We present 60 years of Δ14CO2 measurements from Wellington, New Zealand (41°S, 175°E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest atmospheric Δ14CO2 record and records the rise of the 14C “bomb spike”, the subsequent decline in Δ14CO2 as bomb 14C moved throughout the carbon cycle and increasing fossil fuel CO2 emissions further decreased atmospheric Δ14CO2. The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2 ‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport, and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. Δ14CO2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, Northern Hemisphere clean air sites show a higher and earlier bomb 14C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ14CO2 were quite similar, apparently due to the balance of 14C-free fossil fuel CO2 emissions in the north and 14C-depleted ocean upwelling in the south. The Southern Hemisphere sites show a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14C-depleted and carbon-rich deep waters in the Southern Ocean. This developing Δ14CO2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s, and suggests that upwelling of deep waters plays an important role in this change. DOI: https://doi.org/10.5194/acp-17-14771-2017 Cite as: Turnbull, J. C., Mikaloff Fletcher, S. E., Ansell, I., Brailsford, G. W., Moss, R. C., Norris, M. W., and Steinkamp, K.: Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014, Atmos. Chem. Phys., 17, 14771–14784, https://doi.org/10.5194/acp-17-14771-2017, 2017.

Ultraviolet radiation measurements over the spectral region 290-450 nm with a high precision spectro-radiometer. The spectro-radiometer was installed at Arrival Heights as a two month (November 2006 – January 2007) blind inter-comparison with the established measurement programme run by Biospherical Instruments for the USAP. The data was compared with the USAP data taken simultaneously. These data are held internally by NIWA. GET DATA: contact dan.smale@niwa.co.nz

AntAir ICE is an air temperature dataset for terrestrial Antarctica, the ice shelves, and the seasonal sea ice around Antarctica in a 1km2 spatial grid resolution and a daily temporal resolution available from 2003-2021. AntAir ICE was produced by modelling air temperature from MODIS ice surface temperature and land surface temperature using linear models. In-situ measurements of air temperature from 117 Automatic Weather Stations were used as the response variable. Each day has a bricked spatial raster with two layers, saved as a GeoTIFF format and in the Antarctic Polar Stereographic projection (EPSG 3031). The first layer is the predicted near surface air temperature for that day in degree Celsius * 10 and the second layer is the number of available MODIS scenes for that day ranging from 0 to 4. Areas with cloud contamination or without sea ice are marked with no data. Files for each year (2003-2021) are compressed with a ZIP files for each quarter. Python 3.8 was used for conversion of the MODIS products from HDF files to raster and all data handling and processing was thereafter done in R version 4.0.0. All data processing and modelling procedures are available as R scripts on a public Github repository: https://github.com/evabendix/AntAir-ICE. Using this code it is possible to download new available MODIS LST and IST scenes and apply the model to continue the near-surface air temperature dataset. Related Publication: https://doi.org/10.1038/s41597-023-02720-z GET DATA: https://doi.org/10.1594/PANGAEA.954750

Measurements of chlorine monoxide (ClO) made with a Microwave Chlorine Monoxide Millimeter Wave Spectrometer (ground-based). The instrument (ClOe1) was established in January of 1996 at Scott Base and decommissioned in October 2023. A replacement radiometer (ClOe4) was installed at Scott Base in February 2023 (an overlap in the data for timeseries continuity purposes). These data are produced in collaboration with State University of New York (SUNY) Stoney Brook and Naval Research Laboratory (NRL). “Raw” data are times and recorded microwave emission spectra. “Derived” data are column amounts and vertical profile information of chlorine monoxide (ClO). The instrument has acquired the nickname "CloeTechnique" for vertical profile information uses "optimal estimation" to extract information from pressure broadening of ClO emission line. Significant failure in early 2018 only fixed in November 2018. No data in the July - October 2018 period. Data is held at NRL and in the NDACC database. Data are available as monthly .ndm files, and additional metadata are available in the header. Instrument timeline: - ClOe1 1996-2023 - ClOe4 2023 – present GET DATA: https://www-air.larc.nasa.gov/missions/ndacc/data.html?station=scott.base#

An automated weather station operates at Cape Adare (-71.30492, 170.23256). The station was established in 2014 and continues to transmit live data. Data are logged every 30 minutes. Parameters: - Air Temperature (C) - Relative Humidity (%) - Solar Radiation (W/m2) - PAR (uE) - Wind Speed (m/s) - Wind Gust (m/s) - Wind Direction (true bearing degrees) GET DATA: adminteam@antarcticanz.govt.nz

The WWLLN Very Low Frequency (VLF) Radio Sensor was installed at Scott Base in November 2015 by Dr. James Brundell and Ms. Emma Douma as part of Antarctica New Zealand Event K060-1516-A. The sensor measures the electric field in the Very Low Frequency radio range (~500 Hz-50 kHz) and passes it to a PC which processes the data for the experiments. The antenna is located behind the Hatherton lab. It was installed due to increasing manmade electromagnetic noise levels in the "quiet zone" at Arrival Heights. The observations from this antenna are now the primary WWLLN feed from Ross Island, the Arrival Height's magnetic field antenna is now a backup. WWLLN, uses the VLF feed but processes it to detect the radio-wave pulses from lightning. WWLLN observations are sent to a central processing computer to determine the time and location of lightning pulses all over the globe. The World Wide Lightning Location Network (WWLLN) is an experimental Very Low Frequency (VLF) network of sensors being developed through collaborations with research institutions across the globe. The network exploits the considerable electromagnetic power radiated by lightning as "sferics" present in the VLF band. By combining radio-pulse observations from at least 5 stations, the WWLLN central processing computers can determine the location of the original lightning discharge. As the radio-pulse observations are immediately sent back across the internet to the central processing computers locations are generated within ~10 s of the discharge, and thus near real time. There are currently about 70 active VLF receiving stations operating in the VLF World-Wide Lightning Location Network, including the Scott Base measurements. WWLLN observations are continuously transmitted to one of the WWLLN primary servers, in this case flash.ess.washington.edu at the University of Washington, Seattle, USA. GET DATA: https://space.physics.otago.ac.nz/aarddvark/

