DOCSLIB.ORG

Chapter 13 100 Years of Progress in Forecasting and NWP Applications

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 13 100 Years of Progress in Forecasting and NWP Applications CHAPTER 13 BENJAMIN ET AL. 13.1 Chapter 13 100 Years of Progress in Forecasting and NWP Applications STANLEY G. BENJAMIN AND JOHN M. BROWN NOAA/Office of Oceanic and Atmospheric Research/Earth System Research Laboratory Global Systems Division, Boulder, Colorado a GILBERT BRUNET Environment and Climate Change Canada, Montreal, Quebec, Canada PETER LYNCH University College Dublin, Dublin, Ireland KAZUO SAITO Atmosphere and Ocean Research Institute, University of Tokyo, Tokyo, Japan b THOMAS W. SCHLATTER NOAA/Office of Oceanic and Atmospheric Research, Boulder, Colorado ABSTRACT Over the past 100 years, the collaborative effort of the international science community, including gov- ernment weather services and the media, along with the associated proliferation of environmental observa- tions, improved scientific understanding, and growth of technology, has radically transformed weather forecasting into an effective global and regional environmental prediction capability. This chapter traces the evolution of forecasting, starting in 1919 [when the American Meteorological Society (AMS) was founded], over four eras separated by breakpoints at 1939, 1956, and 1985. The current state of forecasting could not have been achieved without essential collaboration within and among countries in pursuing the common weather and Earth-system prediction challenge. AMS itself has had a strong role in enabling this international collaboration. 1. Introduction in our ability to observe the atmosphere, by application of rigorous physical principles to understanding atmo- Weather forecasting has evolved over the past century spheric phenomena, and by the advent and subsequent from being an empirical, analog-based process with little enormous increase in digital computing capability. Daily skill to an increasingly automated high-tech enterprise decisions, with outcomes from inconsequential to far- demonstrating tremendous prediction accuracy. This reaching in magnitude made by groups and individuals, transformation has been enabled by spectacular advances are based on the forecast community’s assessment of fu- ture environmental conditions—forecasting, and espe- a Current affiliation: Bureau of Meteorology, Melbourne, Vic- cially, weather forecasting. Vilhelm Bjerknes (Bjerknes toria, Australia. 1911) referred to forecasting as the ultimate problem in b Retired. meteorology. In this chapter, we trace the progress of weather fore- Corresponding author: Stan Benjamin, [email protected] casting and scientific questions leading to that progress DOI: 10.1175/AMSMONOGRAPHS-D-18-0020.1 Ó 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses). Unauthenticated | Downloaded 10/08/21 04:54 AM UTC 13.2 METEOROLOGICAL MONOGRAPHS VOLUME 59 TABLE 13-1. Overview—100 years of progress in forecasting within four historical eras and for eight components of forecasting. Community of forecast Observations used for Science understanding providers (government and State of forecasting forecasting influencing forecasting specialized forecasters) Era 1: 1919–39 Empirical; little skill; based Surface obs primarily; Bergen 3D airmass frontal Government agencies were on surface weather maps virtually no real-time structure for extratopics dominant in the early and extrapolation of observations above the but only small impact on forecast-provider patterns surface except for a few forecasting community aircraft soundings Era 2: 1939–56 Forecasting for military Rawinsondes enabled by 3D structure of baroclinic Government–military central in WWII; upper- radio transmission; radar waves and jet streams cooperation; university level charts became developed but not yet revealed by increased departments formed; widely available to available widely upper-air obs; QG theory private sector emerges; understand patterns and baroclinic instability international community of national agencies Era 3: 1956–85 After 1958–60, NWP used Introduction of weather Convective-storm and International meteorology for upper-level changes satellites—images for mesoscale convective community grows but surface conditions short-term forecasting system dynamics; (GARP; WMO) for obs and QPF were inferred; and retrievals for NWP; importance of latent and forecasting; national severe weather radar network in United heating and other physics weather services forecasting added States for NWP modernize Era 4: 1985–2018 Steady increase in Increased satellite coverage, Oceanic cyclogenesis; more Role increases with dependency on NWP especially for microwave complete understanding stronger overall during this era with andGNSSandfor of small-scale processes environmental gradual transformation of geostationary; DA of enabling improved awareness; forecasters human role from radiances; increased radar subgrid-scale physical- become more modifying NWP into data in most countries, process communicators as NWP communication with including Doppler parameterizations (cloud; matures; private sector of users velocity; automated turbulence; fluxes from forecasters strengthens commercial aircraft data ground) with public and academic added, especially in 1990s toward a ‘‘global weather and 2010s enterprise’’ Next 30 years Yet more automation of Integrated, cost-effective Increased understanding of Maturing of GWE with forecasting process, obs network will meet weather systems in terms stronger roles of public, allowing more forecaster demands of seamless of local phenomena and private, and academic focus on communication weather/climate multiscale