DOCSLIB.ORG

Chapter 4. Atmospheric Temperature and Stability

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 4. Atmospheric Temperature and Stability Chapter 4. Atmospheric Temperature and Stability 4.1 The temperature structure of the atmosphere Most people are familiar with the fact that the temperature of the atmosphere decreases with altitude. The temperature outside a commercial airliner at 12 km (36,000 ft) is typically -40°C or colder. Mountains are often capped with snow and ice, while adjacent valleys are green and lush. In this section we introduce students to the physical principles that explain the decline of atmospheric temperatures aloft and examine the condensation process in clouds and its effects on atmospheric temperature. We then study the concept of stability: what determines whether air is buoyant and convection can take place, or whether the atmosphere is stable and air parcels tend to return to their original altitude when displaced. The circulation in the atmosphere, which is driven to a large extent by convective motions, is discussed in Chapter 5; radiative processes (absorption and reflection of sunlight, thermal radiation (radiant heat)), which also play important roles in determining temperature and climate, are discussed in Chapter 6. Latitude=30N mesosphere Fig. 4.1 Average observed temperature distribution with altitude. The temperature of the stratosphere atmosphere on average in summer is shown for 30° N latitude, along with the names given to the major regions of the atmosphere (troposphere, stratosphere, mesosphere). The upper boundaries of the Altitude (km) troposphere and stratosphere ("tropopause", "stratopause", respectively) are indicated as horizontal lines. troposphere 0 102030405060 220 240 260 280 300 T (K) The lowest region of the atmosphere, up to the first temperature minimum at 12 - 16 km, is known as the troposphere, a name derived from the Greek words tropos, turning, and spaira, ball. The troposphere is relatively unstable because of the decrease of temperature with altitude. Air in the troposphere is poised to over-turn (to convect) much like water in 1 a kettle heated from below. Most of the weather of the planet is confined to the troposphere. The upper boundary of the troposphere, the altitude corresponding to the temperature minimum, is known as the tropopause. Temperature increases with altitude in the stratosphere (tropopause to 45 km), from the Latin word stratus meaning stretched out or layered. Vertical motions are strongly inhibited in the stratosphere as a consequence of the increase of temperature with altitude; an air parcel that is pushed upwards becomes denser than the air it seeks to displace and is driven back to its point of origin as we discuss below. The temperature maximum near 45 km (the stratopause) marks the upper boundary of the stratosphere. As we shall see, most of the world's ozone (O3) is contained in the stratosphere. Stratospheric ozone is vitally important to life because it absorbs harmful ultraviolet light from the sun, preventing it from reaching the earth's surface. Stratospheric ozone has been studied intensively for the last 30 years, reflecting concerns that global-scale changes have been caused by human activities (Chapter 7). The region of decreasing temperature above the stratopause is known as the mesosphere (from the Greek word mesos, middle). Above the mesopause (85 km) there is a region of very rapidly increasing temperature called the thermosphere (not shown in the figure), which attains the highest temperatures observed anywhere in the atmosphere. Densities are extremely low, and satellites orbit Earth for extended periods of time in the thermosphere. Thousands of kilometers above the surface, the atmosphere merges slowly with the interplanetary medium. 4.2 Displacement of an air parcel with altitude: work done by an air parcel on the atmosphere We now examine one of the basic factors causing atmospheric temperatures to decrease with altitude in the troposphere: work must be done on the atmosphere by a rising air parcel. (The other major factor, atmospheric radiation, is discussed in Chapter 6). Consider taking a parcel of air and moving it vertically from altitude Z1 to Z2 (see Fig. 4.2), not allowing heat or mass to exchange between the parcel and the environment. If we initially keep the volume fixed, then the pressure remains equal to P1. From the barometric law, we know that the ambient pressure P2 at Z2is lower than the initial pressure P1 that the parcel had at Z1, and we therefore allow the parcel at Z2 to expand until the pressure inside is equal to the ambient pressure. As the air parcel expands, it pushes against the force due to the pressure of the surrounding atmosphere, doing work (Chapter 2). To do this work, the parcel requires energy, but we have not allowed heat to be added to the parcel. Where does this energy come from? The only source is the kinetic energy of the molecules inside the air parcel. We know from Chapter 2 that this internal energy is related directly to temperature, E = 3/2 kT. Since energy is conserved ("1st Law of Thermodynamics") the work done by the parcel on the atmosphere must be accompanied by a drop in temperature. This is a fundamental reason why atmospheric temperature decreases with altitude. 