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Energie-, Wasser-, Spurenstoff-, Drehimpuls- und Gesamtmassenkreislauf

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Präsentation zum Thema: "Energie-, Wasser-, Spurenstoff-, Drehimpuls- und Gesamtmassenkreislauf"—  Präsentation transkript:

1 Energie-, Wasser-, Spurenstoff-, Drehimpuls- und Gesamtmassenkreislauf
Wiederholung 2. Stunde Defintion des Klimasystems über seine Komponenten und als System ineinander verschachtelter Kreisläufe. Welche? Welche Randbedingungen (externen Antriebe) hat das Klimasystem? Welche Raum-Zeit-Skalen sind relevant? → Wieviele Freiheitsgrade hat die Atmosphäre? Energie-, Wasser-, Spurenstoff-, Drehimpuls- und Gesamtmassenkreislauf solare Einstrahlung (extraterrestrisch) geologisch: Land-/Meeverteilung, Orographie (terrestrisch) Auflösung bis in den viskosen Dissipationsbereich → Δx = 1mm Raumgitter: Oberfläche = 4π R2 ~ 5 · 1020 mm2 → Volumen bis 100 km Höhe ~ 5 · 1028 mm3 Variablen: u,v,w,p,T,Gase (CO2,O3, ..), Aerosol & Hydrometeore ca Freiheitsgrade Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

2 Wiederholung 2. Stunde Warum ist eine deterministische Betrachtung des Klimasystems nicht möglich? Mit welchen Maßen wird das Klimasytems beschrieben? zuviele Freiheitsgrade (1031) - derzeitige Rechenzeitkapazität 1010 Anfangswerte können nicht bestimmt werden Nichtlinearität → chaotische Entwicklung Beschreibung des mittleren Zustandes der typischen Abweichungen des mittleren Zustandes der typische Zeitabläufe für diese Abweichungen der Wahrscheinlichkeiten für extreme Abweichungen f(x)dx des Auftretens eines zufälligen Zustands X im Bereich dx (f : Wahrscheinlichkeitsdichte) Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

3 Gliederung Synop-Stationen → bodennahes Klima über Land
freiwillige Handelsschiffe über Ozean → COADS- Datensatz ( ) Radiosondenaufstiege → vertikale Struktur seit ca ca. 7 Stationen pro 2.5°x2.5° Einführung Datengrundlage - Messungen (direkt/indirekt) - Reanalysen (Modelle als Ergänzung) Energiehaushalt der Erde - Strahlungs(konvektions)-gleichgewicht - Räumliche Verteilung, 3D-Energietransporte, „Wärmemaschine“ Klimasystem Hydrologischer Zyklus - terrestrischer/ozeanischer Arm - Energietransporte im Ozean (thermohaline Zirkulation) Natürliche Klimavariabilität - Interne Variabilität (ENSO) - Externe Variabilität (Sonne, Vulkane, Erdbahnparameter) Klimamodellierung - GCM/Ensemble-Vorhersage/Parametrisierung - IPCC, Szenarien, anthropogene Effekte Globaler Wandel - Detektion des anthropogenen Einflusse Seit wann gibt es flächendeckend verlässliche Daten zu Abschätzung des Klimas Klimaskeptiker: Der erste messbare leichte Anstieg erfolgte ca als Langwellensender in Betrieb genommen wurden. Der nächste bereits größere Temperaturanstieg wurde ca nachgewiesen, als Kurzwellensender hinzu kamen. Ein extrem steiler Anstieg wird seit 1950 gemessen der kontinuierlich mit der Einführung neuen Sendetechniken einher geht. Diese globale Temperaturmessungen zeigen, dass parallel zum ansteigenden Funkverkehr die Klimaerwärmung bis heute um 0,7 Grad angestiegen ist. Die aktuelle Situation in Deutschland ist charakterisiert durch ca. 60 Millionen Handys und ca bis Basisstationen. Dazu kommen noch unendlich viele schnurlose DECT-Telefone. Eine Mittelwelle hat ungefähr bis zu 18 Millionen Watt Energie. Ein D 1/D 2-Mast hat maximal 50 Watt, und ein Handy hat 2 Watt. Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

