DOCSLIB.ORG

Rain Shadow Deserts Are Created 15° – 40° on Either Side of the Equator

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Rain Shadow Deserts Are Created 15° – 40° on Either Side of the Equator DESERTS Never-ending sand dunes. Scorching temperatures. Vultures circling over the remains of an unlucky traveler. These are images the word “desert” brings to mind for many people. December and January trigger phone calls to desert parks from potential visitors hoping to escape the chill of winter. They are amazed to hear of nighttime temperatures below freezing. Snow in the desert is an impossibility to them. Isn’t the desert always hot and dry? DESERTS ����� ����� ������� ������ ������ ������ ���������� ������ �������� ������ ������������ �� ��� ������� ������� distributed throughout the year. Weather receives only 40% of possible solar What Is A patterns often create short, violent radiation.) The hot, dry air causes any Desert Anyway? downpours. Flash floods, characteristic available water to evaporate quickly. of some desert areas, are produced. When temperatures are extremely hot, heck five sources and you will Much of the water runs off before it can rain can evaporate before it reaches probably find five, slightly different C soak into the soil. Earth. definitions. Some sources define a A lot of moisture is also lost to The conditions producing high desert as an area receiving no more than evaporation. Many deserts lie in areas daytime temperatures reverse the ten inches of precipitation annually. of high pressure systems where there process after sundown. Approximately However, many areas receiving this is little cloud cover. At least 90% of 90% of the day’s accumulated heat amount of precipitation are not deserts. the sun’s rays reach Earth, producing radiates back toward the sky. In moister This simple definition is not complete. seasonal hot temperatures. (For climates only about 50% of this heat Both the timing and type of comparison, the surface of more humid is lost. These conditions produce precipitation determine the environment lands, covered with more vegetation, the wide range of daily temperatures established. In a desert, rain isn’t evenly UNIT II–2 UNIT II–3 DESERTS DESERTS characteristic of deserts. This range is It cools, dropping heavy rains on often fifty degrees or more. tropical areas. The resulting cooler, The rapid heating and cooling of air drier air then descends, creating zones GLOSSARY create another characteristic of most of high atmospheric pressure as it endemic — belonging exclusively or deserts — strong winds. These winds, moves away from the equator. The confined to a particular place. circulating air which is often hot and descending air hinders cloud formation environment — all those factors, dry, increase the already high rate of and precipitation. It also warms up, both living and non-living, which evaporation. Evaporation in American absorbing any available moisture. The make up the surroundings of an deserts ranges from 70˝ – 160˝ per year. Sahara, the world’s largest hot desert, is organism. A desert then is not so easily defined. a subtropical desert about the size of the evaporation — the process by All these characteristics — seasonal, United States. which water changes into vapor. high temperatures; low, sporadic Coastal deserts are also in areas of rainfall; a high rate of evaporation; wide high pressure. Damp, chilly fog forms flash flood — a sudden, rising flood temperature ranges; strong winds — are when air, chilled by water contact as caused by heavy rainfall. part of the definition. it blows toward shore, meets warm air gneiss — a metamorphic rock where over land. Although humidity is high, intense pressures and temperatures atmospheric disturbances that can cause have caused minerals to segregate Where Are The rainfall are not present. Two coastal giving the rock a banded appearance. Deserts? deserts, the Atacama of Chile and the groundwater — water stored Namib in southern Africa, are among the raw a line around the world, beneath the surface of the ground, driest places in the world. starting mid-center between Joshua coming from precipitation and D Interior deserts, like the Gobi, exist Tree and Death Valley, and you will touch surface water that has percolated because they are too far from moisture- or come close to many of the world’s down. laden, ocean winds. By the time these great deserts — Mojave, Great Basin, metamorphic — changed by great winds reach the center of a large Sahara, Arabian, Iranian, Gobi. Most pressure, stress, and/or chemical landmass, the air is very dry. deserts occur between the latitudes of changes, usually at depth in the crust, Rain shadow deserts are created 15° – 40° on either side of the equator. from pre-existing rocks. when mountain ranges lie parallel to They are found around the world on moist, coastal areas. Prevailing winds native — a plant or animal that every continent, covering approximately moving inland cool as air is forced to rise evolved or was transported to an 20% of the