2 We can determine the temperature change of an air parcel with altitude when the parcel moves verticall without exchanging any heat with its surroundings. This quantity, ∆T/∆Z, is called the adiabatic lapse rate. (The term adiabatic refers to the fact that the parcel is not permitted to exchange heat with the atmosphere.) Consider an air parcel with mass m Pressure and work on a vertically-displaced air parcel Figure 4.2 Vertical displacement of an air parcel. The parcel does work on This diagram illustrates the atm expanding from schematically the upward P1->P2 at Z2 displacement of an air parcel in the atmosphere, from altitude Z1 to Z2.. No exchange of heat or mass is allowed with the environment. Since pressure decreases with height (left panel, Z (km) barometric law), the parcel will P2,Z2 P2,Z2 P1,Z2 P1,Z2 expand in volume and pressure will drop inside; in the process, the parcel does work on the P1,Z1 P1,Z1 atmosphere at Z2, and the temperature of the parcel 0 5 10 15 decreases by an amount given by 0.0 0.4 0.8 the adiabatic lapse rate. P (bar) that is raised distance ∆Z, for example, due to the wind blowing over a mountain. As our parcel goes up the mountain, another parcel goes down. Let us suppose that the distribution of temperature and pressure in the atmosphere is so arranged that no energy has to be supplied to effect the switch--the parcel that is falling gains just enough energy to pull the other parcel up, like a perfectly matched pair of cable cars. What will be the relationship between temperature and pressure, given that pressure and altitude obey the barometric law? Since no energy needs to be supplied to exchange the parcels, and work is done against gravity by the rising parcel, there must be an exact trade between internal energy and gravitational energy. That means that the sum of these two is same in all parcels with the same mass at any altitude. The work done against gravity (mg∆Z, see work defined in Chapter 2) must exactly balance the amount of energy extracted from the internal kinetic energy of the air molecules in the air parcel. The extracted energy is defined as -m cp ∆T, where cp is the specific heat of air, the amount of energy required to raise the temperature of 1 kg of air by 1°C (cp 1005 J/kg). We therefore know that the two quantities are equal (work against gravity and energy extracted from molecules): mg ∆Z=-m cp∆T Eq. 4.1a which can be re-arranged to yield the remarkably simple ∆T / ∆Z = -g / cp = -9.8° C / km. Eq. 4.1b ∆T / ∆Z, the adiabatic lapse rate, is the temperature change for an air parcel (cools if it moves up, warms if it moves down) when it suddenly moves from one altitude to another. 3 Our special atmosphere, where all parcels move up or down freely without exchanging energy with the environment, is said to be neutrally stable as discussed below. There are many ways that an air parcel can be forced to move adiabatically in the real atmosphere. If the air blows over an obstacle, such as a mountain, the upward motion on the front side and downward motion on the rear side occur too rapidly for heat or mass to be exchanged with the surroundings. If air near the ground is heated, for example by absorption of sunlight by the ground, then the scale height H increases and the whole air column will be pushed upwards. Air parcels forced to move in this way have no way to know if their motion is balanced by that of other air parcels, or if they are being push up or down some other way. Therefore, air parcels forced to move up or down adiabatically and which maintain pressure equal to the surrounding atmosphere, change temperature with altitude as given by the adiabatic lapse rate (Eq. 4.1b). Note that the ambient atmosphere need not have this lapse rate (usually the atmosphere is not neutrally stable), so the parcel that has moved will usually be at a different temperature than the surrounding air. It will therefore have a different density (Perfect Gas Law). This distinction, between the temperature change in a parcel forced to move vertically and the temperature change with altitude in the ambient atmosphere, represents a key concept in the discussion that follows. 4.3 Stability adibatic A stable B Fig 4.3 Ambient lapse rates and parcel unstable temperature changes.
