Principal Weather Systems in Subtropical and Tropical Zones - I
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Hadley Cell and the Trade Winds of Hawai'i: Nā Makani
November 19, 2012 Hadley Cell and the Trade Winds of Hawai'i Hadley Cell and the Trade Winds of Hawai‘i: Nā Makani Mau Steven Businger & Sara da Silva [email protected], [email protected] Iasona Ellinwood, [email protected] Pauline W. U. Chinn, [email protected] University of Hawai‘i at Mānoa Figure 1. Schematic of global circulation Grades: 6-8, modifiable for 9-12 Time: 2 - 10 hours Nā Honua Mauli Ola, Guidelines for Educators, No Nā Kumu: Educators are able to sustain respect for the integrity of one’s own cultural knowledge and provide meaningful opportunities to make new connections among other knowledge systems (p. 37). Standard: Earth and Space Science 2.D ESS2D: Weather and Climate Weather varies day to day and seasonally; it is the condition of the atmosphere at a given place and time. Climate is the range of a region’s weather over one to many years. Both are shaped by complex interactions involving sunlight, ocean, atmosphere, latitude, altitude, ice, living things, and geography that can drive changes over multiple time scales—days, weeks, and months for weather to years, decades, centuries, and beyond for climate. The ocean absorbs and stores large amounts of energy from the sun and releases it slowly, moderating and stabilizing global climates. Sunlight heats the land more rapidly. Heat energy is redistributed through ocean currents and atmospheric circulation, winds. Greenhouse gases absorb and retain the energy radiated from land and ocean surfaces, regulating temperatures and keep Earth habitable. (A Framework for K-12 Science Education, NRC, 2012) Hawai‘i Content and Performance Standards (HCPS) III http://standardstoolkit.k12.hi.us/index.html 1 November 19, 2012 Hadley Cell and the Trade Winds of Hawai'i STRAND THE SCIENTIFIC PROCESS Standard 1: The Scientific Process: SCIENTIFIC INVESTIGATION: Discover, invent, and investigate using the skills necessary to engage in the scientific process Benchmarks: SC.8.1.1 Determine the link(s) between evidence and the Topic: Scientific Inquiry conclusion(s) of an investigation. -
Link Between the Double-Intertropical Convergence Zone Problem and Cloud Biases Over the Southern Ocean
Link between the double-Intertropical Convergence Zone problem and cloud biases over the Southern Ocean Yen-Ting Hwang1 and Dargan M. W. Frierson Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195-1640 Edited by Mark H. Thiemens, University of California at San Diego, La Jolla, CA, and approved February 15, 2013 (received for review August 2, 2012) The double-Intertropical Convergence Zone (ITCZ) problem, in which climate models show that the bias can be reduced by changing excessive precipitation is produced in the Southern Hemisphere aspects of the convection scheme (e.g., refs. 7–9) or changing the tropics, which resembles a Southern Hemisphere counterpart to the surface wind stress formulation (e.g., ref. 10). Given the complex strong Northern Hemisphere ITCZ, is perhaps the most significant feedback processes in the tropics, it is challenging to understand and most persistent bias of global climate models. In this study, we the mechanisms by which the sensitivity experiments listed above look to the extratropics for possible causes of the double-ITCZ improve tropical precipitation. problem by performing a global energetic analysis with historical Recent work in general circulation theory has suggested that simulations from a suite of global climate models and comparing one should not only look within the tropics for features that affect with satellite observations of the Earth’s energy budget. Our results tropical precipitation. A set of idealized experiments showed that show that models with more energy flux into the Southern heating a global climate model exclusively in the extratropics can Hemisphere atmosphere (at the top of the atmosphere and at the lead to tropical rainfall shifts from one side of the tropics to the surface) tend to have a stronger double-ITCZ bias, consistent with other (11). -
Tropical Weather Discussion
TROPICAL WEATHER DISCUSSION • Purpose The Tropical Weather Discussion describes major synoptic weather features and significant areas of disturbed weather in the tropics. The product is intended to provide current weather information for those who need to know the current state of the atmosphere and expected trends to assist them in their decision making. The product gives significant weather features, areas of disturbed weather, expected trends, the meteorological reasoning behind the forecast, model performance, and in some cases a degree of confidence. • Content The Tropical Weather Discussion is a narrative explaining the current weather conditions across the tropics and the expected short-term changes. The product is divided into four different sections as outline below: 1. SPECIAL FEATURES (event-driven) The special features section includes descriptions of hurricanes, tropical storms, tropical depressions, subtropical cyclones, and any other feature of significance that may develop into a tropical or subtropical cyclone. For active tropical cyclones, this section provides the latest advisory data on the system. Associated middle and upper level interactions as well as significant clouds and convection are discussed with each system. This section is omitted if none of these features is present. 2. TROPICAL WAVES (event-driven) This section provides a description of the strength, position, and movement of all tropical waves analyzed on the surface analysis, from east to west. A brief reason for a wave’s position is usually given, citing surface observations, upper air time sections, satellite imagery, etc. The associated convection is discussed with each tropical wave as well as any potential impacts to landmasses or marine interests. -
