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Aleutian Islands
Ecosystem Status Report 2018 Aleutian Islands Edited by: Stephani Zador1 and Ivonne Ortiz2 1Resource Ecology and Fisheries Management Division, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA 7600 Sand Point Way NE, Seattle, WA 98115 2 JISAO, University of Washington, Seattle, WA With contributions from: Sonia Batten, Jennifer Boldt, Nick Bond, Anne Marie Eich, Ben Fissel, Shannon Fitzgerald, Sarah Gaichas, Jerry Hoff, Steve Kasperski, Carol Ladd, Ned Laman, Geoffrey Lang, Jean Lee, Jennifer Mondragon, John Olson,Ivonne Ortiz, Wayne Palsson, Heather Renner, Nora Rojek, Chris Rooper, Kim Sparks, Michelle St Martin, Jordan Watson, George A. Whitehouse, Sarah Wise, and Stephani Zador Reviewed by: The Plan Teams for the Groundfish Fisheries of the Bering Sea, Aleutian Islands, and Gulf of Alaska November 13, 2018 North Pacific Fishery Management Council 605 W. 4th Avenue, Suite 306 Anchorage, AK 99301 Aleutian Islands 2018 Report Card Region-wide The North Pacific Index (NPI) was strongly positive from fall 2017 into 2018 due to the relatively high sea level pressure in the region of the Aleutian Low, which was displaced to the northwest, over Siberia, and caused persistent warm winds from the southwest. Positive NPI is expected during La Ni~na,but its magnitude was greater than expected. The Aleutians Islands region experienced suppressed storminess through fall and winter 2017/2018 across the region. The Alaska Stream appears to have been relatively diffuse on the south side of the eastern Aleutian Islands. Although the sea surface temperatures cooled in 2018, relative to the 2014{2017 warm period, the overall temperature was still warm due to heat retention throughout the water column. -
Review of the Draft Climate Science Special Report
THE NATIONAL ACADEMIES PRESS This PDF is available at http://www.nap.edu/24712 SHARE Review of the Draft Climate Science Special Report DETAILS 132 pages | 8.5 x 11 | PAPERBACK ISBN 978-0-309-45664-7 | DOI: 10.17226/24712 CONTRIBUTORS GET THIS BOOK Committee to Review the Draft Climate Science Special Report; Board on Atmospheric Sciences and Climate; Division on Earth and Life Studies; National Academies of Sciences, Engineering, and FIND RELATED TITLES Medicine Visit the National Academies Press at NAP.edu and login or register to get: – Access to free PDF downloads of thousands of scientific reports – 10% off the price of print titles – Email or social media notifications of new titles related to your interests – Special offers and discounts Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the National Academies Press. (Request Permission) Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved. Review of the Draft Climate Science Special Report Committee to Review the Draft Climatee Science Special Report Board on Atmospheric Sciences and Climate Division on Earth and Life Studies A Report of Copyright © National Academy of Sciences. All rights reserved. Review of the Draft Climate Science Special Report THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001 This study was supported by the National Aeronautics and Space Administration under award numbers NNH14CK78B and NNH14CK79D. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project. -
Downloaded 09/27/21 06:58 AM UTC 3328 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 76 Y 2
NOVEMBER 2019 S C H L U T O W 3327 Modulational Stability of Nonlinear Saturated Gravity Waves MARK SCHLUTOW Institut fur€ Mathematik, Freie Universitat€ Berlin, Berlin, Germany (Manuscript received 15 March 2019, in final form 13 July 2019) ABSTRACT Stationary gravity waves, such as mountain lee waves, are effectively described by Grimshaw’s dissipative modulation equations even in high altitudes where they become nonlinear due to their large amplitudes. In this theoretical study, a wave-Reynolds number is introduced to characterize general solutions to these modulation equations. This nondimensional number relates the vertical linear group velocity with wave- number, pressure scale height, and kinematic molecular/eddy viscosity. It is demonstrated by analytic and numerical methods that Lindzen-type waves in the saturation region, that is, where the wave-Reynolds number is of order unity, destabilize by transient perturbations. It is proposed that this mechanism may be a generator for secondary waves due to direct wave–mean-flow interaction. By assumption, the primary waves are exactly such that altitudinal amplitude growth and viscous damping are balanced and by that the am- plitude is maximized. Implications of these results on the relation between mean-flow acceleration and wave breaking heights are discussed. 1. Introduction dynamic instabilities that act on the small scale comparable to the wavelength. For instance, Klostermeyer (1991) Atmospheric gravity waves generated in the lee of showed that all inviscid nonlinear Boussinesq waves are mountains extend over scales across which the back- prone to parametric instabilities. The waves do not im- ground may change significantly. The wave field can mediately disappear by the small-scale instabilities, rather persist throughout the layers from the troposphere to the perturbations grow comparably slowly such that the the deep atmosphere, the mesosphere and beyond waves persist in their overall structure over several more (Fritts et al. -
