宇宙からみる地球の大気 塩谷 雅人 ( 京都大学生存圏研究所 ) 京都大学宇治キャンパス公開 年 10 月 23 日 宇治おうばくプラザ Scientific Interests in the TTL from the Global View - Satellite Observations - Masato Shiotani (Research Institute for Sustainable Humanosphere, Kyoto University) © NASA A U.S. – Japan Workshop on the Tropical Tropopause Layer: State of Current Science and Future Observational Needs October 15-19, 2012, East-West Center, Honolulu, Hawaii

“Earth observations from space” - The first 50 years of scientific achievements - 1 INTRODUCTION 2 EARTH OBSERVATIONS FROM SPACE: THE EARLY HISTORY 3 WEATHER 4 EARTH’S RADIATION BUDGET AND THE ROLE OF CLOUDS AND AEROSOLS IN THE CLIMATE SYSTEM 5 ATMOSPHERIC COMPOSITION: OZONE DEPLETION AND GLOBAL POLLUTION 6 HYDROLOGY 7 CRYOSPHERE 8 OCEAN DYNAMICS 9 ECOSYSTEMS AND THE CARBON CYCLE 10 LAND-USE AND LAND-COVER CHANGE 11 SOLID EARTH 12 CONCLUSIONS

Discovery of the Tropical Tape Recorder “The discovery of the so-called tape recorder (Mote et al. 1996) represents a remarkable scientific achievement in understanding stratospheric dynamics and motions.” Time series of zonal mean water vapor profile measurements by the Microwave Limb Sounder on the Aura satellite.

Conclusions in “Earth observations from space” The daily synoptic global view of Earth, uniquely available from satellite observations, has revolutionized Earth studies and ushered in a new era of multidisciplinary Earth sciences, … To assess global change quantitatively, synoptic data sets with long time series are required. The scientific advances resulting from Earth observations from space illustrate the successful synergy between science and technology Satellite observations often reveal known phenomena and processes to be more complex than previously understood The full benefits of satellite observations of Earth are realized only when the essential infrastructure, such as models, computing facilities, ground networks, and trained personnel, is in place. Providing full and open access to global data to an international audience more fully capitalizes on the investment in satellite technology and creates a more interdisciplinary and integrated Earth science community. Over the past 50 years, space observations of the Earth have accelerated the cross-disciplinary integration of analysis, interpretation, and, ultimately, our understanding of the dynamic processes that govern the planet.

Satellite observation strategy Which atmospheric parameter to be measured? –selection of frequency band Which observation geometry to be taken? –nadir sounding: good horizontal resolution –limb sounding: good vertical resolution emission measurement: high observation frequency occultation measurement: high accuracy Which orbital parameter to be chosen? –sun-synchronous: fixed local time –non-sun-synchronous: varying local time –geostationary: global (disk) picture

EOS-Aura Launched on July 15, 2004 Is the ozone layer changing as expected? What are the processes that control tropospheric pollutants? What are the roles of upper tropospheric aerosols, water vapor and ozone in climate change? Aura’s strategy is to obtain measurements of ozone, aerosols and key gases throughout the atmosphere using technologically innovative space instrumentation. Aura’s four Instruments: HIRDLS: High Resolution Dynamic Limb Sounder MLS: Microwave Limb Sounder OMI: Ozone Monitoring Instrument TES: Tropospheric Emission Spectrometer

Minor species observed from EOS Aura

The “A” Train

CALIPSO: Cloud-Aerosol Lidar and Infrared Pathfinder Satellite observation Launched on April 28,

GPS Radio Occultation (RO)  29 PGS satellites are orbiting at an altitude around 20000km Atmospheric temperature information is retrieved from refractive indexes of the atmosphere

Temperature profile from GPS RO measurements (Nishida et al., JMSJ, 2000)

Global variations in the TTL Annual variations –Temperature, water vapor, ozone, CO… –Monsoon circulation Intraseasonal variations –Kelvin waves –Madden-Julian oscillation Interannual variations –El Niño - Southern Oscillation (ENSO) Diurnal variations?