interaction with components and to decision-makers, forecasting; NEWP DA other systems (e.g., intercoordination; WMO especially in critical high- will become continuous atmosphere–ocean– will continue impact weather events, and use increasing waves), dynamic processes coordinating, and model evaluation traditional and new (e.g., moist and dry air in- disseminating, and sources of atmosphere– teractions), and physical implementing NEWP ocean–land–cryosphere– processes (e.g., chemistry innovations developed by biosphere obs interaction between aero- national services to sol and cloud microphysics) benefit all nations over the last 100 years. This progress is broken down here in understanding the atmosphere–Earth system (e.g., into four 20–30-yr periods, in each of which, the science Randall et al. 2019). Repeated application of the sci- and practice of forecasting underwent major shifts. entific method—asking questions, constructing new This chapter on forecasting complements scientific hypotheses, and then conducting experiments and developments described in other chapters of this collecting observations to test them—is behind the monograph and distills from them. The science of fore- development of weather forecasting and all of the casting has followed close on the heels of overall progress science topics of this monograph. in atmospheric science (understanding and numerical In each era, we identify, where appropriate, obser- representation of physical processes and phenomena vations used for forecasting and the process of ana- described in other chapters) but has often, in turn, lyzing those observations into a coherent picture accelerated research in these related areas, often fol- (a weather map), growth in the scientific under- lowing major forecasting failures. Forecasting, in general, standing that influenced the practice of forecasting, and numerical prediction models have aided tremendously the community of weather forecast providers from Unauthenticated | Downloaded 10/08/21 04:54 AM UTC CHAPTER 13 BENJAMIN ET AL. 13.3 TABLE 13-1. (Extended) Technology advances Media; communication; leading to changes in comprehension of Forecasting applications Quantitative forecasting (NWP) forecasting/science forecasting by the public Public, agriculture, and None yet but groundwork being laid Teletype relay for obs; Primarily newspapers; radio marine safety; aviation (Richardson; Rossby; Bjerknes) rawinsondes developed emerges; skepticism from enters as a major driver using radio relay the public but widespread use enabled by radio Aviation—military and NWP development begins (JNWPU; Invention of digital Radio; television gains civilian; public safety Sweden); not yet used for forecasting computer enables initial prominence NWP development Watch and warning for Rapid advance in NWP from equivalent Steady increase in Television is primary severe weather/flash barotropic to PE models with limited computing; design of first medium; specialized floods; improved physics; initial DA; first global models interactive display cable networks started awareness of aviation systems for weather data hazards from severe local storms Weather dependence Global models, especially spectral, with More powerful computing Increasing accuracy for recognized for public advanced DA, including direct DA of for NWP and interactive weather hazards safety and in all economic satellite radiances; regional models display systems and recognized for longer sectors for decision- used widely for short range; interactive production of duration and at smaller making (transport, severe nonhydrostatic models for severe/local forecasts; Internet used scales; cable, personal weather, energy, etc.); weather; transition into Earth-system for scientific computers, Internet, and climate and subseasonal- prediction; probabilistic and ensemble collaboration cellular-phone to-seasonal-prediction prediction availability
Load more

Recommended publications
  • Satellite Meteorology in the Cold War Era: Scientific Coalitions and International Leadership 1946-1964
    SATELLITE METEOROLOGY IN THE COLD WAR ERA: SCIENTIFIC COALITIONS AND INTERNATIONAL LEADERSHIP 1946-1964 A Dissertation Presented to The Academic Faculty By Angelina Long Callahan In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy in History and Sociology of Technology and Science Georgia Institute of Technology December 2013 Copyright © Angelina Long Callahan 2013 SATELLITE METEOROLOGY IN THE COLD WAR ERA: SCIENTIFIC COALITIONS AND INTERNATIONAL LEADERSHIP 1946-1964 Approved by: Dr. John Krige, Advisor Dr. Leo Slater School of History, Technology & History Office Society Code 1001.15 Georgia Institute of Technology Naval Research Laboratory Dr. James Fleming Dr. Steven Usselman School of History, Technology & School of History, Technology & Society Society Colby College Georgia Institute of Technology Dr. Kenneth Knoespel Date Approved: School of History, Technology & 6 November 2013 Society Georgia Institute of Technology ACKNOWLEDGEMENTS I submit this dissertation mindful that I’ve much left to do and much left to learn. Thus, lacking more elegant phrasing, I dedicate this to anyone who has set aside their own work to educate me. All of you listed below are extremely talented and because of that, managing substantial workloads. In spite of that, you have each been generous with your insight over the years and I am grateful for every meeting, email, and gesture of support you have shown. First, I want to thank my dissertation committee. I am extremely proud to claim each of you as a mentor. Please know how grateful I am for your patience and constructive criticism with this work in progress as it evolved milestone by milestone.