Variability of Martian Turbopause Altitudes M
Variability of Martian turbopause altitudes M. Slipski1, B. M. Jakosky2, M. Benna3,4, M. Elrod3,4, P. Mahaffy3, D. Kass5, S. Stone6, R. Yelle6 Marek Slipski; [email protected] 1Laboratory for Atmospheric and Space Physics, Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, Boulder, CO, USA 2Laboratory for Atmospheric and Space Physics, Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA 3NASA Goddard Space Flight Center, Greenbelt, MD, USA 4CRESST, University of Maryland, College Park, Maryland,USA This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1029/2018JE005704 c 2018 American Geophysical Union. All Rights Reserved. Abstract. The turbopause and homopause represent the transition from strong turbulence and mixing in the middle atmosphere to a molecular-diffusion dominated region in the upper atmosphere. We use neutral densities mea- sured by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmospheric and Volatile EvolutioN (MAVEN) spacecraft from February 2015 to October 2016 to investigate the temperature structure and fluctuations of the Martian upper atmosphere. We compare those with temperature mea- surements of the lower atmosphere from the Mars Reconnaissance Orbiter's (MRO) Mars Climate Sounder (MCS). At the lowest MAVEN altitudes we often observe a statically stable region where waves propagate freely. In con- trast, regions from about 20 km up to at least 70 km are reduced in stabil- ity where waves are expected to dissipate readily due to breaking/saturation. -
DEVELOPMENTS in UPPER ATMOSPHERIC SCIENCE The
DEVELOPMENTS IN UPPER ATMOSPHERIC SCIENCE DURING THE IQSY BY FRANCIS S. JOHNSON SOUTHWEST CENTER FOR ADVANCED STUDIES, DALLAS, TEXAS During the IQSY, there were of course many advances in the area of upper atmo- spheric science, and it would take a great deal of time and space to describe them all adequately. It is therefore necessary to arbitrarily select just a few of the advances that were, in my view, among the more important. Neutral Upper Atmosphere.-The vertical structure of the atmosphere is in large degree controlled by its temperature distribution, and the largest variations in temperature occur above 200-km altitude. This is illustrated in Figure 1, which shows a typical temperature distribution up to 100 km, and three distributions at higher altitudes. The three distributions shown indicate near-extreme conditions and an in-between, or average, situation. The range of variation can be seen to be very great, far more than a factor of 2 at the highest altitudes. The biggest portion of the variation is governed by the solar cycle, with the highest temperatures oc- curring near sunspot maximum. The constant temperature above about 300 km is frequently referred to as the exospheric temperature. The total amount of atmosphere above any location on the earth's surface at sea level, as indicated by the barometric pressure, is nearly constant (within about 5 per cent of its mean value); this near constancy apparently results from the mete- orological circulation of the lower atmosphere. The vertical extension of the atmos- phere is governed by its temperature and molecular weight. -
Surface Flux Variability Over the North Pacific and North Atlantic Oceans
NOVEMBER 1997 ALEXANDER AND SCOTT 2963 Surface Flux Variability over the North Paci®c and North Atlantic Oceans MICHAEL A. ALEXANDER AND JAMES D. SCOTT CIRES, University of Colorado, Boulder, Colorado (Manuscript received 22 January 1996, in ®nal form 9 May 1997) ABSTRACT Daily ®elds obtained from a 17-yr atmospheric GCM simulation are used to study the surface sensible and latent heat ¯ux variability and its relationship to the sea level pressure (SLP) ®eld. The ¯uxes are analyzed over the North Paci®c and Atlantic Oceans during winter. The leading mode of interannual SLP variability consists of a single center associated with the Aleutian low in the Paci®c, and a dipole pattern associated with the Icelandic low and Azores high in the Atlantic. The surface ¯ux anomalies are organized by the low-level atmospheric circulation associated with these modes in agreement with previous observational studies. The surface ¯ux variability on all of the timescales examined, including intraseasonal, interannual, 3±10 day, and 10±30 day, is maximized along the north and west edges of both oceans and between Japan and the date line at ;358N in the Paci®c. The intraseasonal variability is approximately 3±5 times larger than the interannual variability, with more than half of the total surface ¯ux variability occuring on timescales of less than 1 month. Surface ¯ux variability in the 3±10-day band is clearly associated with midlatitude synoptic storms. Composites indicate upward (downward) ¯ux anomalies that exceed |30 W m22| occur to the west (east) of storms, which move eastward across the oceans at 108±158 per day. -
