Description:

AAOE_TOMS_DC8_Data is the Total Ozone Mapping Spectrometer (TOMS) data collected along the flight path of the DC-8 aircraft during the Airborne Antarctic Ozone Experiment (AAOE) suborbital campaign. Data collection for this product is complete. The AAOE suborbital campaign was an international and multi-organizational campaign with NASA, NOAA, NSF, and Chemical Manufacturer’s Association (CMA). It also involved the UK Meteorological Office and the European Center for Medium-range Weather Forecasts (ECMWF). UKMO provided weather forecasters with Falkland Island experience to make predictions for the wind-sensitive ER-2 from Punta Arenas. The main goal of AAOE was to perform a complex study of polar stratospheric clouds and their relation to the late winter and spring ozone loss over the Antarctic (the ozone hole). In order to collect the proper data to complete its objective, AAOE utilized specially instrumented NASA ER-2 and DC-8 aircrafts. The instruments on these aircrafts were used to acquire data on chemical, meteorological, and cloud-physical parameters associated with this ozone loss phenomenon that was observed when this campaign was conducted. Along with the aircrafts, three separate satellite systems, ozone sondes, and ground-based sensors were employed in various locations in Antarctica to collect data. The AAOE mission was conducted from August to October 1987 with flights based in Punta Arenas, Chile. The DC-8 aircraft was equipped with 9 instruments for this campaign. A few of those instruments were the JPL Mark IV Balloon Interferometer (MkIV), the Differential Absorption Lidar (DIAL), the Whole Air Sampler (WAS (NCAR)), the in-situ ozone sampler from NASA Langley, and the NOAA Lyman-Alpha Total Water Hygrometer (NOAA TW). The MkIV was responsible for taking various data points, including temperature and pressure. Along with these, the MkIV took measurements on the vertical column of a multitude of compounds including CO, H2O, NO, NO2, CH4, CO2, O3, and N2O in units of molecules/cm2. The DIAL collected measurements of ozone mixing ratio in parts per billion by volume (ppbv), IR aerosol backscatter, IR atmospheric scattering ratio, visible (VIS) aerosol backscatter, and VIS atmospheric scattering ratio. The WAS (NCAR) was used to take measurements on whole air mixing ratio, which includes CH4, CO, and N2O in different concentrations. Finally, The NOAA TW onboard the DC-8 aircraft collected data sets on H2O mixing ratios in the atmosphere. The ER-2 aircraft was equipped with 16 instruments, including the Multiple Axis Resonance Fluorescence Chemical Conversion Detector for ClO and BrO (ClO/BrO), the NOAA NOy Instrument (NOAA NOy), and the Airborne Tunable Laser Absorption Spectrometer (ATLAS). As its name suggests, the ClO/BrO was used to collect data on ClO and BrO mixing ratios. The NOAA NOy collected measurements of NOy mixing ratio, while the ATLAS took measurements on N2O mixing ratio. Finally, balloon sondes were deployed with the responsibility of gathering data on atmospheric temperature, pressure, wind speed, wind direction, as well as ozone column data in various concentrations. The Journal of Geophysical Research: Atmospheres, Volume 94, Issue D14 and Issue D9 have more information on the AAOE campaign.

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Temporal Extent:

Start: 1987-08-19T00:00:00.000Z

End: 1987-10-05T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 37.18 180

LARC_CLOUD Short Name: AAOE_TOMS_DC8_Data Version ID: 1 Unique ID: C3966812521-LARC_CLOUD

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Description:

AASE2_Satellite_Data is the satellite data collected during the Airborne Arctic Stratospheric Expedition II (AASE II) suborbital campaign. Data from the Total Ozone Mapping Spectrometer (TOMS) is featured in this collection. Data collection for this product is complete. The AASE campaign was a joint mission by NASA, NOAA, and the National Science Foundation (NSF). While this is one overarching campaign, AASE has been broken into two sub-campaigns: AASE and AASE-II namely, which each have their own mission goals. AASE’s primary goal was to study the production and loss mechanism of ozone in the north polar stratospheric environment. This was after it was realized that ozone loss on either side of the 1987 Antarctic vortex during AAOE occurred under conditions found in the Arctic vortex. Along with this, AASE aimed to study the effect of ozone distribution of the Arctic polar vortex as well as the cold temperatures associated with the formation of Polar Stratospheric Clouds. AASE-II aims to answer three science questions. First, AASE-II asks: will significant erosion of stratospheric ozone occur over the Arctic as stratospheric chlorine levels increase during the next decade? Second, AASE-II sought to understand what the causes of mid-latitude stratospheric ozone decreases in late fall through early summer are. This objective comes from the observations of ground and satellite observations the decade prior to the campaign. Finally, due to the eruption of Mt. Pinatubo in June 1991, AASE-II aimed to address the effect volcanoes have on the chemical processes that govern stratospheric ozone. Specifically, this campaign questions if volcanic aerosols could modify depletion of stratospheric ozone associated with industrial halocarbons? In order to accomplish these goals and answer these questions, AASE deployed the NASA DC-8 aircraft, NASA ER-2 aircraft, balloon sondes, and used imagery from satellites. These payloads and instruments were used for both AASE and AASE-II. Flights for AASE (including test flights) were conducted from December 1988 to February 1989, while flights for AASE-II (including test flights) were conducted from August 1991 to March 1992. The ER-2 was equipped with 13 instruments during AASE. Three instruments among those were the NOAA NO/NOy Instrument (NOAA NOy), the Multiple Axis Resonance Fluorescence Chemical Conversion Detector for ClO and BrO (ClO/BrO), and the Dual-Beam UV-Absorption Ozone Photometer (NOAA O3 Classic). The NOAA NOy was responsible for collecting data on NO volume mixing ratio in parts per billion (ppb), as well as NOy volume mixing ratio in ppb. As the name suggests, the ClO/BrO took measurements of BrO and ClO mixing ratio in ppb. The NOAA O3 Classic was enlisted on this campaign to take measurements of ozone in the atmosphere in ppb. The NASA DC-8 aircraft was equipped with 14 instruments. Three of those instruments were the Differential Absorption Lidar (DIAL), the Whole Air Sampler (WAS (NCAR)), and the NOAA Lyman-Alpha Total Water Hygrometer (NOAA TW). The DIAL recorded data on infrared (IR) aerosol depolarization percentages, IR atmospheric scattering ratio, ozone mixing ratio in ppb by volume, VIS aerosol depolarization percentages, and VIS atmospheric scattering ratio. The WAS (NCAR) collected data on mixing ratios of CO2, CH4, CO, N2O, CF2Cl2, CFCl3, C2F3Cl3, and CH3CCl3. The NOCAR (NCAR/NOAA) NO/NOy instrument made in situ observations at DC-8 flight levels which were found to record NOy falling gravitationally on particles formed at higher altitudes. Finally, the NOAA TW collected information about the H2O volume mixing ratio in parts per million (ppm). For AASE, the balloon sondes were used to collect data on air temperature, dew point depression, and wind speed. The ER-2 aircraft was equipped with 18 instruments for AASE-II. Three of those instruments include the Microwave Temperature Profiler (MTP), the Argus Tunable Diode Laser Instrument (ARGUS), and the Aircraft Laser Infrared Absorption Spectrometer (ALIAS). The MTP collected data on atmospheric temperature and potential air temperature. The ARGUS measured N2O mixing ratio in ppb. Finally, the ALIAS collected data on N2O, CH4, HNO3, HCL, and H2O. The DC-8 aircraft was equipped with 16 instruments. Three of the instruments among the 16 include the Differential Absorption Carbon Monoxide Measurement (DACOM), the Whole Air Sampler (WAS (UCI)), and the Forward Scattering Spectrometer Probe (FSSP). The DACOM recorded measurements on the carbon monoxide mixing ratio (ppb), methane mixing ratio (ppb), nitrous oxide mixing ratio (ppb), and the carbon dioxide mixing ratio (ppm). The WAS (UCI) collected data on hydrocarbons/halocarbons in the atmosphere. While the FSSP collected concentrations and distribution of aerosol size. The balloon sondes for AASE-II collected temperature, ozone partial pressure, wind speed, and wind direction.

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Temporal Extent:

Start: 1991-10-01T00:00:00.000Z

End: 1992-03-24T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 90 180

LARC_CLOUD Short Name: AASE2_Satellite_Data Version ID: 1 Unique ID: C3880742612-LARC_CLOUD

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Description:

This dataset provides the annual period of snowpack melting (i.e., snow melt duration, SMD) across northwest Canada; Alaska, U.S.; and parts of far eastern Russia at 6.25 km resolution for the period 1988-2018. SMD is the number of days between the main melt onset date (MMOD) and the last day of seasonal snow cover when the melting of snow is complete. These dates were derived from the Making Earth Science Data Records for Use in Research Environments (MEaSUREs) Calibrated Enhanced-Resolution Passive Microwave (PMW) EASE-Grid Brightness Temperature (Tb) Earth System Data Record (ESDR). This dataset documents variability in SMD across space and the 31-year temporal period. The data from 1988-2016 included a coastal mask removing coastal pixels due to potential water contamination from coarse brightness temperature observations (Dersken et al., 2012). There is not a coastal mask for the 2017-2018 data. The full data are included, and data users should be aware that coastal values can be adversely affected by adjacent water bodies.