11 General Circulation
Copyright © 2017 by Roland Stull. Practical Meteorology: An Algebra-based Survey of Atmospheric Science. v1.02 “Practical Meteorology: An Algebra-based Survey of Atmospheric Science” by Roland Stull is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. View this license at http://creativecommons.org/licenses/by- nc-sa/4.0/ . This work is available at https://www.eoas.ubc.ca/books/Practical_Meteorology/ 11 GENERAL CIRCULATION Contents A spatial imbalance between radiative inputs and outputs exists for the earth-ocean-atmosphere 11.1. Key Terms 330 system. The earth loses energy at all latitudes due 11.2. A Simple Description of the Global Circulation 330 to outgoing infrared (IR) radiation. Near the trop- 11.2.1. Near the Surface 330 ics, more solar radiation enters than IR leaves, hence 11.2.2. Upper-troposphere 331 there is a net input of radiative energy. Near Earth’s 11.2.3. Vertical Circulations 332 poles, incoming solar radiation is too weak to totally 11.2.4. Monsoonal Circulations 333 offset the IR cooling, allowing a net loss of energy. 11.3. Radiative Differential Heating 334 The result is differential heating, creating warm 11.3.1. North-South Temperature Gradient 335 equatorial air and cold polar air (Fig. 11.1a). 11.3.2. Global Radiation Budgets 336 This imbalance drives the global-scale general 11.3.3. Radiative Forcing by Latitude Belt 338 circulation of winds. Such a circulation is a fluid- 11.3.4. General Circulation Heat Transport 338 dynamical analogy to Le Chatelier’s Principle of 11.4. -
Horse Latitudes
HORSE LATITUDES Introduction The Horse Latitudes are located between latitude 30 and latitude 35 north and south of the equator. The region lies in an area where there is a ridge of high pressure that circles the Earth. The ridge of high pressure is also called a subtropical high. Wind currents on Earth, USGS Sailing ships in these latitudes The area between these latitudes has little precipitation. It has variable winds. Sailing ships sometimes while traveling to distant shores would have the winds die down and the area would be calm for days before the winds increased. Desert formation on Earth These warm dry conditions lead to many well known deserts. In the Northern Hemisphere deserts that lie in this subtropical high included the Sahara Desert in Africa and the southwestern deserts of the United States and Mexico. The Atacama Desert, the Kalahari Desert and the Australian Desert are all located in the southern Horse Latitudes. Two explanations for the name There are two explanations of how these areas were named. This first explanation is well documented. Sailors would receive an advance in pay before they stated on a long voyage which was spent quickly leaving the sailors without money for several months while aboard ship. Sailors work off debt When the sailors had worked long enough to again earn enough to be paid they would parade around the deck with a straw-stuffed effigy of a horse. After the parade the sailors would throw the straw horse overboard. Second explanation about horses The second explanation is not well documented. -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere. -
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. -
Weather and Climate Science 4-H-1024-W
4-H-1024-W LEVEL 2 WEATHER AND CLIMATE SCIENCE 4-H-1024-W CONTENTS Air Pressure Carbon Footprints Cloud Formation Cloud Types Cold Fronts Earth’s Rotation Global Winds The Greenhouse Effect Humidity Hurricanes Making Weather Instruments Mini-Tornado Out of the Dust Seasons Using Weather Instruments to Collect Data NGSS indicates the Next Generation Science Standards for each activity. See www. nextgenscience.org/next-generation-science- standards for more information. Reference in this publication to any specific commercial product, process, or service, or the use of any trade, firm, or corporation name See Purdue Extension’s Education Store, is for general informational purposes only and does not constitute an www.edustore.purdue.edu, for additional endorsement, recommendation, or certification of any kind by Purdue Extension. Persons using such products assume responsibility for their resources on many of the topics covered in the use in accordance with current directions of the manufacturer. 4-H manuals. PURDUE EXTENSION 4-H-1024-W GLOBAL WINDS How do the sun’s energy and earth’s rotation combine to create global wind patterns? While we may experience winds blowing GLOBAL WINDS INFORMATION from any direction on any given day, the Air that moves across the surface of earth is called weather systems in the Midwest usually wind. The sun heats the earth’s surface, which warms travel from west to east. People in Indiana can look the air above it. Areas near the equator receive the at Illinois weather to get an idea of what to expect most direct sunlight and warming. The North and the next day. -