4 100-jähr. aerologische Lindenberger Messreihe
1902 entdecken Assmann und de Bort die wärmere Schicht in der Höhe (Stratosphäre)  es kommt zur klassischen Schichteinteilung der Atmosphäre (Troposphäre/Tropopause/ Stratosphäre) Bedeutung der Kenntnis der Vertikalstruktur  schon damals durch Assmann u.a. Forderung nach regelmäßigen Vertikalsondierungen Homogenisierung von Sensoren Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

5 WOCE – World Ocean Circulation Experiment
Beobachtungen von Forschungsschiffen CTDs: T(D), C(D) oberste 400 m zeigen markante Variabilität auf Jahreszeitenskala Messungen der synoptischen Strömungs-verteilung jedoch unmöglich → nur über geostrophische Beziehung (CTD= Conductivity - Temperature - Depth) Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

6 Struktur Internationale Klimaforschung
WCRP World Climate Research Programm GEWEX Global Energy and Water Experiment WOCE World Ocean Circulation Experiment CLIVAR Climate Variability and Prediction Programm SPARC Stratospheric Processes and their Role in Climate CLIC Climate and Cryosphere Programm The WCRP is now organized into five main components, the Global Energy and Water Experiment (GEWEX), the Climate Variability and Prediction (CLIVAR) program, the World Ocean Circulation Experiment (WOCE), the Stratospheric Processes and their Role in Climate (SPARC) program, and the Climate and Cryosphere (CLIC) program. GEWEX focuses on the analysis of global observations, supplemented by process modeling studies, to understand the processes controlling the fast climate feedbacks that determine water supplies for the biosphere, including humans. CLIVAR, as a follow-on to the Tropical Ocean-Global Atmosphere (TOGA) program, focuses on global atmosphere-ocean modeling, supplemented by observations of the upper ocean, to understand the processes causing climate change, including human-induced changes, and the slow climate feedbacks arising from ocean-atmosphere coupling. The objective is to understand these processes well enough to predict climate change. WOCE focuses on observation, analysis and modeling of the whole ocean circulation and the role of the ocean in very long-term climate variations. SPARC focuses on the chemical and dynamical processes that determine ozone abundances and ultraviolet radiation at the surface and on the role of the stratosphere in the climate system. CLIC focuses on the role of the polar cryosphere in the climate system, particularly interactions involving sea ice and the ocean. Under GEWEX, the study of the radiation exchanges in the climate system combines ISCCP with a project to determine the global Surface Radiation Balance (SRB) from satellite observations, anchored by accurate, long-term measurements at the Baseline Surface Radiation Network (BSRN) sites, with projects to determine the global distribution and radiative effects of aerosols, the Global Aerosol Climatology Project (GACP) and the Stratospheric Aerosol and Gas Experiment III (SAGE III), and other investigations of radiative modeling organized by the GEWEX Radiation Panel (GRP), including the Intercomparison of Radiation Codes in Climate Models (ICRCCM) and the International Intercomparison of 3D Radiation Codes (I3RC) projects. These studies also make use of data from a continuing series of satellite experiments to determine the radiation budget at the top of the atmosphere (the NIMBUS-7 Earth Radiation Budget, the Earth Radiation Budget Experiment (ERBE), the Scanner for Radiation Budget (ScaRaB), and the Clouds and the Earth's Radiant Energy System (CERES)). The study of the global water cycle combines ISCCP cloud data with projects to determine the global distribution and variations of precipitation, the Global Precipitation Climatology Project (GPCP) , augmented by the experimental Tropical Rainfall Measuring Mission (TRMM) , the distribution of water vapor, the Global atmospheric water Vapor Project (GVAP) , and of the fluxes of water and heat at the ocean surface (SeaFlux). The key modeling study to understand how atmospheric motions determine the properties of clouds and the formation of precipitation is carried out under the GEWEX Cloud System Study (GCSS), and the GEWEX Global Land/Atmosphere System Study (GLASS). Analyse von globalen Beobachtungen/Prozessmodellierung Schwerpunkt auf „schnellen Rückkopplungen“, welche die Verfügbarkeit von Süßwasser für die Biosphäre beeinflussen ein Teilprojekt: ISCCP Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

