A Total Precipitable Water Product and Its Trend Analysis in Recent Years Based on Passive Microwave Radiometers

Abstract

Total precipitable water (TPW) is a key parameter in global hydrological cycle and plays an important role in climate change as a kind of green house. Especially, a long-term TPW dataset will help us to better understand its impact on hydrological cycle and our living environment under the background of warming climate. Thus, a long-term global TPW product from 2002 to 2017 was created for the first time at the resolution of 0.25° × 0.25° based on the observations from passive microwave radiometers AMSR-E and AMSR2 and TPW product from AIRS2RET in this study. Based on the newly created TPW product, a long-term trend analysis was carried out on both global and regional scale. According to the long-term trend analysis, the linear trend of global average TPW anomaly is 0.34 mm/decade. Especially, there is a faster increasing speed for TPW in recent decade from 2008 to 2017. For the trend analysis on regional scale, the most noteworthy thing is that there is a negative linear trend of TPW anomaly in the atmosphere over rainforest distributed in the Amazon and central Africa, which means the atmosphere is becoming dryer in these areas. The drying atmosphere will cause a decrease in precipitation and will further cause a great damage to the rainforests in the Amazon and central Africa if the dry trend continues.

Keywords

• Microwave remote sensing
• passive microwave radiometer
• total precipitable water (TPW)
• trend analysis