Comparison of Global Observations and Trends of Total Precipitable Water Derived from Microwave Radiometers and COSMIC Radio Occultation from 2006 to 2013

摘要: Abstract. We compare atmospheric total precipitable water (TPW) derived from the SSM/I (Special Sensor Microwave Imager) and SSMIS Microwave Imager/Sounder) radiometers WindSat to collocated TPW estimates derived from COSMIC (Constellation System for Meteorology, Ionosphere, Climate) radio occultation (RO) under clear cloudy conditions over the oceans from June 2006 December 2013. Results show that mean microwave (MW) radiometer – differences range from 0.06 0.18 mm clear skies, from 0.79 0.96 mm skies, 0.46 0.49 mm but non-precipitating conditions, 1.64 1.88 mm precipitating conditions. Because RO measurements are not significantly affected by clouds precipitation, the biases mainly result MW retrieval uncertainties and precipitating All detect a positive TPW trend these 8 years. The trend using all observations collocated with pixels this data set is 1.79 mm decade −1 , 95 % confidence interval of (0.96, 2.63), which in close agreement the trend estimated observations (1.78 mm decade a 95 % confidence 0.94, 2.62). sample RO pairs used in study highly biased toward middle latitudes (40–60 ∘  N 40–65  S), thus trends are not representative global average trends. However, they representative of extratropical storm tracks values are approximately 4 6 times trends, 0.3 mm decade . In addition, two trends independent observations, represent an increase in our about 6.9 %, strong indication water vapor–temperature feedback on warming planet regions where precipitation from storms already large.