7 International Satellite Cloud Climatology Project ISCCP
seit Juli 1983: Archivierung von Satellitenstrahldichten zur Bestimmung der globalen Verteilung von Wolken einschließlich deren Eigenschaften, Tagesgang, saisonale und interanuale Variabilität Klimawirksamkeit von Wolken Effekte auf den Strahlungshaushalt „CRF“: Cloud Radiative Forcing Rolle bezüglich des globalen Wasserkreislaufes The International Satellite Cloud Climatology Project (ISCCP) was established in 1982 as part of the World Climate Research Program (WCRP) to collect weather satellite radiance measurements and to analyze them to infer the global distribution of clouds, their properties, and their diurnal, seasonal and interannual variations. The resulting datasets and analysis products are being used to study the role of clouds in climate , both their effects on radiative energy exchanges and their role in the global water cycle. The ISCCP cloud datasets provide our first systematic global view of cloud behavior of the space and time scales of the weather yet covering a long enough time period to encompass several El Nino - La Nina cycles. Below is a single global snap-shot of clouds. ISCCP was established in 1982 as part of the World Climate Research Programme (WCRP) to collect and analyze satellite radiance measurements to infer the global distribution of clouds, their properties, and their diurnal, seasonal, and interannual variations. Data collection began on 1 July 1983 and is currently planned to continue through 30 June The resulting datasets and analysis products are being used to improve understanding and modeling of the role of clouds in climate, with the primary focus being the elucidation of the effects of clouds on the radiation balance. These data can also used to support many other cloud studies, including understanding of the hydrological cycle. ... bisher im Internet verfügbar: bis Dezember Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

8 Bsp: ISCCP Cloud Amount
Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

9 Cloud Radiative Forcing (CRF)
Einfluss von Wolken auf die Strahlungsbilanz am Oberrand der Atmosphäre Daten: ERBE (Earth Radiation Budget Experiment) & ISCCP 1. Schritt: „clear-sky climatology“ Mittelwert über alle Strahldichtemessungen an einem bestimmten geographischen Ort die als „wolkenfrei“ identifiziert werden 2. Schritt: Bildung der Differenz zwischen den Strahldichtemessungen der clear-sky climatology und dem Mittelwert über alle Beobachtungen am entsprechenden geographischen Ort Einfluss der Wolken auf die Energiebilanz am Oberrand der Atmosphäre („cloud radiative forcing“) Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

10 Cloud Radiative Forcing (CRF)
global: Positive Werte: Energiegewinn für das System Erde-Atmosphäre Negative Werte: Energieverlust für das System Erde-Atmosphäre (abhängig von: solarem Einfallswinkel, Tröpfengrößenspektrum, Phase) Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

11 Earth Radiation Budget Experiment ERBE
Cloud radiative forcingProduct description: Clouds play a significant role in our world's energy balance -- they exert both a cooling effect on the surface by reflecting sunlight back into space, and a warming effect by trapping heat emitted from the surface. Clouds are one of the greatest areas of scientific uncertainty with respect to how much they influence climate on a global scale. The term "cloud radiative forcing" refers to the effects clouds have on both sunlight and heat in the atmosphere. More precisely, cloud radiative forcing measures how much clouds modify the net radiation, at wavelengths ranging from 0.3 to 100 micrometers, of the Earth system. The image above is a false-color map showing the magnitudes of cloud radiative forcing (in Watts per square meter) for the given month(s). Regions of positive cloud radiative forcing indicate areas where clouds act to increase net energy into the Earth system (i.e., regions of deep tropical convection) and areas of negative cloud radiative forcing signify regions where clouds act to decrease net energy into the Earth system (such as areas of stratus clouds off the coast of California). The solar and terrestrial properties of clouds have offsetting effects in terms of the energy balance of the planet. In the longwave, clouds generally reduce the radiation emission to space and thus result in a heating of the planet. While in the solar (or shortwave), clouds reduce the absorbed solar radiation, due to a generally higher albedo than the underlying surface, and thus result in a cooling of the planet. The latest results from ERBE indicate that in the global mean, clouds reduce the radiative heating of the planet. This cooling is a function of season and ranges from approximately -13 to -21 Wm-2. While these values may seem small, they should be compared with the 4 Wm-2 heating predicted by a doubling of atmospheric concentration of carbon dioxide. In terms of hemispheric averages, the longwave and shortwave cloud forcing tend to balance each other in the winter hemisphere. In the summer hemisphere, the negative shortwave cloud forcing dominates the positive longwave cloud forcing, and the clouds result in a cooling. View the maps of cloud forcing given below to answer the following questions: Does the presence of low level clouds over oceans heat or cool the planet? What about the convective clouds over the oceans? Do deserts have a large or small cloud radiative forcing? All of the images in this dataset up to and including February 1990 were acquired by the Earth Radiation Budget Experiment (ERBE) sensor and all of the images from March 2000 onward were acquired by the Clouds and the Earth's Radiant Energy System (CERES) sensor aboard NASA's Terra satellite. (Data courtesy ERBE and CERES Projects, NASA LaRC) Steve Ackerman and Tom Whittaker, 1999 Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