Earth’s land area. over the mountains. Carried moisture falls area through natural means. Sand dunes cover only about 10% on slopes facing the winds. When the Precambrian — all geologic time of this area. Some deserts are very winds move over the crest and down the prior to the Paleozoic Era (prior to mountainous. Most are hot, with warm far side, they are very dry. Descending 570 million years ago). daytime temperatures much of the year, air also makes it hard for additional but others are cold, getting over half precipitation — water received on clouds and precipitation to form. their moisture from snow. the Earth directly from clouds as rain, Without another source of moisture, hail, sleet, or snow. rain shadow deserts are formed on the Why Are Deserts far side of these mountain ranges (see Discovery Activity Page #1). the south (mainly between 34° – 38°N Where They Are? latitudes). Elevations are generally eserts can be divided into four types The Mojave Desert between three and six thousand feet, D— subtropical, coastal, interior, rain although Death Valley National Park shadow — depending on the conditions he Mojave Desert is a rain includes both 11,049-foot Telescope Peak creating them. T shadow desert. It is defined by and the lowest point in the United States, Subtropical deserts lie along the a combination of latitude, elevation, at Badwater, 282 feet below sea level. Tropic of Cancer (23°N latitude) and geology, and indicator plants. It is Temperatures are a function of both the Tropic of Capricorn (23°S latitude). situated between the Great Basin latitude and altitude. Although the Near the equator hot, moist air rises. Desert to the north and the Sonoran to Mojave Desert has the lowest absolute UNIT II–2 UNIT II–3 DESERTS DESERTS elevation and the highest maximum more water available for irrigation, Coast. These mountain ranges create temperature (134°F in Death Valley), it farming in desert areas has increased. the rain shadow effect described in the is north of the Sonoran Desert and its This, along with human population introduction to this unit. average elevations are higher. As a result, growth and its water demands, has 1. Enlarge the rain shadow diagram its average temperatures are lower than depleted groundwater supplies faster on the activity page on a piece of poster those of the Sonoran. than they can replenish themselves. In board. Cut it into pieces to create a The Mojave Desert is in what some some cases, desert plant and animal puzzle. If you have a large group, you geographers call the Basin and Range communities can no longer be supported. may want to make more than one puzzle. Province, a landscape of alternating As the popularity of driving off-road Laminating or covering the pieces with mountain ranges and their adjacent vehicles across the desert increases, clear contact paper will extend their life. basins. Common rock substrates so does the damage done to plants and 2. Give a copy of the activity page include Precambrian gneisses and fragile desert soils. Deserts are mined for to each student. Use the diagram to granites. Slopes are often composed of copper, silver, gold, and other minerals, explain rain shadow deserts. metamorphic rocks, such as gneisses. leaving tremendous scars on the land. 3. Leaving their activity pages Mojave Desert vegetation is Many people seem to have a desert behind, have students stand in a circle, dominated by low, widely spaced shrubs. wasteland mentality. They view deserts surrounding the area where the puzzle Vegetation in the desert’s northern as lifeless, valueless areas. Resource will be assembled. Give puzzle pieces to half closely resembles that of the Great destruction, that might concern them if members in your group. Ask participants Basin Desert, as that in the southern done elsewhere, may not bother them to step in one at a time. Each may either half does the Sonoran. However, nearly when desert areas are the victims. Desert attempt to place the puzzle piece in the one quarter of all Mojave Desert plants education is necessary to increase right location or move a piece already are endemics. Synonymous with the appreciation of these biologically and placed. After the puzzle is completed, Mojave Desert is the Joshua tree. aesthetically rich lands. have a volunteer explain how the rain Other endemics are Parry saltbush and shadow effect creates dry areas. Mojave sage. A more widely distributed EXTENDING THE EXPERIENCE: plant, the creosote bush, dominates Contact areas on both sides of the much of the land surface, often in close Activity 1 mountain ranges and in the mountains association with species of bur-sage. Desert Puzzler to collect rainfall totals for the past three years (such as Los Angeles, Creating Desert OBJECTIVES: Explain the creation of a Big Bear, and Joshua Tree and Death rain shadow desert. Name one desert Valley national parks in California; and Wastelands created this way. Las Vegas and Lake Mead National eserts are growing by an estimated MATERIALS: Discovery Activity Page Recreation Area in Nevada).
