The Total Carbon Column Observing Network (#TCCON): 27+ spectrometers in 16+ countries recording near-IR solar spectra since 2004. Aiming to quantify geographic patterns of #GHG emissions and uptake and provide satellite validation for #GOSAT, #OCO2/#OCO3, TROPOMI, and more!

Park Falls, WI (USA): first dedicated #TCCON lab. Located in Chequamegon Nat'l Forest at WLEF Tall Tower, site of extensive @NOAA_ESRL in situ measurements. Providing continuous, high quality measurements of column CO2 and other trace gases since 2004.

Ile de La Réunion TCCON site (21S,55.5E) is led by BIRA-IASB with local support from OSU-Réunion. It’s one of five stations located in the SH giving background information on #GHG in the southern tropical atmosphere since Sep 2011. Funded by Belspo DOI: doi.org/10.14291/tccon…

Lauder, NZ TCCON site: · 45S,169.5E · Operated by NIWA · Southernmost in network · 2nd longest running since June 2004 · Only site to have used 3 different FTIRs · Measuring some of the cleanest air in the world (but GHG concentrations still rising) tccon-wiki.caltech.edu/Sites/Lauder

The northernmost TCCON station is in the Canadian High Arctic at CANDAC-PEARL in Eureka, Nunavut (80.05°N). When the sun returns in late February, #UofT grad students visit PEARL to turn on the instrument and record spectra. CREATE ArcticScience Canadian Space Agency Environment Canada NSERC / CRSNG

The East Trout Lake #TCCON station (54.3N, 105W) is located in the Canadian Boreal forest, and is led by #UofT with local support from Eagle Bay Resort. Funding is provided by Environment Canada, CFI, ORF, Canadian Space Agency, and NSERC / CRSNG.

Operated by Caltech with support from DOE ARM project, Lamont, OK #TCCON site is nestled between cattle pasture and wheat fields on #ARM's SGP facility, thus allowing for valuable intercomparisons with ARM’s continuous measurements and numerous field campaigns.

The Izaña #TCCON station (28ºN, 16ºW), co-operated by the Shmoopy and AEMET_Izaña, is located in the high-mountain Izaña Observatory, where FTS observations are taken with other high-quality records well-representative of the subtropical North Atlantic free troposphere.

The Darwin #TCCON station (12S, 131E) is operated by UOW Centre for Atmospheric Chemistry (CAC) with support from Caltech and Bureau of Meteorology, Australia and funding from Australian Research Council and NASA. Established in 2005, it is the first and longest running TCCON site in the tropics.

Burgos TCCON station (19N, 121E) is located at EDC’s Wind and Solar Farm facility in PH's Ilocos Norte province. Declared a "coal-free province", the station is ~100% renewable energy powered. The station is operated by the NIES, UOW Centre for Atmospheric Chemistry (CAC), and EDC, and supported in part by #GOSAT.

Operational since 2014, Energy Development Corporation's (EDC) Burgos Wind and Solar Farm facility is the 2nd wind farm in the region and the largest in the country/SE Asia, providing a ~100% renewable energy mix of wind, solar, geothermal and hydroelectric to #TCCON Burgos site.

The Tsukuba #TCCON station (36N, 140E) is located at a Climate Change Research building, National Institute for Environmental Studies (NIES) campus. Operated by NIES and supported in part by the #GOSAT series project, Tsukuba TCCON site is the first TCCON site in Asia.

Rikubetsu #TCCON site (43N, 144E), located inside Rikubetsu's Space and Earth Science Museum (Stratospheric Observatory), is operated by NIES and supported in part by #GOSAT. Free from influences of local air pollution, clean background atmospheric observations are conducted.

Ny-Ålesund (78.9 N, 11.9 E) #TCCON, located on Spitsbergen in Norway's Svalbard archipelago, is known for its long time series (polar day NIR measurements since 2005) and large seasonal xCO2 cycles. Site is operated by #UBremen and funded by the EU projects IMECC and GEOmon.

Sodankylä #TCCON, operated by Finnish Meteorological Institute, is the only station in the Fennoscandia region (67.4N, 26.6E). Regular FTIR measurements (except during Polar Night) have been made since 2009. Frequent AirCore profiles have complimented retrievals since 2013.

Day 2 of our virtual joint TCCON/COCCON meeting with great invited pre-recorded video presentations, regional telecons, asynchronous Slack discussions, and very interactive poster sessions using the gather.town platform!

Congratulations to Paul Wennberg (@wennbergcaltech) on his election to the American Association for the Advancement of Science! Well deserved! aaas.org/page/2021-fell…

NEW GGG2020 datasets have been posted to the TCCON archive: tccondata.org! Missing datasets will be added shortly. Data Use Guidelines are posted: tccon-wiki.caltech.edu/Main/DataUseGu…. We are looking forward to working with you!