    [Show full text]
  • Evidence of Fire in the Pliocene Arctic in Response to Elevated CO2 and Temperature
    1 Evidence of fire in the Pliocene Arctic in response to elevated CO2 and temperature 2 Tamara Fletcher1*, Lisa Warden2*, Jaap S. Sinninghe Damsté2,3, Kendrick J. Brown4,5, Natalia 3 Rybczynski6,7, John Gosse8, and Ashley P Ballantyne1 4 1 College of Forestry and Conservation, University of Montana, Missoula, 59812, USA 5 2 Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Den 6 Berg, 1790, Netherlands 7 3 Department of Earth Sciences, University of Utrecht, Utrecht, 3508, Netherlands 8 4 Natural Resources Canada, Canadian Forest Service, Victoria, V8Z 1M, Canada 9 5 Department of Earth, Environmental and Geographic Science, University of British Columbia Okanagan, Kelowna, 10 V1V 1V7, Canada 11 6 Department of Palaeobiology, Canadian Museum of Nature, Ottawa, K1P 6P4, Canada 12 7 Department of Biology & Department of Earth Sciences, Carleton University, Ottawa, K1S 5B6, Canada 13 8 Department of Earth Sciences, Dalhousie University, Halifax, B3H 4R2, Canada 14 *Authors contributed equally to this work 15 Correspondence to: Tamara Fletcher ([email protected]) 16 Abstract. The mid-Pliocene is a valuable time interval for understanding the mechanisms that determine equilibrium 17 climate at current atmospheric CO2 concentrations. One intriguing, but not fully understood, feature of the early to 18 mid-Pliocene climate is the amplified arctic temperature response. Current models underestimate the degree of 19 warming in the Pliocene Arctic and validation of proposed feedbacks is limited by scarce terrestrial records of climate 20 and environment, as well as discrepancies in current CO2 proxy reconstructions. Here we reconstruct the CO2, summer 21 temperature and fire regime from a sub-fossil fen-peat deposit on west-central Ellesmere Island, Canada, that has been 22 chronologically constrained using radionuclide dating to 3.9 +1.5/-0.5 Ma.
    [Show full text]
  • The Life Cycle of Upper-Level Troughs and Ridges: a Novel Detection Method, Climatologies and Lagrangian Characteristics
    Weather Clim. Dynam., 1, 459–479, 2020 https://doi.org/10.5194/wcd-1-459-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. The life cycle of upper-level troughs and ridges: a novel detection method, climatologies and Lagrangian characteristics Sebastian Schemm, Stefan Rüdisühli, and Michael Sprenger Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland Correspondence: Sebastian Schemm ([email protected]) Received: 12 March 2020 – Discussion started: 3 April 2020 Revised: 4 August 2020 – Accepted: 26 August 2020 – Published: 10 September 2020 Abstract. A novel method is introduced to identify and track diagnostics such as E vectors. During La Niña, the situa- the life cycle of upper-level troughs and ridges. The aim is tion is essentially reversed. The orientation of troughs and to close the existing gap between methods that detect the ridges also depends on the jet position. For example, dur- initiation phase of upper-level Rossby wave development ing midwinter over the Pacific, when the subtropical jet is and methods that detect Rossby wave breaking and decay- strongest and located farthest equatorward, cyclonically ori- ing waves. The presented method quantifies the horizontal ented troughs and ridges dominate the climatology. Finally, trough and ridge orientation and identifies the correspond- the identified troughs and ridges are used as starting points ing trough and ridge axes. These allow us to study the dy- for 24 h backward parcel trajectories, and a discussion of the namics of pre- and post-trough–ridge regions separately. The distribution of pressure, potential temperature and potential method is based on the curvature of the geopotential height vorticity changes along the trajectories is provided to give in- at a given isobaric surface and is computationally efficient.