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Temporal Extent:

Start: 1988-02-09T00:00:00.000Z

End: 2018-07-20T23:59:59.999Z

Spatial Extent:

Minimum Bounding Rectangle: 51.6 -180 72.41 -107.833

ORNL_CLOUD Short Name: SnowMeltDuration_PMicrowave_1843 Version ID: 1.1 Unique ID: C2223093928-ORNL_CLOUD

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Description:

The data are from our Nature Article from June 2018: "Antarctic ice shelf disintegration triggered by sea ice loss and ocean swell". The abstract is: "Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise. An overlooked climate-related causal factor is regional sea ice loss. Here we show that for the disintegration events observed (the collapse of the Larsen A and B and Wilkins ice shelves), the increased seasonal absence of a protective sea ice buffer enabled increased flexure of vulnerable outer ice shelf margins by ocean swells that probably weakened them to the point of calving. This outer-margin calving triggered wider-scale disintegration of ice shelves compromised by multiple factors in preceding years, with key prerequisites being extensive flooding and outer-margin fracturing. Wave-induced flexure is particularly effective in outermost ice shelf regions thinned by bottom crevassing. Our analysis of satellite and ocean-wave data and modelling of combined ice shelf, sea ice and wave properties highlights the need for ice sheet models to account for sea ice and ocean waves." Details of the analyses and data used, and the data generated by this study, are given in the paper: https://www.nature.com/articles/s41586-018-0212-1. Code availability: Analytical scripts used in this study are freely available from the authors via the corresponding author upon reasonable request. Data availability: The datasets and products generated during the current study are available from the corresponding author on reasonable request. The datasets forming the basis of the study are available as follows: (1) Sea ice: Daily estimates of satellite-derived sea ice concentration (gridded at a spatial resolution of 25 x 25 km) derived by the NASA Bootstrap algorithm for the period 1979-2010 were obtained from the US National Snow and Ice Data Center (NSIDC) dataset at: http://nsidc.org/data/NSIDC-0079. Accessed August 2015. (2) Waves: Ocean wave-field data were obtained from the CAWCR (Collaboration for Australian Weather and Climate Research) Wave Hindcast 1979–2010 dataset run on a 0.4 x 0.4° global grid: https://doi.org/10.4225/08/523168703DCC5. Accessed September 2017. (3) Satellite visible and thermal infrared imagery of ice shelves and disintegration events: The NOAA AVHRR image of the Larsen1995 disintegration used in Figure 2 was obtained from the British Antarctic Survey: http://www.nerc-bas.ac.uk/icd/bas_publ.html. Accessed June 2015. MODIS visible and 839 thermal infrared imagery from the US NSIDC archive at: http://nsidc.org/data/iceshelves_images/. Accessed June 2012. The study involved 2 model components, and model output is described below. The 2 models are: (i) a model of ocean swell attenuation by sea ice; and (ii) an ice shelf-ocean wave interaction model. Descriptions of both are given in the Nature paper (Methods section). DESCRIPTIONS OF THE 13 INDIVIDUAL DATA FILES PROVIDED (NB DESCRIPTIONS OF DATASETS GENERATED RELATIVE TO THE FIGURES) ARE GIVEN IN THE FILES: (1) Source data for Figures 4 (parts a-d), 5 and 6a are given in Excel spreadsheet files "Source-Data_2017-07-09041A_Figure.....xlsx". (2) Source data for Extended Data Figures 1 (parts a-b), 3 (parts b,d and parts a,c), 4 (parts b,d and a,c) and 6 are given in Excel spreadsheet files "Source-Data_2017-07-09041A_EDFig.....xlsx".

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Temporal Extent:

Start: 1980-01-01T00:00:00.000Z

End: 2010-12-31T23:59:59.999Z

Spatial Extent:

Minimum Bounding Rectangle: -75.06848 -95.625 -59.80867 -34.45315

AU_AADC Short Name: AAS_4116_IceShelfStudy Version ID: 1 Unique ID: C1542259934-AU_AADC

Description:

NSIDC-0747 contains melt-season indicators that can be used to delineate various stages in the summer melt and freeze-up period of sea ice. The data were primarily derived using Sea Ice Concentration (SIC) observations from the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration (G02202) and the Snow Melt Onset Dates (NSIDC-0105) from SSM/I-SSMIS Brightness Temperatures products. The main parameters for this data set include the dates of melt onset, early melt onset, and continuous melt onset; dates of early and continuous freeze onset; day of opening (last day SIC is above 80%); day of retreat (last day SIC drops below 15%); day of advance (first day SIC increases above 15%); day of closing (first day SIC increases above 80%); total outer ice-free period; total inner ice-free period; seasonal loss-of-ice period; seasonal gain-of-ice period; and the seasonal ice zone. These data are available for 1979 through 2024 and are gridded on the NSIDC northern hemisphere polar stereographic grid at 25 km.

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Temporal Extent:

Start: 1979-03-01T00:00:00.000Z

End: 2024-02-28T23:59:59.999Z

Spatial Extent:

Minimum Bounding Rectangle: 30 -180 90 180

NSIDCV0 Short Name: NSIDC-0747 Version ID: 2 Unique ID: C4085455832-NSIDCV0