12 CRF - global Cloud radiative forcingProduct description: Clouds play a significant role in our world's energy balance -- they exert both a cooling effect on the surface by reflecting sunlight back into space, and a warming effect by trapping heat emitted from the surface. Clouds are one of the greatest areas of scientific uncertainty with respect to how much they influence climate on a global scale. The term "cloud radiative forcing" refers to the effects clouds have on both sunlight and heat in the atmosphere. More precisely, cloud radiative forcing measures how much clouds modify the net radiation, at wavelengths ranging from 0.3 to 100 micrometers, of the Earth system. The image above is a false-color map showing the magnitudes of cloud radiative forcing (in Watts per square meter) for the given month(s). Regions of positive cloud radiative forcing indicate areas where clouds act to increase net energy into the Earth system (i.e., regions of deep tropical convection) and areas of negative cloud radiative forcing signify regions where clouds act to decrease net energy into the Earth system (such as areas of stratus clouds off the coast of California). The solar and terrestrial properties of clouds have offsetting effects in terms of the energy balance of the planet. In the longwave, clouds generally reduce the radiation emission to space and thus result in a heating of the planet. While in the solar (or shortwave), clouds reduce the absorbed solar radiation, due to a generally higher albedo than the underlying surface, and thus result in a cooling of the planet. The latest results from ERBE indicate that in the global mean, clouds reduce the radiative heating of the planet. This cooling is a function of season and ranges from approximately -13 to -21 Wm-2. While these values may seem small, they should be compared with the 4 Wm-2 heating predicted by a doubling of atmospheric concentration of carbon dioxide. In terms of hemispheric averages, the longwave and shortwave cloud forcing tend to balance each other in the winter hemisphere. In the summer hemisphere, the negative shortwave cloud forcing dominates the positive longwave cloud forcing, and the clouds result in a cooling. View the maps of cloud forcing given below to answer the following questions: Does the presence of low level clouds over oceans heat or cool the planet? What about the convective clouds over the oceans? Do deserts have a large or small cloud radiative forcing? All of the images in this dataset up to and including February 1990 were acquired by the Earth Radiation Budget Experiment (ERBE) sensor and all of the images from March 2000 onward were acquired by the Clouds and the Earth's Radiant Energy System (CERES) sensor aboard NASA's Terra satellite. (Data courtesy ERBE and CERES Projects, NASA LaRC) Hartmann, 1994 Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

13 Wolkeneinfluss auf den Strahlungshaushalt in Modellen im Vergleich zu Messungen des ERBE (1985-1989)
DJF 85-89 Potter & Cess, 2004, JGR Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

14 Fehlerabschätzungen: 10-15%
all sky solar clear alle unbewölkt terrestrial B.Carson, GISS 2004 Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

15 Klima Datensätze GEWEX Newsletter solar terrestrial all sky clear alle
all sky solar clear alle terrestrial B.Carson, GISS 2004 Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

16 MSU/AMSU Instrumente auf NOAA Satelliten
MSU GHz (1978-heute) auf 8 NOAA Satelliten (polarumlaufend) AMSU ab 1998, 2.5° Auflösung keine absolute Kalibration (Interkalibration zwischen verschiedenen Satelliten nötig) PSD = particle size distribution Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

17 Satellitentrends - MSU
geographische Breite Vorteil: wahrhaft global Zeitreihe Problem: kurze Zeitreihe, Unsichere Kalibration MSU Kanal 2 (1979 – 2003) Globaler Trend: K/Dekade Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

18 Satellitentrends - MSU
MSU Kanal 2 MSU Kanal 3 Figure 7. Global, monthly time series of brightness temperature anomaly for channels 2, 3, and 4. For Channel 2, the anomaly time series is dominated by ENSO events and slow tropospheric warming. The three primary El Niño's during the past 20 years are clearly evident as peaks in the time series occurring during , , and , with the most recent one being the largest. Channel 4 is dominated by stratospheric cooling (WIESO?), punctuated by dramatic warming events caused by the eruptions of El Chichon (1982) and Mt Pinatubo (1991). Channel 3 appears to be a mixture of both effects. MSU Kanal 4 Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

