ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2013-08-31
    Description: At high Arctic stations such as Barrow, Alaska, springtime near-surface ozone amounts fluctuate between the highest and lowest values seen during the course of the year. Episodes when the surface ozone concentration is essentially zero last up to several days during this time of year. In the Arctic Gas and Aerosol Sampling Program (AGASP-I and AGASP-II) in 1983 and 1986, it was found that ozone concentrations often showed a very steep gradient in altitude with very low values near the surface. The cold temperatures, and snow-covered ground make it unlikely that the surface itself would rapidly destroy significant amounts of ozone. The AGASP aircraft measurements that found low ozone concentrations in the lowest layers of the troposphere also found that filterable excess bromine (the amount of bromine in excess of the sea salt component) in samples collected wholly or partially beneath the temperature inversion had higher bromine concentrations than other tropospheric samples. Of the four lowest ozone minimum concentrations, three of them were associated with the highest bromine enrichments. Surface measurements of excess filterable bromine at Barrow show a strong seasonal dependence with values rising dramatically early in March, then declining in May. The concentration of organic bromine gases such as bromoform rise sharply during the winter and then begin to decline after March with winter and early spring values at least three times greater than the summer minimum.
    Keywords: ENVIRONMENT POLLUTION
    Type: NASA, Goddard Space Flight Center, Polar Ozone Workshop. Abstracts; p 201-203
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2018-06-06
    Description: Abstract: Since 1998 the Southern Hemisphere ADditional OZonesondes (SHADOZ) project has collected more than 2000 ozone profiles from a dozen tropical and subtropical sites using balloon-borne electrochemical concentration cell (ECC) ozonesondes. The data (with accompanying pressure-temperature-humidity soundings) are archived. Analysis of ozonesonde imprecision within the SHADOZ dataset revealed that variations in ozonesonde technique could lead to station-to-station biases in the measurements. In this paper imprecisions and accuracy in the SHADOZ dataset are examined in light of new data. When SHADOZ total ozone column amounts are compared to version 8 TOMS (2004 release), discrepancies between sonde and satellite datasets decline 1-2 percentage points on average, compared to version 7 TOMS. Variability among stations is evaluated using total ozone normalized to TOMS and results of laboratory tests on ozonesondes (JOSE-2O00, Julich Ozonesonde Intercomparison Experiment). Ozone deviations from a standard instrument in the JOSE flight simulation chamber resemble those of SHADOZ station data relative to a SHADOZ-defined climatological reference. Certain systematic variations in SHADOZ ozone profiles are accounted for by differences in solution composition, data processing and instrument (manufacturer). Instrument bias leads to a greater ozone measurement above 25 km over Nairobi and to lower total column ozone at three Pacific sites compared to other SHADOZ stations at 0-20 deg.S.
    Keywords: Meteorology and Climatology
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2013-08-31
    Description: From a network of surface ozone monitoring sites distributed primarily over the Atlantic and Pacific Oceans, the seasonal, day-to-day, and diurnal patterns are delineated. At most of the NH (Northern Hemisphere) sites there is a spring maximum and late summer or autumn minimum. At Barrow, AK (70 deg N) and Barbados (14 deg N), however, there is a winter maximum, but the mechanisms producing the maximum are quite different. All the sites in the SH (Southern Hemisphere) show winter maxima and summer minima. At the subtropical and tropical sites, there are large day-to-day variations that reflect the changes in flow patterns. Air of tropical origin has much lower ozone concentrations than air from higher latitudes. At the two tropical sites (Barbados and Samoa), there is a marked diurnal ozone variation with highest amounts in the early morning and lowest values in the afternoon. At four of the locations (Barrow, AK; Mauna Loa, HI; American Samoa; and South Pole), there are 15- through 20-year records which allow us to look at longer term changes. At Barrow there has been a large summer increase over the 20 years of measurements. At South Pole, on the other hand, summer decreases have led to an overall decline in surface ozone amounts.
    Keywords: GEOPHYSICS
    Type: NASA. Goddard Space Flight Center, Ozone in the Troposphere and Stratosphere, Part 1; p 19-23
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2013-08-29
    Description: A network of 10 southern hemisphere tropical and Subtropical stations, designated the Southern Hemisphere ADditional OZonesondes, (SHADOZ) project and established from operational sites, provided over 1000 ozone profiles during the period 1998-2000. Balloon-borne electrochemical concentration cell (ECC) ozonesondes, combined with standard radiosondes for pressure, temperature and relative humidity measurements, collected profiles in the troposphere and lower- to mid-stratosphere at: Ascension Island; Nairobi, Kenya; Irene, South Africa: Reunion Island, Watukosek Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil.
    Keywords: Meteorology and Climatology
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2013-08-29
    Description: We use clear sky heating rates to show that convective outflow in the tropics decreases rapidly with height between the 350 K and 360 K potential temperature surfaces (or between roughly 13 and 15 km). There is also a rapid fall-off in the pseudoequivalent potential temperature probability distribution of near surface air parcels between 350 K and 360 K. This suggests that the vertical variation of convective outflow in the upper tropical troposphere is to a large degree determined by the distribution of sub cloud layer entropy.