This metadata record represents the code and data used for the first application of WRF-Hydro/Glacier in the McMurdo Dry Valleys (Commonwealth Glacier), which as a fully distributed hydrological model has the capability to resolve the streams from the glaciers to the bare land that surround them. We applied a glacier and hydrology model in the McMurdo Dry Valleys (MDV) to model the start and duration of melt over a summer in this extreme polar desert. To do so, we found it necessary to prevent the drainage of melt into ice and optimize the albedo scheme. We show that simulating albedo (for the first time in the MDV) is critical to modelling the feedbacks of albedo, snowfall and melt in the region. This is a first step towards more complex spatial modelling of melt and streamflow. The Zenodo data includes output point data (*.csv) and namelist used in: Pletzer, T., Conway, J.P., Cullen, N.J., Eidhammer, T., & Katurji, M. (2024). The application and modification of WRF-Hydro/Glacier to a cold-based Antarctic glacier. *Hydrology and Earth System Sciences*, 28(3), 459-478. https://doi.org/10.5194/hess-28-459-2024 The modifications to the WRF-Hydro/Glacier model used in the paper can be found on GitHub: https://github.com/tpletzer/wrf_hydro_nwm_coldglacier GET DATA: https://doi.org/10.5281/zenodo.10565032

Altitude profile measurements of water vapour, ozone and aerosols using balloon packages flown through the troposphere into the stratosphere as part of the Ross Island GRUAN site activities. Maximum altitude recorded was 29 km. This project is a collaboration between the National Institute of Water and Atmospheric Research (NIWA) and NOAA. Timeline: - November 2022: 2 flights - February 2023: 1 flight - October 2023: 3 flights Data are held internally at NIWA and NOAA, and will be stored in the GRUAN database (https://www.gruan.org/data) GET_DATA: https://www.gruan.org/data

Spectroscopic measurements of stratospheric gases Nitrogen Dioxide (NO2), Chlorine Dioxide (OCIO), Bromine Oxide (BrO) and Ozone (O3) using scattered sunlight. Airyx and Envimeas: A dual MAX-DOAS UV/visible wavelength diode array spectrometer is deployed to measure of ozone (O3), nitrogen dioxide (NO2), chlorine dioxide (OClO) and bromine oxide (BrO). The instrument is a similar instrument to that of EnviMeas, and produces overlapping datasets with ADAS-2. Fixed azimuth direction, same as the Antarctic Diode Array spectrometer. System 2 (ADAS-2). The data are currently being held internally by NIWA. “Raw” data are times and recorded spectra of scattered light for several viewing directions. “Derived” data are column amount of NO2, OClO, BrO and O3, which can be split into tropospheric and stratospheric parts. This technique is sometimes referred to as MAX-DOAS Multiple-Axis Dual Optical Absorption Spectrometry. This work is carried out in collaboration the University of Heidelberg. ADAS2, Envimeas and Airyx measurements: UV/visible Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) diode array spectrometers making measurements of ozone (O3), nitrogen dioxide (NO2), chlorine dioxide (OClO) and bromine oxide (BrO). JY: A scanning grating UV/Vis monochromator taking measurements of total slant column of NO2 and Ozone using scattered zenith sunlight. ADAS: A CCD grating UV/Vis grating Acton spectrometer making measurements of total slant column NO2, BrO, OClO and ozone made using scattered light zenith sunlight. Pandora: Direct sun UV/Vis measurements of ozone and NO2. Campaign to test feasibility of long term deployment at Arrival Heights. Instrument timeline JY: 1982 -2023 ADAS: 1993 - 2017 ADAS2: 1998 - present Pandora: 2015 Aug – Oct. Airyx & Envimeas : 2018 – present O3, OCIO and BrO data are in the process of being archived - please contact Richard Querel for data access. NO2 data is available via the "GET DATA" link. GET DATA: https://www-air.larc.nasa.gov/missions/ndacc/data.html?station=arrival.heights

Gas samples (CO2, CH4, CO, N2O, 13CO2, 14CH4, 13CO, C18O, 14CO) are collected from an inlet atop of a mast 5 metres above ground level in North sector wind conditions. Flasks and cylinders are analysed back at NIWA Greta point Gaslab. The sampling was established in November 1989. Samples are only taken when wind is from the Northerly sector and above 5kts. High pressure cylinders: ~1600psi in 30 litre cylinders and low-pressure flask samples taken (~5 litres, 25 psi in 2 litre flask). Air samples in the Cylinders & Flasks shipped to New Zealand regularly. Analysis performed at NIWA's GASLAB located at Greta Point Wellington. Analysis by Gas chromatography (GC) and isotope ratio mass spectrometry (IRMS). A semi-automated flask sampling system was installed in February 2017, allowing extra flask samples with minimal operator intervention. GET DATA: Contact Gordon Brailsford (g.brailsford@niwa.co.nz)