    [Show full text]
  • Tropical Upper Tropospheric Potential Vorticity Intrusions
    Generated using version 3.2 of the official AMS LATEX template 1 Tropical Upper Tropospheric Potential Vorticity Intrusions 2 During Sudden Stratospheric Warmings ∗ 3 John R. Albers, Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder 4 Physical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado 5 George N. Kiladis Physical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado 6 Thomas Birner Department of Atmospheric Science Colorado State University, Fort Collins, Colorado 7 Juliana Dias Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder Physical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado ∗Corresponding author address: John R. Albers, CIRES, University of Colorado 216 UCB, Boulder, CO 80309. E-mail: [email protected] 1 8 ABSTRACT 9 We examine the intrusion of lower stratospheric extratropical potential vorticity into the 10 tropical upper troposphere in the weeks surrounding the occurrence of sudden stratospheric 11 warmings (SSWs). Our analysis reveals that SSW-related PV intrusions are significantly 12 stronger, penetrate more deeply into the tropics, and exhibit distinct geographic distributions 13 compared to their climatological counterparts. 14 While climatological upper tropospheric and lower stratospheric (UTLS) PV intrusions 15 are generally attributed to synoptic scale Rossby wave breaking, we find that SSW-related 16 PV intrusions are governed by planetary scale wave disturbances that deform the extra- 17 tropical meridional PV gradient maximum equatorward. As these deformations unfold, 18 planetary-scale wave breaking along the edge of the polar vortex extends deeply into the 19 subtropical and tropical UTLS. In addition, the material PV deformations also reorganize 20 the geographic structure of the UTLS waveguide, which alters where synoptic scale waves 21 break.
    [Show full text]
  • Chapter 3 Mesoscale Processes and Severe Convective Weather
    CHAPTER 3 JOHNSON AND MAPES Chapter 3 Mesoscale Processes and Severe Convective Weather RICHARD H. JOHNSON Department of Atmospheric Science. Colorado State University, Fort Collins, Colorado BRIAN E. MAPES CIRESICDC, University of Colorado, Boulder, Colorado REVIEW PANEL: David B. Parsons (Chair), K. Emanuel, J. M. Fritsch, M. Weisman, D.-L. Zhang 3.1. Introduction tion, mesoscale phenomena occur on horizontal scales between ten and several hundred kilometers. This Severe convective weather events-tornadoes, hail­ range generally encompasses motions for which both storms, high winds, flash floods-are inherently mesoscale ageostrophic advections and Coriolis effects are im­ phenomena. While the large-scale flow establishes envi­ portant (Emanuel 1986). In general, we apply such a ronmental conditions favorable for severe weather, pro­ definition here; however, strict application is difficult cesses on the mesoscale initiate such storms, affect their since so many mesoscale phenomena are "multiscale." evolution, and influence their environment. A rich variety For example, a -100-km-Iong gust front can be less of mesocale processes are involved in severe weather, than -1 km across. The triggering of a storm by the ranging from environmental preconditioning to storm initi­ collision of gust fronts can actually occur on a ation to feedback of convection on the environment. In the -lOO-m scale (the microscale). Nevertheless, we will space available, it is not possible to treat all of these treat this overall process (and others similar to it) as processes in detail. Rather, we will introduce s~veral mesoscale since gust fronts are generally regarded as general classifications of mesoscale processes relatmg to mesoscale phenomena.