Load more

Recommended publications
  • Rain Shadows
    WEB TUTORIAL 24.2 Rain Shadows Text Sections Section 24.4 Earth's Physical Environment, p. 428 Introduction Atmospheric circulation patterns strongly influence the Earth's climate. Although there are distinct global patterns, local variations can be explained by factors such as the presence of absence of mountain ranges. In this tutorial we will examine the effects on climate of a mountain range like the Andes of South America. Learning Objectives • Understand the effects that topography can have on climate. • Know what a rain shadow is. Narration Rain Shadows Why might the communities at a certain latitude in South America differ from those at a similar latitude in Africa? For example, how does the distribution of deserts on the western side of South America differ from the distribution seen in Africa? What might account for this difference? Unlike the deserts of Africa, the Atacama Desert in Chile is a result of topography. The Andes mountain chain extends the length of South America and has a pro- nounced influence on climate, disrupting the tidy latitudinal patterns that we see in Africa. Let's look at the effects on climate of a mountain range like the Andes. The prevailing winds—which, in the Andes, come from the southeast—reach the foot of the mountains carrying warm, moist air. As the air mass moves up the wind- ward side of the range, it expands because of the reduced pressure of the column of air above it. The rising air mass cools and can no longer hold as much water vapor. The water vapor condenses into clouds and results in precipitation in the form of rain and snow, which fall on the windward slope.
    [Show full text]
  • California Vegetation Map in Support of the DRECP
    CALIFORNIA VEGETATION MAP IN SUPPORT OF THE DESERT RENEWABLE ENERGY CONSERVATION PLAN (2014-2016 ADDITIONS) John Menke, Edward Reyes, Anne Hepburn, Deborah Johnson, and Janet Reyes Aerial Information Systems, Inc. Prepared for the California Department of Fish and Wildlife Renewable Energy Program and the California Energy Commission Final Report May 2016 Prepared by: Primary Authors John Menke Edward Reyes Anne Hepburn Deborah Johnson Janet Reyes Report Graphics Ben Johnson Cover Page Photo Credits: Joshua Tree: John Fulton Blue Palo Verde: Ed Reyes Mojave Yucca: John Fulton Kingston Range, Pinyon: Arin Glass Aerial Information Systems, Inc. 112 First Street Redlands, CA 92373 (909) 793-9493 [email protected] in collaboration with California Department of Fish and Wildlife Vegetation Classification and Mapping Program 1807 13th Street, Suite 202 Sacramento, CA 95811 and California Native Plant Society 2707 K Street, Suite 1 Sacramento, CA 95816 i ACKNOWLEDGEMENTS Funding for this project was provided by: California Energy Commission US Bureau of Land Management California Wildlife Conservation Board California Department of Fish and Wildlife Personnel involved in developing the methodology and implementing this project included: Aerial Information Systems: Lisa Cotterman, Mark Fox, John Fulton, Arin Glass, Anne Hepburn, Ben Johnson, Debbie Johnson, John Menke, Lisa Morse, Mike Nelson, Ed Reyes, Janet Reyes, Patrick Yiu California Department of Fish and Wildlife: Diana Hickson, Todd Keeler‐Wolf, Anne Klein, Aicha Ougzin, Rosalie Yacoub California
    [Show full text]
  • Winter Observations on the Colorado Desert
