WHY HURRICANES RARELY STRIKE COSTA RICA
written by: Tom Rosenberger; tom@CostaRicaHomeBuilder.com
In meteorology, a tropical cyclone (or tropical disturbance, tropical depression, tropical storm, typhoon, or hurricane, depending on strength and location) is a type of low pressure system which generally forms in the tropics. Hurricane is the term used to describe tropical cyclones that form in the Caribbean.
Hurricanes need the warm humid air above tropical oceans in order to develop. That’s why they form over ocean waters close to the equator. And that’s why they form only during the summer and early fall, when those waters are about 80 degrees Fahrenheit or above.
However, you won’t normally see hurricanes form right at the equator, because at zero degrees latitude there isn’t enough turning of winds in the atmosphere to give tropical cyclones the “spin” they need to get started.
This turning of the winds is known as the Coriolis Force or Effect.
Nearly all hurricanes form within 30 degrees of the equator and 87% form within 20 degrees of it, and because the Coriolis Effect initiates and maintains tropical hurricane rotation, such hurricanes almost never form or move within about 10 degrees of the equator where the Coriolis Effect is weakest. The Coriolis Effect initiates and helps maintain the rotation of a tropical hurricane. This rotational force is zero at the equator and increases as you travel away from the equator, being greatest at the north and south poles. Hurricanes can’t actually form within 4 degrees of the equator, because the Coriolis Effect is just too small. Once a tropical storm is formed, wind determines its movement. There is very little cross-equatorial flow of wind at the equator, as the main winds steer the storm away from the equator.
Furthermore, hurricanes that form in the Caribbean are not likely to turn toward Costa Rica, because Caribbean tropical storms either turn northward due to the steering currents of trade winds from the east, then a clockwise flow around a semi-permanent area of high pressure to the north. This has a tendency to turn them northward away from Central America.
Costa Rica is located between 8 and 12 degrees north of the equator, away from the path of most hurricanes.
There are seven tropical cyclone zones, or “basins” where storms occur on a regular basis and Costa Rica is located outside of the affected areas.
Here are some terms and definitions that relate to hurricanes.
Pressure Gradient Force: Directed from high to low pressure. The change in pressure measured across a given distance is called a “pressure gradient”. The pressure gradient results in a net force that is directed from high to low pressure and this force is called the “pressure gradient force”.
Coriolis Force: An artifact of the earth’s rotation. Once air has been set in motion by the pressure gradient force, it undergoes an apparent deflection from its path. This apparent deflection is called the “Coriolis force” and is a result of the earth’s rotation. The Coriolis Effect initiates cyclonic rotation, but it is not the driving force that brings this rotation to high speeds. That force is the heat of condensation.
In the northern hemisphere, the earth’s rotation is deflected to the right by the Coriolis force. The amount of deflection the air makes is directly related to both the speed at which the air is moving and its latitude. Therefore, slowly blowing winds will be deflected only a small amount, while stronger winds will be deflected more.
Geostrophic Wind: Air parcels move from high pressure to low pressure because of the pressure gradient force, and as the air parcels begin to move, they are deflected by the Coriolis Force to the right in the northern hemisphere, and to the left on the southern hemisphere. As the wind gains speed, the deflection increases until the Coriolis Force equals the pressure gradient force. At this point, the wind is referred to as geostrophic.
The fact of the matter is that the Coriolis Effect forces tropical storms to veer to the right, (counterclockwise) in the Northern Hemisphere and to the left (clockwise) in the Southern Hemisphere. Costa Rica is located between 8 and 12 degrees north of the equator in the northern hemisphere and most storms are forced offshore, and do not make landfall in Costa Rica.
The writer, Tom Rosenberger has lived and worked in Costa Rica for 23 years and from his travels throughout the country inspecting property and construction he has acquired a wealth of knowledge about living and doing business in Costa Rica. Tom has other blogs you may like: https://costaricalivingblog.wordpress.com, https://costaricabusinessblog.wordpress.com/ and https://costaricatom.wordpress.com/. You can send Tom an email at; tom@CostaRicaHomeBuilder.com
New Digital System for Topographic Surveys
Costa Rica’s Federated Association of Engineers and Architects, (CFIA) and the National Registry have stated that beginning in January of 2016, they will accept only digital topographic surveys, maps and property plans.
Currently both agencies accept both digital and print documents, but as of next year, registration will only be allowed through an online platform called the; “Administrador de Proyectos Topográficos.”
The new system will send notifications about the status of the registration process through text messages and by e-mail, which will allow for improved controls during the digital registration process.
The CFIA and the National Registry process some 140,000 topographic and survey maps and plans every year and they expect that the migration to the digital system will improve the efficiency of the property registration process.
Costa Rica Traffic Chaos Causes Economic and Health Problems
In the Greater Metropolitan Area, (GAM), we live with traffic chaos every day that gets worse as time passes and no solutions are in sight. Many drivers lose up to two hours a day, to get to and from work, and all entrances and exits to San José, Heredia, Alajuela, Cartago and major metropolitan highways become one big parking lot during rush hour. More than a million people utilize public transportation to and from San Jose, Monday thru Friday, and 18,000 people use public buses, without any exclusive routes. In the center of San José, 255,000 private vehicles enter daily, and traffic accidents are frequent and the time for traffic police to respond is unbearable.
The cost of traffic chaos exceeds $140 million dollars a year and high transportation costs affect Costa Rica’s exports, because thirty-five percent of the value of products distributed throughout the country is related to transportation and logistics costs.
More than 50,000 new vehicles are imported into Costa Rica’s every year, but the infrastructure remains the same. Over 25% of the existing vehicles have emission problems, as over ninety thousand are at least fifteen years old.
Additionally, pollution has increased by thirty percent, with excessive vehicles emissions of carbon dioxide, sulfur dioxide and nitrous oxides. These toxins are wreaking havoc on the health of the residents and the local environment. It has been estimated that in eight years there will be over three million vehicles moving throughout Costa Rica.
The World Health Organization, (WHO) has published that pollution seriously affects human’s health. Some 4.53 million tons of greenhouse gases are attributed to vehicle land transport.
Uncontrolled urban development threatens the local ecosystem and Costa Rica’s ecological footprint is growing, as the country is forced to budget more resources because of lack of experienced engineers to complete proper planning.
The creation of the electric train service was initially seen as a solution to traffic chaos. The current rail system carries 30,000 users daily, but this government owned agency (Incofer) has accumulated losses of $220 million dollars.
Some years ago the government implemented a rail concession without success, and the current railway system is not efficient, as it was originally designed to transport farm products to the ports for export in a previous era. Now there is talk of subsidizing Incofer with more taxes and tolls, without viable proper economic studies for sustainability. This model of mass transit has been very successful in other countries, however in Costa Rica the rail system is not functioning efficiently.
Urban growth in Costa Rica’s central valley (GAM) is becoming more explosive and chaotic, even though the government has spent more than $22 million dollars in studies and evaluations. There are not sufficient regulations governing the 43,000 hectares in the GAM, where 60% of Costa Rica’s population lives, and without joint economic, environmental and urban planning, the future is unclear. There needs to be radical change in urban planning to create the development of more efficient communities with height and density regulations to control the momentum of growth.
Solutions must be found to integrate land use planning for infrastructure and public transportation and the government must make alliances with the private sector to accomplish this, before the problems become unmanageable.