    [Show full text]
  • Another Look at the Index Cycle
    Tellus (1985).37,4,478486 Another look at the index cycle By JOHN M. WALLACE and HUANG-HSIUNG HSU. Departi?leilt o/ Atn7ospheric Scicwccs, AK-40. Uiiiversity of Washirigtoil, Seattle, WA 981 95, USA (Manuscript received September 21. 1984: in final form March 15, 1985) ABSTRACT Relationships between the zonal index, as defined by Rossby. the hemispheric circulation pattern. the amplitude of the zonally asymmetric or "eddy" component of the hemispheric circulation, and the amplitude of the stationary wave pattern during northern hemisphere winter are investigated using 27 years of gridded 5-day mean 500 mb height data from the US National Meteorological Center. In agreement with preliminary results reported in Rossby. the major stationary wave features appear to be displaced to the east of their climatological mean positions during periods of strong zonal flow. and cice cersa. The zonal index shows only a weak negative temporal correlation with an index designed to monitor the hemispherically averaged variance of the eddy component of the 500 mb height field. Eddy amplitude is much more strongly correlated with the amplitude of the climatological mean stationary wave pattern. Hence. the notion of an "index cycle", interpreted in terms of amplitude vacillation. does not appear to have much relevance to the northern hemisphere winter-time circulation. The situation may be different in the southern hemisphere, where the stationary waves are much weaker. 1. Introduction 1938-39 winter. During episodes of weak wester- lies within that winter, the Aleutian low was located During the early years of the long-range as far west as 160" E.
    [Show full text]
  • Atmospheric Centers of Action in Northern Hemisphere from Observations and Simulations: Interannual Variability and Long-Term Tendencies of Change
    Atmospheric Centers of Action in Northern Hemisphere from Observations and Simulations: Interannual Variability and Long-Term Tendencies of Change I.I. Mokhov, V.Ch. Khon A.M. Obukhov Institute of Atmospheric Physics RAS 3 Pyzhevsky, 119017 Moscow, Russia ([email protected]). Interannual and long-term changes of Atmospheric Centers of Action (CoAs) in the Northern Hemisphere (NH) are analyzed using different data sets based on observations (Catalogue, 1988; Jones, 1987; Kistler et al., 2001) and global climate model simulations with anthropogenic IPCC scenarios, including coupled general circulation models ECHAM4/OPYC3 (Oberhuber, 1993; Roeckner et al., 1996), HadCM3 (Collins et al., 2001) and IAP RAS climate model (CM) of intermediate complexity (Petoukhov et al., 1998; Mokhov et al., 2002). Tendencies of change of CoAs are estimated with use of temperature data from (Jones and Moberg, 2003). Special attention is paid to winter seasons with the largest temperature changes near surface. Sensitivity of the CoAs characteristics to the change of the NH surface air temperature (TNH) can be estimated by coefficients of appropriate linear regressions. Table 1 presents coefficients of regression of CoAs characteristics to the TNH variations in winter for the period 1949-2000. All analyzed data show intensification of Aleutian Low and both North Atlantic CoAs during the second half of the XX century. Tendencies of change of the Siberian High intensity from different data sets are quite contradictory. Aleutian Low and Hawaiian High display statistically significant relationship to the El-Nino/La-Nina phenomena with intensification of this relationship to the end of the XX century. Aleutian Low deepens (weakens) and shifts eastward (westward) and Hawaiian High weakens (strengthens) and shifts southward (northward) during the El-Nino (La-Nina) events.
    [Show full text]
  • Cooperative Institute for Mesoscale Meteorological Studies the University of Oklahoma
    COOPERATIVE INSTITUTE FOR MESOSCALE METEOROLOGICAL STUDIES THE UNIVERSITY OF OKLAHOMA Final Report for Cooperative Agreement NA67RJ0150 July 1, 1996-June 30, 2001 Peter J. Lamb, Director Randy A. Peppler, Associate Director John V. Cortinas, Jr., Assistant Director I. Introduction The University of Oklahoma (OU) and NOAA established the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) in 1978. Through 1995, CIMMS promoted cooperation and collaboration on problems of mutual interest among research scientists in the NOAA Environmental Research Laboratories (ERL) National Severe Storms Laboratory (NSSL), and faculty, postdoctoral scientists, and students in the School of Meteorology and other academic departments at OU. The Memorandum of Agreement (MOA) between OU and NOAA that established CIMMS was updated in 1995 to include the National Weather Service (NWS). This expanded the formal OU/NOAA collaboration to the Radar Operations Center (ROC) for the WSR-88D (NEXRAD) Program, the NCEP (National Centers for Environmental Prediction) Storm Prediction Center (SPC), and our local NWS Forecast Office, all located in Norman, Oklahoma. Management of the NSSL came under the auspices of the NOAA Office of Oceanic and Atmospheric Research (OAR) in 1999. The Norman NOAA groups at that time became known as the NOAA Weather Partners. Through CIMMS, university scientists collaborate with NOAA scientists on research supported by NOAA programs and laboratories as well as by other agencies such as the National Science Foundation (NSF), the U.S. Department of Energy (DOE), the Federal Aviation Administration (FAA), and the National Aeronautics and Space Administration (NASA). This document describes the significant research progress made by CIMMS scientists at OU and at our NOAA collaborating institutions during the five-year period July 1, 1996-June 30, 2001.