    MAR., 1902. ( THE CONDOR 37 In some respects the Oregon song sparrow is a remarkable form. It is darker than the races north and south of its range, and duplicates in coloring the sooty song sparrow of the Sitkan District. The races along the coast seem thus to alternate light and dark. But whilephea is nearly identical with ru@a in color, it is conspicuously smaller, and the ranges of the two are separated by several hundred miles. The present form occupies a strip along the coast from the northern limit of the redwoods (?) or at least from Rogue River north to Yaquina. The specimens from Crescent City are probably migrants as the breeding birds seem nearer deonensis (tho not precisely typical). The area ofi intergradation between cdeonen- sis and phcza is probably small, extending perhaps from Crescent City to Chetco R. (northern limit of Sequoia sempervivens). Lack of specimens prevents the exact determination of the limits of$hcPa at the north. I am indebted to Mr. Robert Ridgway and to Dr. C. Hart Merriam forthe use of specimens and types in the collection of the National Museum and in that of the Biological Survey. Winter Observations on the Colorado Desert. IT. S. DAGGETT, PASADENA, CAL. ROM Oct. 27 to Nov. 16, 1901, I dead birds floating on its surface, was spent at the American Girl Gold the cyanide tanks, two in number, con- F Mining Co.s‘ camp, located in the taining a strong solution of cyanide of Cargo Murchacho Mts on the Colorado potassium. Birds that essayed to Desert, five and one-half miles north- quench their thirst at this fount top- east of Ogilby, Cal., and some sixteen pled over dead in an instant.
    [Show full text]
  • One of Five West Coast, Low-Latitude Deserts of the World, the Namib Extends Along the Entire Namibian Coastline in an 80-120 Km Wide Belt
    N A M I B I A G 3 E 0 O 9 1 L - O Y G E I V C R A U S L NAMIB DESERT Source: Roadside Geology of Namibia One of five west coast, low-latitude deserts of the world, the Namib extends along the entire Namibian coastline in an 80-120 km wide belt. Its extreme aridity is the result of the cold, upwelling Benguela Current, which flows up the west coast of Africa as far as Angola, and because of its low temperatures induces very little evaporation and rainfall (<50 mm per year). It does, however, create an up to 50 km wide coastal fog belt providing sufficient moisture for the development of a specialist flora and fauna, many of which are endemic to the Namib. In addition, the lagoons at Walvis Bay and Sandwich Harbour are designated wetlands of international importance, because of their unique setting and rich birdlife, including flamingo, white pelican and Damara tern. Larger mammals like the famed desert elephant, black rhino, lion, cheetah and giraffe can be found along the northern rivers traversing the Skeleton Coast National Park. Geomorphologically, the Namib includes a variety of landscapes, including classic sand dunes, extensive gravel plains, locally with gypcrete and calcrete duricrusts, elongated salt pans, ephemeral watercourses forming linear oases, inselbergs and low mountain ranges. Along the coast, wind-swept sandy beaches alternate with rocky stretches, in places carved into striking rock formations (e.g. Bogenfels Arch). Designated a UNESCO World Heritage Site in 2013, the “Namib Sand Sea“ between Lüderitz and the Kuiseb River encompasses such well-known landmarks as Sossusvlei and Sandwich Harbour, while the fabled Skeleton Coast north of the Ugab River is notorious for its numerous ship wrecks.
