GPS Precipitable Water Vapor Estimations over Costa Rica: A Comparison against Atmospheric Sounding and Moderate Resolution Imaging Spectrometer (MODIS)

The quantification of water vapor in tropical regions like Central America is necessary to estimate the influence of climate change on its distribution and the formation of precipitation. This work reports daily estimations of precipitable water vapor (PWV) using Global Positioning System (GPS) delay data over the Pacific region of Costa Rica during 2017. The GPS PWV measurements were compared against atmospheric sounding and Moderate Resolution Imaging Spectrometer (MODIS) data. When GPS PWV was calculated, relatively small biases between the mean atmospheric temperatures (Tm) from atmospheric sounding and the Bevis equation were found. The seasonal PWV fluctuations were controlled by two of the main circulation processes in Central America: the northeast trade winds and the latitudinal migration of the Intertropical Convergence Zone (ITCZ). No significant statistical differences were found for MODIS Terra during the dry season with respect GPS-based calculations (p > 0.05). A multiple linear regression model constructed based on surface meteorological variables can predict the GPS-based measurements with an average relative bias of −0.02 ± 0.19 mm/day (R2 = 0.597). These first results are promising for incorporating GPS-based meteorological applications in Central America where the prevailing climatic conditions offer a unique scenario to study the influence of maritime moisture inputs on the seasonal water vapor distribution

Estimaciones de vapor de agua precipitable utilizando GPS en Costa Rica: una comparación con el sondeo atmosférico y espectrómetro de imágenes de resolución moderada (MODIS)

Campos Arias, M. P. (2019). Estimaciones de vapor de agua precipitable utilizando GPS en Costa Rica: una comparación con el sondeo atmosférico y espectrómetro de imágenes de resolución moderada (MODIS). [Tesis de Licenciatura]. Universidad Nacional, Heredia, Costa Rica.La cuantificación del vapor de agua en regiones tropicales como Centroamérica es necesaria para 17 estimar la influencia del cambio climático en su distribución y la formación de precipitaciones. Este trabajo de 18 informes diarios de estimaciones diarias de vapor de agua precipitable (PWV) utilizando datos de retardo del Sistema de Posicionamiento Global 19 (GPS) sobre la región del Pacífico de Costa Rica durante 2017. Las mediciones PWV 20 del GPS se compararon con los datos del sondeo atmosférico y del espectrómetro de imágenes de resolución moderada 21 (MODIS). Cuando se calculó el PWV GPS, se encontraron sesgos relativamente pequeños entre las 22 temperaturas atmosféricas medias (Tm) del sondeo atmosférico y la ecuación de Bevis. Las 23 fluctuaciones estacionales del PWV fueron controladas por dos de los principales procesos de circulación en Centro 24 América: los vientos alisios del noreste y la migración latitudinal de la Zona de Convergencia Intertropical 25 (ITCZ). No se encontraron diferencias estadísticas significativas para MODIS Terra durante la temporada seca de 26 con respecto a los cálculos basados en GPS (p > 0.05). Un modelo de regresión lineal múltiple 27 construido sobre la base de variables meteorológicas superficiales puede predecir las mediciones basadas en GPS 28 con un sesgo relativo promedio de 0,02 a 0,19 mm/día (R2 a 0,597). Estos primeros resultados prometen 29 para incorporar aplicaciones meteorológicas basadas en GPS en Centroamérica, donde las 30 condiciones climáticas prevalecientes ofrecen un escenario único para estudiar la influencia de los insumos de humedad marítima en 31 el vapor de agua estacional Distribución.The quantification of water vapor in tropical regions such as Central America is necessary to 17 estimate the influence of climate change on its distribution and precipitation formation. This work of 18 daily reports of daily precipitable water vapor (PWV) estimates using Global Positioning System (GPS) 19 lag data over the Pacific region of Costa Rica during 2017. GPS PWV 20 measurements were compared with atmospheric sounding and Moderate Resolution Imaging Spectrometer 21 (MODIS) data. When the GPS PWV was calculated, relatively small biases were found between the 22 mean atmospheric temperatures (Tm) from the atmospheric sounding and the Bevis equation. The 23 seasonal fluctuations of the PWV were controlled by two of the main circulation processes in Central 24 America: the northeast trade winds and the latitudinal migration of the Intertropical Convergence Zone 25 (ITCZ). No statistically significant differences were found for MODIS Terra during the 26 dry season from GPS-based estimates (p > 0.05). A multiple linear regression model 27 constructed on the basis of surface weather variables can predict GPS-based measurements 28 with an average relative bias of 0.02 to 0.19 mm/day (R2 to 0.597). These first results promise 29 to incorporate GPS-based meteorological applications in Central America, where the 30 prevailing climatic conditions offer a unique scenario to study the influence of maritime moisture inputs on 31 seasonal water vapor distribution.Universidad Nacional, Costa RicaEscuela de Químic