19 SSM/I – Special Sounder Microwave Imager
hier: August 2004, seit 1987, (V/H) GHz, Erdabdeckung ~3 Tage, räumliche Auflösung km, Nachfolge AMSR-E, TMI vv in m/s (Rauigkeitlänge Polarisationsabh.) Wasserdampfsäule, mm PSD = particle size distribution Wolkenwassersäule, mm Regenrate, mm/hr Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

20 Scatterometer Räumliche Auflösung: ~ 45 km (entlang und senkrecht zur Flugrichtung) Windrichtung Bereich: 0 – 360° Genauigkeit: +-20° Windgeschwindigkeit Bereich: 4 ms ms-1 Genauigkeit: 2 ms-1 oder 10 % The purpose of the Wind ~ is to obtain information on wind speed and direction at the sea surface for incorporation into models, global statistics and climatological datasets. It operates by recording the change in radar reflectivity of the sea due to the perturbation of small ripples by the wind close to the surface. This is possible because the radar backscatter returned to the satellite is modified by wind-driven ripples on the ocean surface and, since the energy in these ripples increases with wind velocity, backscatter increases with wind velocity. The three antennae generate radar beams looking 45deg. forward, sideways, and 45deg. backwards with respect to the satellite's flight direction. These beams continuously illuminate a 500 km wide swath (see the figure) as the satellite moves along its orbit. Thus three backscatter measurements of each grid point are obtained at different viewing angles and separated by a short time delay. These "triplets" are fed to a mathematical model which calculates surface wind speed and direction. The main technical characteristics of the Wind Scatterometer are listed below: Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

21 Bestimmung des Windvektors
Rückstreuung ist maximal in und entgegen der Windrichtung, da hier Kapillarwellen senkrecht und Bragg-Streuung optimal so ist minimal senkrecht zur Windrichtung, da hier die Kapillarwellen parallel und kaum Bragg-Streuung Wegen der Form der Kapillarwellen in das relative Maximum entgegen der Windrichtung leicht größer Eine höhere Windgeschw. führt für alle Richtungen zu einer höheren Rückstreuung The purpose of the Wind Scatterometer is to obtain information on wind speed and direction at the sea surface for incorporation into models, global statistics and climatological datasets. It operates by recording the change in radar reflectivity of the sea due to the perturbation of small ripples by the wind close to the surface. This is possible because the radar backscatter returned to the satellite is modified by wind-driven ripples on the ocean surface and, since the energy in these ripples increases with wind velocity, backscatter increases with wind velocity. The three antennae generate radar beams looking 45deg. forward, sideways, and 45deg. backwards with respect to the satellite's flight direction. These beams continuously illuminate a 500 km wide swath (see the figure) as the satellite moves along its orbit. Thus three backscatter measurements of each grid point are obtained at different viewing angles and separated by a short time delay. These "triplets" are fed to a mathematical model which calculates surface wind speed and direction. The main technical characteristics of the Wind Scatterometer are listed below: Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

22 ERS – European Remote Sensing Satellites
ERS1: , ERS2: 1995-???? in ~780 km Höhe Typ: polarumlaufend, sonnensynchron T~100 min “Repeat cycle”: 35 Tage Instrumente SAR “Synthetic Aperture Radar” Wind Scatterometer Radar Altimeter passive Radiometer (ATSR) Active Microwave Instrument (AMI) combining the functions of a Synthetic Aperture Radar (SAR) and a Wind Scatterometer. The SAR operates in image mode for the acquisition of wide-swath, all weather images over the oceans, polar regions, coastal zones and land. In wave mode the SAR produces imagettes (about 5 km x 5 km) at regular intervals for the derivation of the length and direction of ocean waves. The Wind Scatterometer uses three antennae for the generation of sea surface wind speed and direction. Radar Altimeter (RA) provides accurate measurements of sea surface elevation, significant wave heights, various ice parameters and an estimate of sea surface wind speed. Along Track Scanning Radiometer (ATSR) combining an infra-red radiometer and a microwave sounder for the measurement of sea surface temperature, cloud top temperature, cloud cover and atmospheric water vapour content. Precise Range and Range-rate Equipment (PRARE) is included for the accurate determination of the satellite's position and orbit characteristics, and for precise position determination (geodetic fixing). Laser Retro-reflectors (LRR) allow measurement of the satellite's position and orbit via the use of ground-based laser ranging stations. Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