    [Show full text]
  • M O J a V E D E S E R T I S S U E S a Secondary
    MOJAVE DESERT ISSUES A Secondary School Curriculum Bruce W. Bridenbecker & Darleen K. Stoner, Ph.D. Research Assistant Gail Uchwat Mojave Desert Issues was funded with a grant from the National Park �� Foundation. Parks as Classrooms is the educational program of the National ����� �� ���������� Park Service in partnership with the National Park Foundation. Design by Amy Yee and Sandra Kaye Published in 1999 and printed on recycled paper ii iii ACKNOWLEDGMENTS Thanks to the following people for their contribution to this work: Elayn Briggs, Bureau of Land Management Caryn Davidson, National Park Service Larry Ellis, Banning High School Lorenza Fong, National Park Service Veronica Fortun, Bureau of Land Management Corky Hays, National Park Service Lorna Lange-Daggs, National Park Service Dave Martell, Pinon Mesa Middle School David Moore, National Park Service Ruby Newton, National Park Service Carol Peterson, National Park Service Pete Ricards, Twentynine Palms Highschool Kay Rohde, National Park Service Dennis Schramm, National Park Service Jo Simpson, Bureau of Land Management Kirsten Talken, National Park Service Cindy Zacks, Yucca Valley Highschool Joe Zarki, National Park Service The following specialists provided information: John Anderson, California Department of Fish & Game Dave Bieri, National Park Service �� John Crossman, California Department of Parks and Recreation ����� �� ���������� Don Fife, American Land Holders Association Dana Harper, National Park Service Judy Hohman, U. S. Fish and Wildlife Service Becky Miller, California
    [Show full text]
  • The Great Basin Landscape Conservation Cooperative
    September 2010 The Great Basin Landscape Conservation Cooperative What is a Landscape Conservation The Great Basin Landscape Cooperative? Conservation Cooperative Landscape Conservation Cooperatives (LCCs) are applied science and management partnerships between Interior Department bureaus and others involved in natural resource management and What is the Great Basin LCC? conservation. Secretarial Order No. 3289, issued on Sept. 14, 2009 The Great Basin LCC will be a self-directed partnership. The by Interior Secretary Ken Salazar, calls for the establishment of 21 Great Basin LCC will provide a range of scientific and technical LCCs nationwide to better integrate science and management to support tools for landscape-scale conservation design to a wide address climate change and related issues array of managers. These tools will help managers identify and target biological objectives for native species and habitats in the What will the Great Basin LCC do? face of climate change and other stressors. Open public access to In broad terms, the Great Basin LCC will help link and integrate Great Basin LCC products will promote acceptance and use of Interior’s proposed Climate Science Centers with resource managers the science in regional conservation strategies. This effort is being and science users; will bring additional Interior resources to bear on coordinated with other regional partnerships and will be set up in landscape-scale issues and opportunities; and will help in applying a manner that will facilitate coordination and the identification science and facilitating coordination on a wide range of efforts of needs, capacities and gaps. We will link our efforts to bring to respond to climate change, invasive species, wildfires, human additional science capacity to improve conservation strategies development and other change agents across the Great Basin.
    [Show full text]
  • Ecoregions of Nevada Ecoregion 5 Is a Mountainous, Deeply Dissected, and Westerly Tilting Fault Block
    5 . S i e r r a N e v a d a Ecoregions of Nevada Ecoregion 5 is a mountainous, deeply dissected, and westerly tilting fault block. It is largely composed of granitic rocks that are lithologically distinct from the sedimentary rocks of the Klamath Mountains (78) and the volcanic rocks of the Cascades (4). A Ecoregions denote areas of general similarity in ecosystems and in the type, quality, Vegas, Reno, and Carson City areas. Most of the state is internally drained and lies Literature Cited: high fault scarp divides the Sierra Nevada (5) from the Northern Basin and Range (80) and Central Basin and Range (13) to the 2 2 . A r i z o n a / N e w M e x i c o P l a t e a u east. Near this eastern fault scarp, the Sierra Nevada (5) reaches its highest elevations. Here, moraines, cirques, and small lakes and quantity of environmental resources. They are designed to serve as a spatial within the Great Basin; rivers in the southeast are part of the Colorado River system Bailey, R.G., Avers, P.E., King, T., and McNab, W.H., eds., 1994, Ecoregions and subregions of the Ecoregion 22 is a high dissected plateau underlain by horizontal beds of limestone, sandstone, and shale, cut by canyons, and United States (map): Washington, D.C., USFS, scale 1:7,500,000. are especially common and are products of Pleistocene alpine glaciation. Large areas are above timberline, including Mt. Whitney framework for the research, assessment, management, and monitoring of ecosystems and those in the northeast drain to the Snake River.