    [Show full text]
  • Maritime Continent Winter Circulation As a Predictor of El Niño-Southern Oscillation (ENSO) Influence on Ethiopia Summer Rainfall
    Vol. 10(17), pp. 559-569, 15 September, 2015 DOI: 10.5897/SRE2015.6265 Article Number: B6B3E1746894 ISSN 1992-2248 Scientific Research and Essays Copyright©2015 Author(s) retain the copyright of this article http://www.academicjournals.org/SRE Full Length Research Paper Maritime continent winter circulation as a predictor of El Niño-Southern Oscillation (ENSO) influence on Ethiopia summer rainfall Mark R. Jury University of Puerto Rico Mayaguez, PR, USA. University of Zululand, KwaDlangezwa, South Africa. Received 26 May, 2015; Accepted 2 September, 2015 Summer rainfall over the cropping region of Ethiopia is related to the precursor winter circulation around the Maritime Continent and El Niño–Southern Oscillation (ENSO) development and influence. Investigation of this link reveals that sea surface temperature (SST) in the north Indian Ocean and China Sea are anomalously cold and there are low level north-westerly wind anomalies around the Maritime Continent prior to dry summers in Ethiopia. The analysis shows that wind anomalies spread into the Pacific - increasing convection, and across the Indian Ocean and Africa - suppressing convection. Two indices that represent Asian winter monsoon penetration near the Maritime Continent are used to predict Ethiopian summer rainfall at long-lead time. The hindcast fit of the statistical algorithm exceeds 50% during the satellite era (1981-2014). Key words: Climate prediction, Ethiopia. INTRODUCTION Climate variability in Ethiopia is influenced by the Pacific Yeshanew and Jury, 2007; Joly and Voldoire, 2009; El Niño Southern Oscillation (ENSO) (Semazzi et al., Segele et al., 2009; Shaman et al., 2009). 1988; Rowell et al., 1992; Janicot et al., 1996, 2001; Wang and Fan (2009) demonstrate that knowledge on Rowell, 2001) and associated tropical ocean thermocline the evolution of climate patterns in analogue years can (White and Tourre, 2003; Jury and Huang, 2004).
    [Show full text]
  • Parameterization of Atmospheric Convection
    by indicating discount code till Nov20% 30, 2015 Connecting Great Minds WSNEWSU20 off Series on the Science of Climate Change - Volume 1 Parameterization of Atmospheric Convection (In 2 Volumes) Volume 1: Theoretical Background and Formulation Volume 2: Current Issues and New Theories edited by Robert S Plant (University of Reading, UK) and Jun-Ichi Yano (CNRM, Meteo France, France) Precipitating atmospheric convection is fundamental to the Earth’s weather and climate. It plays a leading role in the heat, moisture and momentum budgets. Appropriate modelling of convection is thus a prerequisite for reliable numerical weather prediction and climate modelling. The current standard approach is to represent it by subgrid-scale convection parameterization. Parameterization of Atmospheric Convection provides, for the first time, a comprehensive presentation of this important topic. The two-volume set equips readers with a firm grasp of the wide range of important issues, and thorough coverage is given of both the theoretical and practical aspects. This makes the parameterization problem accessible to a wider range of scientists than before. At the same time, by providing a solid bottom-up presentation of convection parameterization, this set is the definitive reference point for atmospheric scientists and modellers working on such problems. Volume 1 focuses on the basic principles: introductions to atmospheric convection and tropical dynamics, explanations and discussions of key parameterization concepts, and a thorough and critical exploration of the mass-flux parameterization framework, which underlies the methods currently used in almost all operational models and at major climate modelling centres. Volume 2 focuses on the practice, which also leads to some more advanced fundamental issues.