    Keywords: Meteorology and Climatology
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2013-08-29
    Description: This is the second 'reference' or 'archival' paper for the SHADOZ (Southern Hemisphere Additional Ozonesondes) network and is a follow-on to the recently accepted paper with similar first part of title. The latter paper compared SHADOZ total ozone with satellite and ground-based instruments and showed that the equatorial wave-one in total ozone is in the troposphere. The current paper presents details of the wave-one structure and the first overview of tropospheric ozone variability over the southern Atlantic, Pacific and Indian Ocean basins. The principal new result is that signals of climate effects, convection and offsets between biomass burning seasonality and tropospheric ozone maxima suggest that dynamical factors are perhaps more important than pollution in determining the tropical distribution of tropospheric ozone. The SHADOZ data at (〈http://code9l6.gsfc.nasa.gov/Data_services/shadoz〉) are setting records in website visits and are the first time that the zonal view of tropical ozone structure has been recorded - thanks to the distribution of the 10 sites that make up this validation network.
    Keywords: Geophysics
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2013-08-29
    Description: During the Aerosols99 trans-Atlantic cruise from Norfolk, VA, to Cape Town, South Africa, daily ozonesondes were launched from the NOAA R/V Ronald H Brown between 17 January and 6 February l999. A composite of tropospheric ozone profiles along the latitudinal transect shows 4 zones, which are interpreted using correlative shipboard ozone, CO, water vapor, and overhead aerosol optical thickness measurements. Elevated ozone associated with biomass burning north of the ITCZ (Intertropical Convergence Zone) is prominent at 3-5 km from 10-0N, but even higher ozone (100 ppbv, 7-10 km) occurred south of the ITCZ, where it was not burning. Column-integrated tropospheric ozone was 44 Dobson Units (DU) in one sounding, 10 DU lower than the maximum in a January-February 1993 Atlantic cruise with ozonesondes [Weller et al., 1996]. TOMS tropospheric ozone shows elevated ozone extending throughout the tropical Atlantic in January 1999. Several explanations are considered. Back trajectories, satellite aerosol observations and shipboard tracers suggest a combination of convection and interhemispheric transport of ozone and/or ozone precursors, probably amplified by a lightning NO source over Africa.
    Keywords: Environment Pollution
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-07-13
    Description: The SHADOZ network was assembled to validate a new generation of ozone-monitoring satellites and to better characterize the vertical structure of tropical ozone in the troposphere and stratosphere. Beginning with nine stations in 1998, more than 7000 ozone and P-T-U profiles are available from 14 SHADOZ sites that have operated continuously for at least a decade. We analyze ozone profiles from the recently reprocessed SHADOZ dataset that is based on adjustments for inconsistencies caused by varying ozonesonde instruments and operating techniques. First, sonde-derived total ozone column amounts are compared to the overpasses from the EP/TOMS, OMI and OMPS satellites that cover 1998-2016. Second, characteristics of the stratospheric and tropospheric columns are examined along with ozone structure in the tropical tropopause layer (TTL). We find that: (1) Relative to our earlier evaluations of SHADOZ data, in 2003, 2007 and 2012, sonde-satellite total ozone column offsets at 12 stations are 2% or less, a significant improvement. (2) As in prior studies, the ten tropical SHADOZ stations, defined as within +19 degrees latitude, display statistically uniform stratospheric column ozone, 229 + 3.9 DU, and a tropospheric zonal wave-one pattern with a 14 DU mean amplitude. (3) The TTL ozone column, which is also zonally uniform, masks complex vertical structure; this argues against using satellites for lower stratospheric ozone trends. (4) Reprocessing has led to more uniform stratospheric column amounts across sites and reduced bias in stratospheric profiles. As a consequence the variability in total column ozone now averages 5%.
    Keywords: Earth Resources and Remote Sensing
    Type: GSFC-E-DAA-TN48313 , Journal of Geophysical Research: Atmospheres (ISSN 2169-897X) (e-ISSN 2169-8996); 122; 23; 13,000-13,025
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-07-10
    Description: A lack of sounding data has limited the accuracy of ozone satellite retrievals in the tropics and our understanding of chemical-dynamical interactions in a region strongly influenced by natural variability and anthropogenic activity. In 1998, NASA s Goddard Space Flight Center, NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL) and a team of international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap in tropical ozone soundings. SHADOZ augments launches at selected sites and provides a public archive of ozonesonde and radiosonde data from twelve tropical and subtropical stations at http://croc.gsfc.nasa.gov/shadoz. Instrumentation, data and a summary of the first scientific findings from SHADOZ are presented.
    Keywords: Meteorology and Climatology
    Type: Paper 1455
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-07-12
    Description: A series of nearly daily ozone vertical profiles obtained at station T-3 on Fletcher's Ice Island (about 85 deg N, about 90 deg W) during the period January-March 1971 shows several significant ozone intrusions into the troposphere. These intrusions are not only associated with enhanced ozone amounts in the stratosphere but also require tropopause folding events to transport ozone into the troposphere. These folds in the arctic tropopause appear to be capable of contributing significantly to the ozone budget of the arctic troposphere during the late winter and spring seasons. The importance of tropopause folding for bringing ozone into the troposphere seen in the daily ozone profiles confirms the results found in the Arctic Gas and Aerosol Sampling Program aircraft flights.
    Keywords: GEOPHYSICS
    Type: Journal of Atmospheric Chemistry (ISSN 0167-7764); 9; 245-253
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...