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

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. GET DATA: https://www-air.larc.nasa.gov/missions/ndacc/data.html?station=scott.base# Instrument timeline: - ClOe1 1996-2023 - ClOe4 2023 – present

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/

Measurements of boundary layer concentration of ozone are made with insitu instruments that samples air continuously at Arrival Heights, Antarctica and is part of the NOAA Global Monitoring Surface Ozone Network. Original measurements at Arrival Heights were made with a Dasibi Environmental Corp in situ analyser. This was replaced with a TEI-49c in situ analyser. The TEI-49c is owned by NOAA and operated by NIWA at Arrival Heights until October 2023. In October 2023 operation of the TEI was transferred to the USAP Arrival Heights laboratory along with operational responsibility (between NOAA and USAP). This data set contains continuous UV photometric data of surface level ozone collected at 6m above ground level. Data records consist of UTC time, date, and processed ozone mixing ratio (parts per billion). Data is collected from global locations and is provided in 1 minute and 1 hour averages. Data are archived at the NOAA National Climatic Data Center (NCDC), but are produced and available from NOAA Earth System Research Laboratory (ESRL). Instrument timeline: - Dasibi 1997-2003 - TEI49c 2003 – October 2023 - TEI49i November 2023 -present at USAP Arrival Heights laboratory GET DATA: https://gml.noaa.gov/aftp/data/ozwv/SurfaceOzone/ARH/

Measurements of total column of ozone made with Dobson spectrophotometer that measures either direct or zenith scattered ultraviolet light. The instrument was established in September of 1989 at 77° 49.8'S, 166° 39.6'E. Additionally a Brewer spectrophotometer took total column ozone measurements at Scott from 1989 to 1996. From 1989 to 2006 the Dobson (ID 17) was operated in manual mode but had an electronic encoder and computer added in 2006 for recording measurements. The data acquisition system was upgraded in Febuerary 2015 at Lauder, NZ. It is now running the JMA automation system. The Dobson (instrument ID: D17) is shipped out for maintenance and intercomparison with regional standard Dobson in Melbourne approximately every 5 years. Data (for both Dobson and Brewer) is held internally by NIWA and in the NDACC database. Data is also archived in the ozone and UV data centre Toronto, “Raw” data are times and instrument settings for instrument readings. “Derived” data are column amounts of ozone. Time line: Dobson 1987 -present Brewer 1989-1996 GET DATA: https://www-air.larc.nasa.gov/missions/ndacc/data.html?station=arrival.heights#

The AARDDVARK/WWLLN Very Low Frequency (VLF) Radio Sensor was installed at Arrival Heights from 10-15 December 2008 by Dr Craig J. Rodger and Dr. James Brundell as part of Antarctica New Zealand Event K069a. The sensor measures the magnetic 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 primary experiment is the AARDDVARK observations. The secondary experiment, WWLLN, uses exactly the same 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 made at Arrival Heights or near the Hatherton Lab (depending on noise levels). 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. Two near-orthogonal magnetic field loops measuring VLF electromagnetic waves. The centre of the antenna is at 77° 49.790' S, 166° 39.438' E, based on a GPS measurement with 1 m accuracy. Logging is undertaken with standard WWLLN software, with GPS timing. GET DATA: https://wwlln.net/

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 -present 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)

The AARDDVARK/WWLLN Very Low Frequency (VLF) Radio Sensor was installed at Arrival Heights from 10-15 December 2008 by Dr Craig J. Rodger and Dr. James Brundell as part of Antarctica New Zealand Event K069A. The sensor measures the magnetic 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 primary experiment is the AARDDVARK observations, which measures powerful and distant communications transmitters operating in the VLF range. As such, the dataset is "narrowband", taking amplitude and phase measurements at the transmission frequencies. For this sensor, there is 0.2s time resolution. The Konsortia sensors detect changes in ionisation levels from ~30-85 km altitude, with the goal of increasing the understanding of energy coupling between the Earth's atmosphere, Sun, and Space. We use the upper atmosphere as a gigantic energetic particle detector to observe and understand changing energy flows; this Science area impacts our knowledge of global change, communications, and navigation. One of the few experimental techniques that can probe these altitudes uses very low-frequency (VLF) electromagnetic radiation, trapped between the lower ionosphere (~85 km) and the Earth, and thus said to be propagating "subionospherically". The sensor is currently logging transmitters in the northern & southern hemispheres, over a very wide longitude range. Both experiments send the processed data across the internet. AARDDVARK observations are sent to the University of Otago once a day at an agreed time. The new AH receiver was the 10th station in the AARDDVARK network, jointly lead by the University of Otago and the British Antarctic Survey. Two near-orthogonal magnetic field loops measuring VLF electromagnetic waves. The centre of the antenna is at 77° 49.790' S, 166° 39.438' E, based on a GPS measurement with 1 m accuracy. Logging is undertaken with UltraMSK software running on a PC locked to GPS timing. GET DATA: https://space.physics.otago.ac.nz/aarddvark/