    [Show full text]
  • Principal Weather Systems in Subtropical and Tropical Zones - I
    ENVIRONMENTAL STRUCTURE AND FUNCTION: CLIMATE SYSTEM – Vol. I - Principal Weather Systems in Subtropical and Tropical Zones - I. G. Sitnikov PRINCIPAL WEATHER SYSTEMS IN SUBTROPICAL AND TROPICAL ZONES I. G. Sitnikov The Hydrometeorological Research Center of Russia, Moscow, Russia Keywords: Cloud cluster, depression, easterly, general circulation, hurricane, interaction with extratropics, intertropical convergence zone, mesoconvective system, monsoon, numerical modeling, quasi-biennial oscillation, squall line, subtropical highs, tornado, trade winds, monsoons, tropical cyclone, tropical disturbances, typhoon, waves Contents 1. Introduction 2. The general circulation: tropics and subtropics 2.1. Main Elements 2.2. Trade Winds 2.3. The Intertropical Convergence Zone 2.4. Monsoons 3. Main perturbation systems in tropical and subtropical zones 3.1. Tropical Cyclones 3.2. Waves in the Tropical Atmosphere 3.2.1. Easterly Waves 3.2.2. Other Waves in the Tropical and Equatorial Zone 3.3. Monsoon Depressions and Monsoon Lows 3.4. Madden-Julian Oscillation (MJO) 3.5. Quasi-biennial Oscillation (QBO) 3.6. Mesoscale Rain and Convective Systems 3.7. Cloud Clusters and Squall Lines 3.8. Tornadoes 4. Conclusion Glossary Bibliography Biographical Sketch SummaryUNESCO – EOLSS The principal weatherSAMPLE systems in the subtropi calCHAPTERS and tropical zones may be divided into two classes: 1) those comprising immutable links of the general atmospheric circulation (subtropical Highs as centers of action of the atmosphere, trade winds, the Intertropical convergence zone, monsoons) and 2) main perturbation systems in the tropics and subtropics (tropical cyclones, easterly and some other waves, monsoon depressions and Lows, the quasi-biennial oscillation and Madden-Julian oscillation, mesoscale rain and convective systems, cloud clusters and squall lines, small-scale vortices like tornadoes etc.).
    [Show full text]
  • Stratiform Precipitation in Regions of Convection: a Meteorological Paradox?
    Stratiform Precipitation in Regions of Convection: A Meteorological Paradox? Robert A. Houze Jr. University of Washington, Seattle, Washington ABSTRACT It was once generally thought that stratiform precipitation was something occurring primarily, if not exclusively, in middle latitudes—in baroclinic cyclones and fronts. Early radar observations in the Tropics, however, showed large ra- dar echoes composed of convective rain alongside stratiform precipitation, with the stratiform echoes covering great areas and accounting for a large portion of the tropical rainfall. These observations seemed paradoxical, since stratiform precipitation should not have been occurring in the Tropics, where baroclinic cyclones do not occur. Instead it was fall- ing from convection-generated clouds, generally thought to be too violent to be compatible with the layered, gently set- tling behavior of stratiform precipitation. In meteorology, convection is a dynamic concept; specifically, it is the rapid, efficient, vigorous overturning of the atmosphere required to neutralize an unstable vertical distribution of moist static energy. Most clouds in the Tropics are convection-generated cumulonimbus. These cumulonimbus clouds contain an evolving pattern of newer and older pre- cipitation. The young portions of the cumulonimbus are too violent to produce stratiform precipitation. In young, vigor- ous convective regions of the cumulonimbus, precipitation particles increase their mass by collection of cloud water, and the particles fall out in heavy showers, which appear on radar as vertically oriented convective “cells.” In regions of older convection, however, the vertical air motions are generally weaker, and the precipitation particles drift downward, with the particles increasing their mass by vapor diffusion. In these regions the radar echoes are stratiform, and typically these echoes occur adjacent to regions of younger convective showers.
    [Show full text]