The carbon monoxide tape recorder Zonal mean MLS CO data with the annual average removed verses time (months). Black lines show the zero contour for MLS water vapor tape recorder with ‘wet’ and ‘dry’ labels indicating the sign of the perturbation. (Schoeberl et al., 2006)

Annual cycle in ozone and CO above the Tropical Tropopause Time series of MLS CO averaged over 10S–20N. The dashed lines show the respective annual harmonic fits to the time series. A corresponding time series of MLS ozone is also shown for the 68-hPa level (Randel et al., 2007, JAS).

Relation to upwelling across the tropical tropopause (Upper) Time series of standardized anomalies of daily temperatures from ERA- Interim and ozone and CO mixing ratio measurements from MLS. (Lower) Time series of the three upwelling estimates. (Abalos et al., 2012, ACPD).

Temperature at 100 hPa and OLR The horizontal distribution of monthly mean temperatures at 100 hPa and OLR (≤220 W/m2) (Nishimoto and Shiotani, 2012a, JGR). The horseshoe shaped temperature structure is regarded as the Matsuno-Gill pattern with a superposition of the Rossby and Kelvin responses (Gill, 1980, QJRMS).

Asian summer monsoon and associated tracer distribution Horizontal structures of 2-month (July and August 2003) average (a) NCEP geopotential height and horizontal winds at 150 hPa, (b) modified potential vorticity, (c) Atmospheric Infrared Sounder (AIRS) water vapor, and (d) ozone centered in Asian monsoon region at 360 K (Randel and Park, 2006, JGR)

Deep monsoon structure Vertical structures of 2-month (July and August) average NCEP zonal wind (shaded) and temperature anomalies (thin lines) averaged in 60–120E longitudes. Dashed lines denote isentropic surfaces and thermal tropopause from NCEP/NCAR reanalysis is noted by a thick solid line. (Randel and Park, 2006, JGR)

Confinement within the monsoon anticyclone Map of particles initialized on the 150 hPa level on (a) July 1, 2003, and (b) after 10 days and (c) 20 days trajectory runs. Long dashed lines indicate July and August average 14,320 m geopotential height at 150 hPa (Randel and Park, 2006).

Minimum ozone anomaly in the Asian monsoon anti-cyclone Longitude-latitude section of temperature and ozone from HIRDLS; the data are preliminary and subject to change (Gille et al., 2012, presented at QOS2012). T O3O3

Ozone anomaly seen in the nudged CTM and observations ppb Low values in stratosphere extend upward to ~ 60 hPa, suggesting upward motion of air with low ozone (Gille et al., 2012, presented at QOS2012).

Shallow quasi-stationary stable layer over the tropical Indian Ocean Vertical profiles of dry temperature (K) observed by COSMIC around 0N, 60E. Climatological T for Jul.-Aug. at 100hPa Frequency of inversion events during 2007 at 14.5–15 km from 2.5S to 2.5N. (Nishi et al., 2010, JGR)

Structure of the temperature inversion Longitude-height section in the 2.5S–2.5N (left) and latitude-height section at 60E of vertical temperature gradient averaged in July–August 2007 (Nishi et al, 2010, JGR).

Intraseasonal variability in the UTLS from the GPS RO temperatures Composite boreal winter (November–April) MJO cycle of longitude-latitude maps of GPS RO temperature anomalies at 100 hPa (Tian et a., 2012, JGR)

Vertical structure of Intraseasonal temperature variability from GPS RO Composite boreal winter MJO cycle of pressure-longitude cross-sections of GPS RO temperature anomalies over the equatorial region (10S–10N) (Tien et at., 2012, JGR)

TTL Cirrus as represented by CALIPSO lidar observations 7-day running mean cold point temperature at Manus (gray) and CALIPSO cloud fraction with base above 15 km within a 10 o x10 o region over Manus (black) from June 2006 to June (b) As in (a), but an 80-day high-pass filtered (Virts et al., 2012, JAS)

ISO structure of cirrus clouds Correlations between filtered CALIPSO TTL cirrus index within black reference boxes and filtered 58 latitude 3 58 longitude ERA 100-hPa temperatures (colors and contours) andwinds (vectors) throughout the tropics (Virts et al., 2012, JAS)

Intraseasonal variations and their relation to ENSO Longitude-time sections of the ISO locus for every event included in each of Clusters (Nishimoto and Shiotani, 2012b, submitted to JGR) Southern Oscillation Index (SOI) for the ISO events in each cluster.

