What is this experiment about?

This experiment is about understanding as best as possible the mechanismns involved on rainfall production near Lake Titicaca, and the feedback between these mechanisms and the lake. This experiment took place at Lake Titicaca, as a complementary part of the SALLJEX (South American Low Level Jet Experiment). Even though the main interest of SALLJEX is to describe the variability of the flux to the east of the Andes, rainfall variability on the regions located close to the Low Level Jet, are also important. This motivated the execution of the Lake Titicaca Field Experiment.

What is the main objective?

The general objective of this experiment is to measure and describe the physical mechanisms involved on rainfall production and distribution along the Titicaca Lake basin, and especially over the lake. It is also an objective to find the relationship between these mechanisms and the LLJ variability.

Into what parts is this experiment divided?

This experiment is divided into two parts: 1. Field experiment part and 2. Data processing and data analyzing. The first part took place during the first 10 days of January, 2003. The second part is still taking place now.

The field experiment part took place along the shores and into the islands of Lake Titicaca. The intense observation phase took place between January 3 and January 9, 2003. However, the setting up of the experiment started on October 2003, when a large raingauge network was installed on the area. The intense observation period (IOP) was performed by 18 participants: 35 Bolivians, 8 Peruvians, 2 Paraguayans, 2 North Americans and 1 Colombian. Six pilot balloon stations were working with intervals of 1 hour. The operations center was set at Puno, Peru, at the Conde de Lemos Inn.

The stations network worked during the whole experiment registering numerous variables as rainfall, wind profiles by pilot balloon launches, temperature measurements, some radiosonde launches, surface wind measurements and estimation, sky observation and cloud photography. A small maximum and minimum temperature network was also installed between the towns of Huayllata and Ilave. A digital raingauge network was installed as well around the lake, including some islands as Soto, Taquile, Amantani and Isla del sol.

After the IOP, the whole group gathered at Puno on the 9th of January, where a dinner was offered. On January 10 the participants returned to their homes.

What kind of data was registered?

Vertical wind profile observations using hourly pilot balloon soundings, 1-2 meter wind direction and velocity estimation every 15 minutes, 1.5 meter temperature readings every 15 minutes, sky observations every 15 minutes, cloud photography during the morning hours, radiosonde launches, maximum and minimum temperatures between Huayllata and Ilave, high temporal resolution rainfall on 5 points close to the lake (including islands) and other variables using an automated station at Huayllata.


We would like to thank all the participants for their great effort, dedication, patience and hard work, which made possible the execution of this experiment. However, we would also like to thank all the people who gave us their trust, time, dedication and friendship, but especially their homes. Thanks a lot to Roger Incahuanaco and family at Taraco. Thanks a lot to Maximo Pacurricuna and family at Conima. Thanks a lot to the Santa Rosa de Huayllata community, and thanks a lot to Alfredo Aparicio and family at the Conde de Lemos Inn in Puno. Thanks a lot to SENAMHI for their great support in every moment.


  • Spanish version of the the Titicaca Lake Experiment Webpage.

  • Titicaca Lake Experiment webpage at Instituto Geofísico del Perú (IGP).