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This paper reports atmospheric profiles of N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O retrieved from Metop/IASI with the Software for the Retrieval of IASI Data (SOFRID) for the 2008–2018 period and their validation with FTIR data from 12 stations of the Network for the Detection of Atmospheric Composition Changes (NDACC). SOFRID retrievals performed in the 2160–2218 cm<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula> spectral window provide 3 independent pieces of information about the vertical profile of N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O. The FTIR versus SOFRID comparisons display a better agreement in the mid-troposphere (MT, 700–350 hPa) than in the lower (LT, Surface–700 hPa) and upper (UT, 350–110 hPa) troposphere with correlation coefficients (R) in the 0.49–0.83 range and comparable variabilities (3–5 ppbv). The agreement for oceanic and coastal stations (R > 0.77) is better than for continental ones (R < 0.72). The SOFRID MT N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O mixing ratios are significantly biased high (up to 16.8 ppbv) relative to FTIR at continental stations while the biases remain below 4.2 ppbv and mostly unsignificant when oceanic data are considered. The average MT decadal trends derived from SOFRID at the 8 NDACC stations with continuous observations during the 2008–2018 period (1.05 ± 0.1 ppbv·yr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>) is in good agreement with the corresponding FTIR trends (1.08 ± 0.1 ppbv·yr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>) and the NOAA-ESRL trends from surface in-situ measurements (0.95 ± 0.02 ppbv·yr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>). In the Northern Hemisphere where they are clearly detected, the N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O MT seasonal variations from SOFRID and FTIR are phased (summer minima) and have similar amplitudes. SOFRID also detects the UT summer maxima indicating independent MT and UT information. The global MT N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>O oceanic distributions from SOFRID display low geographical variability and are mainly characterized by enhanced tropical mixing ratios relative to mid and high latitudes.