Load more

Recommended publications
  • Pressure Gradient Force Examples of Pressure Gradient Hurricane Andrew, 1992 Extratropical Cyclone
    4/29/2011 Chapter 7: Forces and Force Balances Forces that Affect Atmospheric Motion Pressure gradient force Fundamental force - Gravitational force FitiFrictiona lfl force Centrifugal force Apparent force - Coriolis force • Newton’s second law of motion states that the rate of change of momentum (i.e., the acceleration) of an object , as measured relative relative to coordinates fixed in space, equals the sum of all the forces acting. • For atmospheric motions of meteorological interest, the forces that are of primary concern are the pressure gradient force, the gravitational force, and friction. These are the • Forces that Affect Atmospheric Motion fundamental forces. • Force Balance • For a coordinate system rotating with the earth, Newton’s second law may still be applied provided that certain apparent forces, the centrifugal force and the Coriolis force, are • Geostrophic Balance and Jetstream ESS124 included among the forces acting. ESS124 Prof. Jin-Jin-YiYi Yu Prof. Jin-Jin-YiYi Yu Pressure Gradient Force Examples of Pressure Gradient Hurricane Andrew, 1992 Extratropical Cyclone (from Meteorology Today) • PG = (pressure difference) / distance • Pressure gradient force goes from high pressure to low pressure. • Closely spaced isobars on a weather map indicate steep pressure gradient. ESS124 ESS124 Prof. Jin-Jin-YiYi Yu Prof. Jin-Jin-YiYi Yu 1 4/29/2011 Gravitational Force Pressure Gradients • • Pressure Gradients – The pressure gradient force initiates movement of atmospheric mass, widfind, from areas o fhihf higher to areas o flf
    [Show full text]
  • Chapter 5. Meridional Structure of the Atmosphere 1
    Chapter 5. Meridional structure of the atmosphere 1. Radiative imbalance 2. Temperature • See how the radiative imbalance shapes T 2. Temperature: potential temperature 2. Temperature: equivalent potential temperature 3. Humidity: specific humidity 3. Humidity: saturated specific humidity 3. Humidity: saturated specific humidity Last time • Saturated adiabatic lapse rate • Equivalent potential temperature • Convection • Meridional structure of temperature • Meridional structure of humidity Today’s topic • Geopotential height • Wind 4. Pressure / geopotential height • From a hydrostatic balance and perfect gas law, @z RT = @p − gp ps T dp z(p)=R g p Zp • z(p) is called geopotential height. • If we assume that T and g does not vary a lot with p, geopotential height is higher when T increases. 4. Pressure / geopotential height • If we assume that g and T do not vary a lot with p, RT z(p)= (ln p ln p) g s − • z increases as p decreases. • Higher T increases geopotential height. 4. Pressure / geopotential height • Geopotential height is lower at the low pressure system. • Or the high pressure system corresponds to the high geopotential height. • T tends to be low in the region of low geopotential height. 4. Pressure / geopotential height The mean height of the 500 mbar surface in January , 2003 4. Pressure / geopotential height • We can discuss about the slope of the geopotential height if we know the temperature. R z z = (T T )(lnp ln p) warm − cold g warm − cold s − • We can also discuss about the thickness of an atmospheric layer if we know the temperature. RT z z = (ln p ln p ) p1 − p2 g 2 − 1 4.
    [Show full text]
  • The California Low-Level Coastal Jet and Nearshore Stratocumulus
    Calhoun: The NPS Institutional Archive Faculty and Researcher Publications Faculty and Researcher Publications 2001 The California Low-Level Coastal Jet and Nearshore Stratocumulus Kalogiros, John http://hdl.handle.net/10945/34433 1.1 THE CALIFORNIA LOW-LEVEL COASTAL JET AND NEARSHORE STRATOCUMULUS John Kalogiros and Qing Wang* Naval Postgraduate School, Monterey, California 1. INTRODUCTION* and the warm air above land (thermal wind) and the frictional effect within the atmospheric This observational study focus on the boundary layer (Zemba and Friehe 1987, Burk and interaction between the coastal wind field and the Thompson 1996). The horizontal temperature evolution of the coastal stratocumulus clouds. The gradient follows the orientation of the coastline data were collected during an experiment in the (317° on the average in central California). Thus, summer of 1999 near the California coast with the the thermal wind has a northern and an eastern Twin Otter research aircraft operated by the component and local maximum of both Center for Interdisciplinary Remote Piloted Aircraft components of the wind is expected close to the Study (CIRPAS) at the Naval Postgraduate School top of the boundary layer. Topographical features (NPS). The wind components were measured with may intensify this wind jet at significant convex a DGPS/radome system, which provides a very bends of the coastline like Cape Mendocino, Pt accurate (0.1 ms-1) estimate of the wind (Kalogiros Arena and Pt Sur. At such changes of the and Wang 2001). The instrumentation of the coastline geometry combined with mountain aircraft included fast sensors for the measurement barriers (channeling effect) the northerly flow can of air temperature, humidity, shortwave and become supercritical.