May 8-21, 1968 CHANGES in the LOWER EXOSPIDERE SINCE SOLAR Minm by Gerald M
GES IN THE LOWER EXOSPHERE SINCE SOLAR MTm By Gerald M. Keating NASA Langley Research Center Langley Station, Hampton, Va e GPO PRICE $ CSFTl PRICEtS) $ Presented at 9th COSPAR International Space Science Sp-posiwn Tokyo, Japan May 8-21, 1968 CHANGES IN THE LOWER EXOSPIDERE SINCE SOLAR MINm By Gerald M. Keating Measurements of atmospheric densities between 500 km and 750 km and between BOo latitude have been made by means of the Explorer XIX (1963-53A)and Explorer XXIV (1964-76A)satellites during the period of increasing solar activity (1964-1967) During this period the atmosphere has expanded due to increased solar heating to such an extent that near TOO km recent measurements indicate densities 30 times greater than were measured at minimum solar activity. Latitudinal-seasonal variations have changed during this period of increased solar heating. It was found that peak densities near 650 km have shifted from high latitudes in the winter hemisphere to low latitudes in the summer hemisphere. This change in latitudinal-seasonal variations confirms the prediction of Keating and Phor that at these altitudes with an increase in solar activity, the winter helium bulge would be dwarfed by an expanding summer atomic oxygen bulge. Xt is apparent that atomic oxygen has now replaced helium as the principal constituent near 650 km, After accounting for latitudinal-seasonal variations, a global semiannual and annual variation of atmospheric densities nearly as large as has been observed in the past becomes evident throughout the period of increasing solar activity. Unexpectedly low densities were observed in September of 1964, 1965, and 1966. -
General Disclaimer One Or More of the Following Statements May Affect
General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) UNIVERSITY OF ILLINOIS URBANA AERONOMY REPfC".)IRT NO, 67 1 AN INVESTIGATION OF THE SOLAR ZENITH ANGLE VARIATION OF D-REGION IONIZATION (NASA-CF-143217) AN INVE'STIGATICN CF THE N75 -28597 SOIA; ZENITH ANGLE VAFIATICN CF C-FEGICN IONI2ATICN (I11incis Cniv.) 290 F HC iE.75 CSCL 044 U11C13s G3/4b 31113 by ^' x '^^ P. A. J. Ratnasiri o c n C. F. Scchrist, Jr. m y T April I, 1975 Library of Congress ISSN 0568-0581 Aeronomy Laboratory Supported by Department of Electrical Engineering National Science Foundation University of Illinois Grant GA 3691 IX Urbana, Illinois ii ABSTRACT A review of the D- region ionization measurements and its solar zenith angle variation reveals that a unified model of the D region, incorporating both thenetural chemistry and the ion chemistry, is required for a proper understanding of this region of the ionosphere. -
On the Summertime Strengthening of the Northern Hemisphere Pacific Sea-Level Pressure Anticyclone
On the Summertime Strengthening of the Northern Hemisphere Pacific Sea-Level Pressure Anticyclone Sumant Nigam and Steven C. Chan Department of Atmospheric and Oceanic Science University of Maryland, College Park, MD 20742 (Submitted to the Journal of Climate on November 8, 2007; revised July 27, 2008) Corresponding author: Sumant Nigam, 3419 Computer & Space Sciences Bldg. University of Maryland, College Park, MD 20742-2425; [email protected] Abstract The study revisits the question posed by Hoskins (1996) on why the Northern Hemisphere Pacific sea-level pressure (SLP) anticyclone is strongest and maximally extended in summer when the Hadley Cell descent in the northern subtropics is the weakest. The paradoxical evolution is revisited because anticyclone build-up to the majestic summer structure is gradual, spread evenly over the preceding 4-6 months, and not just confined to the monsoon-onset period; interesting, as monsoons are posited to be the cause of the summer vigor of the anticyclone. Anticyclone build-up is moreover found focused in the extratropics; not subtropics, where SLP seasonality is shown to be much weaker; generating a related paradox in context of Hadley Cell’s striking seasonality. Showing this seasonality to arise from, and thus represent, remarkable descent variations in the Asian monsoon sector, but not over the central-eastern ocean basins, leads to paradox resolution. Evolution of other prominent anticyclones is analyzed to critique development mechanisms: Azores High evolves like the Pacific one, but without a monsoon to its immediate west. Mascarene High evolves differently, peaking in austral winter. Monsoons are not implicated in both cases. Diagnostic modeling of seasonal circulation development in the Pacific sector concludes this inquiry. -
Chapter 7 – Atmospheric Circulations (Pp
