Remotely sensed specific humidity: Development of a derived product from the GOES Imager channel 3

Moody, J. L.; Wimmers, Anthony; Devenport, Joseph

doi:10.1029/1998gl900222

Cited by 24 publications

(19 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dry air at middle levels can have a negative impact on convective activity by reducing the updraft buoyancy via entrainment and decreasing the precipitation efficiency within developing systems (Ruprecht and Gray 1974;Gray 1975;Bister and Emanuel 1997). As described by Moody et al (1999), the geostationary satellite water vapor imagery in cloud-free regions is sensitive to the relative humidity in the mid-to upper troposphere. Hence, the average brightness temperature (BTWARM) within each 58 3 58 latitudelongitude subregion is calculated after removing all pixels colder than 2408C and is used as an approximation of the midlevel moisture.…”

Section: Cloud-cleared Water Vapor Brightness Temperaturementioning

confidence: 99%

Objective Estimation of the 24-h Probability of Tropical Cyclone Formation

Schumacher

DeMaria

Knaff

2009

Weather and Forecasting

View full text Add to dashboard Cite

A new product for estimating the 24-h probability of TC formation in individual 58 3 58 subregions of the North Atlantic, eastern North Pacific, and western North Pacific tropical basins is developed. This product uses environmental and convective parameters computed from best-track tropical cyclone (TC) positions, National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) analysis fields, and water vapor (;6.7 mm wavelength) imagery from multiple geostationary satellite platforms. The parameters are used in a two-step algorithm applied to the developmental dataset. First, a screening step removes all data points with environmental conditions highly unfavorable to TC formation. Then, a linear discriminant analysis (LDA) is applied to the screened dataset. A probabilistic prediction scheme for TC formation is developed from the results of the LDA.Coefficients computed by the LDA show that the largest contributors to TC formation probability are climatology, 850-hPa circulation, and distance to an existing TC. The product was evaluated by its Brier and relative operating characteristic skill scores and reliability diagrams. These measures show that the algorithmgenerated probabilistic forecasts are skillful with respect to climatology, and that there is relatively good agreement between forecast probabilities and observed frequencies. As such, this prediction scheme has been implemented as an operational product called the National Environmental Satellite, Data, and Information Services (NESDIS) Tropical Cyclone Formation Probability (TCFP) product. The TCFP product updates every 6 h and displays plots of TC formation probability and input parameter values on its Web site. At present, the TCFP provides real-time, objective TC formation guidance used by tropical cyclone forecast offices in the Atlantic, eastern Pacific, and western Pacific basins.

show abstract

Section: Cloud-cleared Water Vapor Brightness Temperaturementioning

confidence: 99%

Objective Estimation of the 24-h Probability of Tropical Cyclone Formation

Schumacher

DeMaria

Knaff

2009

Weather and Forecasting

View full text Add to dashboard Cite

show abstract

“…Radiation at this infrared wavelength is emitted by water vapor in the mid and upper troposphere, with water vapor at warmer temperatures emitting greater amounts of radiation. These water vapor images can be interpreted as relative humidity in the mid to upper troposphere [Soden and Bretherton, 1993;Moody et al, 1999], with the blues and purples indicating relatively dry air and the greens, yellows and reds indicating relatively moist air.…”

Section: Goes-east Water Vapor Satellite Imagesmentioning

confidence: 99%

Intercontinental transport and its influence on the ozone concentrations over central Europe: Three case studies

et al. 2003

View full text Add to dashboard Cite

In this paper we report on a detailed analysis of the first clear observation of ozone import from North America in the free troposphere over central Europe in May 1996 and of two more recent cases of transatlantic transport. The analysis is based on calculations with the FLEXTRA trajectory model and the FLEXPART tracer model and data from Measurements of Ozone and Water Vapor by Airbus In‐Service Aircraft (MOZAIC) flights and North American surface sites. Lidar measurements carried out under conditions of developing anticyclonicity at Garmisch‐Partenkirchen, Germany, consistently yield peak ozone mixing ratios in the middle and upper troposphere between 80 and 110 ppb during the warm season. These layers are traced back to North America by FLEXTRA trajectories. The prevailing transport pathway involves a warm conveyor belt exporting high amounts of ozone, formed during a prefrontal high‐ozone episode, from the central part of the eastern United States to the upper troposphere. The polluted air may enter central Europe above an airstream descending from the stratosphere, thus inverting the normal atmospheric stratification, with stratospheric air at low levels and boundary layer air in the upper troposphere. However, the first two cases studied in this paper show that the export from the eastern United States may arrive over Europe at times prior to the onset of the anticyclonic conditions. Analysis of these cases reveals the complexity of the air export from North America. The ozone maxima occurring during the observational periods are traced back to the planetary boundary layer (PBL) in other source areas in the United States. Some of them are related to entrainments even from source areas beyond North America, either in the stratosphere or in Asia. The third case is quite different in its advection pathway, with almost straight and horizontal advection at 6 to 8 km above sea level starting from the Great Lakes area. A positive correlation between ozone and aerosol in that layer verifies the presence of PBL air. However, the very high ozone mixing ratio (up to 130 ppb) and an anticorrelation of ozone and humidity suggest the entrainment of another component from long‐range transport in the upper troposphere from beyond North America. In two of the case studies the export from the PBL was presumably influenced by large‐scale convection.

show abstract

“…Examples of ABI products are presented in the broad categories of imagery/radiances, water vapor band (6.5/6.7 ^m) can be used to estimate upper-level moisture (Soden and Bretherton 1993;Moody et al 1999) and define upper-level jet streaks (Weldon and Holmes 1991). The finer spatial resolutions of the water vapor bands will allow for the monitoring of finer-scale phenomena.…”

Section: Infraredmentioning

confidence: 99%

“…In addition, this band will be used to study clouds. The 6.2 and 7.0-^m bands will be used for upperlevel tropospheric water vapor tracking, jet stream identification, hurricane track forecasting, midlatitude storm forecasting, severe weather analysis, and upper-level moisture estimation (Soden and Bretherton 1993;Moody et al 1999;Weldon and Holmes 1991). The improved spatial resolution of the ABI is demonstrated in Fig.…”

Section: Infraredmentioning

confidence: 99%