    [Show full text]
  • Pressure Gradient Force
    2/2/2015 Chapter 7: Forces and Force Balances Forces that Affect Atmospheric Motion Pressure gradient force Fundamental force - Gravitational force Frictional force Centrifugal force Apparent force - Coriolis force • Newton’s second law of motion states that the rate of change of momentum (i.e., the acceleration) of an object, as measured relative to coordinates fixed in space, equals the sum of all the forces acting. • For atmospheric motions of meteorological interest, the forces that are of primary concern are the pressure gradient force, the gravitational force, and friction. These are the • Forces that Affect Atmospheric Motion fundamental forces. • Force Balance • For a coordinate system rotating with the earth, Newton’s second law may still be applied provided that certain apparent forces, the centrifugal force and the Coriolis force, are • Geostrophic Balance and Jetstream ESS124 included among the forces acting. ESS124 Prof. Jin-Yi Yu Prof. Jin-Yi Yu Pressure Gradient Force Examples of Pressure Gradient Hurricane Andrew, 1992 Extratropical Cyclone (from Meteorology Today) • PG = (pressure difference) / distance • Pressure gradient force goes from high pressure to low pressure. • Closely spaced isobars on a weather map indicate steep pressure gradient. ESS124 ESS124 Prof. Jin-Yi Yu Prof. Jin-Yi Yu 1 2/2/2015 Balance of Force in the Vertical: Pressure Gradients Hydrostatic Balance • Pressure Gradients – The pressure gradient force initiates movement of atmospheric mass, wind, from areas of higher to areas of lower pressure Vertical
    [Show full text]
  • Hohonu Volume 5 (PDF)
    HOHONU 2007 VOLUME 5 A JOURNAL OF ACADEMIC WRITING This publication is available in alternate format upon request. TheUniversity of Hawai‘i is an Equal Opportunity Affirmative Action Institution. VOLUME 5 Hohonu 2 0 0 7 Academic Journal University of Hawai‘i at Hilo • Hawai‘i Community College Hohonu is publication funded by University of Hawai‘i at Hilo and Hawai‘i Community College student fees. All production and printing costs are administered by: University of Hawai‘i at Hilo/Hawai‘i Community College Board of Student Publications 200 W. Kawili Street Hilo, Hawai‘i 96720-4091 Phone: (808) 933-8823 Web: www.uhh.hawaii.edu/campuscenter/bosp All rights revert to the witers upon publication. All requests for reproduction and other propositions should be directed to writers. ii d d d d d d d d d d d d d d d d d d d d d d Table of Contents 1............................ A Fish in the Hand is Worth Two on the Net: Don’t Make me Think…different, by Piper Seldon 4..............................................................................................Abortion: Murder-Or Removal of Tissue?, by Dane Inouye 9...............................An Etymology of Four English Words, with Reference to both Grimm’s Law and Verner’s Law by Piper Seldon 11................................Artifacts and Native Burial Rights: Where do We Draw the Line?, by Jacqueline Van Blarcon 14..........................................................................................Ayahuasca: Earth’s Wisdom Revealed, by Jennifer Francisco 16......................................Beak of the Fish: What Cichlid Flocks Reveal About Speciation Processes, by Holly Jessop 26................................................................................. Climatic Effects of the 1815 Eruption of Tambora, by Jacob Smith 33...........................Columnar Joints: An Examination of Features, Formation and Cooling Models, by Mary Mathis 36....................
