Sounding Network project

Proposal this project is related to:

"A REGIONAL-SCALE ATMOSPHERIC SOUNDING NETWORK IN SUPPORT OF THE NORTH AMERICAN MONSOON EXPERIMENT".

Investigators

Principal Investigator: Michael W. Douglas - National Severe Storms Laboratory

Abstract

The main objective of this project was to strengthen the atmospheric sounding network during the North American Monsoon Experiment field campaign and provide additional observations to:

1. Improve estimation of moisture fluxes from the eastern Pacific Ocean into the NAME Tier 1 domain (Gulf of California and surroundings).  This is needed to determine the relative importance of local (Gulf of California evaporation) versus remote (eastern Pacific) moisture sources in the precipitation over the NAME Tier 1 domain and to determine  if variations in precipitation over the Tier 1 domain are linked to variations in moisture flux into the region from the eastern Pacific.

2. Improve the description of tropical wave variability over central Mexico and south of the Gulf of California.  The proposed network to the east of the southern Gulf of California is not particularly dense, especially north of Mexico City.  Increasing the spatial density of wind soundings will provide a more accurate depiction of the strength and structure of westward propagating waves that are believed to be the primary forcing for the so-called "gulf surges", which are associated with major variations in the northward moisture flux over Tier 1,

and

3. improve the description of variations of the quasi-permanent heat low observed over the southwestern desert of the US and northwestern Mexico.  Fluctuations in the intensity of the heat low contribute  to variations in the pressure gradient along the Gulf of California and thus the up-Gulf moisture transport.

An important aspect of the observation network was that, unlike most other special observations, the sites operated over nearly the entire warm season to capture the onset of the monsoon rains and also any intraseasonal variability in the features noted above.

Pilot balloon sites

The network of 23 pilot balloon sites were established along the NAME Tier 2 domain . Three stations were established in the United States (one of them operated only ~20 days in  August.)  Two island sites, Socorro and Maria Madre, were installed and operated by the Mexican Navy after personnel from the institution received training. Two stations, Tesopaco and Puerto Penasco made radiosonde launchings too. The entire network operated from early July to September 30th. The pilot balloon soundings were made twice a day, around 1400 UTC and 2300 UTC.

The establishment of the network started on May 19th, 2004 in Empalme, Son. and continued through early July in the United States when Lake Havasu City, AZ and Silver City, NM were installed. All stations started operations the day after setting up was completed and continued until the end of September, 2004.

The stations were operated with help from many institutions and individuals in 10 states in northern Mexico, as well as from students and faculty members at the Unified School district in Gila Bend, AZ, and at the other two sites in the Unites States mentioned above. The observations were carried out by college students, professors, staff, engineers, policemen, marines and workers, among others who participated in the activity.

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