel, Andrea D. Melvin, Himanshu Shrivastava, J. Michael Wolfinbarger, Jared P. Bostic, David B. Demko, Ronald L. Elliott, Stephen J. Stadler, J. D. Carlson, and Albert J. Sutherland

installation, soil temperature is also monitored at 30 cm under native vegetation. Soil moisture sensors are installed to the west of the tower at depths of 5, 25, 60, and 75 cm, if possible. During station installation, soil samples were extracted from the locations of the below-ground sensors for soil textural analysis. Northwest of the tower, a 121-cm-diameter Alter shield ( Alter 1937 ) surrounds the aboveground rain gauge. The height of the shield does not exceed that of the orifice of the gauge, and

Full access
Dean Vickers and L. Mahrt

virtual temperature are recorded at a frequency of 10 Hz, resulting in 36 000 data points per record. The spring dataset consists of 63 records and the fall set of 546 records. 3. Microfronts95 The Microfronts95 field program took place during the spring of 1995 in south-central Kansas. The experiment was designed to study coherent structures in the atmospheric surface layer. Instrumentation included multiple towers with wind, temperature, moisture, and radiation instruments at multiple levels. The

Full access
D. D. Turner, B. M. Lesht, S. A. Clough, J. C. Liljegren, H. E. Revercomb, and D. C. Tobin

soundings. This radiosonde incorporates the H-humicap capacitive moisture sensor that is more sensitive and stable than the more commonly used A-humicap ( Antikainen and Paukkunen 1994 ). The 1.5-s raw data sent from the radiosonde are processed with the standard ground-station software, and quality controlled (i.e., filtered, edited, and interpolated) before being output with 2-s resolution. All the soundings are done with 350-g balloons and have an approximate ascent rate of 5 m s −1 . ARM currently

Full access
Nathan M. Reiss and James C. Hofmann

is modularized into sections, each one dealingwith one aspect of the forecast problem. As in the caseof the section dealing with use of existing weather conditions, sections may be skipped altogether, dependingon information that is received during the consultation.Figure 2 is a flowchart of the section that evaluates ifsufficient moisture is available. The diagram illustratesonly the original operational version of the section andobviously does not at this time represent the

Full access
J. H. McCaughey, D. W. Mullins, and M. Publicover

psychrometers pointing NW in the direction of maximumfetch. The pivot system was "free," i.e., allowed to rotate into the wind from 28 August until 1000 localtime 1 September. It was then stabilized and also oriented NW. Supporting data on soil moisture content, horizontalwindspeed, wind direction and sky condition weremonitored (Table 1). Windspeed and wind directionwere measured at the level of the top psychrometerwith a Gill 3-cup anemometer and microvane (models12102 and 12302, respectively). Hourly

Full access