    [Show full text]
  • Using the Weak Temperature Gradient Approximation to Understand Self-Aggregation 1
    Multiple Equilibria in a Cloud Resolving Model: Using the Weak Temperature Gradient Approximation to Understand Self-Aggregation 1 Sharon Sessions, Satomi Sugaya, David Raymond, Adam Sobel New Mexico Tech SWAP 2011 nmtlogo 1This work is supported by the National Science Foundation Sessions (NMT) Multiple Equilibria in a CRM May2011 1/21 Self-Aggregation Bretherton et al (2005) precipitation 1 WVP = g rt dp R nmtlogo Day 1 Day 50 Sessions (NMT) Multiple Equilibria in a CRM May2011 2/21 Possible insight from limited domain WTG simulations Bretherton et al (2005) Day 1 Day 50 nmtlogo Sessions (NMT) Multiple Equilibria in a CRM May2011 3/21 Weak Temperature Gradients in the Tropics Charney 1963 scaling analysis Extratropics (small Rossby number) F δθ ∼ r θ Ro Tropics (Rossby number not small) δθ ∼ Fr θ 2 −3 Froude number: Fr = U /gH ∼ 10 , measure of stratification −5 Rossby number: Ro = U/fL ∼ 10 /f , characterizes rotation nmtlogo Sessions (NMT) Multiple Equilibria in a CRM May2011 4/21 Weak Temperature Gradients in the Tropics Charney 1963 scaling analysis Extratropics (small Rossby number) F δθ ∼ r θ Ro Tropics (Rossby number not small) δθ ∼ Fr θ 2 −3 Froude number: Fr = U /gH ∼ 10 , measure of stratification −5 Rossby number: Ro = U/fL ∼ 10 /f , characterizes rotation In the tropics, gravity waves rapidly redistribute buoyancy anomalies nmtlogo Sessions (NMT) Multiple Equilibria in a CRM May2011 4/21 Weak Temperature Gradient (WTG) Approximation Sobel & Bretherton 2000 Single column model (SCM) representing one grid cell in a global circulation
    [Show full text]
  • NWS Unified Surface Analysis Manual
    Unified Surface Analysis Manual Weather Prediction Center Ocean Prediction Center National Hurricane Center Honolulu Forecast Office November 21, 2013 Table of Contents Chapter 1: Surface Analysis – Its History at the Analysis Centers…………….3 Chapter 2: Datasets available for creation of the Unified Analysis………...…..5 Chapter 3: The Unified Surface Analysis and related features.……….……….19 Chapter 4: Creation/Merging of the Unified Surface Analysis………….……..24 Chapter 5: Bibliography………………………………………………….…….30 Appendix A: Unified Graphics Legend showing Ocean Center symbols.….…33 2 Chapter 1: Surface Analysis – Its History at the Analysis Centers 1. INTRODUCTION Since 1942, surface analyses produced by several different offices within the U.S. Weather Bureau (USWB) and the National Oceanic and Atmospheric Administration’s (NOAA’s) National Weather Service (NWS) were generally based on the Norwegian Cyclone Model (Bjerknes 1919) over land, and in recent decades, the Shapiro-Keyser Model over the mid-latitudes of the ocean. The graphic below shows a typical evolution according to both models of cyclone development. Conceptual models of cyclone evolution showing lower-tropospheric (e.g., 850-hPa) geopotential height and fronts (top), and lower-tropospheric potential temperature (bottom). (a) Norwegian cyclone model: (I) incipient frontal cyclone, (II) and (III) narrowing warm sector, (IV) occlusion; (b) Shapiro–Keyser cyclone model: (I) incipient frontal cyclone, (II) frontal fracture, (III) frontal T-bone and bent-back front, (IV) frontal T-bone and warm seclusion. Panel (b) is adapted from Shapiro and Keyser (1990) , their FIG. 10.27 ) to enhance the zonal elongation of the cyclone and fronts and to reflect the continued existence of the frontal T-bone in stage IV.