23 El Niño im ATSR SST, July1995 SST, July1997 Differenz 1995-1997 ATSR:
Infra-Rot Radiometer (IRR): SST und Wolkenobergrenzen-temperaturen Microwave Sounder (MWS): Wolkenwasser, Wasserdampf, SST El Niño Effect ATSR monthly average Sea Surface Temperature at the spatial resolution of 30 arcminutes The Pacific ocean is usually warmer and higher on the Western side than along the South American coast, due to the Trade Winds blowing constantly from East to West. These winds transport the warm surface water from East to West, where it is piled up. In the East, the warm surface water is replaced by cold, nutricious water coming from deeper layers: this vertical movement is called upwelling. During an El Niño event the Trade Winds relax, become very weak, and may even reverse. This causes the warm surface water to flow back eastwards, and stops the upwelling on the eastern side. This means that along the South American coast the sea surface temperature will rise, and it will drop on the Asian and Indonesian coasts. El Niño is very strong this year. The image difference between July 1995 and July 1997 highlights the El Niño phenomena. In July 95 the water along the South American Coast is much colder than the July 97 water (in blue in the image). Some studies show the interconnection between El Niño and anormal climatic events all over the world. The 1997 El Niño event may be responsible for drought and associated fires in Indonesia and for the Pauline cyclone in Mexico. Image description The monthly composite images have been made using the ATSR spatially averaged Sea Surface Temperature product. One single product consists of about one ATSR orbit. About 340 orbits were used to produced a monthly composite. The spatial resolution is 30 arcminutes, the temperature precision is better than 0.3 Celsius. The data have been processed at RAL July 1997 image is derived from ATSR-2 data, July 1995 is derived from ATSR-1 data. The difference image is just SST (July 1995) minus SST(July 1997). The temperature scale is given in degree Celsius. earth.esa.int Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

24 NDVI – Normalized Difference Vegetation Index
< 0.1: Stein/Wüste/Schnee : Steppe/Grasland : bewaldet - Regenwald Satellite maps of vegetation show the density of plant growth over the entire globe. The most common measurement is called the Normalized Difference Vegetation Index (NDVI). Very low values of NDVI (0.1 and below) correspond to barren areas of rock, sand, or snow. Moderate values represent shrub and grassland (0.2 to 0.3), while high values indicate temperate and tropical rainforests (0.6 to 0.8). NDVI is calculated from the visible and near-infrared light reflected by vegetation. Healthy vegetation (left) absorbs most of the visible light that hits it, and reflects a large portion of the near-infrared light. Unhealthy or sparse vegetation (right) reflects more visible light and less near-infrared light. The numbers on the figure above are representative of actual values, but real vegetation is much more varied. (Illustration by Robert Simmon). NDVI = (NIR — VIS)/(NIR + VIS) Messungen via NOAA AVHRR Instrument (1 km2 Auflösung) bisher 2 Jahrzehnte globale Abdeckung Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