Chapter 7 - Title Chapter 7 – Atmospheric Circulations (pp. 165-195) Contents • scales of motion and turbulence • local winds • the General Circulation of the atmosphere • ocean currents Wind Examples Fig. 7.1: Scales of atmospheric motion. Microscale → mesoscale → synoptic scale. Scales of Motion • Microscale – e.g. chimney – Short lived ‘eddies’, chaotic motion – Timescale: minutes • Mesoscale – e.g. local winds, thunderstorms – Timescale mins/hr/days • Synoptic scale – e.g. weather maps – Timescale: days to weeks • Planetary scale – Entire earth Scales of Motion Table 7.1: Scales of atmospheric motion Turbulence • Eddies : internal friction generated as laminar (smooth, steady) flow becomes irregular and turbulent • Most weather disturbances involve turbulence • 3 kinds: – Mechanical turbulence – you, buildings, etc. – Thermal turbulence – due to warm air rising and cold air sinking caused by surface heating – Clear Air Turbulence (CAT) - due to wind shear, i.e. change in wind speed and/or direction Mechanical Turbulence • Mechanical turbulence – due to flow over or around objects (mountains, buildings, etc.) Mechanical Turbulence: Wave Clouds • Flow over a mountain, generating: – Wave clouds – Rotors, bad for planes and gliders! Fig. 7.2: Mechanical turbulence - Air flowing past a mountain range creates eddies hazardous to flying. Thermal Turbulence • Thermal turbulence - essentially rising thermals of air generated by surface heating • Thermal turbulence is maximum during max surface heating - mid afternoon Questions 1. A pilot enters the weather service office and wants to know what time of the day she can expect to encounter the least turbulent winds at 760 m above central Kansas. If you were the weather forecaster, what would you tell her? 2. -
The Lubbock Tornado: an Elevated Mixed Layer Case Study
THE LUBBOCK TORNADO: AN ELEVATED MIXED LAYER CASE STUDY by TERRANCE JAMES CLARK, B.S. A THESIS IN ATMOSPHERIC SCIENCE Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE Approved Accepted May, 1988 f\t 1o6 n inr lOo.S ACKNOWLEDGMENTS Cop ^ I wish to extend my sincere thanks to Dr. Richard E. Peterson for his encouragements and understanding during the preparation of this thesis. I would also like to thank Dr. Donald R. Haragan and Dr. Chia Bo Chang for their assistance and advice during the course of this work. Everyone's support throughout this endeavor made the final difference. Both Dr. Peterson's and Dr. Ed Rappaport's hospitality during my final visits will not be forgotten. My sincere thanks go to the United States Air Force for their financial support through the Air Force Institute of Technology and Environmental Technical Application Center. A special thanks goes to Glenna Cilento for her assistance typing this thesis. Finally, a special thanks goes to my wife Terry and children, Jennifer, Christina, Andrea and Matthew, for their understanding and support during the long hours I spent closed-in writing text and drawing figures. Also, my mother Beryl Clark and ten brothers and sisters share in keeping my determination directed toward finishing this project. Without this support, I could never have reached this educational goal. 11 TABLE OF CONTENTS Page ACKNOWLEDGMENTS ii ABSTRACT v LIST OF FIGURES vii CHAPTER I. INTRODUCTION 1 II. DATA SOURCES AND ANALYSIS TECHNIQUE 4 Data Sources 4 Analysis Technique 5 III. -
A Climatological Study of Typhoon Formation and Typhoon Visit to Japan
気象砺究所研究報告 第36巷 第2号 61-118頁 昭和60年6月 Papers in Meteorology and Geophysics、ア01. 36,No. 2,PP,61-118.June 1985 A Climatological Study of Typhoon Formation and Typhoon Visit to Japan by Takashi Aoki* ハ4α¢070Jog1αzlノ~2s2α76h lnsオπ㍑彪,ITsz漉%わα,1わα7α勉,305∫‘功αη (Received Feb.28,1985;Revised March28,1985) Abstract The formation of typhoons in the westem North Pacific and typhoon visits to Japan are investigated from a climatological standpoint.The relationship between the frequency of typhoon formation or typhoon visits and the sea surface temperature in the North Pacific is also studied. First,the formation of typhoons for the30.year period from l953to1982is examined. The average number of typhoons formed is27a year. For the amual var量ation of monthly『 frequency of typhoon formation,the maximum frequency occurs in August and the minimum in February。 Typhoons are formed most frequently in the ocean east of the Philippine Islands.The latitude of typhoon formation moves northward in summer and then retreats equatorward. Secular variation in the frequency of typhoon formation is studied by trend analysis and power spectrum analysis。The frequency showed a peak in the middle of the1960ンs.The frequency of typhoon formation increased until the middle of the1960’s an(i then decreased・ There exist two periodicities of3to4years and6to7years in the secular variation of typhoon formation. In the frequent/infrequeht months of typhoon formation the following characteristics are found. The frequency shows a marked increase north of15。N in the case of frequent typhoon