    [Show full text]
  • Thermal Conductivity of Materials
    • DECEMBER 2019 Thermal Conductivity of Materials Thermal Conductivity in Heat Transfer – Lesson 2 What Is Thermal Conductivity? Based on our life experiences, we know that some materials (like metals) conduct heat at a much faster rate than other materials (like glass). Why is this? As engineers, how do we quantify this? • Thermal conductivity of a material is a measure of its intrinsic ability to conduct heat. Metals conduct heat much faster to our hands, Plastic is a bad conductor of heat, so we can touch an which is why we use oven mitts when taking a pie iron without burning our hands. out of the oven. 2 What Is Thermal Conductivity? Hot Cold • Let’s recall Fourier’s law from the previous lesson: 푞 = −푘∇푇 Heat flow direction where 푞 is the heat flux, ∇푇 is the temperature gradient and 푘 is the thermal conductivity. • If we have a unit temperature gradient across the material, i.e.,∇푇 = 1, then 푘 = −푞. The negative sign indicates that heat flows in the direction of the negative gradient of temperature, i.e., from higher temperature to lower temperature. Thus, thermal conductivity of a material can be defined as the heat flux transmitted through a material due to a unit temperature gradient under steady-state conditions. It is a material property (independent of the geometry of the object in which conduction is occurring). 3 Measuring Thermal Conductivity • In the International System of Units (SI system), thermal conductivity is measured in watts per -1 -1 meter-Kelvin (W m K ). Unit 푞 W ∙ m−1 푞 = −푘∇푇 푘 = − (W ∙ m−1 ∙ K−1) ∇푇 K • In imperial units, thermal conductivity is measured in British thermal unit per hour-feet-degree- Fahrenheit (BTU h-1ft-1 oF-1).
    [Show full text]
  • Global Warming Climate Records
    ATM S 111: Global Warming Climate Records Jennifer Fletcher Day 24: July 26 2010 Reading For today: “Keeping Track” (Climate Records) pp. 171-192 For tomorrow/Wednesday: “The Long View” (Paleoclimate) pp. 193-226. The Instrumental Record from NASA Global temperature since 1880 Ten warmest years: 2001-2009 and 1998 (biggest El Niño ever) Separation into Northern/ Southern Hemispheres N. Hem. has warmed more (1o C vs 0.8o C globally) S. Hem. has warmed more steadily though Cooling in the record from 1940-1975 essentially only in the N. Hem. record (this is likely due to aerosol cooling) Temperature estimates from other groups CRUTEM3 (RG calls this UEA) NCDC (RG calls this NOAA) GISS (RG calls this NASA) yet another group Surface air temperature over land Thermometer between 1.25-2 m (4-6.5 ft) above ground White colored to reflect away direct sunlight Slats to ensure fresh air circulation “Stevenson screen”: invented by Robert Louis Stevenson’s dad Thomas Yearly average Central England temperature record (since 1659) Temperatures over Land Only NASA separates their analysis into land station data only (not including ship measurements) Warming in the station data record is larger than in the full record (1.1o C as opposed to 0.8o C) Sea surface temperature measurements Standard bucket Canvas bucket Insulated bucket (~1891) (pre WWII) (now) “Bucket” temperature: older style subject to evaporative cooling Starting around WWII: many temperature measurements taken from condenser intake pipe instead of from buckets. Typically 0.5 C warmer
    [Show full text]
  • Atmospheric Stability Atmospheric Lapse Rate
    ATMOSPHERIC STABILITY ATMOSPHERIC LAPSE RATE The atmospheric lapse rate ( ) refers to the change of an atmospheric variable with a change of altitude, the variable being temperature unless specified otherwise (such as pressure, density or humidity). While usually applied to Earth's atmosphere, the concept of lapse rate can be extended to atmospheres (if any) that exist on other planets. Lapse rates are usually expressed as the amount of temperature change associated with a specified amount of altitude change, such as 9.8 °Kelvin (K) per kilometer, 0.0098 °K per meter or the equivalent 5.4 °F per 1000 feet. If the atmospheric air cools with increasing altitude, the lapse rate may be expressed as a negative number. If the air heats with increasing altitude, the lapse rate may be expressed as a positive number. Understanding of lapse rates is important in micro-scale air pollution dispersion analysis, as well as urban noise pollution modeling, forest fire-fighting and certain aviation applications. The lapse rate is most often denoted by the Greek capital letter Gamma ( or Γ ) but not always. For example, the U.S. Standard Atmosphere uses L to denote lapse rates. A few others use the Greek lower case letter gamma ( ). Types of lapse rates There are three types of lapse rates that are used to express the rate of temperature change with a change in altitude, namely the dry adiabatic lapse rate, the wet adiabatic lapse rate and the environmental lapse rate. Dry adiabatic lapse rate Since the atmospheric pressure decreases with altitude, the volume of an air parcel expands as it rises.