25 Eisbedeckungsgrad/Eisvolumen - ICESAT
Antarktische und Grönländische Eisplatten beinhalten 77% des Süßwassers (≅80 m Meeresniveau!) Schmelzen von 0.1% bedeutet Meeresniveauanstieg von 8.3 cm Jährliche Eisansammlung von 0.8 cm Meereseniveau ausgeglichen durch Rückfluss in den Ozean (Massenbalance) Lokale und langzeitliche Unteschiede Massenbalance sollte möglichst genau bestimmt werden Erstflug, Eisbedeckungsgrad und Eisvolumen vollständig nur via Satellit Es fehlen Zeitreihen This figure illustrates ice sheet elevation and cloud data from ICESat's Geoscience Laser Altimeter System (GLAS) on its first day of operation, February 20, On that day, the instrument collected a 1064 nm wavelength profile across Antarctica: the lower West Antarctica Ice Sheet in the foreground is seperated from the higher East Antarctica Ice Sheet in the background by the steep TransAntarctic Mountains. The elevation profile (in red) is depricted relative to the Earth's standard ellipsoid, with 50x vertical exaggeration. Data collected across floating sea ice and open water of the adjacent Southern Ocean cannot be shown at that scale. Clouds of various thicknesses are indicated by colors changing progressively from light blue (thin clouds) to white (opeque layers). Note that the layer cannot penetrate the thickest clouds causing gaps in the elevation profile below. The RADARSAT (Canadian Space Agency) mosaic is used to illustrate the Antarctic continent. GLAS (the Geoscience Laser Altimeter System) is the first laser-ranging (lidar) instrument for continuous global observations of Earth, which will make unique atmospheric observations as an important component of the ESE climate change program. GLAS is a facility instrument designed to measure ice-sheet topography and associated temporal changes, cloud and atmospheric properties.and give us information on the height and thickness of radiatively important cloud layers which is needed for accurate short term climate and weather prediction. In addition, operation of GLAS over land and water will provide along-track topography. GLAS includes a laser system to measure distance, a Global Positioning System (GPS) receiver, and a star-tracker attitude determination system. The laser will transmit short pulses (4 nano seconds) of infrared light (1064 nanometers wavelength) and visible green light (532 nanometers). Photons reflected back to the spacecraft from the surface of the Earth and from the atmosphere, including the inside of clouds, will be collected in a 1 meter diameter telescope. Laser pulses at 40 times per second will illuminate spots (footprints) 70 meters in diameter, spaced at 170-meter intervals along Earth's surface. ICESAT benutzt Lidar (Light Detecting and Ranging) Technolgie ICESSAT detektiert Änderungen der mittleren Eismächtigkeit von bis zu 0.3 cm → Meeresspiegelanstieg von bis zu 0.1 cm nachweisbar Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

26 Zukünftige Missionen A-Train (USA/Frankreich) EarthCARE (ESA)
The "A-Train" satellite formation consists of six satellites flying in close proximity in a near future. The first one, Aqua, was launched in The second one, Aura, will be launched in June 2004, while CloudSAT, CALIPSO and PARABOL will start their missions in October The last one, OCO, will join them in The individual missions and the A-Train formation are described in this paper, "Formation Flying: The Afternoon 'A-Train' Satellite Constellation" (PDF format, 6 pages, 263 KB). The satellites will cross the equator within a few minutes of one another at around 1:30 p.m. local time. By combining the different sets of observations, scientists will be able to gain a better understanding of important parameters related to climate change. The above document describes the individual mission of all these satellites, before looking at the value of the entire formation. By combining the components, scientists are able to gain a better understanding of important parameters related to climate change. The A-Train formation will allow for synergistic measurements where data from several different satellites can be used together to obtain comprehensive information about various key atmospheric components or processes. Combining the information from several sources gives a more complete answer to many questions than would be possible from any single satellite taken by itself. "This graphic (not to scale) depicts the satellites that make up the Afternoon Constellation -- "The A-Train." Listed under each satellite’s name is its equator crossing time. Note that though Aura crosses the equator eight minutes behind Aqua, in terms of local time, because it is along a different orbit track, it actually lags Aqua by fifteen minutes. Note also that CALIPSO trails CloudSat by only 15 seconds to allow for synergy between Aqua, CloudSat, and CALIPSO. Credit: Alex McClung. EarthCARE (ESA) Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

27 Beobachtungen zur Modellverbesserung
Klimamodelle benötigen kleinskalige Beobachtungen Verbesserte Parametrisierungen - Aerosol/Wolken/Niedersschlagsprozesse - 3D-Strahlungstransfereffekte - Bodenmodule ... Validierung - Satellitenvalidation - Bodengebundene Validation CLIWA-NET CLOUD-NET Atmospheric Radiation Measurement program ARM ... PSD = particle size distribution langzeitliche und detailierte Strahlungs- und mikrophysikalische Messungen notwendig Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

28 Paläoklimatologische Daten
Historische Dokumente Baumringe Korallenringe Eisbohrkerne Speläologie (Höhlenkunde) Sedimente in Seen und Ozean Bohrlöcher Glaziale Oberflächen-Formung (Moränen) Korallen - geochemische Charakteristika Jones & Mann, 2004:, Climate over past millenia, Reviews of Geophysics Physikalische Klimatologie, Susanne Crewell, WS 2006/2007

29 Paläoklimatologische Daten
Korallen - geochemische Charakteristika Jones & Mann, 2004:, Climate over past millenia, Reviews of Geophysics Physikalische Klimatologie, Susanne Crewell, WS 2006/2007


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