    [Show full text]
  • Baja California's Sonoran Desert
    Baja California’s Sonoran Desert By Debra Valov What is a Desert? It would be difficult to find any one description that scarce and sporadic, with an would fit all of the twenty or so deserts found on our annual average of 12-30 cm (4.7- planet because each one is a unique landscape. 12 inches). There are two rainy seasons, December- While an expanse of scorching hot sand dunes with March and July-September, with the northern the occasional palm oasis is the image that often peninsula dominated by winter rains and the south comes to mind for the word desert, in fact, only by summer rains. Some areas experience both about 10% of the world’s deserts are covered by seasons, while in other areas, such as parts of the sand dunes. The other 90% comprise a wide variety Gulf coast region, rain may fail for years on end. of landscapes, among these cactus covered plains, Permanent above-ground water reserves are scarce foggy coastal slopes, barren salt flats, and high- throughout most of the peninsula but ephemeral, altitude, snow-covered plateaus. However, one seasonal pools and rivers do appear after winter characteristic that all deserts share is aridity—any storms in the north or summer storms (hurricanes place that receives less than 10 inches (25 and thunderstorms—chubascos) in the south. There centimeters) of rain per year is generally considered are also a number of permanent oases, most often to be a desert and the world’s driest deserts average formed where aquifers (subterranean water) rise to less than 10 mm (3/8 in.) annually.
    [Show full text]
  • Hurricane Paths: Comparing Places with Different Prevailing Winds
    Name ___________________________ Hurricane Paths: Comparing Places with Different Prevailing Winds To understand where hurricanes usually start and what direction they usually move, it helps to have a clear mental image of the pattern of prevailing winds in the world. One way to get this image is to make a careful comparison of wind observations in several places. The diagrams on the right are examples of a special kind of graph called a wind rose. The number in the center indicates the percentage of time the air is calm (no wind). Each of the eight lines radiating away from the center shows the percentage of time the wind blows FROM that direction. Repeat: The lines point to the direction the wind is blowing FROM. Please answer the following questions. 1) According to the map above, Boston has calm air about 12% of the time; the percentage of time San Juan, Puerto Rico, has calm air is _____ . 2) In San Juan, the wind blows the largest percentage of time from the northeast; in Boston, the wind blows from the _________ more often than from any other direction. 3) Use the wind rose graphs on pages 2 and 3. To get an idea about the net zonal flow of air in each location, add up the total percentage of time the wind blows from the southwest, west, and northwest, and subtract the total percentage from the southeast, east, and northeast total percentage. The result is the net westerly component - it is a positive number if the flow is mainly westerly (from the west), and a negative number if the flow is easterly (from the east).
