Search Results

You are looking at 41 - 50 of 57 items for :

  • Forecasting techniques x
  • Meteorological Monographs x
  • User-accessible content x
Clear All
Baode Chen, Wen-wen Tung, and Michio Yanai

and discussions are given in section 7 . Finally, methods for computing cross-spectra and budget equation residuals are described in the appendixes. 2. Data and analysis procedures The primary dataset used in this study is the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) which is the latest global atmospheric reanalysis produced by the ECMWF to replace ERA-40. The ERA-Interim was generated by a frozen global data assimilation system along with an

Full access
P. R. Field, R. P. Lawson, P. R. A. Brown, G. Lloyd, C. Westbrook, D. Moisseev, A. Miltenberger, A. Nenes, A. Blyth, T. Choularton, P. Connolly, J. Buehl, J. Crosier, Z. Cui, C. Dearden, P. DeMott, A. Flossmann, A. Heymsfield, Y. Huang, H. Kalesse, Z. A. Kanji, A. Korolev, A. Kirchgaessner, S. Lasher-Trapp, T. Leisner, G. McFarquhar, V. Phillips, J. Stith, and S. Sullivan

to make a measurable contribution to remotely sensed variables. Polarimetric radar can provide valuable information on the locations and characteristics of primary and possible secondary ice [see Buehl et al. (2017 , chapter 10) for more discussion about the retrieval of cloud properties using radar techniques]. By transmitting horizontally and vertically polarized waves and looking at the differences in power and phase between the echoes in each polarization, information about the orientation

Full access
Eric D. Maloney and Chidong Zhang

( Takayabu et al. 2016 , chapter 3). In short, Yanai et al. (1968) computed power spectra and conducted an analysis of spectral coherence for winds at 17 radiosonde stations in the west Pacific during April–July 1962. Spectra were examined at vertical levels from the surface to 25 km, including an analysis of the horizontal and vertical structures of the waves as they propagated across the west Pacific. Madden and Julian were motivated by this work because of the analysis techniques and the scientific

Full access
Thomas P. Ackerman, Ted S. Cress, Wanda R. Ferrell, James H. Mather, and David D. Turner

early 2000s to the formation of the Atmospheric Science Research (ASR) program (described later in this chapter). The 2004 plan identified a set of key science goals: Maintain the data record at the remote sites at least through the next 5-yr period. Improve significantly our understanding of and ability to parameterize the 3D cloud-radiation problem at scales from the local atmospheric column to the GCM grid square. Develop new techniques to retrieve the properties of ice clouds and mixed

Full access
Steven K. Krueger, Hugh Morrison, and Ann M. Fridlind

-scale vertical velocity and advective tendencies from sounding arrays. A history of the development of this technique is provided in Zhang et al. (2016 , chapter 24). It is used to process atmospheric soundings of winds, temperature, and water vapor mixing ratio over a network of a small number of stations. Given the inevitable uncertainties in the original data, the basic idea in this objective analysis approach is to adjust these atmospheric state variables by the smallest possible amounts to conserve

Full access
Randy A. Peppler, Kenneth E. Kehoe, Justin W. Monroe, Adam K. Theisen, and Sean T. Moore

, chapter 2; Cress and Sisterson 2016 , chapter 5). Instrument mentors played and continue to play a vital role by 1) independently monitoring the data produced by their assigned instruments using various analytical and interpretive techniques and 2) reporting their findings on potential problems, suggesting solutions to site operators, and actively participating in the problem-resolution process. Instrument mentors were and continue to be a first line of defense in data quality assessment and problem

Full access
Margaret A. LeMone, Wayne M. Angevine, Christopher S. Bretherton, Fei Chen, Jimy Dudhia, Evgeni Fedorovich, Kristina B. Katsaros, Donald H. Lenschow, Larry Mahrt, Edward G. Patton, Jielun Sun, Michael Tjernström, and Jeffrey Weil

Kosović (1997) . The origin of LES has roots in the atmospheric science community, but the engineering community rapidly adopted the technique (e.g., Reynolds 1976 ) and started to benefit the atmospheric boundary layer community, especially in the context of representing subgrid effects. 8 Leonard (1974) and Germano (1986) , for example, provided a useful way to represent SGS parameterization for the filtered Navier–Stokes equations, by dividing the subgrid stresses into three sets of terms that

Full access
Ronald B. Smith

winds aloft. Fig . 20-28. Wind reduction in two CAP events in the Aizu basin in Japan in 1986. This time–height series shows weaker winds in the stippled CAP. Typical CAP depth is 800–1500 m. [From Kondo et al. (1989 ).] The occurrence of CAP is considered a forecasting challenge of the first order. CAP is closely associated with pollution events with human health impacts. CAP forecasting is complex because of the multiple processes involved such as the surface heat budget, shear-induced turbulence

Full access
Lee-Lueng Fu, Tong Lee, W. Timothy Liu, and Ronald Kwok

)]. (bottom) The mean ocean surface dynamic topography estimated from multiple altimeters to spherical harmonics degree and order 2160 (~20 km). (Per Knudsen, with permission via personal communication.) The technique of orbit determination and the associated gravity field has been significantly improved since the mid-1990s, especially via the gravity missions of GRACE and Gravity Field and Ocean Circulation Explorer (GOCE, an ESA mission). Shown in Fig. 5-1 (lower panel) (P. Knudsen 2018, personal

Full access
Carl Wunsch and Raffaele Ferrari

of systematic and stochastic errors in under-resolved models must be understood. b. State estimation/data assimilation The meteorological community, beginning in the early 1950s ( Kalnay 2002 ), pioneered the combination of observational data with system dynamics encompassed in the numerical equations of general circulation models [numerical weather prediction (NWP) models]. Almost all of this work was directed at the urgent problem of weather forecasting and came to be known as “data

Full access