CO₂ annual and semiannual cycles from multiple satellite retrievals and models

Abstract

Satellite CO 2 retrievals from the Greenhouse gases Observing SATellite (GOSAT), Atmospheric Infrared Sounder (AIRS), and Tropospheric Emission Spectrometer (TES) and in situ measurements from the National Oceanic and Atmospheric Administration -Earth System Research Laboratory (NOAA-ESRL) Surface CO 2 and Total Carbon Column Observing Network (TCCON) are utilized to explore the CO 2 variability at different altitudes. A multiple regression method is used to calculate the CO 2 annual cycle and semiannual cycle amplitudes from different data sets. The CO 2 annual cycle and semiannual cycle amplitudes for GOSAT X CO2 and TCCON X CO2 are consistent but smaller than those seen in the NOAA-ESRL surface data. The CO 2 annual and semiannual cycles are smallest in the AIRS midtropospheric CO 2 compared with other data sets in the Northern Hemisphere. The amplitudes for the CO 2 annual cycle and semiannual cycle from GOSAT, TES, and AIRS CO 2 are small and comparable to each other in the Southern Hemisphere. Similar regression analysis is applied to the Model for OZone And Related chemical Tracers-2 and CarbonTracker model CO 2 . The convolved model CO 2 annual cycle and semiannual cycle amplitudes are similar to those from the satellite CO 2 retrievals, although the models tend to underestimate the CO 2 seasonal cycle amplitudes in the Northern Hemisphere midlatitudes and underestimate the CO 2 semiannual cycle amplitudes in the high latitudes. These results can be used to better understand the vertical structures for the CO 2 annual cycle and semiannual cycle and help identify deficiencies in the models, which are very important for the carbon budget study.

Spatial and Temporal Variations of Atmospheric CO2 Concentration in China and Its Influencing Factors

“…Satellite observations effectively increase the breadth of observation data and save time costs. Therefore, satellite remote sensing inversion has become the dominant quantitative observation approach for atmospheric greenhouse gases [15][16][17][18].…”

The Global Spatiotemporal Distribution of the Mid-Tropospheric CO2 Concentration and Analysis of the Controlling Factors

“…Due to these advantages, many researchers have performed extensive and in-depth studies on mid-tropospheric CO 2 concentrations based on AIRS data. However, most of these studies are focused on retrieval methods for CO 2 concentrations [19,20], data accuracy verification [20][21][22], and the temporal and spatial distribution patterns of CO 2 [4,[23][24][25][26]. There are relatively few papers [27][28][29] that quantitatively analyze the factors affecting the temporal and spatial distributions of mid-tropospheric CO 2 concentrations, particularly on a global scale.…”

Distribution of CO2 in Western Pacific, Studied Using Isotope Data Made in Taiwan, OCO‐2 Satellite Retrievals, and CarbonTracker Products

“…A difference of 2 to 3 ppmv in the mixing ratio between the OCO‐2 satellite retrievals and ground measurements is observed over the region. This is because the CO 2 level at the surface is in general larger than the column averaged CO 2 from OCO‐2 (see, for example, Jiang et al, for a composition of surface CO 2 with GOSAT XCO 2 , which has a similar averaging kernel as OCO‐2). One interesting observation is that during the late winter to the spring, the mixing ratio at LLN is higher by ~2 ppmv than that at the other Pacific Ocean stations.…”