Satellite and Ballloonsonde Observations of the Vertical Structure and Long-term Variability of Moisture in the Upper Troposphere and Lower Stratosphere at Costa Rica and Comparisons with Large-scale Model Simulations

The tropical upper troposphere and the lower stratosphere each present unique challenges to measuring water vapor. To properly characterize the vertical structure and variability of water vapor in these two contiguous regions of the atmosphere and to evaluate large-scale models we must rely on combinations of both satellite and in situ measurements. For the San José metropolitan area in Costa Rica we now have a unique set of in situ measurements to compare with UTLS satellite measurements and model simulations. First, there is the 14-plus year dataset of cryogenic frostpoint hygrometer measurements from the Ticosonde project, and second, near-daily soundings since early 2012 using the Vaisala RS-41 radiosonde. Here we look at the vertical structure and variability of these two in situ datasets and compare them to local (Costa Rica) profiles of water vapor from the Microwave Limb Sounder (MLS) on the Aura satellite and the Atmospheric Infrared Sounder (AIRS) on the Aqua satellite. We then examine how each of these datasets compares with results of simulations with the NASA GEOS-5 AGCM with a two-moment moisture scheme implemented. One goal of these intercomparisons among the model output, satellite observations and the in situ data is to assess the ability of the GEOS-5 model to capture the influence of UTLS water vapor in our evolving climate system.