    [Show full text]
  • Atmospheric Thermal and Dynamic Vertical Structures of Summer Hourly Precipitation in Jiulong of the Tibetan Plateau
    atmosphere Article Atmospheric Thermal and Dynamic Vertical Structures of Summer Hourly Precipitation in Jiulong of the Tibetan Plateau Yonglan Tang 1, Guirong Xu 1,*, Rong Wan 1, Xiaofang Wang 1, Junchao Wang 1 and Ping Li 2 1 Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research, Institute of Heavy Rain, China Meteorological Administration, Wuhan 430205, China; [email protected] (Y.T.); [email protected] (R.W.); [email protected] (X.W.); [email protected] (J.W.) 2 Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province, Institute of Plateau Meteorology, China Meteorological Administration, Chengdu 610072, China; [email protected] * Correspondence: [email protected]; Tel.: +86-27-8180-4913 Abstract: It is an important to study atmospheric thermal and dynamic vertical structures over the Tibetan Plateau (TP) and their impact on precipitation by using long-term observation at represen- tative stations. This study exhibits the observational facts of summer precipitation variation on subdiurnal scale and its atmospheric thermal and dynamic vertical structures over the TP with hourly precipitation and intensive soundings in Jiulong during 2013–2020. It is found that precipitation amount and frequency are low in the daytime and high in the nighttime, and hourly precipitation greater than 1 mm mostly occurs at nighttime. Weak precipitation during the daytime may be caused by air advection, and strong precipitation at nighttime may be closely related with air convection. Both humidity and wind speed profiles show obvious fluctuation when precipitation occurs, and the greater the precipitation intensity, the larger the fluctuation. Moreover, the fluctuation of wind speed Citation: Tang, Y.; Xu, G.; Wan, R.; Wang, X.; Wang, J.; Li, P.
    [Show full text]
  • Summary of a Program Review Held at Huntsville, Alabama October 19-21, 1982
    Summary of a program review held at Huntsville, Alabama October 19-21, 1982 - TECH LIBRARY KAFEI, NM lllllllsllllllRlRllffllilrml OOSSE!?b NASA Conference Publication 2259 NASA/MSFCFY-82 Atmospheric Processes Research Review Compiled by Robert E. Turner George C. Marshall Space Flight Center Marshall Space Flight Center, Alabama Summary of a program review held at Huntsville, Alabama October 19-21, 1982 National Aeronautics and Space Administration Sclontlflc and Tochnlcal InformatIon Branch 1983 ACKNOWLEDGMENTS The productive inputs and comments from the participants and attendees in the Atmospheric Processes Research Review contributed very much to the success of the review. The opportunity provided for everyone to become better acquainted with the work of other investigators and to see how the research relates to the overall objective of NASA's Atmospheric Processes Research Program was an important aspect of the review. Appreciation is expressed to all those who participated in the review. The organizers trust that participation will provide each with a better frame of reference from which to proceed with the next year's research activities. ii PREFACE Each year NASA supports research in various disciplinary program areas. The coordination and exchange of information among those sponsored by NASA to conduct research studies are important elements of each program. The Office of Space Science and Applications and the Office of Aeronautics and Space Technology, via Announcements of Opportunity (AO), Application Notices (AN),etc., invites interested investigators throughout the country to communicate their research ideas within NASA and in institutions. The proposals in the Atmospheric Processes Research area selected and assigned to the NASA Marshall Space Flight Center's (MSFC's) Atmospheric Sciences Division for technical monitorship, together with the research efforts included in the FY-82 MSFC Research and Technology Operating Plan (RTOP1 I are the source of principal focus for the NASA/MSFC FY-82 Atmospheric Processes Research Review.
    [Show full text]