ISO temperature variations at the TTL Longitude-time sections of the composite temperature and zonal wind at 100 hPa averaged over 15N-15S (Nishimoto and Shiotani, 2012b, submitted to JGR)

Diurnal variations in stratospheric ozone derived from a sun-asynchronous satellite Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES), which was aboard the ISS, made high-sensitivity measurement of minor species in the middle atmosphere during October 12, 2009 and April 21, Diurnal variations can be captured by measurements from the ISS which is taking a sun-asynchronous orbit (Sakazaki et al., submitted to JGR).

Diurnal cycles of precipitation and clouds in the tropics from TRMM observations Diurnal variation of total volumetric rainfall, population of precipitation systems, area of 20 dBZ reaching 14 km, area of cold clouds with TB11 < 210Kand 235 K, and flash counts over (a) land and (b) ocean in 20S–20N (Liu and Zipser, 2008) TRMM: Tropical Rainfall Measuring Mission

Concluding Remarks The satellite observation provides us spectacular views of the earth like “eyes of the god”, but it is not all-purpose. The TTL is a rather thin region for which usual satellites measurements are not necessarily suited - Complemetary use of ground based or in-situ observations is important. The TTL is highly affected by tropospheric convective activities that are dominated with diurnal, intraseasonal, annual, and interannual periodicities. Intraseasonal variations such as Madden-Julian oscillations may overarch important processes in the TTL. Asian monsoon circulation should be an essential transport process in the TTL during northern summer. Diurnal cycles could be captured for several aspects of the TTL properties.

References - 1 Abalos et al. (2012), Variability in upwelling across the tropical tropopause and correlations with tracers in the lower stratosphere, Atmos. Chem. Phys. Discuss., 12, 18817– Gill (1980), Some simple solutions for heat-induced tropical circulation, Q. J. R. Meteorol. Soc., 106(449), 447–462. Gille et al. (2012),Observations of Trop-Strat exchange: Transport of tropospheric ozone and CFC’s into the UTLS by the Asian monsoon, presented at Quadrennial Ozone Symposium, 26 August 2012, Toronto, Canada. Liu, C., and E. J. Zipser (2008), Diurnal cycles of precipitation, clouds, and lightning in the tropics from 9 years of TRMM observations, Geophys. Res. Lett., 35, L04819, doi: /2007GL Mote et al. (1996), An atmospheric tape recorder: The imprint of tropical tropopause temperatures on stratospheric water vapor. Journal of Geophysical Research 101: 2,989-4,006. NASA (2010), "Our Changing Atmosphere“ Discoveries from EOS Aura, Nishi et al. (2010), Quasi ‐ stationary temperature structure in the upper troposphere over the tropical Indian Ocean inferred from radio occultation data, J. Geophys. Res., 115, D14112, doi: /2009JD Nishida et al. (2000), Seasonal and longitudinal variations in the tropical tropopause observed with the GPS occultation technique (GPS/MET), J. M. S. Japan, 78,

References - 2 Nishimoto and Shiotani (2012a), Seasonal and interannual variability in the temperature structure around the tropical tropopause and its relationship with convective activities, J. Geophys. Res., 117, D02104, doi: /2011JD Nishimoto and Shiotani (2012b), Intraseasonal variations in the tropical tropopause temperature revealed by cluster analysis of convective activity, submitted to JGR. Randel and Park (2006), Deep convective influence on the Asian summer monsoon anticyclone and associated tracer variability observed with Atmospheric Infrared Sounder (AIRS), J. Geophys. Res., 111, D12314, doi: /2005JD Randel et al. (2007), A large annual cycle in ozone above the tropical tropopause linked to the Brewer-Dobson circulation, J. Atmos. Sci., 64, 4479–4488, Sakazaki et al. (2012), Diurnal ozone variations in the stratosphere revealed in observations from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) onboard the International Space Station (ISS), submitted to JGR. Schoeberl et al. (2006), The carbon monoxide tape recorder, Geophys. Res. Lett., 33, L12811, doi: /2006GL Tian et al. (2012), Intraseasonal temperature variability in the upper troposphere and lower stratosphere from the GPS radio occultation measurements, J. Geophys. Res., 117, D15110, doi: /2012JD Virts et al. (2012), Tropical Tropopause Transition Layer Cirrus as Represented by CALIPSO Lidar Observations. J. Atmos. Sci., 67, 3113–3127 DOI: /2010JAS