Combining FY-3D MWTS-2 with AMSU-A Data for Inter-Decadal Diurnal Correction and Climate Trends of Atmospheric Temperature

Xinlu Xia,Xiaolei Zou

doi:10.3390/rs13163148

Abstract

Microwave temperature sounding observations from polar-orbiting meteorological satellites have been widely used for research on climate trends of atmospheric temperature at different heights around the world. Taking the Amazon rainforest as the target area, this study combined the Microwave Temperature Sounder-2 (MWTS-2) data onboard the Chinese FengYun-3D (FY-3D) satellite with the Advanced Microwave Sounding unit-A (AMSU-A) data onboard the National Oceanic and Atmospheric Administration (NOAA) and the European Meteorological Operational (MetOp) polar-orbiting meteorological satellites (i.e., NOAA-15, −18, −19, MetOp-A, -B). The double difference method was used to estimate and thus eliminate the inter-sensor bias, and a decadal diurnal correction was used to reduce the impact of different local equator crossing times on climate trends. The “no-rain” conditions were determined for AMSU-A data by channels 1 and 15, and for MWTS-2 data by channels 1 and 7. Finally, the decadal linear trends of atmospheric temperature from 1998 to 2020 were obtained after applying the inter-sensor bias calibration and inter-decadal diurnal correction to AMSU-A and MWTS-2 data from NOAA-15, −18, −19; MetOp-A, -B; and FY-3D. A warming trend was found in the AMSU-A window and tropospheric channels (1–9 and 15) and a cooling trend in stratospheric channels (10–14). The warming (cooling) trends of channels 7–9 (10) were relatively small. The warming (cooling) trends of AMSU-A channels 1–6 (14–15) were significantly reduced after the inter-decadal diurnal correction.

Highlights

The Chinese third generation polar-orbiting meteorological satellite Feng Yun-3D (FY-3D) was launched in November 2017
Taking the Simultaneous Nadir Overpass (SNO) data point matching among FY-3D, Meteorological Operational (MetOp)-A, and National Oceanic and Atmospheric Administration (NOAA)-18 as an example, Figure 3a shows the spatial distribution of orbits of FY-3D and NOAA-18
Taking NOAA-18 Advanced Microwave Sounding Unit-A (AMSU-A) as the reference, the SNO and Double Difference (DD) methods were used for inter-sensor calibration

Summary

Introduction

The Chinese third generation polar-orbiting meteorological satellite Feng Yun-3D (FY-3D) was launched in November 2017. (MWTS-2), which has 13 channels with central frequencies ranging from 50.3 GHz to. 57.6 GHz that are designed for observing the atmospheric temperature profiles from the Earth’s surface to the lower stratosphere. The center frequency of MWTS-2 channel 2 is located at 51.76 GHz and has no corresponding AMSU-A channel. Compared with surface station measurements [1], ship measurements [2] and radiosonde measurements [3], satellite observations have global coverage that is advantageous for many investigations of the atmosphere. Satellite microwave data have been widely used in numerical weather prediction [4,5,6] and in global climate change studies [7,8,9]

Objectives

Results

Conclusion