The spatial and temporal distributions of the stable isotopes such as HD 16 O (or 1 H 2 H 16 O, or HDO) and H 2 18 O in atmospheric water vapor are related to evaporation in source places, vapor condensation during transport, and vapor convergence and divergence, and thus provide useful information for investigation and understanding of the global water cycle. This paper analyzes spatiotemporal variations of the content of isotope HDO (i.e., δ D ), in atmospheric water vapor, namely, δ D v , and the relationship of δ D v with atmospheric humidity and temperature at different levels in the troposphere, using the HDO and H 2 O data retrieved from the Tropospheric Emission Spectrometer (TES) at seven pressure levels from 825 to 100 hPa. The results indicate that δ D v has a clear zonal distribution in the troposphere and a good correspondence with atmospheric precipitable water. The results also show that δ D v decreases logarithmically with atmospheric pressure and presents a decreasing trend from the equator to high latitudes and from lands to oceans. Seasonal changes of δ D v exhibit regional differences. The spatial distribution and seasonal variation of δ D v in the low troposphere are consistent with those in the middle troposphere, but opposite situations occur from the upper troposphere to the lower stratosphere. The correlation between δ D v and temperature has a similar distribution pattern to the correlation between δ D v and precipitable water in the troposphere. The stable isotope HDO in water vapor (δ D v ), compared with that in precipitation (δ D p ), is of some differences in spatial distribution and seasonal variation, and in its relationship with temperature and humidity, indicating that the impacts of stable isotopic fractionation and atmospheric circulation on the two types of stable isotopes are different.
- precipitable water
- spatial and temporal distributions
- stable isotope
- Tropospheric Emission Spectrometer (TES)
- water vapor