El Niño and Its Impacts on Federated States of Micronesia – Pohnpei And
El Niño and its Impacts on Federated States of Micronesia – Pohnpei and Kosrae What is El Niño? The El Niño – Southern Oscillation (ENSO) is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean and the patterns of sea level pressure, lower- and upper-level winds, and tropical rainfall across the Pacific basin. On periods ranging from about two to seven years, the surface waters across a large swath of the tropical Pacific Ocean warm or cool by anywhere from 1°C to 3°C, compared to normal. This irregular oscillation between warm and cool patterns, referred to as the ENSO cycle, directly affects rainfall distribution in the tropics and can have a strong influence on weather across the Pacific basin. El Niño and La Niña are the extreme phases of the ENSO cycle; between these two phases is a third phase called ENSO-neutral. ENSO-neutral: Under normal conditions strong El Niño in FSM trade winds blow from the east along the equator, pushing warm water into the western Pacific Ocean. Rainfall Less more at first, but then much less; longer and drier dry-season Trade Winds Less weaker, with occasional westerly winds Tropical Cyclones More increased risk, as more storms form closer to the islands El Niño conditions occur when abnormally warm Sea Level Less waters build in tropical region of the central and eastern Pacific Ocean and are usually associated with lower at first, then gradually recovering a weakening of the easterly trade winds, sometimes even reversing to westerlies. -
ESCI 344 – Tropical Meteorology Lesson 3 – General Circulation of the Tropics
ESCI 344 – Tropical Meteorology Lesson 3 – General Circulation of the Tropics References: Forecaster’s Guide to Tropical Meteorology (updated), Ramage Climate Dynamics of the Tropics, Hastenrath Tropical Climatology (2nd ed), McGregor and Nieuwolt Tropical Meteorology, Tarakanov Climate and Weather in the Tropics, Riehl General Circulation of the Tropical Atmosphere, Vol II, Newell et al. “The South Pacific Convergence Zone (SPCZ): A Review”, Vincent, Mon.Wea. Rev., 122, 1949-1970, 1994 “The Central Pacific Near-Equatorial Convergence Zone”, Ramage, J. Geophys. Res., 86, 6580-6598 Reading: Introduction to the Meteorology and Climate of the Tropics, Chapter 3 Vincent, “The SPCZ: A Review” Lau and Yang, “Walker Circulation” James, “Hadley Circulation” Waliser, “Intertropical Convergence Zones” Hastenrath, “Tropical Climates” Madden, “Intraseasonal Oscillation (MJO)” TERMINOLOGY Boreal refers to the Northern Hemisphere Austral refers to the Southern Hemisphere LATITUDINAL HEAT IMBALANCE Net radiation flux is defined as the difference in incoming radiation flux and outgoing radiation flux. A positive net radiation flux indicates a surplus of energy, while a negative net radiation flux indicates a deficit. This figure shows the longitudinally-averaged, annual-mean radiation fluxes at the top of the atmosphere. Outgoing shortwave is due to scattering and reflection. Net shortwave is the difference between the incoming and outgoing shortwave radiation. When the earth-atmosphere system is considered as a whole, there is a positive net radiation flux between about 40N and 40S, while there is a negative net radiation flux poleward of 40 in both hemispheres. In order for a steady-state temperature to be achieved, there must be transport of heat from the earth’s surface to the atmosphere, and from the tropics to the polar regions. -
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. -
PRIME MERIDIAN a Place Is
Lines of Latitude and Longitude help us to answer a key geographical question: “Where am I?” What are Lines of Latitude and Longitude? Lines of Latitude and Longitude refer to the grid system of imaginary lines you will find on a map or globe. PARALLELS of Latitude and MERIDIANS of Longitude form an invisible grid over the earth’s surface and assist in pinpointing any location on Earth with great accuracy; everywhere has its own unique grid location, and this is expressed in terms of LATITUDE and LONGITUDE COORDINATES. Lines of LATITUDE are the ‘horizontal’ lines. They tell us whether a place is located in the NORTHERN or the SOUTHERN HEMISPHERE as well as how far North or South from the EQUATOR it is. Lines of LONGITUDE are the ‘vertical’ lines. They indicate how far East or West of the PRIME MERIDIAN a place is. • The EQUATOR is the 0° LATITUDE LINE. o North of the EQUATOR is the NORTHERN HEMISPHERE. o South of the EQUATOR is the SOUTHERN HEMISPHERE. • Lines of Latitude cross the PRIME MERIDIAN (longitude line) at right angles (90°). • Lines of Latitude circle the globe/world in an east- west direction. • Lines of Latitude are also known as PARALLELS. o As they are parallel to the Equator and apart always at the same distance. • Lines of Latitude measure distance north or south from the equator i.e. how far north or south a point lies from the Equator. • The distance between degree lines is about 69 miles (or about 110km). o A DEGREE (°) equals 60 minutes - 60’.