    [Show full text]
  • The Diffusion of Maize to the Southwestern United States and Its Impact
    PERSPECTIVE The diffusion of maize to the southwestern United States and its impact William L. Merrilla, Robert J. Hardb,1, Jonathan B. Mabryc, Gayle J. Fritzd, Karen R. Adamse, John R. Roneyf, and A. C. MacWilliamsg aDepartment of Anthropology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37102, Washington, DC 20013-7012; bDepartment of Anthropology, One UTSA Circle, University of Texas at San Antonio, San Antonio, TX 78249; cHistoric Preservation Office, City of Tucson, P.O. Box 27210, Tucson, AZ 85726; dDepartment of Anthropology, Campus Box 1114, One Brookings Drive, Washington University, St. Louis, MO 63130; eCrow Canyon Archaeological Center, 23390 Road K, Cortez, CO 81321; fColinas Cultural Resource Consulting, 6100 North 4th Street, Private Mailbox #300, Albuquerque, NM 87107; and gDepartment of Archaeology, 2500 University Drive Northwest, University of Calgary, Calgary, Alberta, Canada T2N 1N4 Edited by Linda S. Cordell, University of Colorado, Boulder, CO, and approved October 30, 2009 (received for review June 22, 2009) Our understanding of the initial period of agriculture in the southwestern United States has been transformed by recent discoveries that establish the presence of maize there by 2100 cal. B.C. (calibrated calendrical years before the Christian era) and document the processes by which it was integrated into local foraging economies. Here we review archaeological, paleoecological, linguistic, and genetic data to evaluate the hypothesis that Proto-Uto-Aztecan (PUA) farmers migrating from a homeland in Mesoamerica intro- duced maize agriculture to the region. We conclude that this hypothesis is untenable and that the available data indicate instead a Great Basin homeland for the PUA, the breakup of this speech community into northern and southern divisions Ϸ6900 cal.
    [Show full text]
  • The Sonoran Desert Borderlands
    Geographic Area Information The Sonoran Desert Borderlands Photograph by CampPhoto / iStock / Getty Images Plus ABOUT The United States-Mexico border is roughly 3,219 kilometers (2,000 miles) long, stretching from the coast of the Pacific Ocean to the Gulf of Mexico. The Sonoran Desert is located on both sides of the border and covers more than 258,999 square kilometers (100,000 square miles) in the U.S. states of California and Arizona and the Mexican state of Sonora. The Sororan Desert is a rich, diverse, and delicate ecosystem, home to a highly diverse array of plant and animal species, some of which are critically endangered. Conservation efforts in the Sonoran Desert have involved organizations in both Mexico and the United States working together to connect habitat and migrations paths for animals. HUMAN IMPACTS In this fragile and diverse borderlands ecosystem, one of the most sever human impacts is the existing barrier (a combination of wall and fencing) that marks the U.S.-Mexico border. There is currently no continuous wall or fence marking the border, but there are segments of the border where there is a near-continuous barrier; one such area is the Sonoran Desert. Construction of a border barrier is ongoing, posing additional ecological concerns for the region. But it is not only the wall that impacts the region; the wall brings with it other human impacts, such as light pollution from stadium security flood-lights that illuminate the border at night and destruction of ecosystems as a result of construction, traffic, and patrolling of the border.
    [Show full text]
  • Synoptic-Scale Control Over Modern Rainfall and Flood Patterns in the Levant Drylands with Implications for Past Climates
    JUNE 2018 ARMONETAL. 1077 Synoptic-Scale Control over Modern Rainfall and Flood Patterns in the Levant Drylands with Implications for Past Climates MOSHE ARMON Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel ELAD DENTE Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Givat Ram, and Geological Survey of Israel, Jerusalem, Israel JAMES A. SMITH Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey YEHOUDA ENZEL AND EFRAT MORIN Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel (Manuscript received 23 January 2018, in final form 1 May 2018) ABSTRACT Rainfall in the Levant drylands is scarce but can potentially generate high-magnitude flash floods. Rainstorms are caused by distinct synoptic-scale circulation patterns: Mediterranean cyclone (MC), active Red Sea trough (ARST), and subtropical jet stream (STJ) disturbances, also termed tropical plumes (TPs). The unique spatiotemporal char- acteristics of rainstorms and floods for each circulation pattern were identified. Meteorological reanalyses, quantitative precipitation estimates from weather radars, hydrological data, and indicators of geomorphic changes from remote sensing imagery were used to characterize the chain of hydrometeorological processes leading to distinct flood patterns in the region. Significant differences in the hydrometeorology of these three flood-producing synoptic systems were identified: MC storms draw moisture from the Mediterranean and generate moderate rainfall in the northern part of the region. ARST and TP storms transfer large amounts of moisture from the south, which is converted to rainfall in the hyperarid southernmost parts of the Levant.
    [Show full text]