GPS PrecipitableWater Vapor Estimations over Costa Rica: A Comparison against Atmospheric Sounding and Moderate Resolution Imaging Spectrometer (MODIS)

Abstract: The quantification of water vapor in tropical regions like Central America is necessary to estimate the influence of climate change on its distribution and the formation of precipitation. This work reports daily estimations of precipitable water vapor (PWV) using Global Positioning System (GPS) delay data over the Pacific region of Costa Rica during 2017. The GPS PWV measurements were compared against atmospheric sounding and Moderate Resolution Imaging Spectrometer (MODIS) data. When GPS PWV was calculated, relatively small biases between the mean atmospheric temperatures (Tm) from atmospheric sounding and the Bevis equation were found. The seasonal PWV fluctuations were controlled by two of the main circulation processes in Central America: the northeast trade winds and the latitudinal migration of the Intertropical Convergence Zone (ITCZ). No significant statistical di erences were found for MODIS Terra during the dry season with respect GPS-based calculations (p > 0.05). A multiple linear regression model constructed based on surface meteorological variables can predict the GPS-based measurements with an average relative bias of 0.02 0.19 mm/day (R2 = 0.597). These first results are promising for incorporating GPS-based meteorological applications in Central America where the prevailing climatic conditions offer a unique scenario to study the influence of maritime moisture inputs on the seasonal water vapor distribution.La cuantificación del vapor de agua en regiones tropicales como Centroamérica es necesaria para estimar la influencia del cambio climático en su distribución y formación de precipitaciones. Este trabajo reporta estimaciones diarias de vapor de agua precipitable (PWV) utilizando datos de retardo del Sistema de Posicionamiento Global (GPS) sobre la región del Pacífico de Costa Rica durante 2017. Las mediciones del GPS PWV se compararon con datos de sondeo atmosférico y espectrómetro de imágenes de resolución moderada (MODIS). Cuando se calculó el GPS PWV, se encontraron desviaciones relativamente pequeñas entre las temperaturas atmosféricas medias (Tm) del sondeo atmosférico y la ecuación de Bevis. Las fluctuaciones estacionales del VOP fueron controladas por dos de los principales procesos de circulación en Centroamérica: los vientos alisios del noreste y la migración latitudinal de la Zona de Convergencia Intertropical (ZCIT). No se encontraron diferencias estadísticas significativas para MODIS Terra durante la estación seca con respecto a los cálculos basados ​​en GPS (p> 0.05). Un modelo de regresión lineal múltiple construido en base a variables meteorológicas de superficie puede predecir las mediciones basadas en GPS con un sesgo relativo promedio de 0.02 0.19 mm / día (R2 = 0.597). Estos primeros resultados son prometedores para incorporar aplicaciones meteorológicas basadas en GPS en Centroamérica, donde las condiciones climáticas predominantes ofrecen un escenario único para estudiar la influencia de los aportes de humedad marítima en la distribución estacional del vapor de agua.Universidad Nacional, Costa RicaEscuela de Químic

GPS Precipitable Water Vapor Estimations over Costa Rica: A Comparison against Atmospheric Sounding and Moderate Resolution Imaging Spectrometer (MODIS)

The quantification of water vapor in tropical regions like Central America is necessary to estimate the influence of climate change on its distribution and the formation of precipitation. This work reports daily estimations of precipitable water vapor (PWV) using Global Positioning System (GPS) delay data over the Pacific region of Costa Rica during 2017. The GPS PWV measurements were compared against atmospheric sounding and Moderate Resolution Imaging Spectrometer (MODIS) data. When GPS PWV was calculated, relatively small biases between the mean atmospheric temperatures (Tm) from atmospheric sounding and the Bevis equation were found. The seasonal PWV fluctuations were controlled by two of the main circulation processes in Central America: the northeast trade winds and the latitudinal migration of the Intertropical Convergence Zone (ITCZ). No significant statistical differences were found for MODIS Terra during the dry season with respect GPS-based calculations (p > 0.05). A multiple linear regression model constructed based on surface meteorological variables can predict the GPS-based measurements with an average relative bias of −0.02 ± 0.19 mm/day (R2 = 0.597). These first results are promising for incorporating GPS-based meteorological applications in Central America where the prevailing climatic conditions offer a unique scenario to study the influence of maritime moisture inputs on the seasonal water vapor distribution